LO •I A- El. The Westinghouse Air-Brake Handbook; A CONVENIENT REFERENCE BOOK For All Persons Interested in The Construction, Installation, Operation, Care, Maintenance, or Repair of the Westinghouse Air-Brake Systems, or in the Control of Trains by Means of the Air Brake BY International Correspondence Schools SCRANTON, PA. 1st Edition, 6th Thousand, 1st Impression \ ) SCRANTON, PA. 7 ") INTERNATIONAL TEXTBOOK COMPANY COPYRIGHT, 1913, BY INTERNATIONAL TEXTBOOK COMPANY COPYRIGHT IN GREAT BRITAIN ALL RIGHTS RESERVED 24611 PREFACE Since the introduction of the quick-action brake, a growing yearly increase in passenger traffic has brought with it a growing increase in the length and weight of passenger trains, in the train speed, and in the frequency of service. Each increase reduced the comparative efficiency of the existing brake system and necessitated improvements. In freight service, the increase in the capacity of the cars, the tonnage, and the length of trains augmented the difficulty of brake control to such an extent that new brake apparatus for both engines and cars had to be devised in order that the brake could safely and efficiently control the train. These improvements have been so rapid and have resulted in such a multiplicity of air- brake systems and air-brake apparatus, and the apparatus is made in so many sizes, that today it is a difficult matter to distinguish the different pieces of apparatus and to tell accurately without special information on the subject, to what par- ticular system a piece of apparatus belongs. The purpose of this handbook is to supply this special information and to present in convenient form complete reliable data relative to the differ- ent Westinghouse Air-Brake Systems. Among iv PREFACE other things, it gives the piece and reference num- bers of each part of the apparatus with special instructions for ordering the apparatus; the weights and dimensions ; the number of sizes in which each piece of apparatus is made, and the particular equipment that each size is to be used with; the construction, operation, and care of the equipment; tables of capacities of reservoirs, and methods of calculation of capacities; tables of capacities of air compressors ; methods of piping two or more compressors to give either greater capacity or greater pressure, and tables of capaci- ties when so piped; tests of apparatus; data of both standing and running tests of trains fitted with the different equipments ; information rela- tive to the air-signal system, and the water-raising system; etc. The various tables have been selected with care, and the rules and formulas given are stated sim- ply and concisely, their applications being clearly illustrated by examples and their solutions. Care has been exercised to arrange the matter in a convenient and logical manner, and a very- full index increases further the facility with which any subject may be located. This handbook was prepared by Mr. J. F. Cosgrove, Dean of the Faculty of the Railway Department. INTERNATIONAL CORRESPONDENCE SCHOOLS April, 1913 INDEX A-l conductor's valve, 378. A-l locomotive brake equip- ment. 6. Action of return-spring ar- rangement, S-6 indepen- dent brake valve, 134. AD locomotive brake equip- ment, 7. AG automatic locomotive brake equipment, 7. Air-brake cylinders, Capacity of, 344. -brake equipment, 1. -brake equipments, Index to Westinghouse, 2. -brake safety valves, Types of, 361. Air compressor, 8-in., 16. compressor, 9i-in., 24. compressor, 8|-in. cross- compound, 31. compressor, 11-in., 27. -compressor faults, 39. -compressor soil cups, 74. compressor, Speed of, 38. compressors, 16. compressors, Comparisons of, 46. compressors, 10i-in. cross- compound, 38. compressors, Dimensions, capacity, and weight of Westinghouse, 37. compressors, Output of, 42. compressors, Tests of, 46. cylinder of 8-in. air com- pressor, Operation of, 21. gauge, Duplex, 390. gauge, Operation of, 392. gauges, 388. -pressure governor valve of water-distributing sys- tem, 408. Air-signal equipments, 14. -signal system, Train, 400. -storage reservoirs, Capac- ities of, 94. -storage reservoirs, Con- struction of, 92. strainer, |-in., 375. strainer. Brake-pipe, with special union nut and swivel, 372. strainers, 371. valves and tanks of water- distributing system, 408. Angle cocks, 393. Application portion of con- trol valve, 296. Automatic brake equipments for freight- or switch- engine tenders, 11. brake equipments for pas- senger-engine tenders, 10 Auxiliary reservoir, Charging, 156. reservoir drain cocks, 352. reservoirs, 349. reservoirs for locomotives, tenders, and cars of dif- ferent weights, 230. reservoirs, Standard sizes of, 350. B B-3 conductor's valve, 377. -6 double-pressure feed- valve, 145. -11 brake valve, 104. -12 brake valve, 105. Blocks, for brake cylinders, • Filling, 346. Brackets, pipes, and reversing cocks, 149. Brake cylinder, Cleaning the, 314. cylinder, Cross-sectional area of. 343. INDEX Brake cylinder, Force exerted in, 345. cylinder, Type K tender-, 324. cylinder, Type L tender-, 324. cylinder, Type M passen- ger-, 329. cylinder, Type N passen- ger-, 333. cylinders for locomotives, tenders, and cars of dif- ferent weights, Proper, 230. cylinders, Piece numbers of engine, 323. cylinders, Piece numbers of Type K tender-, 325. cylinders, Pressure heads for truck- and tender-, 347. Brake, Engine-truck, 8. equipment, A-l locomo- tive, 6. equipment, AD locomo- tive, 7. equipment, AG automatic locomotive, 7. equipment, Locomotive, 1. equipment, No. 5 ET loco- motive, 5. equipment, No. 6 ET loco- motive, 4. equipment, Special loco- "motive, 8. equipments, Freight-car, 13. equipments, Passenger-car, 12. equipments, Tender, 10. -pipe air strainer with special union nut and swivel, 372. -pipe strainers, 371. -pipe vent valve, 233. valve, Engineer's, 103. -valve and feed -valve pipe connection, 150. Brakes with plain triple valve, Applying, 156. with plain triple valve, Releasing, 158. Branch pipe strainer, 1-in., 376. Bursting test for air-brake hose, 386. C strainer and check- valve, 373. -3 conductor's valve, 376. -6 single-pressure feed- valve, 143. -7 brake valve, 107. Calculating main reservoir capacity, 101. Capacities of air-storage reservoirs, 94. Capacity of air-brake cylin- ders, 344. Car discharge valve, 406. Care of B-6 feed-valve, 148. of brake valves, 141. Centrifugal dirt collectors, 369. Charging and release position, H-6 brake valve, 123. and release position of con- trol valve, 301. auxiliary reservoir, 156. position of L triple valve, 215. position of No. 6 distrib- uting valve, 258. Check-valve, C strainer and, 373. Cleaning and oiling straight- air-brake valve, 141. of triple valves, 229. the brake cylinder, 314. tool, 385. Cocks, Angle, 393. Cut-out, 394. Combined automatic and straight-air brake appa- ratus, 9. Comparison of air compres- sors, 46. of plain and quick-action triples, 170. of types K and H-l (F-36) triple valves, 185. Compartment reservoir of control valve, 288. INDEX vii Compression governors, 75. Conductor's valve, Operation of, 378. valves, 376. Connection, Governor union, 396. Control valve, Application portion of, 296. valve, Compartment reser- voir of, 288. valve, Construction of, 286. valve, Emergency portion of, 298. valve, Equalizing cylin- der of, 293. valve, Equalizing portion of, 291. valve, Graduated-release lap position of, 312. valve, Graduated-release position of, 310. valve, Lubricating, 316. valve, No. 3-D passenger, 285. valve, No. 3-E passenger, 280. valve, Operation of, 298. valve, Overreduction lap position of, 307. valve, Overreduction "posi- tion of, 306. valve, Preliminary release position ol, 308. valve, Preliminary service- application position of, 302. valve, Quick-action por- tion of, 298. valve, Quick-action vent- ing valve of, 314. valve, Release and charg- ing position of, 301. valve, Release position of, 313. valve, Secondary release position of, 308. valve, Secondary service- application position of, 303. valve, Service lap position of, 305. Control valve, Service posi- tion of, 304. Couplings and fittings, Hose, 379. Dummy, 383. Cover plates, 346. Cross-compound air compres- sor, 8| in., 31. -compound air compressor, 10| in., 38. -sectional area of brake cylinders, 343. -sectional areas of air-brake main reservoirs, 102. Cut-out cocks, 394. -out cocks, f-in., 398. -out cocks, f-in., and 1-in. double, 399. -out cocks, f-in., 397. -out cocks, f-in., 396. -out cocks, 1-in., 395. -out cocks, li-in., 394. Cylinders, Capacity of air- brake, 344. Driver-brake, 318. Freight brake, 338. D-5, E-6, and "F-6 brake valves, 110. D-8 brake valve. 107. Diagrammatic views of L triple, 212. Dimensions and weights of brake-pipe strainers, 372. and weights of centrifugal dirt collectors, 369. of Type M passenger-brake cylinder, 330. of Type N passenger-brake cylinder, 334. Dirt collectors, Centrifugal, 369. Discharge valve, Car, 406. Distributing valve, Care of, 271. valve, Pressure-maintain- ing feature of, 268. valves, 235. Drain cocks. Auxiliary reser- voir, 352. INDEX Drain cocks, Main-reservoir, 352. cocks, Reservoir, 352. Driver-brake cylinder, Type B, 318. -brake cylinders, 318. -brake cylinders, Piece numbers of, 319. -brake cylinders, Piece numbers of push-down, 321. -brake cylinders, Piece numbers of Type B, 319. -brake cylinders, Piston- rod crossheads for, 321. -brake cylinders, Push- down, 320. -brake cylinders, Type C, 319. Dummy couplings, 383. Duplex air gauge, 390. E ET brake, Development of, 243. Emergency application of plain triple valve, 158. part of quick-action triple, 169. portion of control valve, 298. position, G-6 brake valve, 114. position, H-5 brake valve, 119. position, H-6 brake valve, 125. position, K triple valve, 185. position, L triple valve, 221. position of No. 6 distribut- ing valve, Automatic, 263. position with quick-action cylinder cap, Automatic, No. 6 distnbuting valve, 269. Energy of train at different speeds, 273. to be controlled, Train, 273. Engine and tender hose con- nection, 383. Engine-truck brake, 8. -truck-brake cylinders, 323. Engineer's brake valve, 103. brake valve, History of, 103. Equalizing cylinder of control valve, 293. portion of control valve, 291. reservoir, 351. Equipment, Air-brake, 1. and schedules, 1. Locomotive brake, 1. Triple-valve, 232. F-l (H-24) plain triple valve, 153. -2 (F-46) plain triple valve, 154. crosped-passage pipe brack- et, 149. Feed-valve, B-6 double pres- sure, 145. -valve, C-6 single pressure, 143. -valve gasket, 150. Filling blocks for brake cyl- inders, 346. Force exerted in brake cylin- der, 345. Freight-brake cylinder «nd reservoir combined, Type C, 8" X 12", 338. -brake cylinder and reser- voir combined, Type C, 10" X 12", 339. -brake cylinder and reser- voir detached, Type D, 8" X 12", 340. -brake cylinder and reser- voir detached, Type D, 10"X12", 341. -brake cylinders, 338. -brake equipment, Twin- cylinder type of, 14. -brake tests, 188. •brake triple valves, 159. -car brake equipments, 13. Friction test for air-brake hose. 386. INDEX and charging K triple valve, Full -release position, 181. -service position, K triple valve, 183. -service position, L triple valve, 219. G G-6 automatic brake valve, Operation of, 113. -6 brake valve, 110. -6 brake valve, Emergency position of, 114. -6 brake valve, Lap posi- tion of, 114. -6 brake valve, Release position of, 113. -6 brake valve. Running position of, 114. -6 brake valve, Service position of, 114. Gasket, Feed- valve, 150. Gauge, Duplex air, 390. Operation of air, 392. Gauges, Air, 388. Governor, Adjusting the SF- 5,91. Operation of SD-5, 83. Operation of, SF-5, 87. Type SD-5, 82. Type SF-5, 84. union connection, 396. valve of water-distributing system, Air-pressure, 408. Governors, Compression, 75. Types of, 75. Weights of, 76. Graduated release feature, L triple valve, 208. -release position, L triple valve, 220. -release lap position of con- trol valve, 312. -release position of control valve, 310. H H-l (F-36) quick-action freight triple valve, 164. -2 (H-49) quick-action freight triple valve, 166. H-5 automatic brake valve, 115. -5 automatic brake valve, Operation of, 117. -5 brake valve, emergency position, 119. -5 brake valve, holding position, 119. -5 brake valve, lap position, 118. -5 brake valve, release posi- tion, 119. -5 brake valve, running po- sition, 117. -5 brake valve, service po- sition, 118. -6 automatic brake valve, 120. -6 brake valve, charging and release position, 123. -6 brake valve, emergency position, 125. -6 brake valve, holding po- sition, 125. -6 brake valve, lap position, 125. -6 brake valve, Operation of, 123. -6 brake valve, release po- sition, 125. -6 brake valve, running po- sition, 124. -6 brake valve, service po- sition, 124. direct - passage, pipe bracket, 150. High- and low-pressure re- taining valves, 359. -emergency-pressure fea- ture, L triple valve, 208. -speed reducing valve, 365. -speed reducing valve, Op- eration of, 367. Holding position, H-5 brake valve, 119. position, H-6 brake valve, 125. Hose and FP-4 coupling, 380. and FP-5 coupling, 380. and HP-4 coupling, 381. connection, Engine and tender, 383. INDEX Hose couplings and fittings, 379. couplings and fittings, Weight of, 384. Label for air-brake, 387. MCB specification for air- brake, 385. protecting couplings, 381. Improved automatic quick- action, quick-service graduated-release equip- ments, 12. Independent application posi- tion, No. 6 distributing valve, 266. operation, No. 6 distribut- ing valve, 266. Index to Westinghouse air- brake equipments, 2. K-l triple valve, 171. -2 triple valve, 173. triple valve, emergency position, 185. triple valve, Features of type, 177. triple valve, full release and charging position, triple valve, full-service position, 183. triple valve, lap position, 184. triple valve, quick-service position, 182. triple valve, retarded-re- lease position, 185. L-l-B quick-action passenger triple valve, 200. -2-A quick-action passen- ger triple valve, 202. -3 quick-action passenger triple valve, 205. Label for air-brake hose, 387. LN equipment, Operation of, 215. LN equipment, Piping dia- gram of, 211. triple valve, charging po- sition, 215. triple valve, Diagram- matic views of, 212. triple valve, emergency position, 221. triple valve, Features of type, 208. triple valve, full-service position, 219. triple valve, graduated re- lease feature, 208. triple valve, graduated re- lease position, 220. triple valve, high-emerg- ency-pressure f eature,208. triple valve, quick-recharge feature, 209. triple valve, quick-service feature, 208. triple valve, quick-service position, 217. triple valve, release and re- charge position, 216. triple valve, service-appli- cation safety-valve fea- ture, 209. triple valve, service lap position, 219. triple valves, Styles of type, 207. Lap position, G-6 brake valve, 114. position, H-5 brake valve, 118. position, H-6 brake valve, 125. position, K triple valve, 184. position, S-6 independent brake valve, 132. Locomotive air-signal equip- ment, 14. brake equipment, 1. Low-pressure retaining valves, High- and, 359. Lubricating air cylinder, 40. brake valves, 142. cross-compound air com- pressors, 41. INDEX Lubricating cross-compound air cylinders, 41. cross-compound steam cyl- inder, 41. simple compressors, 40. steam cylinder, 40. the control valve, 316. M Main-reservoir drain cocks, 352. reservoir, Standard tap- ping of, 97. reservoirs, Standard stock sizes of, 98. reservoirs, Style of con- struction of, 96. Maintaining feature of dis- tributing valve, Pres- sure-, 268. Maintenance of simple air compressors, 38. MCB specification for air- brake hose, 385. N No. 3-D passenger control valve, 285. 3-E passenger control valve, 5 distributing valve, 235. 5 ET locomotive brake equipment, Details of, 5. 6 distributing valve, 238, 250. 6 distributing valve, auto- matic charging position, 258. 6 distributing valve, auto- matic emergency posi- tion, 263. 6 distributing valve, Auto- matic operation of, 258. 6 distributing valve, auto- matic release after an emergency application, 265. . 6 distributing valve, auto- matic release position, 262. No. 6 distributing valve, auto- matic service position, 260. 6 distributing valve, Duty of parts 9f , 255. 6 distributing valve, inde- pendent application posi- tion, 266. 6 distributing valve, Inde- pendent operation of, 266. 6 distributing valve, inde- pendent release position, 267. 6 distributing-valve quick- action cylinder cap, 241. 6 ET locomotive brake, 243. 6 ET • locomotive-brake equipment, Details of, 4. 6 ET locomotive brake, Piping arrangement and equipment of, 247. O Oil cups, Air-compressor, 74. Old standard quick-action automatic freight equip- ment, 13. Operating compressors in series, 55. compressors series-com- pound, 55. Operation of air cylinder of 8-in. air compressor, 21. of C-6 feed-valve, 144. of G-6 automatic brake valve, 113. of H-5 automatic brake valve, 117. of H-6 brake valve, 123. of 8J-in. cross-compound air compressor, 35. of LN equipment, 215. of plain triple valve, 156. of quick-action triple valve, 168. of S-3 (J in.) straight-air- brake valve, 137. of S-3-A straight-air-brake valve, 140. xii INDEX Operation of S-6 independent brake valve, 130. of SD-5 governor, 83. of SF-5 governor, 87. of steam cylinder of 8-in. air compressor, 21. of type K triple valves, 181. Output of air compressors, 42. Overreduction lap position of control valve, 307. position of control valve, 306. P P-l (F-27) quick-action pas- senger triple valve, 197. -2 (F-29) quick-action pas- senger triple valve, 198. C brake equipment, Func- tions and features of, 275. C brake equipment, Gen- eral arrangement of, 277. C passenger-brake equip- ment, 272. Passenger-brake cylinders, 329. -brake tests, 222. -brake triple valves, 195. -car air-signal equipment, 15 -car brake equipment, 12. triple valve, Development of, 195. Piece and reference numbers of parts of type K tender- brake cylinders, 326. and reference numbers of type L tender-brake cyl- inders, 327. and reference numbers of type M passenger-brake cylinders, 332. and reference numbers of type N passenger-brake cylinders, 336. numbers of driver-brake cylinders, 319. numbers of engine truck brake cylinders, 323. numbers of type B driver- brake cylinders, 319. numbers of type K tender- brake cylinders, 325. Piece numbers of type M pas- senger-brake cylinders, 331. numbers of type N passen- ger-brake cylinders, 335. Pipe bracket, F, crossed - passage, 149. bracket, H, direct -passage, 150. connection, Brake -valve feed-valve, 150. connections to old-standard governor equipment, 92. Pipes, brackets, and reversing cocks, 149. Piping arrangement and equipment of No. 6 ET brake, 247. diagram for two air com- pressors, 92. diagram of LH equipment, 211. Plain triple valve, Operation of, 156. triple valves for engines and tenders, 152. Piston-rod crossheads for drive - brake cylinders, 321. Pistons and rings for rebored air cylinders, 64. Preliminary release position of control valve, 308. service-application position of control valve, 302. Pressure heads for truck- and tender-brake cylinders, 347. -retaining valves, 354. Pump failures, 38. Push-down driver-brake cyl- inders, 320. Quick-action cylinder cap, No. 6 distributing- valve, 241. -action portion of control valve, 298. -action triple, .Operation of, 168. -action triple, release posi- tion, 168. INDEX Quick-action triple, service position, 168. -action venting valve of control valve, 314. -application position, S-6 independent brake valve, 133. -recharge feature, L triple valve, 209. -service feature, K triple valve, 178. -service feature, L triple valve, 208. -service position, K triple valve. 182. -service position L triple valve, 217. R Rack tests, 222. Rebored air cylinders, Pistons and rings for, 64. Reducing valve, High-speed, 365. valve of water-distributing system, 410. valve, Operation of high- speed, 367. valve, Signal, 403. Regulation of B-6 feed-valve, 147. of C-6 feed-valve, 145. Release after an emergency application, Automatic, No. 6 distributing valve, 265. and charging position of control valve, 301. and recharge position, L triple valve, 216. position, G-6 brake valve, 113. position, H-5 brake valve, 119. position, H-6 brake valve, 125. position, Independent, No. 6 distributing valve, 267. position of control valve, 313. position, No. 6 distributing valve, Automatic, 262. Release position, Quick-action triple, 168. position, S-6 independent brake valve, 131. valve, Operation of, 354. valves, 363. Removing return-spring ar- rangement, S-6 independ- ent brake valve, 135. Replacing return-spring ar- rangement, 135. Reservoir, Charging auxiliary, 156. drain cocks, 352. drain cocks, Auxiliary, 352. drain cocks, Main-, 352. Equalizing, 351. of control valve, Compart- ment, 288. when 1 per car is used, Size of supplementary, 351. when 2 per car are used, Size of supplementary, 351. Reservoirs, Air-storage, 92. Auxiliary, 349. Enameled, 97. Location of, 101. Standard sizes of auxiliary, 350. Supplementary, 349. Retaining valve, Type 15, 355. valves, High- and low-pres- sure, 359. valves, Operation of, 358. valves, Operation of high- and low-pressure, 360. valves. Pressure-, 354. valves, Purpose of, 354. Retarded- or uniform -release, K triple valve, 179. -release position, K triple valve, 185. Return-spring arrangement, 133. Reversing cock, 151. cocks, Pipes, brackets, and, 149. Rotary valve of brake valve working hard, 142. xiv INDEX Running position, G-6 brake valve, 114. position, H-5 brake valve, 117. position, H-6 brake valve, 124. position, S-6 independent brake valve, 131. tests, Freight- and passen- ger-train, 194, 226. S-3 (f-in.) straight-air-brake valve, 136. -3-A (f-in.) straight-air- brake valve, 139. -6 independent brake valve, 128. -6 independent brake valve, lap position, 132. -6 independent brake valve, Operation of, 130. -6 independent brake valve, quick-application posi- tion, 133. -6 independent brake valve, release position, 130. -6 independent brake valve, running position, 131. -6 independent brake valve, slow - application posi- tion, 132. D-5 governor, Operation of, 83. D-5 governor, Type of, 82. F-l independent brake valve, 127. F-5 governor, Adjusting the, 91. F-5 governor, Operation of, 87. F-5 governor, Type of, 84. Safety valves, 361. valves, Operation of, 364. valves, Types of air-brake, 361. Schedules and equipment, 1. Secondary release position of control valve, 308. service-application position of control valve, 303. Service-application safety- valve feature, L triple valve, 209. lap position, L triple valve, 219. lap position of control valve, 305. position, G-6 brake valve, 114. position, H-5 brake valve. 118. position, H-6 brake valve, 124. position No. 6 distributing valve, Automatic, 260. position of control valve, 304. position of quick-action triple, 168. Signal-pipe strainer, 374. reducing valve, 403. system, Train air-, 400. valve, 404. valve, Operation of, 405. whistle, 402. Simple air compressors, Lub- ricating, 40. air compressors, Mainte- nance of, 38. Slow-application position, S-6 independent brake valve, 132. Speed of air compressor, 38. Standard fittings, 379. governors and steam valves, 77. governors and steam valves for steam-driven air com- pressors, 77. quick-action, automatic brake equipments, 12. quick-action, automatic freight equipment, 13. tapping of main reservoirs, 97. Standing tests, Freight- and passenger-train, 194, Steam cylinder, Lubricating, 40. cylinder of 8-in. air com- pressor, Operation of, 21. INDEX Straight-air-brake valves, 136 Strainer, |-in. air, 375. 1-in. branch pipe, 376. and check-valve, C, 373. Single-pipe, 374. with special union nut and swivel, Brake-pipe air, 372. Strainers, Air, 371. Brake-pipe, 371. Stretching test for air-brake hose, 387. Supplementary reservoir when 1 per car is used, Size of, 351. reservoir when 2 per car are used, Size of, 351. reservoirs, 349. Table of capacities of air- storage reservoirs, 94. Tanks and air valves of water-distributing sys- tem, 408. Tapping of main reservoir, Standard, 97. Tender-brake cylinders, 324. brake equipments, 10. hose connection, Engine and, 383. Tensile test for air-brake hose, 387. Test for air-brake hose, Bursting, 386. for air-brake hose, Friction, 386. for air-brake hose, Stretch- ing, 387. for air-brake hose, Tensile, 387. Tests. 222. Freight- and passenger- train running, 194, 226. Freight- and passenger - train standing, 194, 226. Freight brake, 188. of air compressors, 46. Passenger-brake, 222. Three-way cock, 103. Tool, Coupling-groove clean- ing, 385. Train energy at different speeds, 273. energy to be controlled, 273. Triple valve equipment, 232. valve, F-l (H-24) plain, 153. valve, F-2 (F-46) plain, 154. valve, Function of, 155. valve, K-l, 171. valve, K-2, 173. valve, Operation of plain, 156. valve, Operation of quick- action, 168. valves, 152. valves, auxiliary reservoirs, and brake cylinders for locomotives, tenders, and cars of different weights, Proper, 230. valves, Cleaning of, 229. valves for engines and tenders, Plain, 152. valves, Freight-brake, 159. valves, Operation of Type K, 181. valves, Passenger-brake, 195. Truck-hose connection, 382. Twin-cylinder type of freight brake equipment, 14. Type 15 retaining valve, 355. B driver-brake cylinders, 318. C driver-brake cylinders, 319. C, 8"X12", freight-brake cylinder and reservoir combined. 338. C, 1CTX12", freight-brake cylinder and reservoir combined, 339. D, 8"X12", freight-brake cylinder and reservoir detached, 340. D, 10" X 12", freight-brake cylinder and reservoir detached, 341. K tender-brake cylinder, 324. XVI INDEX Type L tender-brake cylinder, 324. M passenger-brake cylin- ders, 329. N passenger-brake cylin- ders, 333. SD-5 governor, 82. SF-5 governor, 84. Types of governors, 75. U Uniform-recharge, K triple valve, 180. Union connection, Governor, 396. T, 242. Valve, Operation of release, 354. Valves, Conductor's, 376. Distributing, 235. Valves, High- and low-pres- sure retaining, 359. Operation of retaining, 358. Pressure-retaining, 354. Purpose of retaining, 354. Release, 353. Safety, 361. Triple, 152. Vent valve, Brake- valve, 233. W Water-distributing system, 408. Weight of hose, couplings, and fittings, 384. Weights of governors, 76. Westinghouse air-brake equipments, Index to, 2. air compressors, Dimen- sions, capacity, and weight of, 37. Whistle, Signal, 402. The Westinghouse Air- Brake Handbook AIR-BRAKE EQUIPMENT EQUIPMENT AND SCHEDULES INDEX OF EQUIPMENT The air-brake and air-signal equipments manufactured by the Westinghouse Air-Brake Company are divided into so many classes and each class contains so many devices that a. positive means of identification is necessary in order to facili- tate the ordering of apparatus. The scheme of identification adopted is given in the accompanying table. It will be noticed that all devices of a similar character are included under a single catalog group number, and that the units of each group are distinguished by individual numbers. For example, triple valves are given under the group 3,210, while the unit number of the type P triple is 3,210-2 and that of the type K triple is 3,210-5. Apparatus no longer furnished, but still in service, and special devices are not listed in the regular catalog of the Company or in the accompanying table; they are listed in Part Catalog Supplements, which are furnished on request. The last column of the table shows the date of current issues of all part catalogs. LOCOMOTIVE BRAKE EQUIPMENTS A large number of locomotive air-brake equipments are in general use, and these differ greatly in detail. Each equipment has, therefore, been given a designating symbol, such as. 2 AIR-BRAKE EQUIPMENT rH J-| O £ O J-H O 05050505050505 |U|1||| sr si ! <3 •— >< •< cc >—>»—,<; t I-H M CO -^ »O 1-1 N CO ^H 1-1 a>O5O505 O 05 05 05 O5 O3 05 O5 05 §: O 05 a a cB C 0) J) «> 0 4^'CtOjS •3 gagged."! SHHHH>22ffi i-l 00 05 -H rH »-l i-H to . . .£ • 3 | :2 ll! ^H (N CO •* 10 (N_ (N 01 (N C^ CO CO CO CO 4 AIR-BRAKE EQUIPMENT ET, A-l, AD, etc. A list of the apparatus found in each equip- ment is here given, together with the symbols and unit desig- nations. The specifications given are for 1-in. pipe on the locomotive, which is the recommended practice, but if desired IJ-in. pipe may be used; if this is desired the fact should be mentioned when the order is given. When two 93-in. compres- sors are ordered for a single locomotive equipment, the SF-5 (ls-in.) pump governor, and IJ-in. steam valve should be specified instead of the SF-4 pump governor and 1-in. steam valve. Owing to the difference in practice, on the different roads, as to the number and capacity of reservoirs, no main reservoirs or their drain cocks are included in the lists. The details of the truck-brake apparatus for the No. 6 ET and the No. 5 ET equipment are given later, under the heading Special Locomotive Brake Equipments. Schedule L air-sig- nal apparatus must be used with these two equipments and not schedule J apparatus, which is used with the A-l brake equipment. DETAILS OF No. 6 ET LOCOMOTIVE BRAKE EQUIPMENT For Engines Air compressor of size specified. SF-4 pump governor. 1-in. steam valve. 1-in. main-reservoir cut-out cock. Union stud for f-in. O. D. copper pipe. B-6 double-pressure feed-valve, with pipe bracket and gasket, complete. 1 H-6 automatic brake valve, with pipe bracket, com- plete. 1 Equalizing reservoir. 1 5-in. duplex air gauge; main and equalizing reser- voirs. 1 3 5-in. duplex air gauge; brake-cylinder and brake pipe. 4 Gauge union studs. 1 1-in. cut-out cock; double heading. 1 C-6 single-pressure feed- valve, with pipe bracket and gasket, complete; for independent brake, and signal system. 1 S-6 independent brake valve, with pipe bracket, complete. 1 No. 6 distributing valve, with E-6 safety valve, i-in. drain cock, and double-chamber reservoir, complete. AIR-BRAKE EQUIPMENT 1 f-in. cut-out cock for distributing valve. 1 Union T for $-in. O. D. copper pipe. 2 Driver-brake cylinders, of specified size and type. 1 f-in. cut-out cock for driver-brake cylinders. 1 Brake-pipe air strainer, 1 in. X 1 in. X f in. 2 Angle fittings, 1 in.Xli in. 2 Hose, 1 in.X 22 in., with FP-4 couplings and IJ-in. nipples, complete. 1 F dummy coupling; for pilot. 1 1-in. cut-out cock; for pilot. 1 f-in. cut-out cock, with choke fitting; for tender- brake-cylinder. 1 f-in. angle fitting. 1 Hose, 1 in.X 22 in., with HP-4 coupling and f-in. nipple, complete. 1 C combined air strainer and check- valve; for dead engine. 1 f-in. cut-out cock; for dead engine. For Tender 1 Tender-brake cylinder of specified size and type. 1 f-in. angle fitting. 1 Hose, 1 in.X 22 in., with HP-4 coupling and f-in. nipple, complete. 1 Angle fitting, 1 in.Xliin. 1 Self -locking angle cock, 1 in.X 11 in. 2 Hose, 1 in.X 22 in., with FP-4 couplings and 11-in. nipples, complete. 1 F dummy coupling. DETAILS OF No. 5 ET LOCOMOTIVE BRAKE EQUIPMENT For Engine 1 Air compressor, of size specified. 1 SF-4 pump governor. 1 1-in. steam valve. 1 1-in. main-reservoir cut-out cock. 1 B-6 double-pressure feed- valve, with pipe bracket and gasket, complete. 1 H-5 automatic brake valve, with pipe bracket, com- plete. 1 Equalizing reservoir. 1 5-in. duplex air gauge; main and equalizing reser- voirs. 1 3i-in. single-pointer air gauge; brake cylinder. 1 1-in. and f-in. double cut-out cock; double heading. 1 C-6 single-pressure feed-valve, with pipe bracket and gasket complete; for independent brake and signal system. 1 SF-1 independent brake valve, with pipe bracket, complete. 1 No. 5 distributing valve, with E-l safety valve and double-chamber reservoir, complete. 6 AIR-BRAKE EQUIPMENT 1 f-in. cut-out cock for distributing valve. 2 Driver-brake cylinders of specified size and type. 1 f-in. cut-out cock for driver-brake cylinders. 1 Brake-pipe air strainer, 1 in.X 1 in. X I in. 2 Angle fittings, 1 in.X 11 in. 2 Hose, 1 in.X 22 in., with FP-4 couplings and 11-in. nipples, complete. 1 F dummy coupling; for pilot. 1 1-in. cut-out cock; for pilot. 1 C combined air strainer and check-valve; for dead engine. 1 f-in. cut-out cock; for dead engine. 1 Hose, 1 in.X 22 in., with HP-4 coupling and f-in. nipple, complete. 1 f-in. cut-out cock, with choke fitting; for tender brake cylinder. 1 f-in. angle fitting. For Tender 1 Tender-brake cylinder of specified size and type. 1 f-in. angle fitting. 1 Hose, 1 in.X 22 in., with HP-4 coupling and f-in. nipple, complete. 1 Angle fitting, 1 in.X 11 in. 1 Self -locking angle cock, 1 in.X 11 in. 2 Hose, 1 in.X 22 in., with FP-4 couplings and 11-in. nipples, complete. 1 F dummy coupling. DETAILS OF A-l LOCOMOTIVE BRAKE EQUIPMENT 1 Air-compressor of size specified. 1 SF-4 pump governor. 1 G-6 engineer's brake valve, with C-6 feed-valve, 1-in. cut-out cock, and equalizing reservoir, com- plete. 1 5-in. duplex air gauge; main and equalizing reser- voirs. 2 Angle fittings, 1 in.X 11 in. 1 1-in. steam valve. 2 Hose, 1 in.X 22 in., with FP-4 couplings and 11-in. nipples, complete. 1 F dummy coupling; for pilot. 1 1-in. cut-out cock; for pilot. 2 Driver-brake cylinders of specified size and type. 1 Brake-pipe air strainer, 1 in.X 1 in.X f in. 1 Auxiliary reservoir of size required. 1 Reservoir drain cock of size required. 1 F-l (H-24) or F-2 (F-46) plain triple valve. 1 f-in. nipple; for triple valve. 1 f-in. cut-out cock; for triple valve. This equipment was for an engine without a truck brake but it has been superseded by the ET equipment. AIR-BRAKE EQUIPMENT 7 DETAILS OF AD LOCOMOTIVE BRAKE EQUIPMENT. 1 Air compressor of size specified. 1 SF-4 pump governor. 1 G-6 engineer's brake valve, with C-6 feed-valve, 1-in. cut-out cock and equalizing reservoir, com- plete. 1 5-in. duplex air gauge; main and equalizing reser- voirs. 2 Angle fittings, 1 in.XU in. 1 1-in. steam valve. 2 Hose, 1 in.X22 in., with FP-4 couplings and IJ-in. nipples, complete. 1 F dummy coupling; for pilot. 1 1-in. cut-out cock; for pilot. 2 Driver-brake cylinders of specified size and type. 1 Auxiliary reservoir of size required ; for driver-brake cylinders. 1 ' Brake-pipe air strainer, 1 in. X 1 in. X I in. 1 Reservoir drain cock of size required. 1 F-l (H-24) or F-2 (F-46) plain triple valve. 1 |-in. nipple; for triple valve. 1 |-in. cut-out cock; for triple valve. 1 Engine-truck brake cylinder of specified size. 1 Auxiliary reservoir of size required ; for truck-brake cylinder. 1 Reservoir drain cock of size required. 1 Hose connection, 1 in.X22 in., with j-in. fittings. 1 i-in. cut-out cock; for truck-brake cylinder. This equipment was for an engine with a truck brake but it has been superseded by the ET equipment. DETAILS OF AG AUTOMATIC LOCOMOTIVE BRAKE EQUIPMENT. 1 Air compressor of size specified. 1 SF-4 pump governor. 1 G-6 engineer's brake valve (less feed- valve), 1-in. cut-out cock, and equalizing reservoir, complete. *1 Reversing-cock-pipe bracket. *1 Reversing cock, complete. *2 C-6 feed-valves, with gaskets. 1 5-in. duplex air gauge; main and equalizing reser- voirs. 1 1-in. steam valve. 2 Angle fittings, 1 in.XlJ in. 2 Hose, 1 in.X22 in., with FP-4 couplings and U-in. nipples, complete. 1 F dummy coupling; for pilot. 1 1-in. cut-out cock; for pilot. *When there is no necessity for adhering to former standards, the B-6 double-pressure feed-valve will be substituted for these items when so specified. AIR-BRAKE EQUIPMENT 2 Driver-brake cylinders of specified size and type. 1 Auxiliary reservoir of size required; for driver-brake cylinders. 1 Brake-pipe air strainer, 1 in. X 1 in. X f in. 2 Reservoir drain cocks of size required. P-l (H-24) or F-2 (F-46) plain triple valve, f-in. nipple; for triple valve, f-in. cut-out cock; for triple valve. Engine-truck brake cylinder of specified size. Auxiliary reservoir of size required; for truck-brake cylinder. Hose connection, 1 in.X22 in., with ^-in. fittings. 3-in. cut-out cock; for truck-brake cylinder. This equipment was for an engine with a truck brake and apparatus required for equipments using high and low pressures, but it has been superseded by the ET equipment. The fixtures included in the AG equipment, by the use of which it is possible to use two standard brake-pipe pressures and change from one to the other at will, are common to the high-speed brake equip- ment and to the double-pressure control, schedule U. To secure complete high-speed brake equipment for an engine, including truck brake, use schedule AG and one high-speed reducing valve of size required. To secure complete double- pressure control brake equipment for an engine, including truck brake, use schedule AG and one E-l safety valve. Cut-out cocks for driver-brake cylinders, for driver-brake aux- iliary reservoir, or for truck-brake auxiliary reservoir are not regularly furnished; if wanted, they should be specified. This schedule provides for a truck brake operated in con- junction with the driver brake. If independent operation is desired, there should be ordered in addition a plain triple valve and a brake-pipe air strainer. Also the cut-out cock should be increased from $-in. to f-in. SPECIAL LOCOMOTIVE BRAKE EQUIPMENTS Engine-Truck Brake.— The additional parts required to equip with an engine-truck brake an engine that is already provided with ET equipment are as follows: One engine-truck brake cylinder of specified size, one J-m. cut-out cock, with choke fitting, one hose connection l-in.X22-in., with $-in. fittings, complete. These are all classed under schedules D-68, D-87, D-1,010, D-812, D-1,012, D-108, D-128. AIR-BRAKE EQUIPMENT 9 The additional parts required to equip with an engine- truck brake an engine that is already provided with equipment A-l, or its equivalent, are as follows: One engine-truck brake cylinder of specified size, one auxiliary reservoir of size required, one reservoir drain cock (J-in.), one hose connection, 1-in. X22-in., with |-in. fittings, one 5-in. cut-out cock; these are all classed as schedule D-2. The A-l equipment, however, has been superseded by the ET locomotive brake equipment. The additional parts required to equip with double-pres- sure control apparatus an engine and tender already provided with equipments AD and PL are as follows: One* C-6 feed- valve, with two gaskets, one* feed- valve pipe connection for brake valve, one* reversing cock, complete, two E-l safety valves for driver and tender-brake cylinders, set at 53 lb.; these are all classed as schedule U. Engines equipped with the old single-top governor, also require another diaphragm portion and a Siamese fitting to transform it to the duplex type. COMBINED AUTOMATIC AND STRAIGHT-AIR BRAKE APPARATUS The combined automatic and straight-air brake apparatus has been superseded by the ET locomotive brake equipment. Additional parts required to equip with appliances for operat- ing engine and tender brakes by straight air an engine, already provided with equipments A-l or AD are as follows: One S-3 straight-air brake valve, one C-6 feed -valve set at 45 lb., one feed-valve pipe bracket, with gasket, one No. 2 double check- valve, one E-l safety valve set at 53 lb.; these are all classed as schedule SWA. It is strongly recommended that a single- pointer air gauge be used with this equipment to indicate brake-cylinder pressure. If desired to provide for an inde- pendent release of the driver brakes with this equipment, a S-3-A brake valve should be specified instead of the S-3. Additional fixtures required to equip with straight-air brake an engine tender, already provided with equipments FL, HK, *When there is no necessity for adhering to former standards, the B-6 double-pressure feed-valve will be substituted for these items when so specified. 10 AIR-BRAKE EQUIPMENT or PK, are as follows: Two* hose, l-in.X22-in., with HP-4 couplings and f-in. nipples, complete, two |-in. angle fittings, one No. 2 double check-valve, one E-l safety valve set at 53 lb.; these are all classed as schedule SWB. TENDER BRAKE EQUIPMENTS The following equipments are only furnished with the old standard locomotive brake equipment, the practice being te furnish quick-action triple valves on passenger-engine tenders, and plain triple valves on freight or switch-engine tenders. The ET locomotive brake equipment, now standard for all classes of service, includes tender brake fixtures. For high- speed service, order one high-speed reducing valve in addition to the proper schedule. For double- pressure control, order one E-l safety valve in addition to the proper schedule. Automatic Brake Equipments for Passenger-Engine Tenders. All automatic brake equipments for passenger-engine tenders are classed as schedules HK-812,PK-1,012,PK-1,212,PK-1,412, PK-1,612. The accompanying specifications are for 1-in. Details of Equipment 1 Type K tender-brake cylinder of size indicated. 1 Auxiliary reservoir of size required. 1 Reservoir drain cock of size required. 1 Quick-action triple valve, with gasket, as indicated. 1 1-in. cut-out cock, for triple valve. 1 1-in. tender drain cup with 1-in. cross-over connec- tion. 1 Self -locking angle cock, 1 in.Xlj in. 1 Angle fitting, 1 in.X 1J in. 2 Hose, 1 in.X 22 in., with FP-4 couplings and IJ-in. nipples, complete. 1 F dummy coupling. brake pipe on the tender, which is recommended practice; if it is desired to use IJ-in. pipe, the order should so state. These schedules were formerly designated HL and PL, instead of HK and PK. The letter L formerly covered tender-brake cylin- ders with heads for both plain and quick-action triple valves. *To preserve existing standards, 1 special hose connection, l-in.X36-in., with f-in. fittings, Piece No. 4,892, may be specified instead of this item. AIR-BRAKE EQUIPMENT 11 These have for some time been separated, however, tender cylinders with heads for plain triple valves being designated by the letter L, while those with heads for quick-action triple valves by the letter K. If the triple valve is to be mounted on a bracket, state so in order that suitable a bracket may be furnished and type L brake cylinder substituted for the type K ' in the equipment. If the combined automatic and straight- air brake schedule, SWB, is to be used in connection with type K cylinders, state so, in order that the cylinder head may be arranged to suit that equipment. Automatic Brake Equipments for Freight- or Switch-Engine Tenders. — All automatic brake equipments for freight- or switch-engine tenders are classed as schedules FL-812, FL-1,012, PL-1,212, FL-1,412, FL-1,612. The accompanying specifica- tions are for 1-in. brake pipe on the tender, which is the recom- mended practice; if it is desired to use IJ-in. pipe, the customer's order should so state. Details of Equipment Type L tender brake cylinder of size indicated. Auxiliary reservoir of size required. Reservoir drain cock of size required. Plain triple valve. J-in. nipple, for triple valve. 1-in. cut-out cock, for triple valve. 1-in. tender drain cup with f-in. cross-over con- nection. 1 Self -locking angle cock, 1 in.X U in. 1 Angle fitting, 1 in.XlJ in. 2 Hose, 1 in.X 22 in., with FP-4 couplings and IJ-in. nipples, complete. 1 F dummy coupling. For engines that are to be used in double-heading service or as helpers in train, the Westinghouse Air-Brake Company will include with this equipment, when specially ordered, a brake-pipe vent valve, with a reservoir, 10 in.X 24 in., at an extra charge of $16. As a vent valve is much less sensitive than a quick-action triple valve, this apparatus can be used wherever brake-pipe venting is desired, with entire freedom from undesired quick action. At the same time, it insures the certainty of obtaining quick action through the entire train when desired. 12 AIR-BRAKE EQUIPMENT PASSENGER-CAR BRAKE EQUIPMENTS Standard, Quick-Action, Automatic, Brake Equipments. Standard, quick-action, automatic, brake-equipments for pas- senger, baggage, mail, or express cars, which were formerly classed as schedule P, are now classed as schedules PM-812, PM-1,012, PM-1,212, PM-1,412, PM-1,612. Details of Equipment Type M brake cylinder of size indicated. Auxiliary reservoir of size required. Reservoir drain cock of size required. Type P triple valve, with gasket, as indicated. 1-in. cut-out cock for triple valve. 1-in. brake-pipe air strainer. Conductor's valve. 2 Self -locking angle cocks, 1 in.XH in. 2 Hose, 1 in.X22 in., with FP-4 couplings and IJ-in. nipples, complete. 2 F dummy couplings. Improved, Automatic, Quick-Action, Quick-Service, Gradu- ated-Release Equipments. — Improved, automatic, quick-action quick-service, graduated-release, quick-recharge, high-emer- gency-pressure brake equipments for passenger, baggage, mail, or express cars, are classed as schedules LN-812, LN-1,012, LN-1,212, LN-1,412, LN-1,612, LN-1,812. Details of Equipment 1 Type N brake cylinder of size indicated. 1 Auxiliary reservoir of size required. 1 Drain cock of size required, for auxiliary reservoir. 1 *Supplementary reservoir. 1 *Drain cock of size required, for supplementary reser- voir. 1 *|-in. cut-out cock, for supplementary reservoir. 1 Type L triple valve, with gasket, as indicated. 1-in. cut-out cock, for triple valve. 1 1-in. brake-pipe air strainer. * During the transition period when schedules PM and LN are being operated together in trains, these items may be omitted from schedule LN, as well as the safety valve on the triple valve. The system will then operate in harmony with schedule PM, and besides including all the operative features of schedule PM, will possess additional advantages. When schedule PM, in such cases is being operated with a high-speed reducing valve, one high-speed reducing valve must be included with schedule LN. AIR-BRAKE EQUIPMENT 13 1 Branch-pipe air strainer. 1 Conductpr's valve. 2 Self -locking angle cocks, 1 in.Xll in. 2 Hose, 1 in.X22 in., with FP-4 couplings and IJ-in. nipples, complete. 2 F dummy couplings. When specified, a pressure-retaining valve will be furnished with each passenger-car brake equipment, without extra charge. With complete LN equipment, however, no retaining valve is required, on account of the quick-recharge feature of the triple valve. If more than one conductor's valve is wanted, or if other than C-3 type is desired, order must so specify. When schedule PM is to be used in high-speed brake service (110-lb. brake-pipe pressure), add one high-speed reducing valve to the details listed. FREIGHT-CAR BRAKE EQUIPMENTS Standard, Quick-Action, Automatic Equipment. — The stand- ard, automatic, quick-action, quick-service, uniform-release, uniform-recharge, brake equipments for a freight car are classed as schedules KC-68, KC-88, KC-812, KC-1,012 when of the combined cylinder-and-reservoir type, and as schedules KD-68, KD-812, and KD-1,012 when of the detached cylinder-and- reservoir type. Details of Equipment {Type C brake cylinder and auxiliary reservoir com- bined, of size indicated; or Type D brake cylinder with plain head and auxiliary reservoir detached, of size indicated. 1 Release valve. 1 Type K triple valve, with gasket, as indicated. IJ-m. cut-out cock, for triple valve. 1 l}-in. brake-pipe air strainer. 2 Self -locking angle cocks, li-in.XH in. 2 Hose, 1J in.X22 in., with FP-5 couplings and IJ-m. nipples, complete. 1 Type 15-O pressure-retaining valve. Old Standard, Quick-Action, Automatic Equipment. — The old standard, quick-action, automatic, brake equipments for a freight car are classed as schedules HC-68, HC-88, HC-812, HC-1,012 when of the combined cylinder-and-reservoir type, and as schedules HD-68, HD-812, and HD-1,012 when of the detached cylinder-and-reservoir type. 14 AIR-BRAKE EQUIPMENT Details of Equipment C Type C brake cylinder and auxiliary reservoir com- j I bined, of size indicated; or I Type D brake cylinder with plain head and auxiliary I reservoir detached, of size indicated. 1 Release valve. 1 Type H triple valve, with gasket, as indicated. 1 1 i-in. cut-out cock, for triple valve. 1 IJ-in. brake-pipe air strainer. 2 Self-locking angle cocks, 1 J-in. X U in. 2 Hose, H in.X22 in., with FP-5 couplings and IJ-in. nipples, complete. 1 Type 15-O pressure-retaining valve. Twin-Cylinder Type. — The quick-action, automatic, brake equipments for a freight car, that are of the twin-cylinder type, are classed as schedule KD2-68 when of the detached cylin- der-and-reservoir type with the standard type K triple valve. When with the old standard type H triple valve, they are classed as schedule HD2-68. Details of Equipment 2 Type D brake cylinders of size indicated. 1 Type D auxiliary reservoir of size required. 1 Release valve. 1 Type K or type H triple valve, with gasket, as indicated. 1 l*-in. cut-out cock, for triple valve. 1 1 j-in. brake-pipe air strainer. 2 Self-locking angle cocks, IJ-in.Xl* in. 2 Hose, H-in.X22 in., with FP-5 couplings and H-in. nipples, complete. 1 Type 15-O pressure-retaining valve. Where conditions require, a double-pressure retaining valve will be furnished with any of the foregoing freight-car equip- ments, instead of the single type listed. Two sizes are carried in stock. Type 15-30 retains either 15 Ib. or 30 Ib. pressure in the brake cylinder; type 25-50 retains either 25 Ib. or 50 Ib. pressure. AIR-SIGNAL EQUIPMENTS Locomotive Equipments. — The air-signal equipment for an engine and tender having A-l, AD, or AG brake equipment is classed as schedule J. AIR-BRAKE EQUIPMENT 15 Details of Equipment 1 Signal reducing valve. 1 Signal valve. 1 Signal whistle. 1 f-in. O. B. air strainer. 2 f-in. cut-out cocks. 4 f-in. angle fittings. 4 Hose, 1 in.X22 in., with HP-4 couplings and J-in. nipples, complete. 2 H dummy couplings The air-signal equipment for a locomotive having ET brake equipment is classed as schedule L. Details of Equipment 1 Signal valve. 1 Signal whistle. 1 B-2 combined check-valve, air strainer, and choke fitting. 2 f-in. cut-out cocks. 4 f-in. angle fittings. 4 Hose, 1 in.X22 in., with HP-4 couplings and f-in. nipples, complete. 2 H dummy couplings. Passenger-Car Equipment. — The air-signal equipment for passenger, baggage, mail, or express car is classed as schedule K Details of Equipment 1 Car discharge valve. 1 i-in. cut-out cock. 1 Signal-pipe air strainer. 2 f-in. cut-out cocks. 2 f-in. angle fittings. 2 Hose, 1 in.X22 in., with HP-4 couplings and f-in. nipples, complete. 2 H dummy couplings. 16 AIR COMPRESSORS AIR COMPRESSORS TYPES OF COMPRESSORS INTRODUCTION The first air compressor employed in connection with air brakes, was a Cameron, steam-driven water pump, in which the hydraulic cylinder was replaced by an air cylinder. This pump demonstrated the practicability of operating brakes by means of compressed air. The 6-in. compressor was the first successful air compressor operated by steam that was furnished as a part of the air-brake system. This type served its purpose for several years, when the demand for greater pump capacity brought forth the 8-in. compressor as its successor. This provided sufficient pump capacity for a considerable period, but eventually was succeeded by the Qj-in. compressor. Still further demand for increased capacity brought out the 11-in. compressor, and later, the 8|-in. cross-compound compressor. The success of this cross-compound compressor in air-brake service, was such that a larger compressor of the same type, known as the lOJ-in. cross-compound compressor, was designed for industrial service. The original 8-in. air compressor, now obsolete, was an 8"X7i"X9" air compressor. This means that it had an 8-in. steam cylinder, a 7^-in. air cylinder, and a 9-in. stroke. The valve mechanism was in the side of the steam cylinder instead of in the top cylinder head. The new standard 8-in. compressor is an 8" X 8" X 10" compressor, and has the same style of valve mechanism as the Q^-in. and the 11-in. compressors. 8-IN. AIR COMPRESSOR The new standard 8"X8"X10" air compressor is shown in Fig. 1 ; the left view being a side view showing a vertical cross- sectional view of the main valve and bushing, and the other a vertical sectional view of the compressor showing the back half. The compressor weighs 450 Ib. The lift of the air valves is &-in. for all valves. AIR COMPRESSORS 17 When ordering this compressor or ordinary parts of one, the piece number, reference number, and name of the part wanted should always be given. The piece number of a 8"X8"X 10" air compressor complete is 11,379; the numbers of the various parts are given in the accompanying list. PC. No. Ref.No. Name of Part 11,380 2 Top head, complete, includes one each 14, 15, 16, 17. 18, 25, 26, 27, 28, 29, eight of 48. 11.382 3 Steam cylinder, complete, includes one each 34, 35, 36, 37, 38, 58, 59, two each 57, 60, four of 61. 11,384 4 Center piece, complete, includes one each J-in. pipe plug and 55, two each of 40, 41, 42. 11.383 5 Air cylinder, complete, includes one each 34. 35, 36. 53, two each 31, 32, 33, four of 30. Lower head, includes 54. Steam piston and rod, includes one of 11 and two each of 9, 10, and 12. Air piston, includes two of 80. Piston ring. Piston-rod nut. Reversing-valve plate. Reversing-valve-plate bolt. Reversing-valve rod. Reversing valve. Reversing-valve-chamber bush. Reversing -valve-chamber-cap. Main-valve bush. Main-valve pistons and stem, complete, includes 19, 21, 23, and four of 24. 5,167 19 Large main-valve piston, includes two of 20. 20 Large main-valve piston ring. 21 Small main-valve piston, includes two of 22. 22 Small main-valve-piston ring. 23 Main-valve stem. 24 Main-valve-stem nut. 25 Main valve. 26 Right main-valve cylinder head. 27 Left main -valve cylinder head. 28 Right main-valve head gasket. 11,385 6 *1 1,387 7 7,255 8 4,629 0 1,557 10 1.925 11 12,068 12 1,928 13 1,868 14 31.253 15 1,869 Iti 31,251 17 2,194 18 1,865 5,168 1,866 1,861 1,864 1,867 1,873 5,166 1,876 *Piece No. 11,387 covers steam piston with standard steel rod. If piston with chrome vanadium steel rod is desired, specify Piece No. 24,583. 3 18 AIR COMPRESSORS -16 -66 A-66 AIR COMPRESSORS 19 23 20 PC. No. Ref. 1,877 29 31,388 30 8,795 31 7,076 32 7,073 33 ,882 34 ,883 35 ,884 36 ,885 37 ,886 38 *1,950 39 1,912 40 1,914 41 1,913 42 2,090 43 1,635 24,937 45 13,172 46 13,170 47 1,878 48 11,389 49 11,390 50 11,391 51 11,391 52 12,659 53 1,919 54 *1,916 55 15,038 56 1,887 57 13,168 58 13,166 59 13,167 60 1,898 61 15,551 62 24,937 66 4,629 80 AIR COMPRESSORS Jo. Name of Part Left main-valve head gasket. Air valve. Air-valve seat. Air- valve cap. Air- valve cage. lj-in. union stud. lj-in. union nut. Ij-in. union swivel. 1-in. steam-pipe stud. Governor-union nut. 1-in. steam-pipe sleeve. Stuffingbox. Stuffingbox nut. Stuffingbox gland. Piston-rod packing (vulcabeston) , set (sufficient for two stuffingboxes) . i-in. pipe plug. | in.X2f in. T-head bolt and nut. Iin.X2J in. T-head bolt and nut. in.X7j in. T-head bolt and nut. in.Xlj in. main-valve head capscrew. pper steam-cylinder gasket. Lower steam-cylinder gasket. Upper air-cylinder gasket. Lower air-cylinder gasket. Air strainer. Cylinder-head plug. Oil cock. Piston-rod swab. Drain cock. Steam-cylinder lagging set. Steam-cylinder jacket. Steam-cylinder-jacket bands. Jacket-band screw, 3^ in.XA in. Packing-nut wrench. T-head bolt and nut, f in.X2| in. Air-piston ping. 1 The list given applies only to standard 8-in. air compressor having air cylinder 8 in. in diameter. Orders for repair parts for special 8-in. compressors having air cylinder other than 8 in. in diameter, or with water-jacket, should omit piece number, but give reference number, name of piece, and either diameter of air cylinder or serial number on name plate of compressor. * Furnished only when specially ordered, when governor is not to be attached directly to compressor. AIR COMPRESSORS 21 When this compressor is ordered complete, for industrial, or other than railroad-brake service, order should so state, and specify Piece No. 19,392. When so ordered, packing and cap- nut wrench, Piece No. 1,935 (instead of Piece No. 15,551), air- valve-seat wrench, Piece No. 7,188, air- valve-cage wrench. Piece No. 7,189, and wrench for f-in. nuts, Piece No. 11,392, are included with the compressor without extra charge. Operation of Steam Cylinder.^When the pump is at rest, the pistons generally settle to the bottom of their cylinders and the reversing plate strikes against the button on the reversing rod and pulls the reversing valve into lowest position. When steam is admitted to the pump, it enters the main-valve bush- ing, and, as the area of the large piston is greater than that of the small piston, forces the main valve to the right, passes into the cylinder below the piston, and forces the piston upwards. Any steam above the piston will exhaust to the atmosphere through the exhaust pipe. As the steam piston nears the end of its upward stroke, the top of the reversing plate strikes the shoulder on the reversing rod and forces the reversing valve upwards. This permits steam to enter the chamber at the right of the large piston and balance the pressure on the piston 20 of the main valve, and the pressure on this piston 20 then forces the main valve and the slide valve to the left until the cavity of the slide valve connects the steam to the lower end of the cylinder port with the exhaust port. The steam port to the upper end of the cylin- der is uncovered and steam flows into the steam cylinder above the steam piston, forcing the piston downwards. The steam below the piston flows through the steam ports and the cavity in the slide valve, and out of the exhaust. As the piston nears the end of its downward stroke, the bottom of the revers- ing plate strikes the button on the reversing rod and pulls the rod and reversing valve to their lowest positions. This move- ment exhausts the steam from the chamber to the right of the piston 20 and allows the main valve to move the slide valve to the right, thus permitting steam to pass underneath the piston and force it upwards. Operation of Air Cylinder. — When the air piston makes an upward stroke, it produces a partial vacuum below it, while 22 AIR COMPRESSORS FIG. 2 (a) AIR COMPRESSORS 23 FIG. 2 (b) 24 AIR COMPRESSORS the air above is compressed. Air then flows in through the screened air inlet and passes downwards through the receiving valve into the lower end of the air cylinder, filling it with air at atmospheric pressure. The air that is compressed above the piston holds the receiving valve on its seat, and passes out through the discharge valve to the main reservoir. On the downward stroke of the air piston, a partial vacuum is formed above, and the air is compressed below it. Air then flows in through the air inlet, passes through the receiving valve, and fills the upper part of the cylinder with air at atmospheric pressure. As the air is compressed below the piston, it holds the receiving valve on its seat and passes out through the discharge valve to the main reservoir. 9J-IN. AIR COMPRESSOR The pump shown in Fig. 2, is a 9f"X93"X10" compressor and is made in two styles, right-handed, and right-and-left- handed. The left-handed pump is furnished only when specially ordered. The compressor weighs 525 Ib. and the lift of all air valves is &-in. The operation of this compressor is exactly the same as the operation of the 8-in. compressor. When ordering this compressor or ordinary parts of one, the piece number, reference number, and name of the part wanted should always be given. The piece number of a right-hand 9J-in. air compressor complete is 1,957; of a right-and-left- hand 9$-in. air compressor complete, it is 1,852. The numbers of the various parts are given in the accompanying list. PC. No. Ref. No. Name of Part 1,853 2 Top head, complete, includes one each 14, 15, 16, 17, 18, 25, 26, 27, 28, 29, 46, eight of 48. *1,880 3 Steam cylinder, complete, includes one each 34, 35/36, 37, 38, 58, 59, 104, three of 57, four of 61, i-in. pipe plug and | -in. pipe plug. tl,958 3 Steam cylinder, complete, includes one each 34. 35, 36, 37, 38, 58, 59, 60, 104, two of 57, four of 61. 1,910 4 Center piece, complete, includes one of 55, two each 40, 41, 42. * For right-and-left-hand compressor, t For right-hand compressor. PC. No. 1,901 5,165 *1,923 8 AIR COMPRESSORS 25 Ref. No. Name of Part 5 Air cylinder, complete, includes one each of 34, 35, 36, 53, two each of 31, 32, 33, four of 30. 6 Lower head, includes 54. 7 Steam piston and rod, includes two each of 9, 10, 70, and one of 11. Air pistpn, includes two of 80. or 80 Piston ring. Piston-rod nut. Reversing valve plate. Reversing-valve-plate bolt. Reversing-valve rod. Reversing valve. Reversing-valve-chamber bush. Reversing-valve-chamber cap. Main- valve bush. Main- valve pistons and stem, complete, includes 19, 21, 23, and four of 24. Large main-valve piston, includes two of 20. Large main- valve-piston ring. Small main-valve piston, includes two of 22. Small main-valve piston ring. Main -valve stem. Main-valve-stem nut. Main slide valve. Right main-valve cylinder head. Left main-valve cylinder head. Right main-valve head gasket. Left main- valve head gasket. Air valve. Air- valve seat. Air- valve cap. Air-valve cage. 11-in. union stud. li-in. union nut. li-in. union swivel. 1-in. steam-pipe stud. Governor-union nut. 1-in. steam-pipe sleeve. Stuffingbox. Stuffingbox nut. Stuffingbox gland. *Furnished only when specially ordered, when governor is not to be attached directly to compressor. tPiece No. 1,923 covers steam piston with standard steel rod. If steam piston with chrome vanadium steel rod is desired, orders should so specify and Piece No. 24,584, will be furnished for this item. 1,557 10 1,925 11 12,068 12 1,928 1:3 1,868 14 31,253 If) 1,869 1C, 31,251 17 18 19 20 21 22 1,861 23 1,864 24 1,867 88 1,873 21 i 5,166 27 1,876 2S 1,877 89 24,396 :«) 8,430 81 1,906 82 1,904 88 1,882 84 1,883 85 1,884 86 1,885 87 1,886 as 1 1.950 80 1,912 40 1,914 41 1,913 42 26 AIR COMPRESSORS PC. No. Ref. No. Name of Part 2,090 43 Piston-rod packing (Vulcabeston) set (suf- ficient for two stuffingboxes) . 1.933 45 Capscrew, f in.Xlf in. 1,879 46 Capscrew, | in. X 2 in. 1.934 47 Capscrew, f in. X 6| in. 1,878 48 Main-valve head capscrew, f in.XH in. 1.929 49 Upper steam-cylinder gasket. 1.930 50 Lower steam-cylinder gasket. 1.931 51 Upper air-cylinder gasket. 1,930 52 Lower air-cylinder gasket. 12,659 53 Air strainer. fl,894 53 Steam-cylinder jacket. 1,919 54 Cylinder-head plug. 1,916 55 Oil cock. 15,038 56 Piston-rod swab. 1,887 57 Drain cock. tl,897 58 Steam-cylinder lagging set. *1,962 58 Steam-cylinder lagging set. *1,960 59 Steam-cylinder jacket. tl.895 60 Upper steam-cylinder-jacket band. *1,961 60 Upper steam-cylinder-jacket band. 1,898 61 Jacket-band screws, & in.XA in. 15,551 62 Packing-nut wrench. t8,728 lj-in. pipe plug. t8,727 l^-in. pipe plug. 1,933 66 Capscrew, f in.Xlf in. tl,896 104 Lower steam-cylinder jacket band. *1,961 104 Lower steam-cylinder jacket band. Right-and-left-hand 9i-in. air compressor arranged with double steam and exhaust connections, so that it can be used on either the left or right-hand side of the locomotive may be obtained on order. The list given applies only to standard 93-in. air compressor having air cylinder 9|-in. in diameter. Orders for repair parts for special 95-in. compressors having air cylinders other than Oi-in. in diameter, or with water-jacket, should omit piece number, but give reference number, name of piece and either diameter of air cylinder or serial number on name plate. When this compressor is ordered complete, for industrial, or other than railroad-brake service, order should so state and specify Piece No. 24,440 for right-hand compressor. When so ordered, packing and cap-nut wrench, Piece No. 1,935 (instead of Piece No. 15,551), air- valve-seat wrench, Piece No. 1,936, *Por right-and-left-hand compressor. fFor right hand compressor. AIR COMPRESSORS •27 air- valve-cage wrench, Piece No. 1,937, and cap screw wrench, Piece No. 1,938, are included with the complete compressor, without extra charge. 11-IN. AIR COMPRESSOR The pump shown in Fig. 3 is a 11" X 11"X12" compressor. It is of the same construction as the 8-in. and 9j-in. pumps and operates in the same manner. The compressor weighs 850 Ib. All air valves have a lift of ^f-in. When ordering this compressor or ordinary parts of one, the piece number, reference number, and name of the part wanted should always be given. The piece number of the 11-in. air compressor complete is 3,679; the number of the various parts are given in the accompanying list. PC. No. Ref. No. Name of Part 3.648 2 Top head, complete, includes one each of 14, 15, 16. 17, 18, 25, 26, 27, 28, 29, 82, ten of 48. 3.649 3 Steam cylinder, complete, includes one each of 101, 102, 57, 58, 59, 103, 37, 38, two of 60, four of 61, H-in. pipe plug, and 2-in. pipe plug. 3.650 4 Center piece, complete, includes one of 55, two each of 40, 41, 42, and 57. 3,653 5 Air cylinder, complete, includes one each of 34. 35, 36, 53, two each of 31, 33, 32, four of 30. 5,170 6 Lower head, includes 112. {7 Steam piston and rod, includes one each of 10, 11, 79, 81. two of 9, and three of 12. 8 Air piston, includes two of 80. 9 or 80 Piston ring. 1,590 10 Piston-rod nut. 1,688 11 Reversing- valve plate. 12,065 12 Reversing-valve plate bolt. 1.709 13 Reversing-valve rod. 1,706 14 Reversing valve. 31,404 15 Reversing-valve-chamber bush. 1.710 16 Reversing-valve-chamber cap. 31,402 17 Main-valve bush. {18 Main-valve pistons and stem, complete, includes one each of 19, 21, 23, and four of 24. *Piece No. 3,654 covers steam piston with standard steel rod,. If steam piston with chrome vanadium steel rod is desired, order should so specify and Piece No. 24,585 will be furnished. AIR COMPRESSORS * ^ Prrt. 3 (c) AIR COMPRESSORS 4d 27 29 26 Ifr 28 .26 62 80 81 64 FIG. 3 (b) 30 AIR COMPRESSORS PC. No. Ref. No. Name of Part {19 Large main-valve piston includes ». wo of 20. 20 Large main-valve piston ring. 21 Small main- valve piston, includes two of 22. 22 Small main- valve piston ring. 1.696 23 Main-valve stem. 2,052 24 Main-valve-stem nut. 1,707 25 Main slide valve. 1,599 26 Right main-valve cylinder head. 5,169 27 Left main-valve cylinder head. 1,716 28 Right main-valve head gasket. 1,715 29 Left main-valve head gasket. 29,177 30 Air valve. 8,269 31 Air-valve seat. 1.697 32 Air-valve cap. ,708 33 Air-valve cage. ,882 34 Air-discharge stud. ,883 35 Air-discharge union nut. ,884 36 Air-discharge union swivel. ,885 37 1-in. steam-pipe stud. ,886 38 Governor-union nut. *1,950 39 1-in. steam-pipe sleeve. 1.702 40 Stuffingbox. 1,704 41 Stuffingbox nut. 1.703 42 Stuffingbox gland. 4,862 43 Piston-rod packing (Vulcabeston) set (suf- ficient for two stuffingboxes) . 1.711 44 Upper steam-cylinder gasket. 3.661 45 Short T-head bolt, f in.X2| in., and hexagon nut. 3.662 46 Long T-head bolt, f in.X3} in., and hexagon nut. 1,759 48 Main- valve-head capscrew, f in.Xli in. 1.712 50 Lower steam-cylinder gasket. 1.713 51 Upper air-cylinder gasket. 1.714 52 Lower air-cylinder gasket. 12,659 53 Air strainer. 1,919 54 Cylinder-head plug. 1,916 55 Oil cock. 17,582 56 Piston-rod swab. 1,887 57 Drain cock. 9,584 58 Steam-cylinder lagging set. 9.582 59 Steam-cylinder jacket. 9.583 60 Steam-cylinder-jacket band. 1,898 61 Jacket-band screw, & in. X& in. 15,496 62 Packing-nut wrench. 3,661 66 T-head bolt, and nut, f in. X2f in. 1,589 79 Piston-rod cotter. 1,591 81 Piston-rod jam nut. 31.405 82 Reversing-valve-rod bush. *Furnished only when specially ordered, when governor not to be attached directly to compressor. AIR COMPRESSORS 31 PC. No. Ref. No. Name of Part 3.269 91 Short capscrew, f in.X2 in. 3.270 92 Long capscrew, fin. X2| in. 2.682 101 Exhaust stud. 2,684 102 Exhaust-union nut. 2.683 103 Exhaust-union swivel. 8,728 li-in. pipe plug. 8,726 2-in. pipe plug. Standard 11-in. air compressor has steam- and exhaust-pipe connections similar to those of the so-called right-and-left- hand 9|-in. compressor, and it can therefore be installed on either side of the locomotive with equal facility. The list given applies only to standard 11-in. air compressor having air cylinder 11 in. in diameter. Orders for repair parts for special 11-in. compressors having air cylinders other than 11-in. in diameter, or with water-jacket, should omit piece number, but give reference number, name of piece, and either diameter of air cylinder or serial number on name plate. When this compressor is ordered complete, for industrial, or other than railroad-brake service, order should so state, and specify Piece No. 19,394. When so ordered, packing and cap-nut wrench, Piece No. 2,482 (instead of Piece No. 15,496), air-valve-seat wrench, Piece No. 2,485, air-valve-cage wrench, Piece No. 2,483, and wrench for f-in. capscrews, Piece No. 1,938, are included with the compressor, without extra charge. 8HN., CROSS-COMPOUND AIR COMPRESSOR Piston- Valve Type. — The 8^-in., cross-compound, air com- pressor, shown in Fig. 4, is of the Siamese type, having two steam and two air cylinders arranged side by side respectively. The steam cylinders are at the top. The high-pressure steam cylinder is 8$ in. in diameter, the low-pressure 14J in. in diam- eter, and the stroke is 12-in. The low-pressure air cylinder is 14$ in. in diameter and the high-pressure air cylinder, 9 in. in diameter. The valve gear is on the top head of the high- pressure steam cylinder and is of a design similar to that of the 9J-in. and 11-in. pumps. The high-pressure steam piston with its hollow rod contains the reversing- valve rod that operates the reversing valve and, thus, the main valve and its slide valve, which controls steam 32 AIR COMPRESSORS admission to, and exhaust from, both the high- and low-pressure steam cylinders. The low-pressure steam and high-pressure air pistons are connected by a solid piston rod, having no mechanical connection with the valve gear, being simply floating pistons. The valve gear and its operation are essentially the same as those of the 9^-and 11-in. pumps. The reversing valve performs the same duties and is operated by the re versing- valve rod in the same manner as that of the 9 5- and 11-in. pumps. The main slide valve is provided with the usual exhaust cavity and four elongated steam ports in its face. The two outer and one of the intermediate ports communicate with two cored passages extending longitudinally in the valve and serve to make the proper connection between the high- and low-pressure cylinders during the expansion of steam from one to the other. The remaining port controls the admission of steam to the high-pressure cylinder. The cavity governs the exhaust from the low-pressure cylinder to the atmosphere. The valve seat has five ports. Of these the two back ones lead to the bottom and top ends, respectively, of the high- pressure cylinder; the first and third ports to top and bottom ends of the low-pressure cylinder and the second port to the exhaust. The steam cylinders are compounded. Steam from the boiler is admitted into the high-pressure cylinder. After doing its work, it is delivered to the low-pressure cylinder where it is expanded again and is then exhausted to the atmosphere. The air cylinders, also, are compounded. Free air is taken out the larger air cylinder and by compression is forced into the smaller cylinder where it is compressed to main-reservoir pressure and forced into the reservoir. The compressor is designed for 200 Ib. steam pressure, working against 140 Ib. air pressure. Its normal speed under those conditions is 131 single strokes per min., and its displace- ment is 150 cu. ft. per min. The weight of the pump is 1 ,500 Ib. ; the lift of all air valves is A -in. The piece number of the 8$-in., cross-compound air com- pressor is 23,736; the number of the various parts are given in the accompanying list. PC. No. 23,617 23,616 11,312 20,503 12,417 20,632 24,837 6 24,842 8 12,410 9 12,411 10 11,276 11 11,278 12 11,278 13 11,277 14 12,136 15 12,137 16 1,018 17 1,688 18 12,065 19 20,103 21 1,706 22 31,328 23 13,302 24 20,592 25 34,762 27 34.764 28 34,763 29 20,591 30 1,625 31 20,565 33 1,759 34 24,147 35 4 AIR COMPRESSORS Ref. No. Name of Part Top head, complete, includes one each 2, 22, 24, 25, 33, 35, 61, 62, four each of 34 and 36. 2 Top head, bushed, includes 23, 87, 106, 107. 3 Steam cylinders, complete, includes one each 63, 77, 78, two of 79, six of 91. 4 Center piece, complete, includes one 65, two each 37, 39, 43, 44, 46, 47, 64, 76, four each 53, 54, 55. 5 Air cylinders, complete, includes one each 41, 42, 49, 50, 89. Lower head, complete, includes one 65, two each 38, 40, 45, 48, 67. High-pressure steam piston and rod, com- plete (Vanadium steel), includes one each 15, 16, 17, 18, two of 11, three of 19. Low-pressure steam piston and rod, com- plete (Vanadium steel), includes one each 15, 16, 17, two of 12. Low-pressure air piston, includes two of 13. High-pressure air piston, includes two of 14; High-pressure steam-piston ring. Low-pressure steam-piston ring. Low-pressure air-piston ring. High-pressure air-piston ring. Piston-rod nut. Piston-rod jam nut. Piston-rod cotter. Reversing-valve plate. Reversing-valve-plate bolt. Reversing-valve rod. Reversing valve. Reversing-valve-chamber bush. Reversing-valve-chamber cap. Piston valve, complete, includes one of 30, 117, 118, 119, 120, two each 27, 29, six of 28. Large piston-valve ring. Exhaust-piston-valve ring. Small piston-valve ring. Piston- valve bolt, complete, includes two of 31. Piston-valve-bolt nut. Large piston- valve cylinder head. Large piston-valve cylinder -head cap- screw, | in. X 1 $ in. 35 Small piston-valve cylinder head. AIR COMPRESSORS PC. No. Ref. 1,759 36 1,705 37 1,705 38 1,905 39 1,905 40 1,705 41 1,705 42 20,623 43 1,697 44 1,708 45 8,430 46 1,906 47 1,904 48 1,697 49 1,708 50 1,702 53 1,704 54 1,703 55 21,414 56 11,227 57 11,227 58 11,310 59 11,310 60 20,561 61 20,560 62 1,887 63 7,716 64 12,124 65 1,919 67 17,582 68 32,608 69 12,146 71 12,146 72 12,146 73 12,146 74 12,150 75 17,990 76 11,315 77 11,313 78 11,314 79 15,496 82 4,862 86 31,329 87 8,269 89 1,898 91 12,148 92 12,152 93 25,092 94 No. Name of Part. Small piston -valve cylinder-head cap- screw, f in. X 1 5 in. Upper inlet valve. Lower inlet valve. Upper intermediate valve. Lower intermediate valve. Upper discharge valve. Lower discharge valve. Upper inlet- valve seat. Upper inlet-valve-chamber cap. Lower inlet-valve cage. Upper intermediate- valve seat. Upper intermediate-valve cap. Lower intermediate- valve cage. Upper discharge-valve cap. Lower discharge- valve cage. Stuffingbox. Stuffingbox nut. Stuffingbox gland. Air-cylinder lubricator. Upper steam-cylinder gasket. Lower steam-cylinder gasket. Upper air-cylinder gasket. Lower air-cylinder gasket. Small piston-valve cylinder-head gasket. Large piston- valve cylinder-head gasket. i-in. drain cock. 5-in. drain cock. Air strainer. Lower head plug. Piston-rod swab. Top head-bolt and nut, f in.XSf in. T-head bolt and nut, - in. X 2 in.X2 in.X2 in.X2 in.X3 upper in. in. in. in. in. intermediate T-head bolt and nut, T-head bolt and nut, T-head bolt and nut, T-head bolt and nut, Guard plate for valves. Lagging. Jacket. Jacket band. Packing-nut wrench. Piston-rod packing (Vulcabeston) set (suf- ficient for two stuffingboxes). Reversing-valve-rod bush. Upper discharge-valve seat. Jacket-band screw. T-head bolt and nut, f in.X3| in. T-head bolt and nut, f in. X 5 in. T-head bolt and nut, f in.XSl in. AIR COMPRESSORS 35 PC. A7o. Ref. No. Name of Part *2 1,497 Lubricator, bracket, and pipe connections, complete, includes one each 99, 103, 104, two of 56, four each 100, 101, 102. 21,439 99 Lubricator bracket. 21.595 Oil-pipe-union connection, complete, in- cludes 100, 101, and 102. 20,470 100 Union stud. 2,001 101 Union nut. 1,892 102 Union swivel. 21,597 103 Oil pipe to low-pressure air cylinder. 21.596 104 Oil pipe to high-pressure air cylinder. 25,848 106 Piston-valve bush. 25,847 107 Large piston bush. 36.239 Large piston portion with rings includes one each of 28 and 117, and two of 27. 20.583 Large piston portion, less rings. 36.240 117 Exhaust-piston portion with rings includes one of 118 and four of 28. 20,585 Exhaust-piston portion, less rings. 36.241 118 Small piston portion with rings includes 28, 29, and 119. 20.584 119 Small piston portion, less rings. 36.242 Small piston follower with rings includes 29 and 120. 20,590 120 Small piston follower, less rings. Operation of Compressor. — While steam is being admitted to the bottom end of the high-pressure cylinder, forcing the piston upwards, the main slide-valve cavity opens the bottom end of the low-pressure cylinder to the exhaust; also the cored passages in the slide valve connect the top end of the high-pressure cylinder to the top end of the low-pres- sure cylinder, thus allowing the steam above the high-pressure piston to expand into the low-pressure cylinder and force the piston downwards. During this time, free air is taken into the bottom end of the low-pressure air cylinder, while that in the top end is compressed into the high-pressure cylinder to about 40 Ib. A similar increase obviously takes place in the pressure above the high-pressure air piston, which exerts a downward force on that piston the same as does the steam above the low-pressure steam piston. On the lower side of the high- pressure air piston, the air under compression to the main *When air-cylinder lubricator is to be mounted on the boiler head or inside of the locomotive cab, state so and specify Piece No. 21,984 instead of Piece No. 21,497. 36 AIR COMPRESSORS reservoir exerts a resistance equal to the area of the piston times the main-reservoir pressure; this is considerably less than the combined pressures exerted by the steam and air pressure on top of their respective pistons. When the pump mechanism is reversed the action is simply a repetition of that just described. It is of little importance whether the high- pressure air piston varies in its stroke or not, since it can neither interfere with the valve-gear travel nor govern the quantity of free air taken into the pump; therefore, its action is immaterial so long as it forces all the air received from the low-pressure cylinder into th<- main reservoir. AIR COMPRESSORS 37 •8 O^rH^^ 0 gXS S— - 9 8XSJ1S J3 c * • " s f-lil^-i 1J i .4 1 l iti «f 0 0 5?^ 38 AIR COMPRESSORS With 200 Ib. steam pressure, full throttle, and working against a main-reservoir pressure of 130 Ib., the piston cycles will be about 65 per min.; when working against 70 Ib. main-reservoir pressure the piston cycles will be about 81 per min. With 200 Ib. steam pressure and pumping main-reservoir pressure from 30 to 70 Ib., the piston makes about 82 f cycles per min. Thus, the possibility of racing is eliminated. 10i-IN.f CROSS-COMPOUND, AIR COMPRESSORS The lOs-in., cross-compound, air compressor, shown in Fig. 5, was designed for industrial service and not for train air-brake service. It was designed for 100 Ib. steam pressure working against 80 Ib. air pressure. Under these conditions, its normal speed is 131 single strokes per min. and its displace- ment is 150 cu. ft. per min. It will operate satisfactorily on steam pressures ranging from 80 to 160 Ib., the air pressures ranging from 40 to over 150 Ib. depending on the steam pres- sure. The rated boiler power for operating the compressor is 25 H. P. The construction of the 10^-in. compressor is similar to that of the Sf-m., and the operation of the two is the same. The lift of the air valves is: Intermediate, i-in.; suction, &-in.; discharge, &-in. MAINTENANCE OF SIMPLE AIR COM- PRESSORS CAUSES OF PUMP FAILURES Speed of Compressor. — The heating of the air cylinder is a feature of air compression that cannot be prevented. As an example of the normal heating resulting from extreme duty, a 9^-in. compressor in good order that for 1 hr. maintained an average speed of 174 single strokes or exhausts per min., work- ing constantly against 100 Ib. of air pressure, was discharging the air at a temperature of 408° F. Higher speed or greater air pressure would have increased the heating, while slower speed, shorter time of test, or lower air pressure would have decreased it. Speaking generally, the speed should not exceed 140 ex- hausts per min. and such a speed should not be continuously AIR COMPRESSORS 39 maintained for any considerable time, as even this speed will cause excessive heating. This is shown by another test where an average speed of about 60 exhausts per min., after the main- reservoir pressure was pumped up, and a maximum of 77 strokes per min. at the completion of 1 hr. and 50 min. of the test, gave a discharge temperature of 316°. The foregoing show plainly the great need of good maintenance, of not wasting air either by leakage or poor handling, and of giving the com- pressor as much time to do its work as is practicable. With two compressors per engine, the separate throttles should be kept wide open and the speed regulated by the main compressor throttle, in order to divide the work equally between the two compressors. Compressor Faults. — It is evident that a compressor can- not compress more air than it draws in and not that much if there is any leakage to the atmosphere about the air cylinder. Bearing this in mind, practice frequently listening at the air inlet when the compressor is working slowly while being con- trolled by the governor, and wherever a poor suction is noted on either or both strokes locate and report the fault. One of the most serious leaks is through the air-cylinder stumngbox, as it not only greatly decreases the air delivered, and, by the faster speed required, increases the heating, but it also causes pounding through loss of cushion. When tightening the packing, do not bind the rod, as to do so will damage both the packing and the rod. Be careful not to cross the gland nut threads. If necessary to replace a broken air valve on the road or elsewhere, not permitting of proper fitting, at the earliest opportunity have the repairman replace the temporary valve with another so as to insure the correct angle and width of valve and seat 'contact, the needed ground joint and the requi- site lift for all valves. Never remove or replace the upper steam-cylinder head with the reversing-valve rod in place as to do so will almost invari- ably result in bending the rod and causing a pump failure. Any unusual click or pound should be reported as it may indicate either a loose piston or a reversing-valve plate cap- screw or other serious fault. 40 AIR COMPRESSORS Any steam leakage that can reach the air inlet of the com- pressor should be promptly repaired as such increases the danger of water entering the brake pipe. Keeping the suction strainer clean is of the utmost importance as even a slightly clogged strainer will greatly reduce the capacity where the speed is at all fast. A seriously or com- pletely obstructed strainer, as by accumulated frost, aggra vated by rising steam, will increase the compressor speed and will also be indicated by inability to raise or maintain the desired pressure. It is an aid to good operation to clean the air cylinder and its passages thoroughly at least three or four times a year, by circulating through them a hot solution of lye or potash. This should always be followed by sufficient clean, hot water to thoroughly rinse out the cylinder and passages, after which a liberal supply of valve oil should be given the cylinder. Suit- able tanks and connections for performing this operation can easily be arranged in portable form. Never put kerosene oil in the air cylinder to clean it. LUBRICATING SIMPLE COMPRESSORS Steam Cylinder. — A sufficient quantity of good valve oil should be used in the steam cylinder to keep the parts well lubricated and prevent groaning. The quantity of oil neces- sary will depend on the kind of oil used, and also on the pump itself, as some pumps require more than others. If the pump groans constantly, and the pump exhaust or the drain cocks show that considerable water is being worked through the steam cylinder, its dry pipe should be examined for leaks that might allow water to reach the pump and wash out the oil. Air Cylinder. — The quantity of oil to be used in the air cylinder depends to a great extent on the pump, but in any case it should be used very sparingly. The amount should only be sufficient to keep the packing rings free and prevent the cylinder walls from cutting. If too much is used, a gummy deposit is formed in the air cylinder and air passages, and on the air valves, which tends to cause heating; also, oil works back into the brake valve and triples and causes them to AIR COMPRESSORS 41 work poorly. Good valve oil is considered best for use in the air cylinder. The oil may be fed to the cylinder by means of a swab on the piston rod, or through the air-cylinder oil cups, but it should never be fed through the air inlets, as it will close the air passages, gum up the valves, reduce their lift, and sooner or later result in overheating. Animal or vegetable oils should not be used in the air cylinder, as they gum very readily; also, mineral oils that have a low flashing point, as, for instance, kerosense, should not be used in a hot cyl- inder, as they generate an explosive gas that ignites at a comparatively low temperature, and may, therefore, cause trouble. LUBRICATING CROSS-COMPOUND COMPRESSORS Steam Cylinders. — The steam-cylinder lubricator should not be started until all condensation has escaped from the com- pressor and the drain cocks closed. After closing the drain cocks start the lubricator to feed in 10 or 15 drops of oil as rapidly as possible, then regulate the feed to about 1 or 2 drops per min. for each steam cylinder. No definite amount can be specified, as the amount of lubrication required depends on the work the compressor has to do, the quality of the steam, condition of compressor, and so on. Keep the lubricator feed- ing while the compressor is running. Air Cylinders. — On account of the high temperatures devel- oped by air compression, the variation between maximum and minimum delivered air pressures, and the necessity of preventing oil from passing into the system, one of the vital problems in efficient compressor operation is to provide a simple means for supplying lubrication to the air cylinders in proper quantity and at regular intervals. To overcome the difficulties attending the lubrication of the air cylinders of the 8$-in. and lOJ-in. cross-compound compressors, two non-automatic oil cups are mounted on a bracket, which, in turn, is connected to the air cylinders by the necessary piping, thereby establishing an independent pas- sage from each cup to the high- and low-pressure air cylinders respectively. This cup, shown in the accompanying illustration, is threaded for a f-in. tapped opening, while the upper end is 42 AIR COMPRESSORS provided with a tight-fitting screw cap. A screen prevents any dirt in the oil being carried into the cylinder. When the handle is turned, a cavity in the key, which normally forms the bottom of the oil cup, deposits a definite amount of oil in the air cylinders, at the same time pre- venting back pressure from reaching the oil chamber. The bracket may be attached to the top head of the compressor, or placed in the locomotive cab, to suit the conve- nience or standard practice of any railroad. To oil the low-pressure air cylinder, open its oil cup and blow out all dirt, close and fill it with valve oil, and on the down stroke of the piston open the cup to allow the oil to be drawn into the cylinder, closing the cup before the beginning of the up stroke. This is most easily done when the speed is moderate and the air pressure low. To oil the high-pressure air cylinder, open its oil cup and blow out all dirt, then close and fill with valve oil and screw on the cover. Now open the cup and leave it open for a short time so as to permit the oil to find its way into the cylinder, after which it should be left closed. Valve oil only should be used in the air cylinder, a lighter oil will not last and is dangerous; a heavier oil soon slogs and restricts the air passages, causing the compressor to heat and com- press air slowly. A swab well oiled, is essential on each piston rod. OUTPUT OF AIR COMPRESSORS In the accompanying tables are given the cubic feet of free air compressed and delivered per minute for different diameters of air cylinders. These tables also give the delivery air pressures for different steam pressures when the 8-in. and 9$-in. compressors operate at the rate of 120 single strokes permin. and the 11-in. compressor at the rate of 100 single strokes per min. AIR COMPRESSORS 43 r ooo»cooo t^MOrHt'-l o >o o c >o o 00 O5 --H CO LO O5 ^ffi §3 §3 »o M H as so « O «O Tf M O 00 1^ E--~ . «**» >» c 5^°^ 44 AIR COMPRESSORS !CTtC §3 §3 cOOOOiOOOOOiOOiCi feSi2S§2§5g! OO'-nO'OO'CiCO «5 00 O rH CO -^ CO 0> i-iUJO rH OQ 1C J 00 »C iO 1C O ^H-* 35 00 ^H rH,-l_l,H(M O CC "0 1C 10 O5COCO OOO (NO'*'-lt^»CiM05COTt<- Tf CO CO M - t>.iOOOO 5 iH •* CO 00 O O rf »C O i TH CC tO CC §ioo»o IN iO CO O CO CO . 8 aS o §3 AIR COMPRESSORS The accompanying table shows that the capacity of the 8f-in., cross-compound compressor is over 3| times that of the 9f-in. and 2J times that of the 11-in. compressor. COMPARISON OF 9J-IN., 11-IN., AND 8HN., CROSS- COMPOUND, AIR COMPRESSORS Constant Free Steam Type of Pump Steam Pressure Pounds Main- Reservoir Pressure Air per Minute Cubic Con- sumption per 100 Pounds Feet Free Air Qi-in 200 130 39 6000 11-in 200 130 58 58.00 8^-in. cross-com- pound 200 130 131.04 19.65 COMPARATIVE TESTS OF 11-IN. AND 9J-IN. AIR COMPRESSORS TEST No. 1, TIME REQUIRED TO PUMP FROM 0 TO 90 LB. PRESSURE WITH I-!N. STEAM AND IJ-lN. EXHAUST PIPE Time •8 B Boiler Pressure Required to Compress Air From 0 8 1 Piston Speed 1.1 Name of Com- Pounds to 90 Lb. per Square Inch w o. "o 3 Feet Wl pressor B .0 ZtV e o O Start Fin- ish Min. Sec. s £ Total Per Min. 03 O 11-in 195 189 1 55 168 336.0 175.3 37,850 9Hn 198 190 2 36 263 438.3 168.5 38,200 11-in 199 197 1 55 171 342.0 178.2 38,130 9J-in 195 190 2 36 244 406.6 156.4 38,200 AIR COMPRESSORS ntinued) 47 Amount of Compression 11-In. Compressor 9*-In. Compressor Time Required Time Required Min. Sec. Min. Sec. Min. Sec. 0 to 20 Ib 0 to 40 Ib 1 1 1 1 24 48 2 15 28 55 1 1 1 1 24.5 49.0 2.0 15.0 27.0 55.0 1 1 2 30 10 36 0 to 45 Ib. . 0 to 50 Ib 0 to 60 Ib 0 to 70 Ib 0 to 90 Ib TEST No. 2, TIME REQUIRED TO PUMP FROM 0 TO 90 LB PRESSURE WITH I-!N. STEAM AND IJ-lN. EXHAUST PIPE Time 52 Name of Com- Boiler Pressure Pounds Required to Compress Air From 0 to 90 Lb. per Square Inch Piston Speed Feet 'o || pressor a; Start Fin- ish Min. Sec. 1 Total Per Min. 1 11-in 195 185 1 48.5 189 378 208.8 38,100 11-in 195 180 1 48.5 190 380 210 38,100 Amount of Compression With an 11-In. Compressor From Time Required Min. Sec. Min. Sec. 23.0 46.0 59.0 11.0 23.0 48.5 0 to 20 Ib 1 1 1 23.0 46.5 58.5 11.0 23.0 48.5 1 1 1 0 to 40 Ib 0 to 50 Ib 0 to 60 Ib. Oto701b... Oto901b •18 AIR COMPRESSORS « . j « * co Tj* IOIO 05 O5O5 fi • o I O Q> §§ o oco i* § ££ 1C OO SS'S sort 3 ii** O ON si cS bfl ^Q i-HOSi-H 0 I .s.s.sll.s AIR COMPRESSORS 4S> •JH I -IOJ laaj paadg uo;si O O CD CO 0 CO ;'" •s Stf-i" iu ia* •o S 1 :J, i28a°c r0&§|2 ill-si's 4 PH CJ 52 AIR COMPRESSORS Approximate data on the 10|-in., cross-compound, air com- pressor showing capacity, steam consumption, volumetric efficiency, displacement, steam pressures for operating at constant speed with various air pressures, and steam pressures 'acemenf- Cu.f/. wrM/nl- 4O 60 80 100 120 140 16O PIG. 1 for operating against constant air pressure at various speeds are shown in the charts given in Figs. 1 and 2. The first chart shows that at a constant speed of 130 single strokes per min. and 80 Ib. air pressure, the steam pressure required AIR COMPRESSORS 53 is 96 Ib. The actual amount of free air delivered is 122 cu. ft. per min. The volumetric efficiency is 81 $%. The steam PIG. 2 consumption is 18i Ib. per 100 cu. ft. of free air and the dis- placement is approximately 149 cu. ft. per min. AIR COMPRESSORS AIR COMPRESSORS 55 The second chart shows that at 90 Ib. constant air pressure and 120 single strokes per min. the steam pressure required is 98 Ib. The actual amount of free air delivered is 108 cu. ft. per min. The efficiency is 80%. Steam consump- tion is 19 Ib. per 100 cu. ft. of free air and the displacement is 138 cu. ft. per min. OPERATING COMPRESSORS IN SERIES In industrial service, to deliver air pressures between 150 and 300 Ib., two compressors are often operated in series, as here shown. The left-hand, or low-pressure compressor discharges through a radiating coil into a long, narrow, intermediate reser- voir, which has the greatest possible cooling surface. The right-hand or high-pressure compressor receives its air supply from this reservoir and discharges through a second radiating coil into the air-storage reservoir. The governor is connected to the steam-admission pipe to the high-pressure compressor and is actuated by the pressure in the air-storage reservoir. When the pressure in the reservoir reaches normal, the gov- ernor stops the high-pressure compressor, and the low-pressure compressor is in turn stopped by the intermediate-reservoir pressure when that pressure becomes high enough to stop the compressor. Each radiating coil should contain at least 25 ft. of cooling pipe. The steam throttle valves of each compressor should be regulated so as to cause the relative speeds to give the required intermediate-reservoir pressure; otherwise the final delivery pressure will not correspond to that in the accom- panying table. All sizes of 8-in. compressors given in the accompanying table refer to the new pattern compressor. OPERATING COMPRESSORS SERIES-COMPOUND When the question of economy in steam consumption is important, two compressors of different sizes may be connected in series, not to obtain a high -delivery air pressure, but to increase the quantity of air compressed at the ordinary pres- sure per unit of steam used. The low-pressure pump has an air cylinder of large diameter and the pumps are connected as before. The size of the air cylinders, the speeds of both 56 AIR COMPRESSORS £^fe «* i-IOOOO'-l'-iO^'COCOTtli-iiO ^H (N i-H rH CO M 1-H « TH rH CO (N 1-4 ^'f, o ill l >i> 10 oo i> co oo-coos oo co ooo t- o oot>. o a> £|£ R j5 h § -6 |gj3 S2 3 O. G "S 4s O <""Q it ^ AIR COMPRESSORS b»e!2(Q S«*«QO »»H »»^ WQWHwg IO»H cgl» «"" W»» •*«-«' T-H -tf (N •* »0 1C — 1 1-1 --H <-* ^H rt (N — I O5 N ^ ^H (N —I --t IN 1-1 r-i CO 00 0&G» »H O O N r« t^ 'f. 'f. ~f. -f. V ~ ~. r. - .-. — ~ ~ r. r. C^C^WC^C^C^IMC^MMC^^IC^INC^ 58 AIR COMPRESSORS 1*3 1 |l O..S S"aj >5 £ $ *&• o 2 a siliH ^ -^ Q O "-" O5 X i-l O3 00 t-l C6 00 rH O5 00 i-l O 00 1-4 O5 i-l Ci i-l ^H ^-1 S 3 -8 § gi fi oooooooooooooco ec eo 9 9 9 u5 >5 >o ® 9 « P» F» F- oo !*LII AIR COMPRESSORS O5'->'-ioot^'-coTf<»-Hi.'5Tti1-nCQo^t»c^Tfi>' X( ^H (N rH IN r-4 -ioTj«t^w<*cooc-noo CM M'-iT-lrH W-l >-l N i-H i-H iH 1-1 IN i-H i-l i-l >-l iH C<) .-I ^^ i-l i-H I-I t-H 00'-HOOOOO5O500000000QOOOO5OSOiO»O»OiO»C O'O'O'O'O'OOOOO'C'CiO'OiO High- ressure mpress if £•-' Approx- imate ooooooooooooooo J AIR COMPRESSORS 64 AIR COMPRESSORS compressors, and the intermediate-reservoir capacity are so proportioned as to divide the work of compression about equally between the two compressors, thus obtaining the most economical condition. To obtain the final pressure and free- air capacity desired, it is important that the steam pressures and approximate speeds be maintained as nearly as possible to the values given in the accompanying table. This method of compression is called the series- compound method. In this method, the steam throttle of each compressor should be regu- lated so as to cause the relative speeds to give the required intermediate-reservoir pressure; otherwise the final delivery pressure will not correspond to that given in the table. PISTONS AND RINGS FOR REBORED AIR- COMPRESSOR CYLINDERS To facilitate repair work in railroad shops, reduce to a mini- mum the number of pieces necessary to carry in stock, and greatly simplify the ordering of repair parts, the Westinghouse Air-Brake Company has adopted standard repair pistons and rings for both air and steam cylinders as well as main-valve bushings worn in service, when rebored to certain dimensions. It recommends reboring steam and air cylinders in steps of l"ff-in. and main-valve bushings in steps of aV-in. In no case, however, should the maximum cylinder diameters specified in the accompanying tables be exceeded. Also, for both new and worn pistons the company advises that packing rings of the standard thickness, viz, the dimension of a ring fitting between the sides of a new piston groove, be employed. The adoption of packing rings of standard thickness is a decision that has been brought about by extended experience and experiments, which demonstrated that the wear of the piston groove is practically negligible except in case of defective material or lack of maintenance. A true bearing is an indispensable con- dition for satisfactory and efficient air-compressor operation, hence, since a true bearing is rarely if ever obtained by filing a piston ring to fit a groove, the practice is not recommended. In order to meet all possible conditions and methods of fitting rings both to standard and to recut grooves, the AIR COMPRESSORS 65 Westinghouse Air-Brake Company furnishes in addition to rings of standard thickness, cut rings for air and steam pistons .006 in. thicker than standard, uncut rings for air and steam pistons .012 in. thicker than standard, and uncut main- valve FIG. 1 piston rings .006 in. thicker than standard. No extra charge is made for repair pistons and rings of the standard stock sizes listed. The reference numbers for the parts of the steam and aii pistons for 8-in., 05-in., and 11-in. pumps are given in Fig. 1, while the reference numbers for the parts of the main- valve pistons are given in Fig. 2. Only the sizes of pis- **" tons and rings given in the accompanying tables are made and carried in stock. The pis- tons and rings are designated by the diameter of the cylindet for which they are suitable, proper allowance for clearance and fitting being provided for. FIG. 2 FIG. 3 The reference numbers for the parts of the high-pressure steam piston and low-pressure air piston are given in Fig. 3. AIR COMPRESSORS d 2 § 53 3 § l> «O O3 O5 T}* CO 00 s d i-l i-l l> 00 1C r-l O5 00 OO OS 5 S 28" 28" S S" 28' o j o o ra T« M< « 1 00 2 28" 28" S S" ^ M § d •g §co f^ Q ^ 3 a f g Tj< rj< CO CO Tj» AIR-CO 1 d 00 1 OO »O "5 (O . t^ W i-l (N rH W "-1 O 00 l> l> O5 t^ O 05 O5 •* 0 S Tj< Tj< CO CO ^* § d 00 1C (N t^- Oi 5 00 •H t^ Tf CC Tj< I— 1 i-H CO ) RINGS FOR 8- ime of Part •Si 1 '-I :-£ ^« •± 5 '-o "1-p^S ?-§ 3 s ^g4:^ ":d •§ « •.a^-s-o •gscji jglal rt«« a -"SS'^o's §21': |8.31i t*gd.g Blt^lt3 1 M & 5 a°o| jfj« ll^sililil lI'SA'sMlslfe W o a> suo^sid JIB pun uiea^s AIR COMPRESSORS 67 1~ ^ iO ^ ^H ^ OO O COO "* T** lO CO I-H Tt1 CO ^ o^o^ o^ cq (N O5 t>- 1> CO &i A s "0 O ft (M T-I >O (N CO CO ^H O" t>" CO C<3 CC 00 (N 00 O O^ t^ CD C5 CD C5* t* t>-" CO iM~ rH i-l i-H N 5 A Jr J3 1 | §O ^ "3 O3 i-H C-) (N O o* t> oo" co > o A «*« O 1 VO T}< T-4 1-1 00 t> rH 00 Co" (N* £ 5 O C* Tf t^ CO (N (N -l«O •3 '• ° 3 •S :o ri :s g ^ : M : ' *O C ' X "C C * Q 4J M:ii..i:i:i i ;«-o- • i-; . *-j (_ 2 K3iJ Si 00 C3SO O --KM Cl <-H i-" Is! CN CN CN N SUOJSld 70 AIR COMPRESSORS r» g 3* >o g Is- CO CD CO OC I a i 1 1 2 s l> C^ iO *O I s s s O W 2 io 1 S 3 2 ,_! Tfl O 1-H TH lO C^l 1C O 00 •* 1> O> O5 O o" •* co" co" t^ O t^b- t>- t» §fa s as a a *H c^t^ Oi *O CO O CO i 88" i a i-t Is! CO i-4 N II 00 C5O O —KN CN UO;Sld 3A[B 72 COMPRESSORS § 8 § 85 8 3 t« st t is iFI [••fi .« £i2s ;8 re steam-pisto ard, cut re steam-pisto ard, uncut. . . oo oo" oo oo CC CC CC CC t>r t>r CO CC 00 >O l^ CC CC CC CC ^asst; "« £ c e fc CC CC CO AIR COMPRESSORS ± •*t 7 zii d 3 S 00 t- 00 i^ i>- r^ OS -o l.T8: c :c^ t| |J ;-5.|£|£|5 S 73 i I CO CO CO 05 O S3 S3 CO CC CO fe connection with standard locomotive brake schedules, having been replaced by the SF-5 duplex governor. The type S-6 governor is furnished for any service for which it is suitable. It is recommended for all equipments that include two 11-in. or two Sj-in. simple, cross-compound air compressors. The SD duplex governor is made in two sizes: the SD-4 (1-in.) governor and the SD-5 (lj-in.) governor. The SD-4 type replaced the S-4 governor as standard for one 9|-in. compressor; and this, in turn, has been replaced by the SF-4 governor. The SD-4 governor is still furnished when specified. The SD-5 governor has been superseded by the SF-5 governor for locomotive equipments specifying two compressors; it can be obtained, however, when specified. The SF duplex governor is made in two sizes: the SF-4 (1-in.) governor supplied with all locomotive brake equipments requiring one 9^-in. air com- pressor and the SF-5 (lj-in.) governor supplied with all loco- motive brake equipments requiring two 95-in., one 11-in., or one Si-in. cross-compound pump. The substitution of the duplex for the single governor was to facilitate the subsequent application of the high-speed brake in passenger service and the high-pressure control apparatus in freight service. Also, it made possible the duplex- main-reservoir regulation system when connected up as illus- trated in Figs. 3 and 5. WEIGHTS OF COMPRESSOR GOVERNORS S-3 .............. 11 SD-4 ............... 19 S-4 ................ 13J SD-5 ............... 25 S-5 .. ____ 19* SF-4 ............... 19 S-6 .......... 23* SF-5 .............. 25 AIR COMPRESSORS 77 STANDARD GOVERNORS AND STEAM VALVES FOR STEAM-DRIVEN AIR COMPRESSORS The Westinghouse Air-Brake Company made an extended series of tests to determine the conditions under which their several types and combinations of one or more compressors will operate to the best advantage. They recommend the following combinations: Size of Branch No. of Compres- sors Size of Compres- sor Size of Steam Valve Size of Governor Size of Main Steam Supply Pipe to Each Compres- sor Inches Inches Inches Inches Inch:s 1 9* 1 1 1 2 9i 11 1 1 11 u 2 11 1* u 1 *8* 11 2 *8* H n TYPE S-4 (1-IN.), COMPRESSOR GOVERNOR The piece number for the type S-4 compressor governor, complete, shown in Fig. 1, is 24,974; for the steam portion, complete, it is 2,048; and for the diaphragm portion, complete, 20,782. The piece and reference numbers of the various parts are given in the accompanying list. The 1-in. union swivel, Pc.No. Ref. No. Name of Part 2,018 2 Steam-valve body. 2,028 3 Cylinder body. 2,024 4 Cylinder cap. 2.023 5 Steam valve, complete. 2,173 6 Piston, includes 7, for standard cylinder, 2J in. diameter. 17.282 6 Piston, includes 7, for rebored cylinder, 2^ in. diameter. 17.283 6 Piston, includes 7» for rebored cylinder, 2fg in. diameter. 17.284 6 Piston, includes 7, for rebored cylinder, 2H in. diameter. 17.285 6 Piston, includes 7, for rebored cylinder, 2| in. diameter. 15,013 7 Piston ring, for standard cylinder, 2J in. diameter. 15,583 7 Piston ring for rebored cylinder, 2^y in. diameter. *These are the 8$ -in., cross-compound, air compressors. 78 AIR COMPRESSORS FlG. 1 PC No. . Ref. 15,584 7 17,214 7 17,215 7 2,022 8 2,027 9 1,948 10 1,949 11 2,051 11 9,033 15 2,033 10 2,034 17 2,035 IS 2,036 19 2,043 20 1,064 21 2,046 29 5,384 80 15,291 31 2,041 32 2,039 33 2,040 34 2,042 3.5 2,038 3C, 2,045 to AIR COMPRESSORS 79 Jo. Name of Part Piston ring for rebored cylinder, 2ff in. diameter. Piston ring, for rebored cylinder, 2ft in. diameter. Piston ring, for rebored cylinder, 2| in. diameter. Piston nut. Piston spring. 1-in. union nut. 1-in. union swivel, f-in. union swivel. Diaphragm body, includes 29. Spring box. Check-nut. Regulating nut. Regulating spring. Diaphragm, complete, 32 to 36, inclusive. Diaphragm ring. Strainer. Union swivel, f-in. O. D. copper pipe. Union nut. Diaphragm nut. Diaphragm valve. Diaphragm washer. Diaphragm-valve spring. Diaphragm, 2 pieces, each. Union swivel, J-in. iron pipe. Piece No. 1,949, is used with the new-style 8-in. (8"X8"X 10"), the 9 i-in., and the 11-in. pumps. The 1-in. union swivel, Piece No. 2,051, is used with the old-style 8-in. pump (8"X?i"X9"). Where J-in. iron pipe is to be used for air connection, specify Piece No. 2,049, for the S-4 steam compressor governor, com- plete, and Piece No. 2,047, for diaphragm portion complete; then union swivel, Ref. No. 40, will be substituted for union swivel, Ref. No. 30. If governor is to be used with old-style 8-in. (8"X 7|"X9") air compressor, specify Piece No. 24,975, for S-4 steam compressor governor, complete, with air con- nection for copper pipe, or Piece No. 10,700, for S-4 steam compressor governor, complete, with air connection for J-in. iron pipe; and Piece No. 10,701, for steam portion only; f-in. union swivel, Piece No. 2,051 will then be supplied. Operation of Governor. — The regulating spring is, generally, adjusted to just withstand a main-reservoir pressure of 90 Ib. pushing upwards on the diaphragm. When the pump is in 80 AIR COMPRESSORS operation the pressure in the main reservoir increases until it reaches 90 Ib. When the pressure below the diaphragm slightly exceeds the force exerted by the regulating spring, the diaphragm is raised, carrying the diaphragm valve with it. The air below the diaphragm passes by the unseated dia- phragm and into the chamber on top of the piston, forcing it down and thus seating the steam valve. As long as main- reservoir pressure remains at 90 Ib., the diaphragm valve will be held from its seat and the pressure in the chamber above the piston will hold the steam valve to its seat. If the main -reservoir pressure falls below 90 Ib., the thrust of the spring tending to force down the diaphragm will overcome that of the air pressure tending to force it up; consequently, the diaphragm will move downwards and seat the diaphragm valve. This shuts off the air supply from the chamber above the piston, and the air confined therein by the diaphragm valve closing will escape to the atmosphere through the vent port c. The pressure now being removed from above the piston, the piston spring, aided by the steam under the steam valve, forces the piston upwards, unseating steam valve, and allowing steam to pass through the governor to the pump. The piston is made enough larger than the steam valve to enable a moderate air pressure to hold the steam valve to its seat against the combined upward force of the steam pressure under the valve and the push of the piston spring. Regulating the Governor. — To increase main-reservoir pres- sure, remove check-nut 17 and turn regulating nut 18 to the right, increasing the tension of the regulating spring 19 until the desired pressure is obtained; then replace check-nut 17. To decrease main-reservoir pressure, turn the regulating nut 18 to the left, decreasing the tension on the regulating spring 19 until the pressure is decreased to the desired amount. Testing the Governor. — The pump governor should be tested to see whether standard pressure is obtained when it stops the pump, also to see whether it will start the pump promptly when a light reduction of not more than 2 Ib. is made in the pressure that operates the governor. If the pump stops either before or after standard pressure is obtained, adjust the governor by means of the adjusting screw, until it AIR COMPRESSORS SI FIG. 2 82 AIR COMPRESSORS regulates the pump properly. If the governor does not start the pump promptly on a slight reduction, it may be due to leaky diaphragm valve, or to the vent port being stopped up. TYPE SD-5 COMPRESSOR GOVERNOR The piece number of the SD-5, compressor governor, com- plete, shown in Fig. 2, is 22,067; for the steam portion, com- plete, 17,879; and for the diaphragm portion, complete, 20,782. The piece and reference numbers of the various parts are given in the accompanying list. If j-in. iron pipe is to be used for air connections, specify Piece No. 18,019, for SD-5 compressor governor, complete, and Piece No. 2,047, for diaphragm por- tion, complete; then union swivel, Ref. No. 40 will be substi- tuted for union swivel, Ref. No. 30. PC. No. Ref. No. Name of Part 17,668 2 Steam- valve body. 17,672 3 Cylinder body. 17,671 4 Cylinder cap. 17..670 5 Steam valve, complete. 17,916 6 Piston, includes 7, for standard cylinder, 2J in. diameter. 21,606 6 Piston, includes 7, for rebored cylinder, 2ff in. diameter. Piston, includes 7, for rebored cylinder, 2ff in. diameter. Piston, includes 7, for rebored cylinder, 2f£ in. diameter. Piston, includes 7, for rebored cylinder, 2 1 in. diameter. Piston ring, for standard cylinder, 2f in. diameter. Piston ring for rebored cylinder, 2ff in. diameter. Piston ring for rebored cylinder, 2£f in. diameter. Piston ring for rebored cylinder, 2£J in. diameter. Piston ring, for rebored cylinder, 2J in. diameter. Piston nut. Piston spring. IJ-in. union nut. li-in. union swivel. Siamese fitting. Diaphragm body, includes 29. Spring box. 21,607 6 21,608 6 21,609 6 18,033 7 21,598 7 21,599 7 21,600 7 21.601 7 17,674 17,673 2,154 2,155 6,558 9,033 2,033 8 9 10 11 14 18 16 AIR COMPRESSORS 83 Pc.No.Ref.No. Name nf Part 2.034 17 Check-nut. 2.035 18 Regulating nut. 2.036 19 Regulating spring. 2,043 20 Diaphragm, complete, includes 32 to 36, inclusive. 1,064 21 Diaphragm ring. 6,868 22 Vent-port screw. 2,046 29 Strainer. 5,384 30 Union swivel, f-in. O. D. copper pipe. 15,291 31 Union nut. 2.041 32 Diaphragm nut. 2.039 33 Diaphragm valve. 2.040 34 Diaphragm washer 2.042 35 Diaphragm- valve spring. , 2,038 36 Diaphragm, 2 pieces, each. 2,045 40 Union swivel, i-in. iron pipe. Operation of Governor. — The operation of the duplex gov- ernor is exactly the same as that of the S-4 governor, since only one diaphragm portion operates at a time. Both the dia- phragm portion and the steam portion of the duplex governor are exactly the same as the corresponding parts of the improved single governor. The only difference is that the duplex gov- ernor is provided with the Siamese fitting and an extra dia- phragm portion. This valve is merely a combination of two ordinary governors, and it operates in exactly the same way as the ordinary governor, since one or the other of the dia- phragm bodies is always cut out. The description of the improved single governor applies to this governor also. The pipe connections between the duplex governor and the engi- neer's brake valve are shown in Fig. 3. The duplex pump governor is necessary on engines equipped with the high-speed brake and the high-pressure control or special apparatus, for loaded freight trains, and it is also neces- sary on many engines not used in this special service. It pro- vides a means for carrying two pressures in the main reservoir; a moderate one while running with brake released and a much higher one while the brake is applied, so as to provide a high excess pressure for the prompt release of the brake. This is done by piping the low-pressure side of the governor to the feed-valve port / in the F-6 brake valve shown, a hole being drilled through the bottom case of the valve through the lower 84 AIR COMPRESSORS gasket into the port. When the brake valve is in running posi- tion, the air in port /is at main-reservoir pressure; when this pressure reaches 90 Ib. it operates the governor, which shuts off steam from the pump. During an application of the brake or while the brake valve is on lap, the pressure in port /is shut off from the main reservoir and is much lower than 90 Ib. Usually it is the same as that in the brake pipe, and cannot be raised to 90 Ib.; consequently, the low-pressure side of the governor being cut out by the brake valve, does not operate, and the To Train P/pe FIG. 3 pump continues to work and raises main-reservoir pressure until the high-pressure side of the governor (usually set at 110 Ib. and operated by main-reservoir air) stops it. TYPE SF-5 COMPRESSOR GOVERNOR The piece number of the SF-5, compressor governor, com- plete, shown in Fig. 4, is 21,799; for the steam portion, complete, which includes No. 2 to No. 11, inclusive, it is 17,879; for the excess-pressure head, complete, 20,783; for the AIR COMPRESSORS 86 AIR COMPRESSORS maximum-pressure head, complete, 20,782. The piece and ref- erence numbers of the various parts are given in the accompany- ing list. The SF-5 (IJ-in.) duplex steam compressor governor is recommended with all locomotive brake equipments that include two 9|-in., one 11-in., or one 8^-in. cross-compound air compressor. If £-in. iron pipe is to be used for the air connections, specify Piece No. 18,672, for type SF-5 steam compressor governor, complete; Piece No. 13,552, for excess- pressure head, complete; and Piece No. 2,047, for maximum- pressure head, complete; union swivel, Ref. No. 40, will then be substituted for union swivel, Ref. No. 30, and union con- nection, Piece No. 20,485, which includes Ref. Nos. 37, 38, 39, will be omitted. PC. No. Ref. 17,668 2 17,672 3 17,671 4 17,670 5 17,916 6 21,606 6 21,607 6 21,608 6 21,609 6 18,033 7 21,598 7 21,599 7 21,600 7 21,601 7 17,674 8 17,673 9 2,154 10 2,155 11 6,558 14 9,033 15 2,033 16 2,034 17 !Vo. Name of Part Steam-valve body. Cylinder body. Cylinder cap. Steam valve, complete. Piston, includes 7, for standard cj'linder, 2f in. diameter. Piston, includes 7, for rebored cylinder, 2ff in. diameter. Piston, includes 7, for rebored cylinder, 2£| in. diameter. Piston, includes 7, for rebored cylinder, 2f£ in. diameter. Piston, includes 7, for rebored cylinder, 2 1 in. diameter. Piston ring, for standard cylinder, 2f in. diameter. Piston ring for rebored cylinder, 2ff in. diameter. Piston ring for rebored cylinder, 2H in. diameter. Piston ring for rebored cylinder, 2f| in. diameter. Piston ring for rebored cylinder, 2$ in. diameter. Piston nut. Piston ring, li-in. union nut. 11-in. union swivel. Siamese fitting. Diaphragm body, includes 29. Spring box for maximum-pressure head. Check-nut for maximum-pressure head. AIR COMPRESSORS 87 iVo. Name of Part Regulating nut for maximum-pressure head. Regulating spring for maximum-pressure head. Diaphragm, complete, for maximum-pres- sure head, includes 32, 33, 34, 35, and 36. Diaphragm ring. Vent -port screw. Spring box, for excess-pressure head. Spring-box extension for excess-pressure head. Check-nut for excess-pressure head. Regulating nut for excess-pressure head. Regulating spring for excess-pressure head. Diaphragm, complete, for excess-pressure head, includes 32, 33, 34, 35, and 36. Strainer. Union swivel, f in. O. D. copper pipe. Union nut. Diaphragm nut. Diaphragm valve. Diaphragm washer. Diaphragm-valve spring. Diaphragm, 2 pieces, each. Union connection, complete, includes 37, 38, and 39. Union nut. Union swivel. Union stud. Union swivel, J-in. iron pipe. Operation of Governor. — The duty of the SF pump governor is to so restrict the speed of the pump, when the desired main- reservoir pressure is obtained, as to prevent this pressure from rising any higher. During most of the trip, the brake valve is carried in running position to keep the brakes charged. But little excess pressure is then needed, and the governor regulates the main-reservoir pressure to about 20 Ib. above the brake-pipe pressure, thus making the work of the pump easier. When the brakes are applied (lap position of the brake valve following the use of its service position) a high main-reservoir pressure is needed to insure the prompt release and recharge of the brake. Therefore, as soon as the use of lap, service, or emergency positions is commenced, the governor allows the pump to work freely until the maximum main-reservoir pressure is obtained. Again, when the brake-pipe pressure is changed PC. No. Ref. 2,035 18 2,036 19 2,043 20 1,064 21 6,868 22 13,457 23 13,456 24 13,459 25 13,458 26 2,676 27 10,734 28 2,046 29 5,384 30 15,291 31 2,041 32 2,039 33 2,040 34 2,042 35 2,038 36 20,485 2,001 37 16,286 38 20,470 39 2,045 40 88 AIR COMPRESSORS from one amount to another by the feed- valve, as where a locomotive is used alternately in high-speed-brake and ordinary service, the governor automatically changes the main-reser- voir pressure to suit, and at the same time maintains the other features just described. Also, before commencing and during the descent of steep grades, this governor enables the engineer to raise and maintain the brake-pipe pressure about 20 Ib. above the feed-valve regulation merely by the use of release position of the automatic brake valve. Air from the main reservoirs flows through the automatic brake valve (when the latter is in release, running, or holding position) to the automatic brake- valve connection 30 into the chamber below diaphragm 36. Air from the feed-valve pipe enters at the feed-valve connection 39 to the chamber above the diaphragm 36, thus aiding the pressure of the regulating spring 27 in holding the diaphragm down. As this spring is adjusted to about 20 Ib., this diaphragm will be held down until the main-reservoir pressure in the chamber below the diaphragm slightly exceeds the combined air and spring pressure in the chamber above the diaphragm. At such time, the diaphragm will be raised, unseat its pin valve, and allow air to flow to the chamber above the governor piston, forcing the latter down- wards, compressing its spring and restricting the flow of steam past steam valve 5 to the point where the pump will just supply the leakage in the brake system. When the main-reservoir pres- sure in chamber 36 becomes reduced, the combined spring and air pressures above the diaphragm force the diaphragm down, seating its diaphragm valve. As the chamber above the gov- ernor piston is always open to the atmosphere through the small vent port, the pressure in that chamber will then escape to the atmosphere and allow the piston spring, and steam pressure below the steam valve 6, to raise the valve and the governor piston. Since the connection from the main reser- voir to the chamber below the diaphragm 36 is open only when the handle of the automatic brake valve is in release, running, or holding positions, in the other positions this governor head is cut out. The main-reservoir connection in the maximum- pressure head should be connected to the main-reservoir cut- out cock, or to the pipe connecting the two main reservoirs, so AIR COMPRESSORS 89 as to be always in communication with the main reservoir, so that when the excess-pressure head is cut out by the brake valve, or by the main-reservoir cut-out cock, this head will control the pump. When main-reservoir pressure in the cham- ber below the diaphragm 36 exceeds the adjustment of spring 19, the diaphragm will raise the diaphragm valve and allow air to flow into the chamber above the governor piston, controlling the pump as just described. The adjustment of spring 19 thus 90 AIR COMPRESSORS forms the maximum limit of main-reservoir pressure. Thus, when the brake-valve handle is in running position, the excess- pressure side of the governor limits the main-reservoir pressure to 20 Ib. above the feed-valve pressure, no matter what feed- valve pressure is being carried. The maximum-pressure side forms a limit beyond which the main-reservoir pressure can- TO fSEo Mi ve f/pE (E r.). ro BKAKE P/PE (ontat sc* not rise. Therefore, a change in feed-valve regulation auto- matically produces a corresponding change in the governing pressures. As each governor head has a vent port 22, from which a small amount of air escapes whenever pressure is present in the chamber above the governor piston, to avoid an unnecessary waste of air, one of these should be plugged with a vent-port screw 22. AIR COMPRESSORS 91 Adjusting the Governor. — To adjust the excess-pressure head of the SF-5 governor place the handle of the automatic brake valve in running position, remove the cap nut 25 and turn the adjusting nut 26 until the compression of spring 27 gives the desired difference between main-reservoir and brake- pipe pressures. To adjust the maximum-pressure head, place the handle of the automatic brake valve on lap, remove the cap nut 17 and turn adjusting nut 18 until the compression of the spring 19 causes the pump to stop at the maximum main-reservoir pressure required. It is recommended that spring 27 be 92 AIR COMPRESSORS adjusted for 20 Ib. excess pressure, and spring 19 for a pressure ranging from 120 to 140 Ib., depending on the service. Pipe Connections to Old-Standard Equipment. — The method of connecting an SF governor with the old standard equipment is shown in Fig. 5. When so connected it is appli- cable to the high-speed brake or the double-pressure control equipments without changing or moving any of the governor- pipe connections. By regulating the maximum -pressure side to, say, 140 Ib., duplex main-reservoir regulation may be obtained, for feed-valve pressures up to 110 Ib, since the excess- pressure head will stop the pump at 130 Ib. thereby giving an excess pressure of 10 Ib. PIPING DIAGRAMS FOR TWO AIR COMPRESSORS For two O^-in. compressor installations, a 1 J-in. steam supply pipe should be used together with an SF-5 (IJ-in.) governor and a IJ-in. steam valve. A 1-in. supply pipe, governor, and steam valve are too small and throttle the supply of steam, reducing the speed of the compressors too much. Where both pumps are on one side of the locomotive, they should be con- nected up as in Fig. 6 (a); where they are on opposite sides of the locomotive, connected up as in (b). For two 11-in. pumps, a 1^-in. supply pipe, governor, and steam valve should be used, the pumps being connected up as shown. AIR-STORAGE RESERVOIRS The necessity for an air reservoir in connection with nearly all air compressor plants is well understood. It receives the air in pulsations from the compressor and delivers it at uni- form pressure. The reservoir also acts as a depository for such moisture, oil, and other foreign matter as passes through the compressor. The condensation of water resulting from the compression of air can never be entirely prevented, but the amount may be lessened by obtaining the coolest and driest air possible for the air intake to the compressor, and by locating the reservoir and radiating pipe in the coolest possible place. These conditions are requisite for the most satisfactory service. Each reservoir should have a drain AIR COMPRESSORS 93 cock or small pipe connection at its lowest point by means of which all residue may be drawn off at frequent intervals, as water or oil collecting will soon materially decrease the air- storage capacity of the reservoirs. Fig. 1 shows the welded pipe, that is, steel tubing with heads welded in, furnished in diameters of 16 in. and under, and FIG 1 FIG. 2 Fig'. 2 the riveted type, made of steel sheets with longitudinal seam and heads riveted, furnished in diameters of 18$ in. and over. The reservoirs are tested to a pressure of 140 Ib. They are built to the W. A. B. standard specifications for railroad service and designed for pressures up to 125 Ib. per sq. in. The accompanying table gives the standard sizes of these reser- voirs; they may be placed either vertically or horizontally, as preferred. In either case, however, it is advisable to have the air inlet and outlet near the top and on opposite sides of the reservoir, but not directly opposite each other, and the drain cock should be located at the lowest point. Main Reservoir. — The standard main reservoir is a store chamber in which a large supply of compressed air is main- tained to charge the brake pipe and auxiliaries; to release brakes, if set, by charging the brake pipe to a higher pressure than that in the auxiliaries; and to feed any brake-pipe leaks while the brakes are released. Also, it often provides air for operating sand blowers, bell ringers, blow-off cocks, water scoop, and other devices with which the engine is equipped. The usual main-reservoir pressure is 90 Ib., but this is exceeded in mountainous districts when handling very long trains, when the train is equipped with the high-speed brake, or when the Westinghouse special attachment for controlling heavy trains on long down grades is used, 94 AIR COMPRESSORS AIR-STORAGE RESERVOIRS Size Inches Approximate Capacity Cubic Inches Size Inches Approximate Capacity Cubic Inches 12 X 60 6,000 20 |X 72* 21,700 12 X 66 6,600 20| X 78 23,600 12 X 72 7,200 20 -X 84* 25,500 12 X 78 7,800 20 X 90 27,400 12 X 84 8,500 20- X 96* 29,200 14 X 54 7,300 20 X102 31,000 14 X 60 8,200 20 X108 33,000 14 X 66 9,000 201X114 35 000 14 X 72 9,900 20 X120 37,000 14 X 78 10,800 22 X 36 12,600 14 X 84 11,600 22|X 42 14,900 16 X 48 8,500 22| X 48* 17,100 16 X 54 9,600 22|X 54 19,400 16 X 60 10,800 22£X 60* 21,700 16 X 66 11,900 22|X 66 24,000 16 X 72 13,000 22 X 72* 26,300 16 X 78 14,200 22 X 78 28,500 16 X 84 15,300 22 |X 84* 30,800 16 X 90 16,400 22^ X 90 33,100 16 X 96 17,600 22 |X 96* 35,400 16 X102 18,700 22iX102 37,700 16 X108 19,800 22 |X108 39,900 16 X114 21,000 22^X114 42,200 16 X120 22,000 22 §X120 44,500 18 X 42 10,000 24| X 36 15,000 18 X 48* 11,500 24 X 42 17700 18- X 54 13,000 24 X 48* 20,400 18 X 60* 14,500 24 X 54 23,100 18| X 66 18| X 72* 10,100 17,600 24 24 X 60* X 66 25,800 28,500 18^ X 78 19,100 24 X 72* 31,200 18- X 84* 20,600 24 X 78 34,000 18< -X 90 22,200 24 |X 84* 36,700 18 X 96* 23,700 24|X 90 39,400 18 X102 25,200 24 |X 96* 42.100 18 X108 26,700 241X102 44,800 18 X114 28,300 24|X108 47,500 18 X120 29,800 26|X 36 17,500 20 X 36 10,400 26 X 42 20,700 20 X 42 12,300 26 X 48* 23,900 20 X 48* 14,200 26 X 54 27,100 20 X 54 16,000 26 |X 60* 30,300 20 X 60* 18,000 26| X 66 33,500 20 X 66 19,800 26| X 72* 36,700 * These sizes are always in stock. AIR COMPRESSORS TABLE — (Continued) Size Inches Approximate Capacity Cubic Inches Size Inches Approximate Capacity Cubic Inches 2b\ X 78 39,800 285X 90 53,600 26 X 84* 43,000 28: X 96* 57,300 26 X 90 46,200 30^ X 36 23,400 26i X 96* 49,400 30 X 42 27,600 28 i X 36 20,300 30 X 18* 31,800 28 \ X 42 24,000 30i X 54 36,100 28J X 48* 27,700 30^ X 60* 40,300 28i X 54 31,400 30^ X 66 44,600 28^ X 60* 35,100 30^ X 72* 48,800 28 \ X 66 38,800 30\ X 78 53,000 28J X 72* 42,500 30^ X 84* 57,300 28i X 78 46,200 30J X 90 60,500 28i X 84* 49,900 30* X 96* 64,800 The main reservoir varies in size according to the kind of service — freight or passenger — in which the engine is employed. In the best practice, a main reservoir of not less than 40,000 cu. in. capacity for passenger, and from 50,000 to 70,000 cu. in. for freight, service is used. For freight service the following schedule is recommended. Main -Reservoir Pump Capacity Capacity Cubic Inches One 9*-in 50,000 Two 9i-in 65,000 One 11-in 60,000 Two 11-in 70,000 One 8J-in. cross-compound 70,000 If the train is long and the main reservoir small, a high pressure must be carried in the latter in order that it may equalize with the brake pipe at a sufficiently high pressure to promptly release the brakes and recharge the auxiliaries. When the main reservoir is large, a much lower reservoir pressure can be carried, and the pump can also store a greater quantity of air while the brakes are applied. When, there- fore, the main reservoir is small, the pump must work both *These sizes are always in stock. AIR COMPRESSORS STYLE OF CONSTRUCTION OF MAIN RESERVOIRS Shell, Riveted Joint; Semiconvex Heads Riveted in I 1 r*« I-H 8 1 ^ X I | - " S d 1j HM ?-l Shell, Riveted Joint; Semiconvex Heads Welded in IN I -W 8 a H« ^ 00 a ~ X Shell, 0. D. Pipe; Semiconvex Heads Welded in 2 I* •* X s eg .si wd - - 3 Q S cq g o 1 Type of Construction Outside diameter in inches 1 O,^; Ot^ rt o Jo o ** S G AIR COMPRESSORS 97 faster (or longer) and against a higher pressure, either of which tends to cause overheating. A much higher pressure is required in the main reservoir than in the brake pipe, not only to release brakes, but also to force the air through the brake pipe in the shortest time possible and thus release all brakes on a long train promptly and as nearly simultaneous as possible. About 20 Ib. more pressure in the reservoir than in the brake pipe is usually needed with a large reservoir; with a small reservoir, more than 20 Ib. is necessary. In ordering main reservoirs, the pressure, outside diameter, and length over all, in inches, and any special features, such as special pipe tapping, handholes, etc., must always be given. Styles of Reservoirs. — Main reservoirs are made in three styles: The shell of drawn tubing with convex heads welded in; the shell of drawn tubing with semiconvex heads welded in; the shell riveted with semiconvex heads welded in. Also, reservoirs are made with brazed seams for shell and heads. Standard Tapping. — The standard method of tapping main reservoirs is shown in the accompanying figure. Pipe tap B is central, and there is one tap in each head. If there are two tap holes in the same reservoir head, they must not be closer than 4 in. between centers. Also, no hole should be placed closer to the shell than 5 in. from the center of the hole to the shell of the reservoir. The proper size of pipe taps for the different size reservoirs is given in the table showing the style of construction. Enameled Reservoirs. — Reservoirs enameled by special process are recommended on account of their durability and because both inside and outside surfaces are protected against corrosion, oxidation, etc., thereby preserving the initial factor of safety. The reservoir is thoroughly cleaned in an acid bath, neutralized by an alkali, and carefully washed 8 AIR COMPRESSORS S9UOUT £ IIVJ9AO nv -«AO 9ZTS S3UOUT oioi>ooO'-irot--.occcoosocoooi-cc ct-oiON oc*'**o t-cii-H 55 35 S5 « » » « W » « * ^ S 1-! i-l r^ rH ^H « * * SOO'* O>-l< * * * * * * XXXXXXXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXXXXXXX AIR COMPRESSORS -cooTj»asTf"-i-^-t>.OOOOOOa5OC5 co to as c< "5 oo «- OCOOl— t^t^OO XXXXXXXXXXXXXXXXXXXXXXXXXXXXXX « c I 12 O5'-ieo'Ot^c:^HCOTtioooowc^TfHcocO'-Heo'OooocOfO- Ct '-iiM'*i O'-iC-'CC10'-IO5t^»OCO'-l< ^MMOO^lX-NOp^OMt-^O^CftCCMOQeCOpCO^CJt-CJb.^ ric^j c^ 1 XXXXXXXXXXXXXXXXXXXXXXXXXXXXXX -- tC ^ »O Oi JO '-T O 'T 30 CS -sO O ?0 t>- ^H««£0 W O -t X C^l O ^ C5 O -«f N OS XXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 1IN 100 AIR spuno. 00 <0 ;O»OO5rt-H xxxxxxxxxxx IIIIIIIIIIS xxxxxxxxxxxx I , — — < t^ rH >C _ o •* t^ *+ >o o w" co o co t>- r* OO xxxxxxxxxxxx AIR COMPRESSORS 101 and dried. It is then dipped in warm enamel to coat both inside and outside surfaces, and baked at a high temperature, the dipping and baking operations being repeated to give a second coat. The mark )0(f just above the pipe tap in the head of a reservoir indicates enamel reservoir. The mark )@( indicates plain reservoir. Location of Reservoirs. — It is strongly recommended that the main-reservoir capacity be divided into two reservoirs of suitable dimensions, so located and so connected by piping, as to give the greatest possible radiating surface to cool the air to atmospheric temperature, and cause the precipi- tation of as much moisture as possible before the air is drawn out of the reservoir. Main reservoirs should be located in as cool a position as possible and never at the side of the firebox. The standard sizes of main reservoirs are designed for a maximum pressure of 140 lb.; special reservoirs built to carry more than 140 lb. can be obtained on special specifications. Calculating Main-Reservoir Capacity. — To find the capacity of a main reservoir, apply the following rule: Rule. — To calculate the approximate capacity of a reservoir, in cubic inches, multiply its cross-sectional area, in square inches, by the inside length, in inches. EXAMPLE 1. — What is the capacity of a reservoir 18 in. in diameter and 100 in. in length (inside measurements)? SOLUTION. — The cross-sectional area of the reservoir is 20 X 20 X. 7854 = 314. 16 sq. in. The length is 100 in. There- fore, the capacity is 314.16X100 = 31,416 cu. in. To calculate approximately the capacity of a main reservoir from its outside dimensions, subtract \ in. from its diameter and 3 in. from its length, so as to reduce the outside measure- ments to inside measurements; then proceed as before. The J in. from the diameter allows for the thicknesses of metal in the walls, while the 3 in. from the length allows for the thick- ness of metal of the ends and for the way the ends are secured in place. EXAMPLE 2.— What is the capacity of a main reservoir 26i in. in diameter by 96 in. long? 102 AIR COMPRESSORS SOLUTION. — The internal dimensions of the reservoir (found by subtracting 5 in. from diameter and 3 in. from the length) are 26 in. in diameter by 93 in. long. The area of a 26-in. reservoir is 503.93 sq. in.; therefore, its capacity is 503.93 X93 = 49,377 cu. in., say 49,400. The accompanying table gives the cross-sectional areas of the standard sizes of main reservoirs as well as the special sizes, 33£, 34|, and 36| in. The areas were calculated after subtracting f in. from the diameters, so that multiplying them by the length of a reservoir, after subtracting 3 in. from its length, will give the approximate capacity of the reservoir, in cubic inches. CROSS-SECTIONAL AREAS OF AIR-BRAKE MAIN RESERVOIRS Diameter Inches Cross Sectional Area Square Inches Diameter Inches Cross-Sectional Area Square Inches 10 12 14 16 18| 20i 22 £ 70.88 103.87 143.14 188.69 254.47 314.16 375.83 24^ 26^ 28^ 30 32 \ 34i 36 r 452.39 503.93 615.75 706.86 804.20 907.90 1,017.90 ENGINEER'S BRAKE VALVES 103 ENGINEER'S BRAKE VALVES HISTORY OF VALVE The engineer's brake valve is that part of the air-brake equipment by means of which the engineer can control the action of the brakes. It is located in the cab of the engine in a position convenient to the engineer. Its function is to regulate the flow of air from the main reservoir to the brake pipe, and through the chamber in the brake valve to the small equalizing reservoir under the right running board; from the brake pipe through the engineer's valve to the atmosphere; and from the chamber, the equalizing reservoir, and brake pipe to the atmosphere; also, if desired, it prevents any flow, of air whatsoever. The equalizing reservoir is connected to the chamber of the brake valve, with the object of increasing the volume of that chamber. Air passes through the chamber when going either into or out of the brake-valve reservoir. Three- Way Cock.— The first style of valve (used with the non-automatic or straight-air brake as early as 1868) con- trolled the passage of the air from the main reservoir to the train pipe and brake cylinders to apply the brake, and held the air in the brake cylinders and train pipe to keep the brake applied; also, it allowed the air to pass out to the atmosphere to release the brake. It was a three-way cock, as shown in Fig. 1, having three ports in the plug that could connect with pIG the passages in the body of the cock and control the passage of the air. The pipe on the right was connected to the main reservoir, that on the left to the train pipe, while the middle one was the exhaust, leading to the atmosphere. Some three-way cocks are still in service, but 104 ENGINEER'S BRAKE VALVES their use is not considered a sign of progress in the air-brake field. B-ll Brake Valve. — Next in order of invention was the B-ll engineer's brake valve in 1876, shown in Fig. 2; it was the first to have a rotary valve. In this an attempt was made to have the valve automatic in closing the discharge of air from the train pipe. The handle was connected to a quick- thread screw in the top, which, when turned to the right, would To Tra/'n Pipe FIG. 2 reduce the tension of the spring shown in the handle and allow the train-pipe discharge valve to be raised off its seat by train-pipe pressure; then train-pipe air would flow out to the atmosphere until it was reduced so that the spring could close the discharge valve and stop the flow of air. The rotary valve had ports straight through it to feed air direct from the main reservoir to the train pipe with rotary valve in full-release position. Cavities in the face of the rotary valve connected the train pipe direct to the atmosphere in ENGINEER'S BRAKE VALVES 105 emergency position. There was an excess-pressure valve in the rotary valve which, in running position, would retain an excess of pressure in the main reservoir over that in the train pipe. This higher main-reservoir pressure was found necessary to release promptly all triple valves in a train equipped with the automatic brake. B-12 Brake Valve. — The spring equalization against air pressure was not found satisfactory, so the next valve, known as the B-12 valve, had an equalizing piston with air pressure on both sides of it; this valve is shown in Fig. 3. The B-12 brake valve was invented in 1886. With this valve the first attempt was made to overcome the evil effects resulting from the engineer clo- sing the exhaust port too suddenly, which on a long train generally .caused several of the head brakes to release. This releasing of the brakes was due to the air (rushing through the train pipe) not stopping as soon as the exhaust port was closed; conse- FIG. 3 quently, the air banked up in the front end of the train pipe and raised the pressure above that in the auxiliary reservoir, thus causing the brakes to release. The equali- zing feature provides for a constant flow of air from the train pipe until the pressure is uniform throughout the train. The valve is also provided with a direct-application port, which is used in cases of emergency only. The chamber above the equalizing piston has a small reservoir attached 106 ENGINEER'S BRAKE VALVES to it to increase its volume; in full release and running positions, main-reservoir air passes through this chamber and through the small holes in the equalizing piston on its way to the train pipe, as can be seen by the line of arrows. This valve has an excess-pressure valve in one side through which the air from the main reservoir has to pass when the rotary valve is in run- ning position. ENGINEER'S BRAKE VALVES 107 C-7 Brake Valve. — The B-12 brake valve was not satisfactory in its operation, so another form, called C-7, was put in service in 1887, in which the main-reservoir air passed through the rotary valve and its seat into the chamber connected to the brake-valve reservoir, and thence through openings in the equalizing piston, as in the B-12. The slide valve and springs in the B-12 were not used in this one, which made it much less complicated and more certain in its action. The perforated equalizing piston gave trouble, as any dirt or foreign substance between the lower side of this piston and the spring washer would allow the air to pass either way through the piston, and the piston would not respond to moderate variations of pressure. To avoid the leakage from the train-pipe exhaust elbow, it was provided with a stop-cock. This could be closed if the piston failed to seat the discharge valve; the cock was usually found closed, and the brake valve used in the emergency posi- tion to discharge air from the train pipe. Cross-sectional views of this valve are shown in Fig. 4 (a) and (6). D-8 Brake Valve. — The D-8 brake valve, shown in Fig. 5 (a) and (b), was invented in 1889, and was intended to overcome the objectionable features in the valve preceding it. In this valve the main-reservoir air does riot pass through the chamber above the equalizing piston on its way to the train pipe, but [has a direct connection with the train pipe in full-release position through a port and cavities in the rotary valve and seat, and the direct-application-and-supply port that leads to the train pipe. It will be noted that the direct-application-and-supply port in this valve is not a supply port in the valve preceding it, that port being used only in applying the brakes. The bottom of the equalizing-piston stem forms a seat over the train-pipe exhaust port and has a small projection continuing on below the seat to regulate the rate of the train-pipe discharge; the top and bottom faces of the equalizing piston are directly con- nected in full-release and running positions by a small port known as the equalizing port. The valve also has an excess- pressure valve similar to the one in the C-7 valve. In running position, the air from the main reservoir passes this valve on its way to the train ojpe. 108 ENGINEER'S BRAKE VALVES ENGINEER'S BRAKE VALVES 109 110 ENGINEER'S BRAKE VALVES There are certain objectionable features about this valve that were brought out in the process of evolution that the air brake underwent as the length of trains increased, and these have been changed in the later type of brake valve. The excess-pressure valve has given way to the feed-valve or train-pipe governor. The feed-ports are increased in size. The arrangements of the ports in the valve and seat are slightly altered. The projection of the equalizing discharge-valve stem below the train-pipe exhaust-valve seat is made tapering instead of straight, as shown. • D-5, E-6, F-6 Brake Valve. — The D-8 brake valve was superseded by D-5, E-6, or F-6 brake valve (the 1892 model) the latter three terms denoting one and the same valve, the letter and number being changed as each new catalog was issued by the Westinghouse Air-Brake Company. It is shown in Fig. 6. In this brake valve the excess-pressure valve of the D-8 valve was replaced by the feed-valve attachment. G-6 Brake Valve. — The F-6 brake valve was in turn super- seded by the G-6 brake valve, which differs from it only in the type of feed- valve used, the G-6 brake valve being fur- nished with the slide-valve feed-valve. G-6 ENGINEER'S BRAKE VALVE PIECE AND REFERENCE NUMBERS The G-6 brake valve, shown in Figs. 1 and 2, is regularly fur- nished with old standard A-l, AD, and AG engine brake equip- ments. Its weight, including the feed-valve, is 50 Ib. Its piece number with brass handle and C-6 feed-valve, complete, is 19,427; with brass handle, complete, less feed-valve and feed- valve case gasket, is 2,169; with malleable-iron handle and C-6 feed-valve, complete, is 20,231 ; with malleable-iron handle, com- plete, less feed-valve, 22,093; with brass handle and B-3 feed- valve, complete, 2,168; with malleable-iron handle and B-3 feed- valve complete, 22,094; with brass handle and feed- valve pipe connection, complete, 2,585; with malleable-iron handle and feed-valve pipe connection, complete, 22,096. The piece ENGINEER'S BRAKE VALVES 111 FIG. 1 and reference numbers of the various parts are given in the accompanying list: PC. No. Ref. No. Name of Part 12,670 2 Body, includes 34. 2,170 3 Rotary-valve seat, complete. 2,489 4 Bottom case, complete, includes 25 and 28. 1.990 5 Bottom cap. 1.991 6 Handle locknut. 1.992 7 Handle nut. 1.993 8 Brass handle, complete, includes 9, 10, and 11. 18,713 8 Malleable-iron handle, complete, includes 9, 10. and 11. 1.996 9 Latch. 1.367 10 Latch spring. 1.368 11 Latch screw. 1.997 12 Rotary -valve key. 1.998 13 Key washer. 1.999 14 Rotary valve. 112 ENGINEER'S BRAKE VALVES g O D COPPER PIPE TO GAGE " ENGINEER'S BRAKE VALVES 113 PC. No. Ref. No. Name of Part. 6,672 15 Gauge and equalizing reservoir T. 2001 16 Gauge and governor union nut. 16,286 17 Gauge and governor union swivel. 2,172 18 Equalizing piston, includes 19. 10,032 19 Piston ring. 35,299 20 f-in. union nut. 2,005 21 |-in. union swivel. 15,284 22 Exhaust fitting. 2.007 23 1-in. union nut. 2,008 24 1-in. union swivel. 2,010 25 Holding nut. 2,011 2,012 26 27 Gauge-pipe L. Feed-valve gasket. 2,009 28 Holding stud. 11,014 29 5 -in. bolt and nut. 35,385 30 Stud and nut. 2,015 31 Upper gasket. 2,016 32 Lower gasket. 13,109 33 Rotary- valve spring. 6,753 34 Oil plug. 18,480 C-6 single pressure feed-valve. 1,635 J-in. pipe plug. OPERATION OF G-6 AUTOMATIC BRAKE VALVE Release Position. — Three views of the G-6, engineer's, auto- matic, brake-valve are shown in Figs. 1 and 2. When the brake valve is in release position, main-reservoir air is free to pass out into the brake pipe. As the brake-pipe pressure increases, the triple pistons are forced to release position and the auxiliaries are charged. While the air is passing through the brake valve into the brake pipe, it is free to pass down through the rotary valve into the chamber above the equal- izing piston, and thence out to the equalizing reservoir through the T fitting 15. In release position, one large port leads from the main reservoir to the brake pipe, and two small ports lead to the equalizing reservoir. A small port r, called the engineer's warning port, is drilled through the rotary valve in such a position that, when the latter is in full-release position, this warning port is directly over the exhaust port in the rotary seat. Main-reservoir air on top of the rotary blows through this small warning port into the exhaust port, and the sound of the escaping air is heard by the engineer. This is to warn him that he must not leave the valve in full -release position too long. 9 114 ENGINEER'S BRAKE VALVES Running Position. — In running position, air from the main reservoir passes through the feed-valve attachment into the brake-pipe. The air continues to flow thus until the brake- pipe pressure reaches 70 lb., when the feed- valve attachment closes. As air passes through the feed- valve attachment, some of it passes up into a cavity in the rotary valve and down through a port into chamber D, the chamber above the equalizing piston 18. Connection is thus maintained between the brake pipe and chamber D, that is, between both sides of the equalizing piston 17. The black gauge hand is piped to the equalizing-reservoir connection at union swivel 1 7, and, as in running position there is a port connection between the brake pipe and chamber D through the cavity in the rotary and a port, the black hand must, in this position, indi- cate both chamber D and brake-pipe pressures. The same movement that changes the rotary from full-release to running position closes the warning port. Lap Position. — In lap position, the rotary has been moved around so as to close all connections. Service Position. — In service position, the rotary has been moved so that a groove in the face of the rotary valve connects the preliminary-exhaust port in the rotary seat with a port, which leads into the direct-application-and-exhaust port. A direct connection is thus established between chamber D and the atmosphere, and air from chamber D can pass to the atmosphere. The reduction of the pressure in chamber D causes the equalizing piston to rise and open the brake-pipe exhaust valve, thus producing a brake-pipe reduction. Emergency Position. — In emergency position, the rotary has been moved around so that its cavity connects a large port leading to the train pipe with the exhaust port leading to the atmosphere. The opening of these large ports causes a sudden brake-pipe reduction, which gives an emergency application of the brakes. Also, a groove in the rotary valve connects a port from chamber D with a groove leading to the atmosphere, thus exhausting the air from chamber D and allowing the black hand of the gauge to drop to zero. ENGINEER'S BRAKE VALVES 115 H-5 AUTOMATIC BRAKE VALVE PIECE AND REFERENCE NUMBERS The H-5 automatic brake valve, shown in Figs. 1 and 2, is standard for use with the No. 5-ET locomotive brake equip- ment; its weight is 50 Ib. The piece number of the H-5 automatic brake valve, complete, is 11,596. The piece and reference number of the various parts are given in the accom- panying list. PC. No. Ref. No. Name of Part Bottom case, bushed, includes 35. Rotary -valve seat, complete. Top case, includes 29. Pipe bracket, includes 25, 26, and 31. Rotary valve. Rotary-valve key. Key washer. Handle, includes 10, 11, and 12. Latch spring. Latch. Latch screw. Handle nut. Handle locknut. Equalizing piston, includes 16. Equalizing-piston-packing ring. Upper gasket. Middle gasket. Lower gasket. i-in. union nut. Brake valve T. J-in. union swivel. 1-in. union nut. |-in. union swivel. Holding stud. Holding nut. Bolt and nut. Capscrew. Oil plug. Rotary-valve spring. 1-in. union nut. 1-in. union swivel. 1-in. pipe plug. f-in. pipe plug. Exhaust fitting. 9,733 2 10,406 3 12,277 4 17,310 5 33,362 6 9,759 7 1,998 8 1,993 9 1,367 10 1,996 11 1,368 12 1,992 13 1,991 14 11,045 15 10,032 16 9.758 17 9.757 18 15,534 19 2,001 20 6,672 21 16,286 22 35,299 2:5 2,005 24 2,009 26 2,010 26 11,016 27 4,110 28 6,753 29 13,109 80 2.007 81 2,008 32 1,636 1,734 14,464 35 116 ENGINEER'S BRAKE VALVES FIG. 1 ENGINEER'S BRAKE VALVES 117 OPERATION OF THE H-5 AUTOMATIC BRAKE VALVE This H-5 automatic brake valve, although modeled to a considerable extent upon the principles of previous valves, is necessarily different in detail, as it not only performs all the functions of the other types but also those absolutely necessary to obtain all the desirable operating features of the distributing valve, which is used in connection with this brake valve. The FlG. 2 positions of the brake-valve handle are shown in Fig. 2, from which it will be noted that there is an extra position, called holding position. In describing the operation of this brake valve, the positions are taken up in the order in which they are most generally used. Running Position. — To release the engine and tender brakes, or when the brakes are not being used and the system is charged and ready for an application, the handle should be placed in the running position. In this position, cavity / in the rotary valve connects ports b and d in the valve seat, affording a large direct passage from the feed- valve to the brake pipe, so that the latter will charge up as rapidly as the feed-valve can 118 ENGINEER'S BRAKE VALVES supply the air, but cannot attain a pressure above that for which the feed-valve is adjusted. Cavity k in the rotary valve connects ports c and g in the valve seat, so that chamber D and the equalizing reservoir charge uniformly with the brake pipe, keeping the pressures on the two sides of the equalizing piston equal. Port s in the rotary valve registers with port p in the valve seat, permitting main-reservoir pressure, which is present at all times above the rotary valve, to pass to the excess-pressure head of the pump governor. Port h in the rotary valve registers with port I in the seat, connecting the application-chamber pipe to the exhaust cavity ex. Service Position. — The service position gives a gradual reduction of brake-pipe pressure to cause a service applica- tion. Port h in the rotary valve registers with port 5 in the valve seat, allowing air from chamber D and the equalizing reservoir to escape to the atmosphere through cavities o in the rotary valve and exhaust cavity ex in the valve seat. Port e is restricted so as to make the pressure in the equalizing reservoir and chamber D fall gradually. The fall of pressure in chamber D allows the brake-pipe pressure under the equali- zing piston to raise it, and unseat the discharge valve, allowing brake-pipe air to flow to the atmosphere. When the pressure in chamber D is reduced the desired amount, the handle is moved to the lap position, thus stopping any further reduc- tion in that chamber. Air will continue to discharge from the brake pipe until its pressure has fallen to an amount a trifle less than that retained in chamber D, permitting the pressure in this chamber to force the piston downwards and stop the discharge of brake-pipe air. It will be seen, therefore, that the amount of reduction in the equalizing reservoir determines that in the brake pipe, regardless of the length of the train. Lap Position. — The lap position is used while holding the brakes applied after a service application until it is desired either to make a further brake-pipe reduction, or to release them; also to prevent loss of main-reservoir pressure or the release of the brake in the event of a burst hose, a break in two, or the opening of the conductor's valve. Lap position is also used on all engines in a train that are not controlling the train brakes, as, with the handle in this position, port h ENGINEER'S BRAKE VALVES 119 in the rotary valve connects with port » in the seat. There- fore, when the double cut-out cock is turned to the position that cuts out the brake pipe, it makes a direct opening from port i in the distributing valve through the double-heading pipe to the atmosphere, and is the passage through which the air escapes from the application chamber when the automatic brakes are being released. Release Position. — The purpose of release position is to provide a large and direct passage from the main reservoir to the brake pipe, to permit a rapid flow of air into the latter to insure a quick release and recharging of the train brakes, but without releasing the engine and tender brakes. Air at main-reservoir pressure flows through port a in the rotary valve to port b in the valve seat and to the brake pipe. At the same time, port j in the rotary valve registers with the equalizing port g in the valve seat, permitting main-reservoir pressure to enter chamber D above the equalizing piston. In this position, port 5 in the rotary valve registers with warning port r in the seat and allows a small quantity of air to escape into the exhaust cavity ex, which makes sufficient noise to attract the engineer's attention to the position in which the valve handle is standing. If the handle is allowed to remain in this position, the brake system will be charged to main-reservoir pressure. To avoid this, the handle must be moved to running or holding positions. The small groove in the face of the rotary valve that connects with port s, extends to port p, in the valve seat, allowing main-reservoir pressure to flow to the excess-pressure head of the pump governor. Holding Position. — The holding position is so named because the locomotive brakes are held applied, as they are in release position, while the train brakes feed up to the feed- valve pressure. All ports register as in running position, except port I, which is closed. Therefore, the only difference between run- ning and holding positions is that in the former the application chamber is open to the atmosphere, while in the latter it is not. Emergency Position. — The emergency position is used when the most prompt and heavy application of the brakes is desired. Port x in the rotary valve registers with port c in 120 ENGINEER'S BRAKE VALVES the valve seat, making a large and direct communication between the brake pipe and atmosphere through cavity o in the rotary valve and the exhaust cavity in the valve seat. This direct passage causes a sudden and heavy discharge of brake-pipe pressure, causing the triple valves and distributing valve to go to the emergency position and apply the brake in the shortest possible time. In this position the groove n in the rotary valve connects ports g and I in the valve seat, thereby allowing equalizing reservoir air to flow into the application chamber. The oil plug 29 is placed in the top case 4 at a point to fix the level of the oil surrounding the rotary valve. A leather washer 8 prevents air in the rotary -valve chamber from leaking past the rotary-valve key to the atmosphere. A spring 30 keeps the rotary- valve key firmly pressed against the washer 8 when no main-reservoir pressure is present. The handle 9 contains a latch 11 that fits into notches in the top case; these notches are so located as to indicate the different posi- tions of the brake-valve handle. The spring 10 back of the latch forces the latter against the body with sufficient pres- sure to distinctly indicate when the handle arrives at each position. To remove the brake valve, take off nuts 27, thus allowing it to come away without disturbing the pipe bracket or breaking any pipe joints. To take the valve proper apart, remove cap- screws 28. The brake valve should be located so that the engineer can operate it from his usual position, while looking forwards or backwards out of the side cab window, and in such a manner that the handle will not meet with any obstruction through- out its entire movement. H-6 AUTOMATIC BRAKE VALVE PIECE AND REFERENCE NUMBERS The H-6 automatic brake valve, shown in Fig. 1, is a part of, and is regularly supplied with, the No. 6 ET locomotive brake equipment; its weight is 50 Ib. The piece 'number of H-6 brake valve, with brass handle and pipe bracket, complete, ENGINEER'S BRAKE VALVES 121 r \ SO. a Copper /'//ye 2O4 FIG. 1 122 ENGINEER'S BRAKE VALVES is 18,462; with brass handle, complete, without pipe bracket, 22,091; with malleable-iron handle and pipe bracket, complete, 19,288; with malleable-iron handle, complete, without pipe bracket, 22,092. The piece and reference numbers of the FIG. 2 various parts are given in the accompanying list. In Fig. 2 are shown enlarged views of the face and the top of the rotary valve. PC. No. 9,733 18,434 12,277 18,432 18,413 9.759 1,998 1,993 18,713 1,367 1,996 -1,368 1,992 1,991 11,045 10,032 9,758 9,757 Ref. No. Name of Part 2 Bottom case, bushed, includes 31. • 3 Rotary- valve seat, complete. 4 Top case, includes 29. 5 Pipe bracket includes 25, 26, 32, 33, and 6 Rotary valve. 7 Rotary-valve key. 8 Key washer. 9 Brass handle, complete, includes 10, 11, and 12. 9 Malleable-iron handle, complete, includes 10, 11, and 12. Latch spring. Latch. Latch screw. Handle nut. Handle locknut. Equalizing piston, includes 16. Piston ring. Upper gasket. Middl ' Idle gasket. ENGINEER'S BRAKE VALVES 123 PC. No. Rcf. No. Name of Part 15,534 19 Lower gasket. 20,485 Governor-union connection, complete, includes 20, 22, and 35. 2,001 20 Gauge and governor-union nut. 6,672 21 16,286 22 Gauge and equalizing reservoir T. Gauge and governor-union swivel. 15,292 23 |-in. union nut. 2,005 24 f-m. union swivel. 2,009 25 Holding stud. 2,010 26 Holding nut. 11.016 27 Bolt and nut. 4,110 28 Capscrew. 6,753 29 Oil plug. 13,109 30 14,464 31 Rotary-valve spring. Exhaust fitting. 1,004 32 1.636 33 $-in. pipe plug. 1-in. pipe plug. 1,734 34 20,470 35 |-in. pipe plug. Governor -union stud. 18.365 Distributing-valve union connection, com- plete, includes 202, 203, and 204. 18,364 202 Union stud. 15.292 203 Union nut. 18,363 204 Union swivel. OPERATION OF H-6 AUTOMATIC BRAKE VALVE Charging and Release Position. — The purpose of the char- ging and release position is to provide a large, direct passage from the main reservoir to the brake pipe, to permit a rapid flow of main-reservoir air into the brake pipe to charge the" train-brake system; to quickly release and recharge the brakes; to hold the locomotive brakes, if they are applied. Air at main-reservoir pressure flows through port a in the rotary valve and port b in the valve seat into the brake pipe. Port j in the rotary valve registers with equalizing port g in the valve seat, permitting main-reservoir air to blow into chamber D above the equalizing piston. If the handle is allowed to remain in this position, the brake system will be charged to main-reservoir pressure. To avoid this, the handle must be moved to running or holding position. A small port discharges feed-valve pipe air to the atmosphere in release position, to prevent the engineer from forgetting that the handle is in release position. Cavity / in the rotary valve connects port d with warning port r in the seat 124 ENGINEER'S BRAKE VALVES and allows a small quantity of air to escape into the exhaust cavity ex which makes sufficient noise to attract the engineer's attention to the position in which the valve handle is standing. The small groove in the face of the rotary valve that connects with port 5, extends to port p in the valve seat, allowing main- reservoir pressure to flow to the excess-pressure head of the pump governor. Running Position. — The running position is the proper posi- tion of the handle when the brakes are charged and ready for use, when the brakes are not being operated, and when the locomotive brakes are to be released. In this position, cavity / in the rotary valve connects ports b and d in the valve seat, affording a large direct passage from the feed-valve pipe to the brake pipe, so that the latter will charge up as rapidly as the feed-valve can supply the air, but cannot attain a pres- sure above that for which the feed-valve is adjusted. Cavity k in the rotary valve connects ports c and g in the valve seat, so that chamber D and the equalizing reservoir charge uni- formly with the brake pipe, keeping the pressure on the two sides of the equalizing piston equal. Port 5 in the rotary valve registers with port p in the valve seat, permitting main- reservoir pressure, which is present at all times above the rotary valve, to pass to the excess-pressure head of the pump governor. Port h in the rotary valve registers with port / in the seat, connecting the distributing-valve release pipe through the exhaust cavity ex with the atmosphere. Service Position. — The service position gives a gradual reduc- tion of brake-pipe pressure to cause a service application. Port h in the rotary valve registers with port e in the valve seat, allowing air from chamber D and the equalizing reservoir to escape to the atmosphere through cavities o, in the rotary valve, and ex, in the valve seat. Port e is restricted so as to make the pressure in the equalizing reservoir and chamber D fall gradually. As all other ports are closed, the fall of pressure in chamber D allows the brake-pipe pressure under the equal- izing piston to raise it, and unseat its valve, allowing brake- pipe air to flow to the atmosphere gradually through the open- ing marked exhaust, Fig. 1. When the pressure in chamber D is reduced the desired amount, the handle is moved to lap ENGINEER'S BRAKE VALVES 125 position, thus stopping any further reduction in that chamber. Air will continue to discharge from the brake pipe until its pressure has fallen to an amount a trifle less than that retained in chamber D, permitting the pressure in this chamber to force the piston downwards gradually and stop the discharge of brake-pipe air. It will be seen, therefore, that the amount of reduction in the equalizing reservoir determines that in the brake pipe, regardless of the length of the train. Lap Position. — The lap position is used while holding the brakes applied after a service application until it is desired either to make a further brake-pipe reduction, or to release them; and to prevent loss of main -reservoir pressure in the event of a burst hose, a break-in-two, or the opening of the conductor's valve. In this position all ports are closed. Release Position. — The release position, which is used for releasing the train brakes after an application, without releas- ing the locomotive brakes, has already been described under Charging and Release Position. The air flowing from the main-reservoir-pipe connection through port a, in the rotary valve, and port b, in the valve seat, to the brake pipe, raises the pressure in the latter, thereby causing the triple valves and equalizing portion of the distributing valve to go to release position, which releases the train brakes and recharges the auxiliary reservoirs and the pressure chamber in the distribut- ing valve. When the brake-pipe pressure has been increased sufficiently to cause this, the handle of the brake valve should be moved to either running or holding position; the former when it is desired to release locomotive brakes, and the latter when they are to be still held applied. Holding Position. — The holding position is so named because the locomotive brakes are held applied while the train brakes recharge to feed-valve pressure. All ports register as in run- ning position, except port /, which is closed. Therefore, the only difference between running and holding positions is that in the former the locomotive brakes are released, while in the latter they are held applied. Emergency Position. — The emergency position is used when the most prompt and heavy application of the brakes is required. Port x in the rotary valve registers with port c in the valve 126 ENGINEER'S BRAKE VALVES AUTOMATIC BRAKE VALVE ENGINEER'S BRAKE VALVES 127 seat, making a large and direct communication between the brake pipe and atmosphere through cavity o in the rotary valve and the exhaust cavity in the valve seat. This direct passage makes a sudden and heavy discharge of brake-pipe pressure, causing the triple valves and distributing valve to go to the emergency position and give maximum braking power in the shortest possible time. SF-1 INDEPENDENT BRAKE VALVE PIECE AND REFERENCE NUMBERS The SF-1 independent brake valve, here shown, is a part of, and regularly supplied with, the No. 5 ET locomotive brake equipment; its weight is 14 Ib. The SF independent brake valve, formerly supplied with the No. 5 ET equipment, differs from the SF-1 valve in the items, Ref. Nos. 9, 10, 12, 27, and 28, in the accompanying list. The SF valves now in service may be readily changed to incorporate the new type of spring and housing by drilling a A-in. hole for the stop-pin and substituting Ref. Nos. 9, 10, 12, 27, and 28 in place of similar details removed. It is impossible to apply either the spring or any detail of the new construction to old SF valves unless the complete set of details comprised in the improved arrangement is first changed and the A-in. hole is drilled according to directions, which will be furnished by the West- inghouse Air-Brake Company on request. In ordering repair parts for this valve, it should therefore be carefully noted whether they are desired for the SF or SF-1 valve. The piece number of SF-1 independent brake valve with brass handle and pipe bracket, complete, is 21,736; with malleable-iron handle and pipe bracket, complete, 21,737. The piece and reference numbers of the various parts are given in the accompanying list. PC. No. Ref. No. Name of Part 10,214 2 Rotary -valve seat. 21,738 3 Body, includes 11, 20, and 27. 12,306 4 Pipe bracket, includes 23 and 24. 11 934 5 Rotary valve. 128 ENGINEER'S BRAKE VALVES Pc.No. Ref.No. Name of Part 14.299 6 Rotary-valve key. 6,763 7 Rotary-valve spring. 6,760 8 Key washer. 17,445 9 Return spring. 19,072 10 Return-spring casing. 11,943 11 Screw for return-spring casing. 19,071 12 Upper clutch. 11,925 13 Cover. 12.304 14 Cover screw. 11,966 15 Brass handle, complete, includes 17, 18, and 19. 18,748 15 Malleable-iron handle, complete, includes 17, 18, and 19. 9,926 16 Handle nut. 9,810 17 Latch spring. 11,932 18 Latch. 1 368 19 Latch screw. 6,753 20 Oil plug. 28,659 21 Upper gasket. 36,475 22 Lower gasket. 12.305 23 Holding stud. 10,844 24 Holding nut. 15,332 25 Bolt and nut. 12,309 26 Fillister-head screw. 17,138 27 Return-spring stop. 19.070 28 Lower clutch. S-6 INDEPENDENT BRAKE VALVE PIECE AND REFERENCE NUMBERS The S-6 independent brake valve, shown in Fig. 1, is a part of, and regularly supplied with, the No. 6 ET locomotive brake equipment. Its weight is 14 Ib. The piece number of S-6 independent brake valve with brass handle and pipe bracket, complete, is 15,326; with brass handle, complete, with- out pipe bracket, is 21,990; with malleable-iron handle and pipe bracket, complete, 19,293; and with malleable-iron handle, complete, without pipe bracket, 21,991. The piece and refer- ence numbers of the various parts are given in the accompanying list. Pc.No. Ref.No. Name of Part 15,328 2 Pipe bracket, includes 22, and 23. 15,300 3 Rotary-valve seat. 15,327 4 Body, includes 8, 20, and 27. 19,072 5 Return-spring casing. ENGINEER'S BRAKE VALVES 129 FIG. 1 130 ENGINEER'S BRAKE VALVES PC. No. Ref. No. Name of Part 17,445 6 Return spring. 15.303 7 Cover. 11,943 8 17,255 9 17,248 10 13,109 11 6,760 12 19,071 13 9,926 14 11,966 15 Screw for return-spring casing. Rotary valve. Rotary-valve kej'. Rotary- valve spring. Key washer. Upper clutch. Handle nut. Brass handle, complete, includes 16, 17, and 18. 18,748 15 Malleable-iron handle complete, includes 16, 17, and 18. 9,810 16 Latch spring. 1,368 17 Latch screw. 11,932 18 Latch. 12.304 19 Cover screw. 6,653 20 Oil plug. 15,332 21 Bolt and nut. 12.305 22 Holding stud. 10,844 23 Holding nut. 15,307 24 Upper gasket. 28,467 25 Lower gasket. 19,070 26 Lower clutch. 17,138 27 Return-spring stop. 12,304 28 Fillister-head screw. _ 18,365 Distributing-valve union connection, com- plete, includes 202, 203, and 204. 18,364 202 Union stud. 15,292 203 Union nut. 18,363 204 Union swivel. OPERATION OF S-6 INDEPENDENT BRAKE VALVE The independent brake valve receives air from the main reservoir through a reducing valve so that the pressure in this brake valve will not exceed 45 lb., the amount for which the reducing valve is adjusted. It is connected to the exhaust port of the distributing valve by the distributing- valve release pipe, and to the automatic brake valve by the release pipe. Also, it is connected to the application cylinder of the distributing valve through the application-cylinder pipe, a T-connection being placed in this pipe to which the application-cylinder pipe from the automatic brake valve is coupled. The independent brake valve does not deliver air direct to the brake cylinders, but passes it into and out of the appli- cation cylinder of the distributing valve. This operates the ENGINEER'S BRAKE VALVES 131 distributing valve and causes it to admit air to the locomotive brake cylinders and exhaust air from them. Also, the inde- pendent brake valve controls the passage of air from the exhaust port of the distributing valve through the release pipe. Release Position. — The release position is to be used to release the locomotive brakes without regard to the position of the automatic brake valve and equalizing valve in the dis- tributing valve; also, to release the locomotive brakes while the train brakes are being held on by the automatic brake valve, as well as to release the brakes, when desired, on the following engine of a double-header. When the valve is held in this position, air from the application cylinder of the distributing valve passes through the application-cylinder pipe, a port in the rotary-valve seat, a groove in the rotary valve, and the exhaust port in the rotary-valve seat to the atmosphere and releases the locomotive brakes. Also, in release position, a port in the rotary valve, which acts as a warning port to the engineer, registers with a port in the rotary-valve seat and allows air to pass out to the atmosphere through the warning port. The handle of the independent brake valve must be held in release position against the ten- sion of the return spring 6; otherwise, the spring will automat- ically return the handle to running position. Running Position. — The independent brake valve should be carried at all times in running position except when it is being used to operate the distributing valve to apply or release the locomotive brakes or to keep the locomotive brakes applied. If it is carried in any other than running position, it will be impossible to control the release of the locomotive brakes by the use 'of the automatic brake valve. In this position, a groove in the face of the rotary valve is moved away from a port in the rotary- valve seat, so that air from the application cylinder of the distributing valve cannot exhaust to the atmosphere. The port leading to the distributing-valve release pipe is connected by means of a groove in the rotary valve with a port in the valve seat, which leads to the release pipe and to the automatic brake valve; consequently, the air in the application cylinder and the chamber of the distributing 132 ENGINEER'S BRAKE VALVES valve can pass through the distributing-valve release pipe to the independent brake valve, thence into the release pipe, and out to the atmosphere through the automatic brake valve, provided the latter also is in running position. To release the locomotive brakes through the automatic brake valve, both brake valves must be in running position. If the automatic brake valve is in running position and the locomotive brakes are being operated by the independent brake valve, they can be released by placing the independent brake valve in running position, because air from the application cylinder of the dis- tributing valve can then pass through the release pipe and automatic brake valve to the atmosphere. Lap Position. — The lap position is used when it is desired to blank all ports in the rotary-valve seat and prevent air from passing through the brake valve. When the valve handle is in this position, all ports are blanked so that air cannot pass through the brake valve. With the independent brake valve in lap position, the locomotive brakes can be applied by means of the automatic brake valve by reducing brake-pipe pressure, but they cannot be released through the automatic brake valve. Slow-Application Position.— The slow-application position is to be used when it is desired to apply the locomotive brakes lightly or gradually and independently of the train brakes. Also, when the locomotive is standing, this position is used to maintain brake-cylinder pressure so as to prevent the locomo- tive brakes from leaking off through brake-cylinder leakage and thus allow the engine to start when standing on a grade or when the throttle is leaking. When the handle of the valve is placed in this position, the ports in the rotary valve and its seat are still blanked as in lap position, except that one port in the face of the rotary valve registers with a port in the rotary- valve seat. This allows air at a pressure of 45 Ib. to pass from the reducing- valve pipe into the application-cylinder pipe and the application cylinder of the distributing valve, thus applying the locomotive brakes slowly. To graduate the application of the locomotive brakes, the handle should be moved to slow-application position until the desired pressure is obtained in the application cylinder, when it should be returned to lap position. The red hand on the duplex gauge ENGINEER'S BRAKE VALVES 133 will register the brake-cylinder pressure of the application. When the engine is standing at a coal chute, a water plug, or on a turntable, or while work is being done on it, the independent brake valve should be left in slow-application position so as to keep the locomotive brakes applied. Quick-Application Position. — The quick-application position is used when it is desired to make a quick application of the independent brake. In such cases, the handle of the independ- ent brake valve should be moved to quick-application position and held there until the locomotive brakes are fully applied. If the handle is not held in quick-application position, the return spring 6 will move it back to slow-application position. When the handle is in quick-application position, the rotary valve forms a direct connection between the reducing-valve pipe and the application cylinder of the distributing valve. RETURN-SPRING ARRANGEMENT The return-spring arrangement of the S-6 independent brake valve, shown in Fig. 2, is intended to make it impossible for FIG. 2 the engineer to leave the brake-valve handle either in release position or in quick-application position. It consists of a return-spring casing 5, a return spring 6, an upper clutch 13, and a lower clutch 26, all of which when assembled fit in the return-spring chamber in the body of the brake valve, This chamber is shown in Fig. 3, which is a sectional view of the brake-valve body with the return-spring arrangement removed. In this view is shown the return-spring casing screw 8 and the return spring stop 27. Moving the valve handle from running position to release position puts the return spring under tension, so that the 134 ENGINEER'S BRAKE VALVES spring will return the handle to running position if the handle is let go. The spring exerts no influence on the brake- valve handle between running and slow-application positions. Moving the handle from slow- to quick - application position again puts the spring under tension that returns the handle to slow - application position if the handle is let go. The brake valve, therefore, will not stay in either release or quick-applica- tion position unless held there. Action of Mechanism. — The return-spring mechanism is operated through the medium of the rotary-key stem and the FIG. 3 brake- valve handle. The lower clutch has a lug on its lower end that by resting against the return-spring stop, Fig. 3, prevents this clutch from being turned to the left in the spring chamber. Its upper end is notched out to fit a similar notch in the bottom end of the upper clutch. These notches are such that the brake-valve handle can turn the upper clutch from slow-application position to release position without disturbing the lower clutch. In moving the handle to the right, however, the two clutches engage in slow-application position, so that moving the handle beyond that position toward quick-appli- cation position causes the upper clutch to rotate the lower clutch to the right. As the casing holds the upper end of the spring stationary, this places the spring under tension and fur- nishes the power to move the handle back to slow-application position. The lower end of the return spring rests against the far side of the lug of the lower clutch, which holds it stationary; the upper end of the spring rests against the stop lug of the casing. In the running position of the brake valve, the lug on the upper clutch strikes against the lug on the casing, and moving the handle to release position causes the casing to be rotated to the left. As the lower end of the spring is held ENGINEER'S BRAKE VALVES 135 stationary by the lower clutch, turning the casing to the left puts the spring under tension and furnishes the power to return the handle to running position. Removing Return-Spring Arrangement. — To remove the return-spring arrangement, first move the rotary- valve handle to release position and while holding it there remove the casing screw, Fig. 3. Move the handle back to running position, i-emove the handle nut, take off the rotary-valve handle, take out the three cover screws, and remove the cover. Place the thumb over one of the casing lugs and hold down the cas- ing while prying up the upper clutch by inserting a pointed tool under the lug that engages the lug of the casing. This will disengage the upper clutch from the lower one and release the tension of the return spring, as will be indicated by a slight click. The upper clutch, casing, spring, and lower clutch can then be removed in the order stated. Replacing Return-Spring Arrangement. — In order to replace the return-spring arrangement easily, the rotary-valve key and stem should be in position in the valve body and the casing screw removed. Place the lower clutch on the rotary- key stem with the lug down, drop it into the return-spring chamber, and turn it until the lug is against the return-spring stop and to the right of it, the front of the brake valve facing the person doing the work. Next, drop the spring over the key stem and lower clutch and bring the end of the spring against the right face of the lug of the lower clutch. Next, drop the casing over the spring and bring the return- spring stop lug up against the top end of the spring. Turn the rotary -valve key until the position pin (located near the top of the key stem) points toward the casing-screw hole. Place the upper clutch properly on the key stem with the flat end up, and press the clutch down as far as it will go; this brings the clutch lug between the lugs of the casing. Next, place the brake-valve handle on the key stem and move it to release position; this will put tension on the spring and will bring the screw slot opposite the casing screw. Press down the casing until its lugs are flush with the top of the valve body, and then screw the casing screw all the way in ; it will extend into the slot in the casing as intended. Let the brake-valve return to running position and 136 ENGINEER'S BRAKE VALVES press the upper clutch down as far as it will go; this will cause it to take its proper position with respect to the lower clutch, the two clutches fitting together. Next, remove the handle, secure the cover in place, and replace the handle and secure it by means of the handle nut. STRAIGHT-AIR BRAKE VALVES S-3 (f-IN.) STRAIGHT-AIR BRAKE VALVE Piece and Reference Numbers. — The S-3 (f-in.) straight-air J PIPE TO - DOUBLE -*! « CHECK VALVE FIG. 1 brake valve, shown in Fig. 1, is a part of, and is regularly supplied with, the combined automatic and straight-air brake; ENGINEER'S BRAKE VALVES 137 it is known as schedule SWA and weighs 16 Ib. The piece number, with brass handle, complete, is 2,626; with a malleable- iron handle, 19,382. The piece and reference numbers of the various parts are given in the accompanying list. PC. No. Ref.No. 2,617 2 2,620 3 2,621 4 1,289 5 2,310 6 2,628 7 2,426 8 2,619 9 2.616 10 2,629 4,855 11 2,623 12 2,624 13 2,625 14 2,616 15 2,632 10 Name of Part 18,721 1,367 1,292 1,368 5,191 1.293 1,294 1,291 2,616 Body. Shaft-cap nut. Valve cap nut. Quadrant. Quadrant bolt and nut. Shaft, complete, includes steel wearing plates. Leather shaft washer. Shaft-spring washer. Shaft spring. Valve, complete, includes 11, 12, 13, and 14. Valve stem. Valve. Valve leather. Valve nut. Valve spring. Brass handle, complete, includes 17, 18, 19, 20, 21, and 22. Malleable-iron handle complete, includes 17, 18, 19, 20, 21, and 22. Latch spring Latch. Latch screw. Handle clamp bolt, complete, includes 21 and 22. Clamp bolt, only. Thumb-nut. Pin. Valve spring. Operation. — To apply the brake, the handle 4 is moved to application position. This movement causes valve 12 to be unseated, and allows air to flow from the chamber below the valve, past valve 12, into the upper chamber and thence into the pipe leading to the brake cylinder. In this position, the other valve is closed so that no air can escape to the exhaust. If the handle is left in this position, the brake-cylinder pressure will equalize at 45 Ib. — that being the pressure at which the slide-valve feed-valve for the straight-air equipment is set to reduce to — and no higher brake-cylinder pressure can be obtained with the straight air. 138 ENGINEER'S BRAKE VALVES To make a partial application of the brake, the handle 4 is moved to application position until the desired brake- cylinder pressure is obtained, when it is moved to lap. To increase the application, move 'the handle to application posi- tion for the proper increase, and then back to lap. In lap position, both valves are closed, so no air can pass into the brake cylinder, or from the brake cylinder to the atmos- FIG. 2 phere. Valve 12 is held up against its seat by the combined efforts of spring 15 and the pressure beneath the valve; the other valve is held up against its seat by spring 27 and the pressure beneath it. To release the brake, move the handle to release position. This allows valve 12 to close and cut off the supply of air to ENGINEER'S BRAKE VALVES 139 the brake cylinder, and the other valve is opened and allows brake-cylinder air to escape to the atmosphere. A graduated release can be made with this brake valve when desired. To partly release the brakes, move the handle to release position until the desired reduction of brake-cylinder pressure is made, and then move it to lap. The notches at the ends of the quadrant that the latch fits into are intended to hold the handle in position against the tension of the springs 15 and 27. If these notches become worn, the force of the spring 27 is liable to return the handle to lap position from release position. S-3-A (|-IN.) STRAIGHT-AIR BRAKE VALVE Piece and Reference Numbers. — The S-3-A (|-in.) straight- air brake valve, shown in Fig. 2, is special and is supplied instead of the S-3 brake valve where independent driver- brake release is desired and when specified on orders; its weight is 18 Ib. Its piece number, with brass handle, com- plete, is 17,537; with a malleable-iron handle, 19,168. The piece and reference numbers of the various parts are given in the accompanying list. If it is desired to add the inde- pendent driver-brake release feature to S-3 straight-air brake valves already in service, order should specify Piece No. 16,235, which includes all parts necessary to change an S-3 into an S-3-A brake valve; viz., Ref. Nos. 5, 23, 25, 26, 27. PC. No. Ref. No. Name of Part 2,617 2 Body. 2.620 3 Shaft cap nut. 2.621 4 Valve cap nut. 16,125 5 Quadrant. 2,310 6 Quadrant bolt and nut. 2.628 7 Shaft, complete, includes 9. 2,426 8 Leather shaft washer. 2,619 9 Shaft-spring washer. 2,616 10 Shaft spring. 2.629 Valve, complete, includes 11, 12, 13, and 14. 4,855 11 Valve stem. 2.623 12 Valve. 2.624 13 Valve seat. 2.625 14 Valve-stem nut. 2,616 15 Valve spring. 2,632 16 Brass handle, complete, includes 17, 18, 19, 20, 21, and 22. 140 ENGINEER'S BRAKE VALVES PC. No. Rej. No. Name of Part 18,721 16 Malleable-iron handle, complete, includes 17,18, 19, 20, 21, and 22. 1.367 17 Latch spring. 1.292 18 Latch. 1.368 19 Latch screw. 5,191 Handle clamp bolt, complete, includes 21 and 22. 1.293 20 Clamp bolt, only. 1.294 21 Thumb nut. 1,291 22 Pin. 16,124 23 Check-valve stem, complete, includes two each of 13 and 24. 1,738 24 Check- valve nut. 16.121 25 Check-valve case. 16.122 26 Check- valve cap nut. 16,190 27 Valve spring for driver-brake release attachment. Operation of S-3-A Straight-Air Brake Valve.— The S-3-A straight-air brake valve is a special valve furnished only when specially ordered, where it is desired to provide for independ- ent driver brake release. It is similar to the S-3 straight-air brake valve, except for the addition of a device called the driver-brake release attachment (reference numbers 23, 24, 25, and 26), and the addition of a running -position notch to the quadrant corresponding to the release position of the S-3 brake valve, the release position of the S-3-A brake valve being used for the independent release of the driver-brake cylinders. The driver-brake release attachment is arranged to screw into the body of the brake valve as shown in Fig. 2, in place of the valve cap nut 4, Fig. 1, and makes possible the releasing of the driver brakes after an automatic application, without affecting the brakes on the train or tender, thereby providing for independent operation of the driver brakes. The driver-brake release attachment is connected by piping to the automatic side of the driver-brake double check-valve, the other connections to the brake valve remaining the same as for the S-3 brake valve. When brakes are applied automatic- ally, the double-seated check-valve 23 will be forced upwards against the upper seat, preventing escape of air through the brake-valve exhaust port. To make an independent release of the driver brakes after an automatic application, the straight- air brake-valve handle is moved to release position, as usual, ENGINEER'S BRAKE VALVES 141 which will force the extended portion of release valve 14 against the upper projection of the double-seated check-valve, forcing the latter downwards from its seat and allowing the driver-cylinder air to pass by the check-valve through the vertical grooves in its circumference, and to the atmosphere through the brake-valve exhaust opening. The operation when applying the brakes by straight-air is the same as with the S-3 brake, except that the brake-cylinder pressure is on top of the check-valve 23 and forces it to its lower seat, thus preventing brake-cylinder air from escaping through the triple-valve exhaust port by way of connection to the automatic side of the double check-valve. The release can be made by using either release or running position, but after releasing the brakes the handle should invariably be returned to and left in running position. Cleaning and Oiling. — In cleaning and oiling the straight-air brake valve, all parts should be wiped clean and the applica- tion and release valves replaced without oil; a little heavy oil or brake-cylinder grease, however, can be used to good advantage on the main shaft and its gasket. The slide-valve reducing valve should be thoroughly cleaned and a small amount of valve oil used on its piston and slide-valve. The double check- valves and safety valves should be cleaned, but no oil is required. CARE OF BRAKE VALVES There is a wide range of variation in the time a rotary valve will continue working satisfactorily in general service. Some valves will run 3, 4, or 6 mo. while others will not run as many weeks. Tallow or vaseline are good lubricants for the rotary, but oil of any kind should be used sparingly on any part of the brake apparatus, except the steam end of the pump. Oil that has a tendency to gum should never be used. Whenever the rotary valve works hard, the brake valve should be taken apart and the rotary cleaned and oiled, to prevent cutting. At the same time, the packing ring should be cleaned, but without removing it, since, if removed, it is liable to be sprung out of true, which will necessitate refitting 142 ENGINEER'S BRAKE VALVES to the bushing in which it works. Also clean the stem and seat of the brake-pipe exhaust valve thoroughly, but leave no oil on either, as it will catch particles of dirt and scale and cause trouble. Rotary Working Hard. — The chief causes of a rotary working hard are: too free use of oil in the air end of the pump, or the use of poor oil; constant use of the emergency position of the valve, which tends to draw dirt and scale from the train pipe on the rotary seat; a hot pump, the heat from which will cake the oil on the rotary seat; the handle nut 7 being screwed down so tight as to cause key washer 13 to bind on the top casing of the engineer's valve; the gasket may be worn so thin that the rotary key 12 rubs against the valve body. Lubricating Brake Valves. — If the handle of either the automatic or the independent brake valve does not operate easily, the rotary valve or the rotary-valve-key gasket is prob- ably dry from lack of lubrication. To remedy this trouble when the brake system is charged, close the double-heading cock in the brake pipe below the brake valve; also, close the main-reservoir cock in the main-reservoir pipe. Operate the brake valves to remove all pressure from them; then, remove the oil plug in the automatic brake-valve body, fill the hole with good valve oil, and move the brake-valve handle from full-release to emergency position and back to release position a few times, to work the oil between the rotary and its seat. Again fill the oil hole and replace the plug. Next, remove the cap nut from the top of the rotary-valve key, fill the hole in the key with oil, push down on the key, and move the handle a few times; then, again fill the hole with oil and replace the cap nut. Treat the independent brake valve in the same manner. ENGINEER'S BRAKE VALVES 143 FEED-VALVES C-6 SINGLE-PRESSURE FEED-VALVE Piece and Reference Numbers. — The C-6 single-pressure feed-valve, shown in Fig. 1, has superseded the B-3 single- pressure feed- valve and is a part of, and is regularly supplied with, G-6 brake valve. Also, it is regularly supplied as a reducing valve with tb.6 ET locomotive brake equipments, and with schedule SWA. Its weight is 10 lb. The piece num- FIG. 1 ber of the C-6 double-pressure feed-valve, complete, without pipe bracket or gasket, is 18,480; with F crossed -passage pipe bracket and gasket, complete, 18,481; with H direct -passage pipe bracket and gasket, complete, 18,482. The piece and reference numbers of the various parts are given in the accom- panying list. PC. No. Ref. No. Name of Part 18,460 2 Valve body, bushed. 18,458 4 Flush nut. 8,946 5 Cap nut. 144 ENGINEER'S BRAKE VALVES PC. No. Ref. No. Name of Part 18.454 6 Piston. 18.455 7 Supply valve. 1,411 8 Supply- valve spring. IS, 286 9 Piston spring. 3,054 10 Piston-spring tip. 16,183 12 Regulating valve. 1,060 13 Regulating-valve spring. 6,509 14 Regulating-valve cap nut. 1.062 15 Spring box. 1.064 16 Diaphragm ring. 1.063 17 Diaphragm, 2 p:eces required, each. 1.065 18 Diaphragm spindle. 1,068 19 Regulating spring. 11,261 20 Regulating nut. 1,067 21 Check-nut. Operation of Feed-Valve.— At such times as the feed-valve is not under pressure, the supply valve 7 is closed while the regulating valve 12 is open. The regulating spring 19 forces the supply valve 17 back until it covers its port, while the regu- lating spring 19 forces the diaphragm to unseat the regulating valve 12. When the brake pipe is charged to less than 70 lb., both the supply valve and the regulating valve are open and air is feeding through the feed-valve into the brake pipe. Under those conditions, main-reservoir air enters the chamber to the left of piston 6, forcing the piston forwards until the supply valve uncovers its port. The air then flows through the feed valve into the brake pipe, increasing the pressure there. While brake-pipe pressure is less than 70 lb., the regulating valve is held off its seat by the regulating spring and there is direct communciation between the chamber on the right of piston 6 and the brake pipe through the regulating valve. The leakage that takes place past the piston 6 therefore passes directly to the brake pipe, so that the chamber to the right of piston 6, and the chamber to the left of diaphragm 17, are maintained at brake-pipe pressure. When 70 lb. is obtained in the brake pipe, the pressure on the diaphragm 1 7 is sufficient to compress the regulating spring enough to allow the regulating valve to close. This cuts off communication between the cham- ber to the right of piston 6 and the brake pipe, and the leakage occurring past piston 6 then quickly charges the chamber to the same pressure as the pressure in the chamber to the left ENGINEER'S BRAKE VALVES 145 of piston 6, which allows the piston spring to move piston 6 and the supply valve to closed position. In this position no air can feed into the brake pipe, since the supply port is closed. The parts of the feed-valve remain in these positions as long as the brake-pipe pressure remains at 70 Ib. Any reduc- tion of brake-pipe pressure, however, allows the regulating spring 19 to expand and unseat the regulating valve; pressure in the chamber to the right of piston 6 is then immediately reduced to brake-pipe pressure, so that the greater pressure of the air in the chamber to the left of piston 6 forces the piston to open position. Regulation of Feed-Valve. — If the feed-valve does not regulate brake-pipe pressure to the proper amount, it can be made to do so by adjusting the tension of the regulating spring by means of the regulating nut 20. If it maintains a pres- sure below the standard, slowly turn the regulating nut to the right until the tension of the spring is sufficiently increased to give proper regulation. If it maintains too high a pressure place the brake valve in service position and reduce the brake- pipe pressure several pounds below standard; then turn the regulating nut to the left so as to relieve the spring of a little of its tension, place the brake valve in running position, and note the pressure that is then maintained. If still too high, proceed as before, and continue until the feed-valve is properly adjusted. In order to turn the regulating nut 20, the check- nut %l must first be removed. After the regulating spring has been properly adjusted, the check-nut must be replaced. B-6 DOUBLE-PRESSURE FEED-VALVE Piece and Reference Numbers. — The B-6 double-pressure feed-valve, shown in Fig. 2, has superseded the B-4 double- pressure feed-valve, and is a part of, and is regularly supplied with, the ET locomotive brake equipments; its weight is 10J Ib. The piece number of the feed-valve, complete, with- out pipe bracket or gasket, is 18,477; with F crossed-passage, pipe bracket and gasket, complete, 18,478; and with H direct- passage, pipe bracket and gasket, complete, 18,479. The piece and reference numbers of the various parts are given in the accompanying list. 11 146 ENGINEER'S BRAKE VALVES FIG. 2 PC. No. Ref. No. Name of Part 18,460 2 Valve body, bushed. 18,458 4 Flush nut. 8,046 5 Cap nut. 18.454 6 Piston. 18.455 7 Supply valve. 1,411 8 Supply-valve spring. 18,286 9 Piston spring. 3,054 10 Piston-spring tip. 16,183 12 Regulating valve. 1,060 13 Regulating- valve spring. 6,509 14 Regulating-valve cap nut. 13,241 15 Spring box. 1,064 16 Diaphragm ring. 1,063 17 Diaphragm, 2 pieces required, each. 13,243 18 Diaphragm spindle. 2,036 19 Regulating spring. 13,259 20 Regulating hand wheel. 13.858 21 Inner hand wheel stop, includes 23. 13.859 22 Outer hand wheel stop, includes 23. 12,304 23 Stop-screw. Description of B-6 Feed- Valve. — The B-6 feed-valve, used with the No. 6 ET equipment, is an improved form of feed-valve. In construction and operation it is practically the ENGINEER'S BRAKE VALVES 147 same as the C-6 feed-valve except that it will charge to the regulated pressures somewhat quicker and will maintain the pressure more accurately under the variable conditions of short and long trains. It is connected to a pipe bracket located in the piping between the main reservoir and the H-6 brake valve, and is supplied with air from the main reservoir. It regulates the pressure in the feed-valve pipe as well as in the brake pipe in running and holding positions of the H-6 brake valve. It has a double-regulation feature, so that it can be quickly adjusted to change the regulated pressure from one standard pressure to another. This feed-valve is inter- changeable with previous types of slide-valve feed-valves and can be attached to the F-6 and G-6 brake valves, thereby doing away with the reversing cock, the extra feed-valve, and the pipes connecting it to the brake valves. There is a quick-thread screw on the regulating hand wheel 20 that will change the adjustment of the regulating spring 19 from 70 to 110 lb., or to other moderate differences of pressure when the wheel is turned. Stops 21 and 22 are split rings that fit around the spring box 15 and are clamped in their proper positions by the screws 23. The regulating spring unseats the regulating valve and determines the pressure to be carried in the feed-valve pipe. When the pressure in the chamber above the diaphragm 17 is less than the tension of the spring 19, the diaphragm is held over against the pressure of the air and the regulating valve is held off its seat. When the pressure in the feed-valve pipe reaches the stand- ard desired, the pressure above the diaphragm will overcome the tension of spring 19 and move the diaphragm to the right, allowing the regulating-valve spring to move the regulating •valve to its closed position. Spring 13 holds the regulating valve 12 against the diaphragm in open position, and against its seat in closed position. The diaphragm ring 16 makes an air-tight joint with the diaphragm against the valve body, and prevents the escape of air past it into the regulating-spring chamber. Regulation of B-6 Feed-Valve. — To insure accuracy in regulating, the B-6 feed-valve should be connected with a correct pressure gauge. The regulating hand wheel 20 should 148 ENGINEER'S BRAKE VALVES be screwed in to increase the pressure at which the valve will close, and screwed out to reduce the pressure. To adjust the wheel, first slacken screw 23 and turn the adjusting wheel until the valve is adjusted properly for the desired lower pressure. Then move the outer hand wheel stop 22 until it comes against the pin in the wheel and fasten the stop in this position on the spring case 15 by means of screw 23. Next, turn the hand wheel 20 in the opposite direction until the valve is adjusted properly for the desired higher pressure and then move the inner hand-wheel stop 21 around to bring the stop against the pin in the wheel and secure it in that position with screw 23. Once the feed-valve is adjusted for the proper high and low pressures, the pressure in the feed-valve pipe can be quickly changed from high to low or from low to high by simply turning the regulating wheel so as to move the stop-pin from stop 21 to stop 22 or from stop 22 to stop 21. If it is desired to carry a pressure between the low and the high pressure, the wheel can be stopped at any point between the stops 21 and 22. Care of B-6 Feed- Valve. — In order that the feed-valve may perform its functions properly, it is necessary that it be cleaned and oiled occasionally. If the feed-valve is to be cleaned when the air-brake system is charged with air, it must be relieved of all pressure before it can be taken apart. To do this, close the cut-out cock in the brake pipe underneath the brake valve, so as to save the air in the brake pipe, and place the brake valve in service or emergency position to empty the feed-valve and the short piece of brake pipe above the cut-out cock; the feed- valve may then be taken apart and cleaned. Clean both the piston 6 and its cylinder, and the supply valve 7 and its bushing, very carefully, leaving no lint on the parts, for it will cause trouble; clean, also, the regulating valve and its seat and the hole in the regulating-valve cap nut into which the regulating valve extends. In oiling the supply valve, only a small amount of valve oil, vaseline, mutton tallow, or some similar lubricant shoulc be used, the oil being applied with the finger. Only a very small amount of some light lubricating oil (engine oil will do) should be used on the supply-valve piston and its cylinder, ENGINEER'S BRAKE VALVES 149 and that should be well rubbed on with the fingers. If too much or too heavy oil is used on these parts, it will get into the grooves of the piston and act as an oil packing and will interfere very materially with the action of the feed-valve. The regulating valve should not be oiled, but should be replaced dry. PIPES, BRACKETS, AND COCKS REVERSING PIPE BRACKETS When the feed-valve is placed in the piping of a brake equip- ment instead of on the brake valve, as in the ET and the SWA equipments, a pipe bracket to which the feed- valve is attached must be used. /i'Bo» (T F, Q ^i— «i — v. FlG. I F, Crossed-Passage, Pipe Bracket. — The P pipe bracket shown in Fig. 1 is the standard for the ET locomotive brake equipment, and is regularly furnished therewith unless other- wise specified on orders; its weight is oi Ib. The piece number of the F crossed-passage, pipe bracket, complete, is 18,240; of the F pipe-bracket body, 18,239; and of the stud and nut, 2,305. The reference number of the pipe-bracket body is 2; and of the stud and nut, 3. 150 ENGINEER'S BRAKE VALVES H, Direct-Passage, Pipe Bracket. — The H pipe bracket shown in Fig. 2 (a), is the standard for schedule SWA, and is regularly furnished therewith unless otherwise specified on orders; its weight is 5 Ib. The piece number of H, direct-passage, pipe bracket, complete, is 18,463; of the H pipe-bracket body, 18,464; and of the stud and nut, 2,305. The reference number of the pipe-bracket body is 2; and of the stud and nut, 3. V ^/ (b) FIG. 2 The two ports between the two studs 3 are the inlet and outlet ports of the bracket. They come opposite the similar ports of the feed-valve. The arrow on the projecting part at the top of the bracket shows the direction of flow of air through the brackets. Feed-Valve Gasket. — The piece number of the feed-valve gasket is 2,012; the gasket is shown in Fig. 2 (b). BRAKE-VALVE FEED-VALVE PIPE CONNECTION In the schedule U and the high-speed equipments, the feed- valve is removed from the brake valve and two feed-valves are placed on a reversing cock. In these equipments, therefore, ENGINEER'S BRAKE VALVES 151 the brake valve is supplied with a feed-valve pipe bracket to which the pipes to the reversing cocks are connected. The feed-valve pipe connection, shown in Fig. 3, is furnished with the G-6 engineer's brake valve, piece numbers 2,585 and 2,2096, in connection with the high-speed brake, schedule AG, and the double-pressure control, schedule U; its piece number is 2,586, and its weight, | Ib. REVERSING COCK The reversing cock, shown in Fig. 4, is used in connection with double-pressure control, schedule U, and high-speed FIG. 4 brake, schedule AG, equipments; its weight is 14 Ib. The piece number of the reversing cock complete is 2,574; the piece and reference numbers of the various parts are given in the accompanying list. Name of Part Body, bushed. Key Key spring. Cap. Handle. Stud and nut. i-in. pipe plug. Two feed-valves are connected to the body of the reversing cock by the studs 7. The feed -valve on the left is adjusted, usually, to 70 Ib., while the one on the right is adjusted to 110 Ib. There are two positions in which the handle of the PC. No. Ref.No. 2,576 2,579 2,098 2,097 2,100 2,305 1,635 152 TRIPLE VALVES reversing cock may stand. The position to the left is used when the engine is to be coupled to a train having the ordinary quick-action brake. In this position, the feed-valve that is adjusted for 70 Ib. is cut in and the one for 110 Ib. is cut out, and the brake-pipe pressure is regulated to 70 Ib. per sq. in. If the engine is to be coupled to a train of high-speed brakes, the handle of the reversing cock is moved around to the right into the second position. This cuts into service the feed-valve that is adjusted for 110 Ib., and the train-p'ipe pressure is then regulated to that amount. This duplex feed-valve is usually placed in the cab. TRIPLE VALVES PLAIN TRIPLE VALVES FOR ENGINES AND TENDERS Prior to 1903, the F-24 plain triple valve and, later, the G-24 triple were recommended for all driver-brake cylinders 10 in. or less in diameter, with or without track brakes. The F-25 plain triple was recommended for 12-in., 14-in., and 16-in. driver brakes, with or without truck brakes. The F-46 was recommended for high-speed brakes with all sizes of driver- brake cylinders with or without truck brake. Later, the F-46 triple was recommended for universal use for 12-in., 14-in., and 16-in. driver-brake cylinders, with or without truck brake. The H-24 triple was then designed for use with all driver-brake cylinders 10-in. or less, with or without truck brake. For both freight-engine and switch-engine tenders, the G-24 triple was supplied for use with 8-in. and 10-in. cylinders, and the F-25 triple for 12-in. cylinders. The G-24 plain triple valve, formerly furnished for use with 8-in. and 10-in. freight- and switch-engine tender brake equipments, has been superseded by the F-l (H-24) triple valve. The F-25 plain triple valve, formerly furnished for use with 12-in. freight- and switch-engine tender brake equip- ments, has been superseded by the F-2 (F-46) triple valve. TRIPLE VALVES 153 Triple valves cin be distinguished by their letter and number (such as F-25, H-24, etc.) which is cast on the valve body. F-l (H-24) PLAIN TRIPLE VALVE The F-l (H-24) plain triple valve, shown in Fig. 1. is used with 6-in., 8-in., and 10-in. freight- and switch-engine tender brake cylinders, and with all 6-in., 8-in., and 10-in. driver- and truck-brake cylinders either with or without high-speed 154 TRIPLE VALVES attachments. It is tapped for f-in. pipe connections and marked F-l on the valve body; its weight is 24£ lb. The piece number of the F-l plain triple valve, complete, is 4,233; the piece and reference numbers of the various parts are given in the accompanying list. PC. No Ref. No. Name cf Part 4,234 2 Body, bushed. 1,837 3 Cylinder cap. 1,838 4 Cap nut. 4,236 5 Piston includes 12. 1,835 6 Slide valve. 1.8C9 1,748 7 8 Graduating valve. Graduating stem. 1,811 9 Graduating spring. 1,747 10 Graduating-stem nut. 1,839 10,031 11 12 Cylinder-cap gasket. Piston ring. 4,879 13 Bolt and nut. 1,787 14 Slide-valve spring. F-2 (F-46) PLAIN TRIPLE VALVE The F-2 (F-46) plain triple valve, formerly designated as the high-speed plain triple valve, and shown in Fig. 2, is now used with 12-in., 14-in.( and 16-in. freight- and switch-engine tender brake cylinders; and for all 12-in., 14-in., and 16-in. driver- and truck-brake cylinders, either with or without high-speed attachments. It is tapped for f-in. pipe connections and marked F-2 on the valve body; its weight is 24 J lb. The piece number of the F-2 plain triple valve, complete, is 1,826; the piece and reference numbers of the various parts are given in the accompanying list. PC. No. Ref. No. Name of Part 1,827 2 Body, bushed. 1,837 3 Cylinder cap. 1,838 4 Cap nut. 1.832 5 Piston includes 12. 1,835 6 Slide valve. 1,809 7 Graduating valve. 1,748 8 Graduating stem. 1,811 1,747 9 Graduating spring. 10 Graduating-stem nut. 1,839 11 Cylinder-cap gasket. 10,032 12 Piston ring. 4,879 13 Bolt and nut. 1,787 14 Slide-valve spring. TRIPLE VALVES FUNCTIONS OF TRIPLE VALVE 155 The triple valve has three duties to perform: to charge the auxiliary, to apply the brakes, and to release the brakes. When an engine is coupled to a car, air from the main res- ervoir flows into the brake pipe, thence through the branch n £ o> n o o pipe, into the triple valve. When the triple is cut in, the air can flow in at the brake-pipe connection, and down through a port into the chamber below piston 5. If piston 5 were down, the air pressure B would force it up into release position. 156 TRIPLE VALVES This movement of the piston opens a feed-groove in the body bushing and air therefore feeds past piston 5, through the feed-groove into the slide-valve chamber which communicates with the auxiliary reservoir. The air continues to feed past piston 5 as long as brake-pipe pressure is greater than the auxiliary pressure. The usual brake-pipe pressure is 70 lb., and when the auxiliary pressure has reached this amount, the pressures in the chambers above and below the piston are equal and the auxiliary is said to be fully charged. The lower side of piston 5 is generally referred to as the train-pipe side and the upper as the auxiliary side, or the ^tide-valve side. Charging Auxiliary Reservoir. — A modern triple valve should charge an auxiliary from 0 to up 70 lb. in about 70 sec., with a constant train-pipe pressure of 70 lb. With the triple in release position and the auxiliary charged, there will be 70 lb. in the train pipe, 70 lb. in the auxiliary, and the atmospheric pressure in the brake cylinder, since the slide-valve cavity connects the brake cylinder with the atmosphere. OPERATION OF PLAIN TRIPLE VALVES Applying Brakes. — To apply brakes, it is necessary that the brake-pipe pressure be reduced below auxiliary pressure; this may be made in the usual way by the engineer, by the use of the conductor's valve, or by a break-in-two, a burst hose, or a heavy leak in the brake pipe. If the engineer makes a reduc- tion of 7 lb. in the brake pipe, only 63 lb. will remain in the chamber below piston 5, whereas at the beginning of the reduc- tion there will be 70 lb. in the chamber above piston 5. The greater auxiliary pressure will force piston 5 downwards; this closes the feed-groove and unseats the graduating valve 7, allowing auxiliary air to enter the slide valve. By the time the graduating valve is unseated and the feed-groove closed, the shoulder on the upper end of the piston stem has engaged the slide valve and begun to move it down. As the slide valve moves down, the exhaust cavity is first closed, preventing the escape of brake-cylinder air. When the knob touches the graduating stem, the piston 5 is prevented from making any further downward movement. With the triple piston in this position, the service port of the slide valve is directly TRIPLE VALVES 157 in front of a port leading to the brake-cylinder pipe connection. This position of the valve is called the service position. When the graduating valve is off its seat, there is an open communication between the auxiliary and the brake cylinder and air flows from the auxiliary into the brake cylinder, where the pressure will force out the brake piston and set the brakes. Just as long as the auxiliary pressure is greater than that in the brake pipe, so long will piston 5 be held down and the gradu- ating valve remain unseated; but the auxiliary pressure gradu- ally expands into the brake cylinder, until the pressure in the lower chamber is sufficiently greater than that in the upper chamber to overcome the small friction of the packing ring 6 and cause piston 5 to be moved upwards and seat the graduating valve. The pressure on the brake-pipe side of the piston 5 still slightly exceeds that in the auxiliary, but not to such an extent as to overcome the additional friction encountered in moving the slide valve 3; the piston therefore stops as soon as the graduating valve has been seated. This is called the lap position of the triple valve. In this position all ports are blanked. The brakes are now partly set; a further brake-pipe reduction will be necessary to apply them harder. If another 5-lb. brake-pipe reduction is made, the greater auxiliary pressure again forces down the piston, but in this case the slide valve is already in service position, and it is only necessary to move the piston sufficiently to unseat the graduating valve. This is accomplished by the time the knob touches the graduating stem 8\ and once more, by means of the service port of the slide valve, communication is established between the auxiliary and the brake cylinder. The graduating valve is again seated automatically by the piston 5 when the auxiliary pressure becomes a little less than that in the brake pipe. After the slide valve has once been moved down, it remains in service position until the brakes are released. Each reduc- tion of brake-pipe pressure causes the brake to set harder, and these reductions may be continued just as long as the pressure in the auxiliary is greater than that in the brake cylinder. When these pressures become equalized, the brake is fully set, and a further brake-pipe reduction will be a waste 158 TRIPLE VALVES of brake-pipe air. Ordinarily, a braKe-pipe reduction of about 20 Ib. will cause a full application of the brakes. Releasing Brakes. — To release brakes, either the brake-pipe pressure must be increased above auxiliary pressure, or auxiliary pressure must be reduced below brake-pipe pressure. The usual method is for the engineer to allow the air stored in the main reservoir to feed quickly into the brake pipe. When the pressure on the brake-pipe side of piston 5 is sufficient to overcome auxiliary pressure and the friction of the working parts, the piston is forced upwards to release position, carrying the graduating and slide valves with it. In this position, the feed -groove is opened, and air from the brake pipe feeds through to recharge the auxiliary. At the same time, the pressure in the brake cylinder escapes through the exhaust port into the atmosphere. Emergency Application. — To apply brakes in an emergency, it is necessary to make a sudden and heavy brake-pipe reduc- tion. This sudden reduction causes piston 5 to move down very quickly and, compressing the graduating spring, to trav- erse the full length of its stroke. In this position, a direct connection is established between the auxiliary and brake cylinder across the upper end of the slide valve. Auxiliary air passes direct into the brake cylinder without having first to pass through the service ports of the slide valve. As the large ports are used only in emergency position, they allow the pressure in the auxiliary and brake cylinder to equalize more quickly than do the smaller ports used in the service position. With a plain triple, the brake sets more quickly in emergency than in service, but not with greater force. To get the full emergency action of the brakes with plain triple valves, it is necessary to make a sudden reduction of over 20 Ib. in train-pipe pressure. After an emergency application, the release of the brakes is accomplished in the same way as after a service application. TRIPLE VALVES 159 FREIGHT-BRAKE TRIPLE VALVES DEVELOPMENT OF FREIGHT TRIPLE VALVE The original idea of providing a system of brakes that could be applied to all the cars of a train and be under the direct control of the engineer was suggested to George H. Westinghouse in 1866 by a collision between two freight trains. In its beginning, therefore, the brake was regarded merely as a safety device and as such it was brought into use and developed. The first air brake, namely, the straight-air brake, was applied to a train consisting of a locomotive and four cars. On the first run of this train, the engineer, by a prompt appli- cation of the brakes, prevented what would likely have been a serious accident had the train been equipped with any other brake then in existence, thus demonstrating the value of the air brake as a safety device. The control of the train equipped with the straight-air brake was so superior to the control that could be obtained by means of any other brake then in use that the idea of using the brake to control a train made up of more than four cars suggested itself. Accordingly, in September, 1869, a six-car Pennsylvania Railroad train was equipped with the air brake, and in November of the same year a ten-car train was thus equipped. As the brake in most general use at that time was a cumbersome chain brake applicable to only four- or five-car trains, the success of the air brake in handling ten-car trains at once made it valuable as a dividend earner. The earning power of the air brake consisted in its ability to handle longer and heavier trains at higher safe speeds than was possible with other brakes then in existence. The adoption of the straight-air brake by a number of the leading railroads, on which it was pressed into general service, eventually brought out the serious defects of the air brake and made a further development of it necessary. This resulted, in 1872, in the invention of the plain automatic brake, the triple valve of which made possible the automatic brake of the present day. 160 TRIPLE VALVES The automatic brake was developed during the years 1872 and 1873, and it was so superior to all other forms of brake that it was adopted as the standard for passenger-train service. Up to that time no power brake was in use in freight service, and the attempts to increase the length of freight trains led to numerous accidents and break-in-twos, caused chiefly by lack of proper train control. These accidents led to the belief that the automatic brake could be successfully used in handling long freight trains. To find out whether or not this could be done, the Westinghouse Air Brake Company, in 1882, fitted up a fifty-car train with the plain automatic air brake and took it over the Alleghany Mountains. Tests made on this trial trip clearly demonstrated that the braking power of this type of brake was sufficient to control the speed of the train even on the heaviest grades. The success of the automatic air brake brought several competitive brake systems into the field, and in 1885 the Master Car Builders' Association appointed a committee to investigate the relative merits of these brake systems as well as to report on the feasibility of controlling a fifty-car freight train by means of a continuous power brake, a point much in controversy at that time. A series of tests with fifty-car trains, known as the "Burlington tests," was begun in 1886 and completed in 1887. The Westinghouse brake and three others were entered in these tests, which clearly demonstrated that none of the brake systems could be successfully used in every-day service on trains of fifty cars. The Westinghouse brake worked satisfactorily in service applications, but in applying it in emergency the interval between the application of the brake on the first car and the last car was so long that the shock caused by the rear cars running into the front cars was terrific. This necessitated a modification of the plain triple valve for fifty-car freight-train service. Accordingly, in 1887, the quick-action triple valve was brought out. This triple was applied to the fifty-car train, which had been left at Burling- ton. Tests were made to try out the triples and they were found to be so satisfactory by the railway officials and by the persons conducting the tests that the train was sent on TRIPLE VALVES 161 a tour through the Middle West and the East. This tour established the quick-action brake as the standard for both freight and passenger service. As will be noted, the straight-air brake and the plain triple valve were developed for passenger service, whereas the quick-action triple valve was developed for freight service, although eventually it was adopted as standard for both freight and passenger service, also, the quick-action triple was designed and developed for use on trains of fifty cars or less, the fifty-car train to be the maximum. From the very beginning, the length, weight, and speed of trains have been limited by the capacity of the brake for the safe and efficient control of the train. The hauling power of the locomotive has always been a step or two in advance of the brake control; consequently, when the length of the train was limited to fifty cars by the brake control, the tonnage of the train was increased to the hauling power of the loco- motive by increasing the capacity of the cars. As the capacity of the cars increased, the braking power on the car was neces- sarily increased in proportion, as was also the hauling power of the locomotive. The desire to haul trains of more than fifty cars led to the "part-air train" practice, which consisted in using a sufficient number of the head-end brakes to control the train, the rear- car brakes not being used. This practice was quite success- ful, and under it the length of the train gradually increased from fifty to eighty and ninety cars. As fifty or fewer than fifty brakes were in use on such trains, the brake system oper- ated without difficulty and engineers soon learned to control the slack of the non-air cars so as to prevent severe shocks and break-in-twos. Next came the rule to increase the percentage of air-braked cars from time to time, until now it is customary to run all-air trains. As sixty- to eighty-car trains have become a fixed practice, and one-hundred-car trains are not uncommon, the air-brake manufacturers have been kept busy experiment- ing and improving their apparatus in the endeavor to keep the brake up to the requirements of the service. To control an all-air train of eighty to one hundred cars by means of the 12 162 TRIPLE VALVES brake is a vastly different proposition from controlling an eighty-car part-air train. The length as well as the volume of the brake pipe is practically twice that of the original fifty-car train." Therefore, the difficulty experienced in 1887 in emergency applications with the plain automatic brake is now experienced in service applications of the automatic brake; that is, the interval between the application of the brake on the first car and that on the last car is so great in service applications that if a heavy reduction is made without taking due precautions a terrific shock will be caused by the rear cars running in the amount of the slack and colliding with the front cars held by a good application of the brake. In addition, the recoil of the rear cars after the shock, aided by the action of the compressed springs and the application of the brake taking hold on them, tends to snap the train in two. Another serious difficulty, due to the increased brake-pipe volume (which is twice as great as with a fifty-car train) and to the increased back flow of air into the brake pipe from the auxiliaries, due in turn .to the slower reduction, is that the time necessary to make a given brake-pipe reduction is doubled. This makes the time of application twice as long, which makes the application qf the rear brakes more uncertain and very materially lengthens the distance required to make a stop. Every second lost at high speed in getting the brake fully applied adds many feet to the length of the stop. In releasing brakes, the interval between the release of the first brake and the last brake is so great that the brakes on a good portion of the train release and the slack runs out before the brakes on the rear portion release, tending to break the train in two. Also, the brake is slow in releasing, and the rear brakes are especially slow on account of the increased brake-pipe volume to be discharged and the increased size of the auxiliary reservoirs of the large capacity cars that are taking air from the brake pipe during recharge. As the brakes are slow in applying and releasing, both the danger and the time of making a stop and a start are increased. The difficulty of brake control increased with the length of the train above the limit of fifty cars. However, the brake manufacturers, profiting by their experience, foresaw TRIPLE VALVES 163 the difficulties ahead and bent their energies to improve the brake apparatus so that it would correct the defects of the quick-action brake. Their efforts were along the lines of a uniform application and a uniform release and recharge of all brakes, for if that object could be attained the brake would safely and efficiently control trains of any practical length. The 164 TRIPLE VALVES result of the experiments and tests conducted resulted in an improved type of freight triple valve called the type K triple valve. H-l (F-36), QUICK-ACTION, FREIGHT, TRIPLE VALVE The H-l (F-36), quick-action, freight, triple valve, shown in Fig. 1, was used with 6-in. and 8-in. freight-car brake cylinders and 8-in. passenger-tender brake cylinders, but it has been quite generally superseded by the K-l quick-action, quick- service, uniform-release, and uniform-recharge freight triple valve, which is regarded as standard for this service. It weighed 38 Ib. Though similar in appearance, this valve differs essentially from other quick-action triple valves, and should never be used except as specified. In addition to being marked H-l on the valve body, it may be distinguished from the passenger triple valves, type P, by the fact that it has two exhaust outlets (one of which is plugged) and from the H-2, 10-in., freight, triple valve in having two instead of three bolt holes in the back flange. The bore of the H-l slide- valve bush is 1J in. in diameter. The piece number of the H-l triple valve, complete, is 1,717, the piece and reference numbers of the various parts are given in the accompanying list. PC. No. Ref. No. Name of Part 20,220 2 Body, complete, includes f-in. pipe plug. 1.729 3 Slide valve. 1,725 4 Main piston, includes 5. 10,032 5 Main-piston ring. 1.730 6 Slide-valve spring. 1.732 7 Graduating valve. 1.733 8 Emergency piston. 1,740 9 Emergency-valve seat. 1,735 10 Emergency valve, includes 11 and 28. 1,737 11 Rubber neat. 1.745 12 Check- valve spring. 12,850 13 Check-valve case, complete, includes i-in. pipe plug. 1.754 14 Check-valve-case gasket. 1,744 15 Check-valve. 1,751 16 Strainer. 1.749 17 1-in. union nut. 1.750 18 1-in. union swivel. 1.746 19 Cylinder cap. TRIPLE VALVES 165 PC. No. Rtf. No. Name of Part 1.747 20 Graduating-stem nut. 1.748 21 Graduating stem. 1,057 22 Graduating spring. 1,753 23 Cylinder-cap gasket. 4,879 24 B9lt and nut, for cylinder cap. 1,752 25 i-in. capscrew. 1,004 i-in. pipe plug. 1,755 27 1 -in. union gasket. 1,738 28 Emergency- valve nut. 1,734 |-in. plug for exhaust outlet, not shorni. 2.427 Triple-valve gasket. 166 TRIPLE VALVES H-2 (H-49), QUICK-ACTION, FREIGHT, TRIPLE VALVE The H-2 (H-49), quick-action, freight, triple valve, shown in Fig. 2, was used with 10-in. freight-car brake cylinders only; it weighed 44 Ib. It has been quite generally superseded by the K-2 quick-action, quick-service, uniform-release, and uniform-recharge freight triple valve, which is regarded as standard for this service. Though similar in appearance, this valve differs essentially from other quick-action triple valves, and should never be used except as specified. In addition to being marked H-2 on the valve body, it may be distinguished from the passenger triple valves, type P, by the fact that it has two exhaust outlets (one of which is plugged) and from the H-l 8-in. freight triple valve in having three instead of two bolt holes in the back flange. The bore of its slide-valve bush is If in. Fig. 3 shows two perspective views of the slide valve 8. In or- dering slide valve or gradua- ting valve for the H-2 freight triple valve, the order should state clearly whether old- or new-style parts are desired, because these are not inter- changeable. The new-style (present standard) slide valve, Piece No. 29,138, has straight drill through longitudinal cen- ter line of slide valve, for the new (present standard) &-in. graduating valve, Piece No. 29,139. The old-style slide valve, Piece No. 1,769, has J-hi. drill with counter bore for the old- style, graduating valve, Piece No. 1,732. The graduating valves may be distinguished by the difference in diameter and the fact that the old-style has a shoulder, whereas the new- style has none. The piece number of the H-2 triple valve, complete, is 4,870; the piece and reference numbers of the various parts are given in the accompanying list. FIG. 3 TRIPLE VALVES 167 PC. No. Ref. No. Name of Part 20,216 2 Body, complete, includes f-in. pipe plug. Slide valve. Main piston, includes 5. Main-piston ring. Slide-valve spring. Graduating valve. Emergency piston. Emergency- valve seat. Emergency valve, includes 11 and 28. Rubber seat. Check-valve spring. Check-valve case, complete, includes §-in. pipe plug. Check- valve-case gasket. Check-valve. Strainer. 1-in. union nut. 1-in. union swivel. Cylinder cap. Graduating-stem nut. Graduating stem. Graduating spring. Cylinder-cap gasket. Bolt and nut, for cylinder cap. Bolt and nut, for check- valve case |-in. pipe plug. 1-in. union gasket. Emergency-valve nut. f-in. plug for exhaust outlet, not shown. *Triple- valve gasket. If the old-style slide valve or graduating valve is desired, specify as follows: PC. No. Ref. No. Name of Part 1,769 3 Slide valve. 1,732 7 Graduating valve. These parts are not interchangeable with the standard parts. The new-style slide valve, Piece No. 29,138, has a straight drill through the longitudinal center line of the slide valve for the new rV-in. graduating valve, Piece No. 29,139. The old-style slide valve, Piece No. 1,769, has J-in. drill with counter bore for the old graduating valve, Piece No. 1,732. The graduating valves may be distinguished by the difference in diameter and the fact that the old-style has a shoulder, whereas the new-style has none. 29.138 i 1.767 4 10,032 — & 1.730 8 29.139 7 1.733 8 1,740 9 1,735 10 1.737 11 1,745 12 13,392 13 4.S76 14 ,744 15 ,751 16 ,749 17 1,750 18 1,746 19 ,747 20 ,748 21 1,057 22 1,753 23 4,879 24 4,880 25 1.004 1,755 27 1,738 28 1,734 *Listed for convenience only, not included in H-2 triple valve. 168 TRIPLE VALVES OPERATION OF QUICK-ACTION TRIPLE The quick-action triple contains two distinct sets of mechan- ism. One of these, consisting of the triple piston 4 with stem, slide valve 3, and graduating valve 7 with graduating stem 21 and graduating spring 22, is used in making service stops and in releasing brakes; it is often called the service part of the triple. The other set, consisting of the emergency piston 8, emergency valve 10, and brake-pipe check- valve 15, is only brought into use in an emergency application of the brakes; hence, it is often called the emergency or quick-action part of the triple. Release Position. — The operation of the quick-action triple in released position is the same as that of the plain triple. The slide valve of the quick-action triple is shown in release posi- tion in the figures. In this position, any air that may be in the brake cylinder can pass through the slide valve, out through the exhaust port to the. atmosphere, thus releasing the brake. At the same time, brake-pipe air can pass the main piston 4 through the feed -groove, thus recharging the auxiliary reservoir. Service Position. — The operation of the quick-action triple in service application is the same as that of the plain triple. When a service application of the brakes is made, the triple piston 4 moves out until the knob touches the graduating stem, after which any further movement is prevented. The exhaust port closes first, and the service port and graduating port of the slide valve connect with the brake cylinder by way of the brake-cylinder port. As the graduating valve 7 opens before the slide valve moves forwards, air passes from the auxiliary reservoir through this graduating port to the brake cylinder until auxiliary pressure is reduced just a trifle below brake-pipe pressure, when the triple piston moves to lap position and the graduating valve 7 is closed. During suc- ceeding reductions, the graduating valve simply opens and closes without moving the slide valve, as in the plain triple. TRIPLE VALVES 169 EMERGENCY PART OF TRIPLE When, in cases of danger, etc., a sudden reduction of brake- pipe pressure is made, the emergency part of the triple valve is called into play; the triple piston 4 moves out quickly, the graduating spring 22 is compressed, and the triple piston trav- els the full length of its stroke. In this position, auxiliary pressure can pass into the brake cylinder. The removed corner of the slide valve has reached a position directly above a port leading to the chamber above the emergency piston, thus allowing axuiliary air to pass down on to the top of the emer- gency piston 8, forcing it downwards. This downward move- ment unseats the emergency valve 10, and allows the air in the chamber above the emergency check 15 to escape. Brake- pipe pressure beneath this check-valve forces the latter from its seat and air from the brake pipe passes up by it through the unseated emergency valve 10, into the brake cylinder. The emergency valve remains unseated until the pressures above and below piston 8 are nearly equalized, when the spring 12 forces the emergency valve to its seat. The position of the removed corner q on the slide valve is such that, as the valve moves forwards to emergency position, it connects the port leading to the chamber above the emer- gency piston with auxiliary pressure before the emergency port in the slide-valve port connects with the port leading to the brake cylinder. The emergency valves therefore open first, consequently, brake-pipe air — which passes like a flash through the large openings of the emergency valves — is admitted in suffi- cient quantity to give a pressure in an 8-in. brake cylinder, with standard piston travel of about 24 i Ib, when check- valve 15 closes. Afterwards, auxiliary pressure discharges into, and equalizes with, the brake cylinder; but, as the cylinder already contains about 24$ Ib. pressure, they equalize at about 60 Ib. pressure instead of at 50 Ib., as in a service application. The opening through the emergency port of the slide valve is made smaller than the service port, to retard the flow of air somewhat from the auxiliary reservoir to the brake cylinder during an emergency application of the brakes, so as to allow as much air as possible to enter the brake cylinder from the brake pipe, and thus increase the final brake-cylinder pressure. 170 TRIPLE VALVES COMPARISON OF PLAIN AND QUICK-ACTION TRIPLES Plain and quick-action triples work exactly the same in a service application, but in emergency the quick-action triple sets the brake quicker and gives a greater brake-cylinder pressure. Also, the quick-action triple sets its brake harder in emergency than it does in service application, owing to the emergency valve, piston, and check- valve operating so as to allow train-pipe pressure to enter the brake cylinder and aid the auxiliary pressure in applying the brake. The plain triple sets its brake quicker in emergency than it does in ser- vice, owing to the use of larger ports; but the brake does not set any harder, because it simply has auxiliary pressure to use in applying the brakes in either service or emergency. When a quick-action triple goes into emergency position, a sudden brake-pipe reduction is made near it when the emer- gency valve opens. This sudden reduction starts the next quick-action triple, and that starts the next, and so on through- out the train. If from any defect one triple goes into quick action, all will follow. Ordinarily, a gradual brake-pipe reduction of about 20 Ib. will cause a plain or a quick-action triple valve to equalize the pressures between the auxiliary and brake cylinders at about 50 Ib. In emergency, with a quick-action triple, the pressures are equalized at about 60 Ib., while with a plain triple, the same pressure is obtained in the cylinder in emer- gency as in a full-service application, namely, 50 Ib. With quick-action triples, a sudden brake-pipe reduction of 10 or 12 Ib. will produce a full emergency action of the brakes; while, with a plain triple, a reduction of about 20 Ib. is necessary. The reason for this is that a 12-lb. reduction will cause the emergency valves of the first triples to open and produce a further brake-pipe reduction. Brake-pipe pressure is not affected in this way when a plain triple goes into emergency, and, therefore, while a sudden 12 Ib. reduction would force the triple to emergency position, it would not stay there, as it would be forced back to lap or perhaps to release, as soon as auxiliary pressure had reduced the 12 Ib. It is necessary, therefore, to reduce brake-pipe pressure below that at which TRIPLE VALVES 171 the auxiliary and brake cylinders equalize, to obtain a full emergency application with plain triples. K-l TRIPLE VALVE The K-l triple valve, shown in Fig. 4, is used with 6-in. and 8-in. freight-car brake cylinders; its weight is 40 Ib. The piece number of the valve, complete, is 27,852; the piece and reference numbers of its parts are as follows: 12,852 10,032 6,520 12,514 1.733 1.740 1,735 1,737 1,745 12,850 PC. No. Ref. No. Name of Part 27,851 2 Body, complete, includes |-in. pipe plug. 12,513 3 Slide valve. 4 Main piston, includes 5. 5 Main-piston ring. 6 Slide-valve spring. 7 Graduating valve. 8 Emergency piston. 9 Emergency-valve seat. 10 Emergency valve, includes 11 and 28. 11 Rubber seat. 12 Check-valve spring. 13 Check-valve case, complete includes J-in. pipe plug. 14 Check-valve-case gasket. 15 Check-valve. 16 Strainer. 17 1-in. union nut. 18 1-in. union swivel. 19 Cylinder cap. 20 Graduating-stem nut. 21 Graduating stem. 22 Graduating spring. 23 Cylinder-cap gasket. 24 Bolt and nut, for cylinder cap. 25 Capscrew. J-in. pipe plug. 27 1-in. union Basket. 28 Emergency-valve nut. 29 Retarding-device body, marked K-l. 31 Retarding stem. 33 Retarding spring. 35 Graduating-valve spring. 1,754 1,744 1,751 1,749 1,750 1,746 1,747 1,748 1,057 1,753 4,879 1,752 1,004 1,755 1,738 27,328 27,846 29,105 9,862 1,734 2,427 |-in. plug for exhaust outlet, not shown. *Trii" iple- valve gasket. The standard retarded-release portion of the K-l triple valve, illustrated in Fig. 4 and 5 (b), is not interchangeable with the *Listed for convenience only; not included in K-l triple valve. 172 TRIPLE VALVES retarded-release portion supplied with the old-standard K^l triple valve, Piece No. 20,319, illustrated in Pig. 5 (a); there- fore, the following piece numbers, covering the retarded- release portion, must be specified when ordering repair parts for old-standard triple valve, Piece No. 20,319, otherwise all repair parts for both triple valves are identical. Pc.No.Ref.No. TRIPLE VALVES Name of Part 173 10,498 Release-retarding device, complete, in- cludes 29 to 34 inclusive. 20,278 2 Triple-valve body, complete, includes f-in. pipe plug. 10,511 29 Retarding-device body. 18,581 30 Retarding-device screw. 10,510 31 Retarding stem. 9,919 32 Retarding-spring collar. 1,523 33 Retarding spring. 10,068 34 Retarding-stem pin. ifc^ ('0 FIG. 5 When the old-standard H-l triple valve, Piece No. 1,717, is converted to the K-l, Piece No.' 28,991, a special retarded- release portion, as illustrated in Fig. 5 (6), is supplied; there- fore, the following piece numbers, covering the retarded-release portion, must be specified when ordering repair parts for converted triple valve, Piece No. 28,991, otherwise all repair parts for both triple valves are identical. PC. No. Ref. No. Name of Part 29,001 2 Triple-valve body, complete, includes f-in. pipe plug. 27,325 29 Retarding-device body, marked K-l-C. 28,944 31 Retarding stem. K-2 TRIPLE VALVE The K-2 triple valve, shown in Fig. 6, is used with 10-in. freight-car brake cylinders; it weighs 35 Ib. Its piece number is 28,968; the piece and reference numbers of its various parts are given in the accompanying list. 174 TRIPLE VALVES PC. No. Ref. No. Name of Part 28,888 2 Body, complete, includes |-in. pipe plug. 28,959 3 Slide valve; 12,864 4 Main piston, includes 5. 10,032 5 Main-piston ring. 6,520 6 Slide-valve spring. 28,956 7 Graduating valve. 1,733 8 Emergency piston. 1,740 9 Emergency-valve seat. PC. No. Ref. No. 1,735 1,737 1,745 13,392 10 11 12 13 TRIPLE VALVES Name of Part 175 Emergency valve, includes 11 and 28. Rubber seat. Check-valve spring. Check- valve case, complete, includes J-in. pipe plug. 4,876 14 Check-valve-case gasket. ,744 15 Check-valve. ,751 16 Strainer. ,749 17 1-in. union nut. ,750 18 1-in. union swivel. ,746 19 Cylinder cap. 1.747 20 Graduating-stem nut. 1.748 21 Graduating stem. 1,057 22 Graduating spring. 1,753 23 Cylinder -cap gasket. 4.879 24 Bolt and nut, for cylinder cap. 4.880 25 Bolt and nut, for check-valve case. 1,004 Hn. pipe plug. 1,755 27 1-in. union gasket. 1,738 28 Emergency-valve nut. 27.334 29 Retarding-device body, marked K-2. 28,613 31 Retarding stem. 29,105 33 Retarding spring. 31,528 35 Graduating- valve spring. 1,734 -f-in. plug for exhaust outlet, not shown. 4,886 Triple- valve gasket. The present standard retarded-release portion of the K-2 triple valve, illustrated in Fig. 6, is not interchangeable with the retarded-release portion supplied with the old-standard K-2 triple valve, Piece No. 20,230, illustrated in Fig. 7 (a), therefore the following piece numbers, covering the retarded-release *Listed for convenience only; not included in K-2 triple valve. 176 TRIPLE VALVES portion, must be specified when ordering repair parts for the old-standard triple valve, Piece No. 20,230, otherwise all repair parts for both triple valves are identical. FIG. 8 PC. No. Ref.No. Name of Part 10,563 Release-retarding device, complete, in- cludes 29 to 34 inclusive. 20,148 2 Triple- valve body, complete, includes f-in. pipe plug. 10,561 29 Retarding-device body. 18..T81 30 Retarding-device screw. ] 0,081 31 Retarding stem. 9,919 32 Retarding-spring collar. 1,523 33 Retarding spring. 10,0r,8 34 Retarding-stem pin. When the old-standard H-2 triple valve, Piece No. 4,870, is converted to the K-2, Piece No. 29,191, a special retarded TRIPLE VALVES 177 release portion, as illustrated in Fig. 7 (b), is supplied; therefore, the following piece numbers, covering the retarded-release portion, must be specified when ordering repair parts for the converted triple valve, otherwise all repair parts for both triple valves are identical. PC. No. Ref. No. Name of Part 29,206 2 Triple-valve body, complete, includes f-in. pipe plug. 27,331 29 Retarding-device body, marked K-2-C. 28,942 31 Retarding stem. 0 o, 0- 0' FIG. 9 FIG. 10 Fig. 8 shows two perspective views of the slide valve 3, and Fig. 9, the slide-valve seat; Fig. 10 is a perspective view of the graduating valve 7. FEATURES OF TYPE K TRIPLE VALVE The type K freight triple valve is used only in freight service and was designed to meet the conditions brought about by the increase in train speeds, in length of trains, and in car capacities that obtain at the present time. It is made in two sizes, which can be distinguished by the mark K-l or K-2 on the side of the valve body. The K-l triple is used with 6-in. and 8-in. brake cylinders, and the K-2 triple with 10-in. brake cylinders. Another difference between the K-l and K-2 triples is that the K-l triple has but two bolt holes while the K-2 triple has three bolt holes in the reservoir flange. The K-l triple and the F-36 triple are so made that they will bolt to the same reservoir; the K-2 triple and the H-49 triple are so made that they will bolt to the same reservoir. The old type H triple valve that is in general use in freight service was designed for maximum trains of fifty cars of 30-T. capacity. The practice of running trains of greater 13 178 TRIPLE VALVES length and weight necessitated a quicker serial action of the brake in service applications, a retarded release of the head brakes, and a uniform recharge of the head and rear auxiliaries to permit the train to be handled successfully. The type K triple valve embodies these additional features as well as all the features of the type H triple. A diagrammatic view of the triple valve is given in Fig. 11. FIG. 11 Quick-Service Feature. — The object of the quick-service feature is to quicken the serial application of the brakes on long trains, so as to reduce the interval between the application of the first and the last brakes. This is accomplished by each triple valve venting brake-pipe air momentarily through a restricted passage into the brake cylinder, thus producing at each triple a slight brake-pipe reduction that is quickly transmitted from car to car throughout the brake pipe in a TRIPLE VALVES 179 manner similar to a quick-action application. With a train of all K triple valves, this feature very materially reduces the time of application below that required by H triples; applies the brakes more uniformly throughout the train; insures the application of all the brakes with light brake-pipe reductions; gives a higher brake-cylinder pressure, increasing the brake- cylinder pressure about 1 Ib. on equalization with standard piston travel; and effects a considerable saving in air. By venting brake-pipe air into the brake cylinders, the K triple reduces the time of discharge of brake-pipe air from the brake- valve exhaust for a given reduction considerably below the time necessary with H triples. The quick-service feature operates only on trains of such lengths that the volume of the brake pipe is too large for brake-pipe pressure to be reduced at the proper rate through the brake-valve exhaust. If the reduction can be made at the proper rate, as with short trains, the quick-service feature automatically becomes inoperative. Retarded- or Uniform-Release Feature. — To release the brakes, main-reservoir pressure is thrown into the brake pipe, so as to cause a wave of pressure to flow from the head end toward the rear. The head triples feel the impulse first and move to release position quite 'an interval before the rear triples. They cannot be prevented from going to release position first; therefore, to get a uniform release of the brakes throughout the train the exhaust port of the head triples is restricted, which retards the exhaust of brake-cylinder air sufficiently to permit the head and rear brakes to let go at about the same instant. The object of the retarded- or uniform-release feature is to retard the exhaust from the brake cylinders of the head brakes so as to make the release of the brakes more uniform throughout the train. With H triples, the head brakes begin to release first. After a 15-lb. reduction on an eighty-car train, they fully release 30 sec. before the rear brakes. With K triples, the head triples move to release position first, but about the first thirty triples are forced past normal release to retarded-release position and their brake cylinders release through a restricted port; only the rear triples move 180 TRIPLE VALVES to normal release position and exhaust through the full size of the exhaust port. The relative sizes of the restricted and normal exhaust ports are such that the head and rear triples exhaust their brake cylinders in approximately the same time; consequently, the brakes release uniformly throughout the train and in less than half the time required by H triples. This results in much smoother operation, and greatly reduces the shocks and consequent break-in-twos, slid flat wheels, and damage to equipment and lading. To move a triple valve to retarded-release position, the brake-pipe pressure must be raised about 3 Ib. above auxiliary- reservoir pressure. On a long train it has been found impossible to obtain this difference of pressure beyond about thirty cars back of the engine; consequently, the triple valves beyond that point do not go to retarded-release position. Uniform-Recharge Feature. — The object of the uniform-re- charge feature is to increase the rate of rise of brake-pipe pressure in the rear end and to make the auxiliary reservoirs throughout the train recharge at approximately the same rate, thus insuring a more prompt action of the rear-end brakes and preventing the head brakes from reapplying when the brake valve is moved to running position. When H triple valves are used, all the feed -grooves are of the same size; consequently, the head auxiliaries overcharge on account of the higher brake-pipe pressure they are subjected to with the brake valve in release position. Thus, when the brake valve is moved to running position, the pressure in the head end of the brake pipe drops until it equalizes with the lower pressure in the rear end of the brake pipe and the head-end brakes reapply. With K triple valves, the feed-groove (located in the ridge on the back of the triple position) through which the auxiliary charges when the triple is in retarded-release position, is about half as large as the feed-groove used when the triple is in normal release position; consequently, the head-end auxiliaries charge through a restricted opening that compensates for the higher brake-pipe pressure in the head end and permits more of the air passing into the brake pipe to flow to the rear end of the train, charging the brake pipe to a higher pressure, and releasing and recharging the brakes more promptly. TRIPLE VALVES 181 In releasing the brakes, the pressure in the head end of t>he train rises much more rapidly and to a higher pressure than in the rear end. This is due to the head end being nearer the supply of air, to the frictional resistance offered to the flow of the air by the brake pipe, and to the fact that each triple valve starts to recharge its auxiliary the moment it moves to release position. The primary object of the uni- form-recharge feature, therefore, is to increase the rate of rise of brake-pipe pressure toward the rear end, thereby obtain- ing a quicker release and recharge of the rear brakes; this results in shortening the time necessary to release all brakes, in a more uniform release of all brakes, and in a more uniform and quicker recharge of all auxiliaries. OPERATION OF TYPE K TRIPLE VALVES Full-Release and Charging Position. — When the engineer's brake valve is placed in full-release or running position, the air entering the brake pipe raises the pressure in chamber B above that in the slide-valve chamber C and the auxiliary reservoir, and moves the triple piston, slide valve, and gradu- ating valve to the right. If brake-pipe pressure in chamber B does not exceed the auxiliary -reservoir pressure in chamber C by 3 lb., as is usually the case on all cars back of the thirtieth car of a long train, the retarded -release stem and spring will stop the triple piston and slide valve in full-release position. When in this position, the feed -groove in the triple-piston bushing is uncovered and brake -pipe air passes through it past the triple piston and charges the auxiliary reservoir; also, a port in the slide valve registers with a port in the slide- valve seat and conveys air to the slide-valve chamber and the ^auxiliary, thus assisting in charging the auxiliary reservoir, the check- valve 15 being unseated by brake-pipe pressure while air is passing to the auxiliary reservoir. The cavity in the slide valve fully connects the brake cylinder with the exhaust so that brake-cylinder air can escape freely to the atmosphere. Air flows from the brake pipe through the feed-groove into the auxiliary until the pressures equalize and the auxiliary reservoir is fully charged. Air flows through the feed-port 182 TRIPLE VALVES into the auxiliary until the pressures are equalized near enough for the check- valve spring to seat the check- valve, after which the auxiliary charges through the feed-groove alone. Quick-Service Position. — When a service reduction is made in the brake-pipe pressure at the brake valve, the pressure on the brake-pipe side of the triple piston is reduced faster than auxiliary-reservoir pressure can reduce through the feed-groove. This produces a difference of pressure on the two faces of the piston, and when this difference becomes about 2 Ib. per sq. in., the auxiliary-reservoir pressure, being the greater, forces the piston forwards to application position, taking the graduating valve 7 with it and closing the feed groove. This movement of the triple piston first causes the graduating valve to uncover the graduating port and to connect two ports in the back of the slide valve through the cavity in the valve; then the shoulder on the triple -piston stem engages the slide valve and moves it to application position. If the difference in pressure on the two faces of the triple piston is not sufficient to compress the graduating spring 22, these parts will be held in quick-service position. In this position, the triple piston is close to or against the graduating stem but does not compress the graduating spring. The slide valve cuts off the connection between the exhaust ports so that brake-cylinder pressure cannot pass to the atmosphere. Auxiliary -reservoir air now flows into the brake cylinder and applies the brakes; also, brake-pipe pressure, raising check- valve 15, passes to the chamber above the emer- gency piston, from which place it can pass the emergency piston, which fits loosely in its cylinder, to the brake cylinder. Ports' leading to the chamber above the emergency piston are so restricted that the flow of air through them, when con- nected, is not great enough to raise sufficient pressure above the emergency piston to force it down and cause an emergency action of the triple, but the air that passes to the brake cylinder reduces the brake-pipe pressure locally at each triple valve just enough to cause the next triple valve to operate promptly. This local reduction acts to transmit quickly and uniformly the brake-valve reduction from car to car in a manner similar to the serial action during an emergency application, only the TRIPLE VALVES 183 amount of the reduction is not so great. As a result of this serial action, the time interval between the operation of the first and last brakes on a long train is greatly reduced; also, with a long train of K triples, the time required for the air to exhaust from the brake-pipe exhaust valve of the brake valve for a given reduction will be greatly reduced below the time required with a train of H triples. The venting of brake- pipe air into the brake cylinder results in a pressure on equali- zation that is about 1 Ib. higher. After the triple piston has moved the slide valve to quick- service position, the slide valve does not move again until the brake is released or a sufficient reduction is made in brake- pipe pressure to move it to full-service or emergency position; the graduating valve controls the quick-service ports in the slide valve, so that they are opened each time the graduating valve opens the service port and closed each time the piston moves the graduating valve to lap position. The quick-service feature of the K triple valve operates only when the brake-pipe reduction is being made at less than the proper rate, as when the train is long. With a short train, the brake valve can reduce brake-pipe pressure as fast as is necessary, and the local reduction is not desirable; hence, under such conditions, the quick-service feature automatically goes out of service by the triple valve going to full-service position. Full-Service Position. — The strength of the graduating spring 22 is such that when the reduction in the brake pipe is being made at the proper rate, the difference in pressure on the triple piston will be great enough to compress the gradu- ating spring sufficiently to permit the slide valve to assume full-service position. Thus, as the quick-service feature is not needed, it is automatically cut out of commission. When the brake-pipe reduction is slower than it should be, as when the train is long or during moderate reductions, the service port is opened sufficiently to prevent enough differ- ence of pressure from being formed to compress the graduating spring 8£. With the triple valve in full -service position, the graduating port and brake-cylinder port register fully. The quick-service 184 TRIPLE VALVES port is blanked by the slide valve so that no brake-pipe air can pass to the brake cylinder through the feed-port. The local reduction of brake-pipe pressure at each triple valve is thus prevented because the reduction is being made as fast as desirable at the brake valve, and any local reduction will cause undesired quick action of the brakes. However, the brakes will apply promptly because the service port is fully open and auxiliary pressure reduces at the same rate as brakepipe pressure. Lap Position. — The lap position assumed, by the triple valve, from quick-service position is different from the lap position assumed from full-service position. This is due to the fact that the slide valve remains stationary and is not moved when the triple piston moves the graduating valve to lap the service ports. The triple valve is held in service position as long as the brake-pipe pressure continues to reduce. When it ceases, auxiliary-reservoir air still flows into the brake cylin- der until the auxiliary pressure is reduced below brake-pipe pressure sufficiently to cause the triple piston to be moved toward release position and the shoulder of the stem comes in contact with the slide valve. The difference in pressure necessary to move the piston and graduating valve is not sufficient to overcome the friction of the slide valve, so that any further movement of the piston is stopped by the slide valve. When the piston starts to lap position from quick-service position, the parts come to rest in quick-service lap position. In this position the graduating valve 7 closes the top ends of the graduating port and the port leading to the top of the emergency piston 8, so no more air can pass to the brake cylinder either from the auxiliary reservoir or from the brake pipe. If the triple valve is in full-service position when the reduc- tion of brake-pipe air at the brake valve ceases, it will assume lap position in the manner just explained, but the triple piston will be assisted in its movement to lap position by the gradu- ating spring 22, which was slightly compressed, and the piston will be stopped in full-service lap position, instead of in quick- service lap position. TRIPLE VALVES 185 Retarded-Release Position. — If, when releasing the brakes, the brake-pipe pressure is 3 Ib. or more in excess of the auxil- iary-reservoir pressure as is usually the case on the head cars of a train, the triple piston, instead of stonging when it strikes the retarding stem SI, will compress the retarding spring 33 and move to retarded-release position, taking the slide and graduating valves with it. When in this position, the ridge on the back of the triple piston is against the end of the slide-valve bushing, with which it makes an air-tight joint except at the feed-groove. Brake- pipe air therefore passes the triple piston through the feed- groove; thence through the feed-groove in the shoulder of the piston to the auxiliary reservoir. As the feed-groove in the shoulder of the pisfon has only about half the area of the feed- groove in the bushing, the auxiliary reservoir will be recharged much more slowly when the triple valve is in retarded-release position than when it is in full-release position. The feed-port in the slide-valve seat is covered by the slide valve in retarded- release position, so that the auxiliary reservoir can get no air from that source. In this position of the triple valve, the exhaust passage is through a restricted passage through the body of the slide valve, so that brake-cylinder air escapes very slowly to the exhaust port and the atmosphere. When the difference of pressure between the brake-pipe and auxiliary reservoir is less than the tension of the retarded-release spring by an amount sufficient to compensate for the friction of the parts , the triple piston and slide valve will be moved back to full- release position by the spring. Emergency Position. — The emergency application of the K triple valves is the same as for all other types of triple valves. COMPARISON OF TYPES K AND H-l (F-36) TRIPLE VALVES In the accompanying table are given the results of compara- tive tests of types K and H-l (F-36) triple valves; the table shows the pressures in the brake cylinder with different piston travels and reductions. There was 15 Ib. in the brake cylinder when the second reduction was made. 186 TRIPLE VALVES T8ABJJ, UO^SIJ uotipnpa^ ia*JV ajnssaij CD lO T}< — ^ ^~ —7* — 1 L, ~7^ X ^— It If x // I/ \ ^ t ^ f\^ K i-fi /O 2O 30 40 30 60 70 SO 905ec. /TZr&eM&t FIG. 5 The time required to obtain 20 Ib. brake-cylinder pressure with H and K triple valves on an eighty-car train is shown in Fig. 6. The curves show that the H triple required 25, 93, and 95 sec. to give 20 Ib. pressure in the first, fiftieth and eightieth cars, respectively. The K triple required only 17 i, 37, and 39 £ sec., respectively. The K triples, therefore, gave 20 Ib. brake-cylinder pressure in the last car 55J sec. before the H triples did, or before 20 Ib. was obtained in the TRIPLE VALVES /CO '0 /O 20 JO 40 JO 60 70 3O Cars FlG. 6 III f- HI- FIG. 7 , ^*J I" \* r \t / x * x< / x • / ''''/ / / $ 1 % ' 500 1000 ISO % Itngf/l off top infect 14 FIG. 8 194 TRIPLE VALVES twentieth car. This shows why the slack in a train equipped with K triples gives so much less trouble from bunching and recoiling than it does in a train of H triples. Standing Tests. — The time required to release brakes on an eighty-car train, equipped with H and K triple valves and standing, is shown in Fig. 7. These curves show that all the brakes having K triple valves released at practically the same time, in approximately from 14 to 16 sec. The brakes having H triples, however, were very ununiform; the first 1 ll § §• | 111 t •si eg K CO o nj S'^ Ki ^ 0>> ft! HH ^ (H •gil & 12 <5 J3 "6 13 %& £ fit M 0 ^ S'i a i3 a w ^< ^ P 5 $°2 5 H l°§ j K 5.2 73.9 K 20.2 591.4 KandH 5.7 104.3 Xandtf 19.6 743.6 H 5.5 117.4 tf 20.2 885.0 K 10.2 221.8 K 25.0 817.6 KandH 10.4 269.5 X and H 25.0 1,069.8 H 10.1 295.7 tf 27.0 1,447.2 K 15.1 391.4 # 30.5 1,068.8 Kan6 H lo.O 465.3 KandH 29.2 1.300.3 H 15.2 584.9 7f 29.8 1,517.8 brake released in 4$ sec., whereas the last brake required 40 sec. to release, a difference of 35j sec. This shows why it is impossible to release brakes at slow speeds with H triples without danger of breaking in two, whereas the danger is practically eliminated where K -triples are used. Running Test. — The distance required to stop, from different speeds, trains equipped with H, K, and mixed H and K triple valves, when a 15-lb. reduction is made, is shown in Fig. 8 and in the accompanying table, TRIPLE VALVES 195 PASSENGER-BRAKE TRIPLE VALVES DEVELOPMENT OF PASSENGER TRIPLE VALVE The governing factors in passenger-train control are speed, weight, and frequency of trains. The limits of time and dis- tance in which a train must be stopped in emergencies to insure safety in train operation were worked out in connec- tion with the quick-action automatic brake at the time when the weight and speed of trains were moderate and the fre- quency of trains was not such a controlling factor. The prob- lem today is to devise a brake that will enable the modern, heavy, high-speed trains to be stopped in approximately the same time and distance as were the lighter trains of the past. Since the introduction of the quick-action brake, a growing yearly increase in passenger traffic has brought with it a grow- ing increase in the length and weight of passenger trains, in the train speed, and in the frequency of the service. Each increase reduced the comparative efficiency of the existing brake system and necessitated improvements to compensate for this inefficiency, in order that stops could be made within the limits prescribed by safety. These improvements con- sisted in additions of apparatus to the existing quick-action brake systems that resulted finally in the brake known as the high-speed brake. For a time, this brake accomplished its purpose, but later changes in operative conditions so reduced its efficiency as to neutralize partly the improvements that had been made on the older forms of brake, and further improve- ments were imperative. In order to determine the necessary improvements, exhaust- ive tests and experiments were conducted to ascertain the limitations of the standard passenger triple valves when used in the latest modern service. These tests emphasized the facts that to fill the present requirements the improved brake not only would have to meet the requirements for emergency stops, but also would have to be flexible enough to make service stops with due regard for other factors, such as the comfort of the passengers; economy of time in making stops; necessity of accuracy and smoothness in making stops; 196 TRIPLE VALVES necessity for making several applications one after the other, in quick succession; necessity for easy, smooth control of train at both high and low speeds, in order that quick, smooth stops could be made with the least liability of wheels sliding. It was impossible to fulfil all these requirements except by adding new features to the brake system, and for this reason TRIPLE VALVES 197 the LN passenger equipment was designed and perfected. The LN equipment proved satisfactory for cars up to 130,000 lb., but the construction of cars of over 150,000 Ib. made the development of the PC passenger equipment necessary. P-l (F-27), QUICK-ACTION, PASSENGER, TRIPLE VALVE The P-l (F-27), quick-action, passenger, triple valve, shown in Fig. 1, is used with the 8-in. and 10-in. passenger-car brake cylinders and the 10-in. passenger -tender brake cylinders; its weight is 38 lb. Though similar in appearance, this valve differs essentially from the H-l and H-2 freight triple valves, and should never be used in connection with freight-car brakes. In addition to being marked P-l on the valve body, it may also be distinguished from the freight triple valves by the fact that it has one exhaust outlet while the freight triple valves have two; it may be distinguished from the P-2 triple valve in having two instead of three bolt holes in the back flange. The bore of the P-l slide-valve bush is If in. The operation of this triple valve is the same as the type H triple. The piece number of the P-l triple valve, complete, is 1,760; the piece and reference numbers of the various parts are given in the accompanying list. PC. No. Ref. No. Name of Part 1,761 2 Body, bushed. 29.138 3 Slide valve. 1,767 4 Main piston, includes 5. 10,032 5 Main-piston ring. 1,730 6 Slide-valve spring. 29.139 7 Graduating valve. 9,752 8 Emergency piston, includes 30. 1,740 9 Emergency-valve seat. 1,735 10 Emergency valve, includes 11 and 28. 1,737 11 Rubber seat. 1.745 12 Check- valve spring. 12,850 13 Check-valve case, complete, includes i-in. pipe plug. 1,754 14 Check- valve-case gasket. 1,744 15 Check- valve. 1,751 16 Strainer. 1.749 17 1-in. union nut. 1.750 18 1-in. union swivel. 1.746 19 Cylinder cap. 1.747 20 Graduating-stcm nut. 198 TRIPLE VALVES PC. No. Ref. No. Name of Part 1,748 21 Graduating stem. 1,523 22 Graduating spring. 1,753 23 Cylinder-cap gasket. 4,879 24 Bolt and nut, for cylinder cap. 1,752 25 Capscrew. 1,00-1 ^-in. pipe plug. 1,755 27 1-in. union gasket. 1,738 28 Emergency- valve nut. 1,773 30 Emergency-piston ring. 2,427 Triple-valve gasket. If the old-style valve or graduating valve is desired, specify as follows: PC. No. Ref. No. Name of Part 1,769 3 Slide valve. 1,732 7 Graduating valve. These parts are not interchangeable with present standard parts. The new-style slide valve, Piece No. 29,138, has a straight drill through the longitudinal center line of the slide valve for the new j^-in. graduating valve, Piece No. 29,139. The old-style slide valve, Piece No. 1,769, has a i-in. drill with counter bore for the old graduating valve, Piece No. 1,732. The graduating valves may be distinguished by the difference in diameter and the fact that the old-style has a shoulder, whereas the new-style has none. The slide valve of this triple valve is similar to that of the H triple valves. P-2 (F-29), QUICK-ACTION, PASSENGER, TRIPLE VALVE The P-2 (F-29), quick-action, passenger, triple valve, shown in Fig. 2, is used with the 12-in., 14-in., and 16-in. passenger car and passenger-tender brake cylinders; its weight is 43 Ib. Though similar in appearance, this valve differs essentially from all other quick-action triple valves, and should never be used except as specified. In addition to being marked P-2 on the valve body, it may also be distinguished from the freight triple valves by the fact that it has but one exhaust outlet, while the freight triple valves have two ; it may be distinguished from the P-l triple valve in having three instead of two bolt holes in the back flange. The bore of the P-2 slide-valve *Listed for convenience only; not included in P-l triple valve. TRIPLE VALVES 199 bush is 1 J in. The operation of this triple valve is the same as the type H triple. The piece number of the P-2 triple valve complete, is 1,775; the piece and reference numbers of the various parts are given in the accompanying list. PC. No. Ref. No. Name of Part 2,187 2 Body, bushed. 1,786 3 Slide valve. 1,783 4 Main piston, includes 5. 200 TRIPLE VALVES . No. Name of Part Main-piston ring. Slide-valve spring. Graduating valve. Emergency piston, includes 30. Emergency-valve seat. Emergency valve, includes 11 and 28. Rubber seat. Check-valve spring. Check- valve case, complete, includes § pipe plug. Check-valve-case gasket. Check-valve. Strainer. 1-in. union nut. 1-in. union swivel. Cylinder cap. Graduating-stem nut. Graduating stem. Graduating spring. Cylinder-rap gasket. Bolt and nut, for cylinder cap. Capscrew. f-in. pipe plug. 1-in. union gasket. Emergency-valve nut. Emergency-piston ring. *Triple- valve gasket. L-l-B QUICK-ACTION, PASSENGER, TRIPLE VALVE The L-l-B triple valve, in Fig. 3, is used with the 8-in. and 10-in. brake cylinders; it weighs 50 Ib. The piece num- ber of the triple valve, with E-7 safety valve, complete, is 16,101; the piece and reference numbers of the various parts are given in the accompanying list. PC. No. Rej 10,032 5 1,787 6 1,789 7 9,753 8 1,795 9 28,912 10 1,737 11 1,745 12 12,850 13 1,754 14 1,744 15 1,751 16 1,749 17 1,750 18 1,746 19 1,747 20 1,748 21 1,523 22 1,753 23 4,879 24 1,752 25 1.004 1,755 27 1,794 28 1,791 30 4,760 PC. No. Rff. No. Name of Part 16,184 2 Body, bushed. 16,127 3 Slide valve. Main piston, includes 5. Main-piston ring. Slide-valve spring. Graduating valve. Emergency piston. Emergency-valve seat. Emergency valve, includes 11 and 16. 16,187 10,032 9,326 16,128 1,733 1,740 12,249 10 *Listed for convenience only; not included in P-2 triple valve. TRIPLE VALVES 201 202 TRIPLE VALVES PC. No. Ref.No. Name of Part 10,417 11 Rubber seat for emergency valve. 1.745 12 Check- valve spring. 12,187 13 Check-valve-case, complete. 12,183 14 Check- valve-case gasket. 1,744 15 Check-valve. 1,738 16 Emergency- valve nut. 9,844 17 Graduating-valve spring. 13,247 18 Cylinder cap. 14,357 19 Gradua ting-spring nut. 13,251 20 Graduating sleeve. 1,523 21 Graduating spring. 1,753 22 Cylinder-cap gasket. 4.879 23 Bolt and nut, for cylinder cap. 4.880 24 Bolt and nut, for check-valve case. 13,136 25 By-pass piston, includes 26. 14,284 26 By-pass-piston ring. 36,208 27 By-pass valve. 13,861 29 By-pass-valve spring. 14,560 30 By-pass-valve cap. 12,984 31 By-pass-piston cap. 16,214 32 Strainer. 15,549 33 E-7 safety valve. 12,211 34 End cap. 8,969 *Triple- valve gasket. If the triple valve is used in connection with a brake cylinder equipped with a high-speed reducing valve, the safety valve is not used, and orders should specify as follows: Piece No. 19,060, L-l-B triple valve, complete, less safety valve, with safety-valve opening plugged; and Piece No. 19,052, cap nut for safety-valve onening. L-2-A QUICK-ACTION, PASSENGER, TRIPLE VALVE The L-2-A triple valve, shown in Fig. 4, is used with the 12-in. and 14-in. brake cylinders; it weighs 60 Ib. The piece number of the triple valve with E-7 safety valve, complete, is 15,500; the piece and reference numbers of the various parts are given in the accompanying list. PC. No. Ref. No. Name of Part 15,478 2 Body, bushed. 15,450 3 Slide valve. *Listed for convenience only; not included in L-l-B triple valve. TRIPLE VALVES ¥ 203 = 829 n PC. No. 15,503 12,891 0,895 15,452 1,733 1,740 12,249 10,417 1,745 Ref.No. Name of Part 4 Main piston, includes 5. 5 Main-piston ring. R Slide-valve spring. Graduating valve. Emergency piston. Emergency- valve seat. Emergency valve, includes 11 and 16 Rubber seat for emergency valve. Check-valve spring. 204 TRIPLE VALVES FIG. 5 No. Name of Part Check-valve case, complete. Check- valve-case, gasket. Check-valve. Emergency-valve nut. Graduating- valve spring. Cylinder cap. Graduating-spring nut. Graduating sleeve. Graduating spring. Cylinder-cap gasket. Bolt and nut, for cylinder cap. Bolt and nut, for check-valve case. By-pass piston, includes 26. By-pass-piston ring. By-pass valve. By-pass-valve spring. By-pass-valve cap. By-pass-piston cap. Strainer. E-7 safety valve. End cap. *Triple- valve gasket. *Listed for convenience only; not included in L-2-A triple valve. PC. No. Ref. 12,187 13 12,183 14 1,744 15 1,738 16 12,342 17 14,404 18 14,357 19 13,251 20 1,523 21 12,755 22 4,879 23 4,880 24 13,136 25 14,284 26 36,208 27 13,861 29 14.560 30 12,984 31 16,214 32 15,549 33 12,339 34 9,356 TRIPLE VALVES 205 If the triple valve is used in connection with a brake cylinder equipped with a high-speed reducing valve, the safety valve is not used, and orders should specify as follows: Piece No. 19,059, L-2-A triple valve, complete, less safety valve, with Cy 99> ©00 FIG. 6 FIG. 7 safety-valve opening plugged; and Piece No. 19,052, cap nut for safety-valve opening. Fig. 5 shows two perspective views of the slide valve 3; and Fig. 6, a view of the slide-valve seat; Fig. 7 is a perspective view of the graduating valve 7. L-3, QUICK-ACTION, PASSENGER, TRIPLE VALVE The L-3 triple valve, shown in Fig. 8, is used with 16-in. and 18-in. brake cylinders. The piece number, with E-7 safety valve, complete, is 16,370; the piece and reference numbers of the various parts are given in the accompanying list. Its weight is 70 pounds. PC. No. Ref. No. Name of Part 16,080 2 Body, bushed. 16,095 3 Slide valve. 16,372 4 Main piston, includes 5. 16,306 5 Main-piston ring. 16,294 6 Slide-valve spring. 16.292 7 Graduating valve. 1,733 8 Emergency piston. 1,740 9 Emergency -valve seat. 12,249 10 Emergency valve, includes 11 and 16. 10,417 11 Rubber seat for emergency valve. • 1,745 12 Check- valve spring. 12,187 13 Check-valve case, complete. 12,183 14 Check- valve-case, gasket. 1,744 15 Check-valve. 1,738 16 Emergency-valve nut. 16.293 17 Graduating-valve spring. 16.287 18 Cylinder cap. 16,289 19 Graduating-spring nut. 16.288 20 Graduating sleeve. 206 TRIPLE VALVES TRIPLE VALVES 207 PC. No. Ref. No. Name of Part 16,301 21 Graduating spring. 16,305 22 Cylinder-cap gasket. 4.879 23 Bolt and nut, for cylinder cap. 4.880 24 Bolt and nut, for check- valve case. 13,136 25 By-pass piston, includes 26. 14,284 26 By-pass-piston ring. 36,208 27 By-pass valve. 13,861 29 By-pass-valve spring. 14,560 30 By-pass-valve cap. 12,984 31 By-pass-piston cap. 16,214 32 Strainer. 15,549 33 E-7 safety valve. 12.848 34 End cap. 12.794 Triple valve gasket. If the triple valve is used in connection with a brake cylinder equipped with a high-speed reducing valve, the safety valve is not used, and orders must specify as follows: Piece No. 19,061, L-3 triple valve, complete, less safety valve, with safety-valve opening plugged; and Piece No. 19,052, cap nut for safety-valve opening. STYLES OF TYPE L TRIPLE VALVES The LN passenger brake equipment derives its name from the fact that a type L triple valve is used in combination with a type N passenger-brake cylinder. The older form of equip- ment was known as the PM equipment, because a P triple was used in combination with an M brake cylinder. The type N passenger-brake cylinder is designed for use with the L triple valve, the seat for the triple on the pressure head being suitable for the L triple. All the pipe connections are made direct to the brake-cylinder head, no pipe connections being made to the triple valve. A triple can be removed and replaced by another in a short time, and without disturbing any of the pipe connections, by simply removing from the triple-valve stud the nuts that hold the triple valve to the cylinder head. The brake-cylinder head has pipe connections for the pipes from the brake pipe, auxiliary reservoir, brake cylinder, and supplementary reservoir. The L triple valve is made in three styles: Style L-l-B is used with 8-in. and 10-in. brake cylinders; style L-2-A, with *Listed for convenience only; not included in L-3 triple valve. 208 TRIPLE VALVES 12-in. and 14-in. cylinders; and style L-3,with 16-in. and 18-in. cylinders. The letters and numerals designating the style of triple are cast in the side of the valve body. Other features that distinguish the L triple valve are the by-pass arrangement and the safety valve. FEATURES OF TYPE L TRIPLE VALVES The features added to the brake system by the L triple valve are: (1) High -emergency pressure feature; (2) quick- service feature; (3) graduated-release feature; (4) quick- recharge feature; and (5) service-application safety-valve feature. High-Emergency Pressure Feature. — With the same brake- pipe pressure, the high -emergency pressure feature gives a much higher brake-cylinder pressure in emergency than the high-speed brake, and the full pressure is retained during the complete stop, thus enabling much shorter stops to be made. The feature consists in the use of a supplementary reservoir in addition to the regular auxiliary reservoir. The supplement- ary reservoir has about two and one-half times the capacity of the auxiliary reservoir, and in emergency applications it equalizes with the auxiliary reservoir and the brake cylinder, providing a high pressure, which is held throughout the stop. The supplementary reservoir assists, also, in obtaining the graduated release of the brakes. Quick-Service Feature. — With the high-speed brake, the interval between the application of the first and the last brake increases with the length of the train. The quick-service feature of the L triple reduces this interval by venting a small quantity of brake-pipe air into the brake cylinder in service applications so as to produce a serial application of the brakes similar to the quick action in emergency applications, only less in degree. Graduated-Release Feature. — The proper way to stop a train is to make as heavy an application at the commencement of the stop as the speed, weight of train, and other conditions will permit, graduating the brakes off as the speed decreases. This cannot be accomplished with the type P and older forms of triple valves, but the supplementary reservoir of the type TRIPLE VALVES 209 LN equipment makes a graduated-release feature possible for the type L triple valve. With type L triples, therefore, the brakes can be graduated either on or off, thus adding much to the flexibility of the brake. This results in reducing shock effects on long, heavy trains, and eliminates the loss of time and the risk incident to two-application stops. Also, graduat- ing the brake off greatly reduces the risk of wheel sliding, and, in connection with the quick-recharge feature, makes it possible for a large number of applications to be made without exhaust- ing the air supply. Quick-Recharge Feature. — Increased weight of coaches neces- sitated an increase in the size of the brake cylinders used, until on the heavy coaches of today 16-in. and 18-in. cylinders are used instead of 10-in. and 12-in. cylinders. With an 8-in. piston travel, the 18-in. cylinder has a capacity of 2,036 cu. in. against a capacity of 675 cu. in. for the 10-in. cylinder. The 18-in. cylinder, therefore, will take three times as much air from its auxiliary at each application as the 10-in. cylinder. In recharging, therefore, the feed-groove of the triple of the 18-in. cylinder must be much larger than that of the triple of the 10-in. cylinder, in order to have the two recharge in the same time. Large feed-grooves, however, have a tendency to make a brake sluggish in applying on moderate reductions, on account of the back flow from the auxiliary- reservoir; consequently, they are undesirable. The L triple valve uses the regular size of feed-groove; besides, it employs in the slide-valve seat a quick-recharge port that is controlled by the slide valve, the check- valve pre- venting any back flow from the auxiliary reservoir during applications. This results in a rapid recharging of the auxiliary reservoirs, to nearly standard pressure, so that nearly full braking power is obtained immediately after a release has been made; consequently, a number of applications can be made in quick succession without materially reducing the pressure in the brake system. Service-Application Safery-Valve Feature. — The auxiliary reservoir used with the LN equipment is smaller for the same size of brake cylinder than the auxiliary reservoir used with the other equipments. This limits the brake-cylinder pressure 15 210 TRIPLE VALVES TRIPLE VALVES 211 at equalization to an amount that gives the proper braking power with the proper brake-pipe pressure while reducing the danger of wheel sliding to a minimum. As a protection against excessive brake-cylinder pressure during service appli- cations, due to too high brake-pipe pressure, there is provided a reducing valve that operates only in service applications and is automatically cut out of service when an emergency application is made. This constitutes the service-application safety-valve feature of the L triple valve. PIPING DIAGRAM OF LN EQUIPMENT Fig. 1 shows the piping diagram of the type LN passenger equipment. The general arrangement of the piping and the location of the parts of this equipment are practically the same as in the ordinary PM passenger equipment, except that with the LN equipment the L triple valve replaces the older form of triple valve and the N brake-cylinder head, which is especially designed for use with the type L triple valve, takes the place of the older form of brake-cylinder head. Besides, a supplementary reservoir is added to the older form of passenger- car equipment. The brake-pipe, which extends throughout the length of the car, has a branch pipe that connects to the brake-pipe connection on the brake-cylinder head. The centrifugal dirt collector in the branch pipe takes the place of the brake- pipe strainer formerly used with the car equipment. The cut-out cock in the branch pipe is for the purpose of cutting out the brake on that car when necessary. The function of the auxiliary reservoir is the same as in the older equipment. The pipe leading from the ^auxiliary reservoir is connected to the brake-cylinder head at the auxiliary-reservoir connection and this reservoir is charged through the triple valve the same as in the older form of equipment. The supplementary reservoir, which has a capacity about two and a half times that of the auxiliary reservoir, carries an extra supply of air, which assists in obtaining the graduated release of the brakes and makes possible the very high brake-cylinder pressure obtained in emergency applications. Also, it recharges the auxiliary reservoir quickly, after a service application and 212 TRIPLE VALVES release, to nearly standard pressure. The supplementary reservoir is charged through the triple valve from the brake pipe at the same time and to the same pressure as the aux- iliary reservoir. It is connected to the triple valve by means of a pipe leading from the reservoir to the supplementary- reservoir connection on the brake-cylinder head. There is no direct connection between the auxiliary and the supple- mentary reservoir. The triple slide yalve controls the flow of air from the auxiliary reservoir to the supplementary reservoir and from the supplementary reservoir to the auxiliary reservoir. The cut-out cock in the supplementary-reservoir pipe is for the purpose of cutting out the reservoir when desired, as in the case of the car being in a train in which most of the cars are equipped with the type PM brake. At such times, the cut-out cock between the triple valve and supplementary reservoir should be closed in order to have the L triple valve work in harmony with the older forms of triple valves. Closing this cut-out cock renders the graduated-release and the high emer- gency-pressure features inoperative. In trains of mixed LN and PM equipments, the LN equip- ment may be left cut in if desired and the brakes operated accordingly, provided that more than half the cars have the LN equipment. However, it must be remembered that, in using the graduated-release feature, the PM equipments will release entirely at the first graduated release. The cars having the LN equipment, therefore, will have to do the braking for the entire train during the remainder of the stop, and there will be danger of wheel sliding on those cars. To avoid wheel sliding, the brake-cylinder pressure should be graduated down to a safe pressure before the speed is low. DIAGRAMMATIC VIEWS OF TRIPLE Fig. 2 gives a diagrammatic view of a type L triple valve with the check-valve case 13, and the cylinder cap 18 removed. The triple valve is represented as having the auxiliary-reser- voir end, the cylinder-cap end, the check-valve-case end, the slide-valve seat, and the by -pass mechanism in the same plane so as to show more readily the relations of the ports to each other. TRIPLE VALVES 213 214 TRIPLE VALVES It will be noticed that port e in the cylinder-cap end leads to port e in the check- valve-case end; also, that the ports a in the auxiliary-reservoir end lead to the ports a in the check- valve-case • end. The ports a connect with corresponding ports in the brake- cylinder head and convey brake-pipe air to the space under the check- valve 15, thence through port e and passage G to chamber H. Port C in the auxiliary-reservoir end connects with a port in the brake-cylinder head that leads into the brake cylinder. Port C leads from the auxiliary-reservoir end of the triple valve to chamber X, and the ports r in the slide-valve seat lead into port C; hence all air entering in the brake cylinder through the triple valve must pass through port C. Port p in the auxiliary-reservoir end leads to port p in the slide-valve seat and connects with a port in the brake-cylinder head that leads to the atmosphere. Port x in the auxiliary-reservoir end divides, one branch leading to port x in the slide-valve seat and the other branch leading to chamber x back of the by-pass valve. Also, port x connects with a port in the brake-cylin- der head that leads to the supplementary-reservoir connection. Port c in the slide-valve seat leads to the chamber back of the by-pass piston. Port g, located in the upper part of the slide- valve bushing, is used to supply auxiliary-reservoir pressure to chamber /, in front of the by-pass valve, and through port h to the chamber in front of the by-pass piston. Port y in the check- valve-case end leads to port y in the slide-valve seat; also, it connects with a port in the check- valve case 13 that leads to chamber F, between the emergency valve and the check-valve. Port t leads from the slide-valve seat to the chamber above the emergency piston. Port b in the slide-valve seat leads through the triple- valve body to the chamber below the safety valve. In most of the illustrations, port b is indi- cated as being but one port, whereas, there is one port b in the slide-valve seat and two ports extending from the outer surface of the slide-valve bushing to the chamber below the safety valve. The only reason for having the two ports b is that it is desirable to drill the ports and the thickness of the metal in the triple-valve body will not permit of a single drill of suit- able size to be used. As the ports b are drilled, the drilling must naturally commence at the check-valve-case face of the TRIPLE VALVES 215 triple valve, which accounts for the ports extending from the safety-valve chamber to the check-valve-case face. It is not necessary to plug this end of the ports, because the check- valve-case gasket blanks the ends of the ports. FIG. 3 Fig. 3. is a diagrammatic view of the triple valve showing the positions the parts assume in full-release and charging positions. OPERATION OF LN EQUIPMENT Charging Position. — When the brake pipe is first charged, brake-pipe air will pass through the passages into chamber H and move the main piston 4 to the right to full-release position, provided it is not already in that position. This movement opens the feed-groove and allows brake-pipe air to pass into cham- ber R and the auxiliary reservoir. The slide and graduating 216 TRIPLE VALVES valves are moved with the main piston to release position. The pressure in passage c raises the check- valve 15 and as port y in the slide-valve seat and port j in the slide valve register, brake-pipe air can also pass through port y into chamber R and the auxiliary reservoir. Port k in the slide valve registers with port x in the slide-valve seat, so that air can pass to the supplementary reservoir, which is charged at the same time and to the same pressure as the auxiliary reser- voir. In this position of the slide valve, port c in the seat is not covered; hence, the chamber back of the by-pass piston into which port c opens, is charged to auxiliary -reservoir pres- sure. The chamber in front of the by -pass piston into which port h opens, is at all times connected to chamber R and the auxiliary reservoir through the ports g and h; thus, the pres- sures on both sides of the by-pass piston 25 are always equal except during emergency applications, when port c is connected to the brake cylinder through ports d , n, and r, and the by -pass- valve spring holds the by -pass valve 27 to its seat. Also, port / leads from port g to the chamber in front of the by-pass valve 27, and this chamber is likewise charged to auxiliary-reservoir pressure. In the charging position, port n in the slide-valve registers with port r in the seat, cavity w in the graduating valve connects the upper ends of the ports with another port in the slide-valve face that registers with the exhaust port p, so that any air in the brake cylinder can pass to the atmosphere through this passage. Release and Recharge. — When releasing the brakes, the brake-pipe pressure and the pressure in chamber H is increased above the auxiliary-reservoir pressure. This causes the main piston 4, with the slide valve and the graduating valve, to be moved to full-release and charging position. Port n registers with port r, port m registers with port p, and cavity w in the graduating valve connects ports m and n on the back of the slide valve, thus allowing brake-cylinder air to escape to the atmosphere. The main piston 4 uncovers the feed-groove t, which allows brake-pipe air to pass to the auxiliary reservoir. Port j registers with port y, which also allows brake-pipe air from chamber F to pass to chamber R and the auxiliary reservoir; also, port x registers with port k and, as standard TRIPLE VALVES 217 auxiliary-reservoir pressure was confined in the supplementary reservoir during the time that the brakes were applied, this pressure now assists in recharging the auxiliary reservoir. The auxiliary reservoir, therefore, begins to recharge from two sources — from the brake pipe through the feed-groove and through ports y and j, and from the supplementary reservoir, equalizing with it through ports x and k. As the supplement- ary reservoir is charged only to standard auxiliary-reservoir pressure, it only assists in quickly recharging up to the point of equalization of the two reservoirs, after which both reser- voirs must be recharged together. As the supplementary reservoir is about two and one-half times the size of the aux- iliary reservoir, every pound of pressure it is reduced in charg- ing raises auxiliary pressure 2? Ib. Thus, after a 21-lb. reduction from 90 Ib., equalization will occur when supple- mentary-reservoir pressure is reduced 6 Ib., or to 84 Ib.; aux- iliary pressure will be raised 15 Ib., or from 69 to 84 Ib. The reservoirs, therefore, will equalize for about two-thirds of the recharge, and will have to be recharged from the brake pipe for the other third ; but as this occurs through the feed -groove t and the quick-recharge port y, the time of full recharge is much less than the time for the old triples. During recharge and while graduating the release of the brakes, the pressures on the brake-pipe and auxiliary-reservoir sides of the main piston 4 are nearly balanced. This insures a prompt response of the brakes to any reduction or increase of brake-pipe pressure, irrespective of what operation may have just preceded. If, after releasing the brakes, the brake valve is placed in run- ning position, the triple piston will remain in release position, and the auxiliary and supplementary reservoirs will be fully recharged. Quick-Service Position. — When a service reduction is made in brake-pipe pressure, the pressure in chamber H is reduced faster than air can pass through the feed-groove *. As the auxiliary-reservoir pressure in chamber R is then greater than that in chamber H, the main piston 4 will be moved to the left, closing the feed -groove i, and shutting off comnranica- tion between the brake pipe and the auxiliary reservoir. The graduating valve moves with the main piston 4 and closes 218 TRIPLE VALVES ports j, nt, and k at the top of the slide valve, shutting off communication between the auxiliary and supplementary reservoirs, chamber F, and the slide-valve chamber R, and between the brake cylinder and the atmosphere. It also uncovers port z, and cavity v in the graduating valve connects ports / and o. As the main piston 4 continues to move, the shoulder on the end of its stem engages the slide valve; all these parts then move together until the knob on the main piston 4 strikes the graduating sleeve; the triple valve is then in quick-service position. In this position port k in the slide valve is moved away from port x, which leads to the supple- mentary reservoir; port z registers with port r, and the aux- iliary-reservoir air can pass to the brake cylinder through ports z and r and passage C; ports y and o register so that brake- pipe air from chamber F passes to the brake cylinder through ports y and o, cavity v in the graduating valve, port I, cavity q, port r, and the passage C. The pressure in chamber F being reduced, check- valve 15 will rise and allow brake-pipe air from passage a to be supplied to this chamber as fast as it passes out through port y. This local reduction in brake-pipe pressure will assist in applying the brakes, but will not cause an emergency application, because the air must pass through the restricted port /. The tendency to produce quick action is also guarded against by proportioning the valves and locating the ports so that the service port z will not fully register with port r while port y is connected to port o, and any movement tending to compress the graduating spring will increase the opening of the service port z and decrease the opening through port y. This grad- ually increases the rate of discharge from the auxiliary reser- voir, and decreases the rate of discharge from the brake pipe, until port z is opened its full extent and port y is entirely closed. When this takes place, the triple valve is said to be in full-service position. Triple valves in a short train will usually assume this position, because the reduction in a short brake pipe is more rapid than that in a long brake pipe. When in either quick-service or full-service position, cavity q in the slide valve connects the brake-cylinder port r with port b, thus connecting the brake cylinder with the safety TRIPLE VALVES 219 valve. The safety valve, being set at a pressure of 62 lb., will prevent the brake-cylinder pressure from rising above this amount during a service application. Full-Service Position. — When a service reduction is made with a short train, brake-pipe pressure will reduce faster than when the train is long, resulting in a greater difference between brake-pipe pressure and auxiliary-reservoir pressure being formed. This will cause the triple piston to compress the graduating spring slightly and move the slide valve and gradu- ating valve a little beyond quick-service position until port o ceases to register with port y. The triple is then in full-service position. When the slide valve is in this position, ports z and r register fully, the quick-service port y is blanked by the slide valve, and no brake-pipe air can pass to the brake cyl- inder from chamber Y. The local reduction of brake-pipe pressure at each triple valve is thus prevented, for the reason that it is not necessary; the reduction is as quick as desirable. The brakes apply promptly, because the service port z is then fully opened. Service Lap Position. — The lap position assumed by the triple valve from quick-service position differs from the posi- tion it assumes from full-service position, owing to the fact that the slide valve is not moved when the piston moves the graduating valve to lap the service ports. The triple valve is held in service position as long as the brake-pipe reduction continues. When the brake-pipe reduction ceases auxiliary-reservoir air continues to flow into the brake cylinder until auxiliary-reservoir pressure is reduced below brake-pipe pressure sufficiently to cause the triple piston to be moved toward release position and the shoulder of the piston stem to come in contact with the slide valve. The difference in pressure necessary to move the piston and graduating valve is not sufficient to overcome the additional friction encountered in moving the slide valve, so that further movement of the piston is stopped by the slide valve. When the piston starts to lap position from quick-service position, the parts come to rest in quick-service lap position. In this position the graduating valve 7 closes port z and its cavity v is moved from over port /, so that no more air can 220 TRIPLE VALVES pass to the brake cylinder either from the auxiliary reservoir through port z or from the brake pipe through port y. If the triple valve is in full-service position when the reduc- tion of brake-pipe air at the brake valve ceases, it will assume lap position in the same manner as just explained, but the triple piston will be assisted in its movement to lap position by the graduating spring, which was slightly compressed, and the piston will be stopped in full-service lap position instead of in quick-service lap position. Graduated Release. — The triple assumes full-release posi- tion in discharging air from the brake cylinder to the atmos- phere during a graduated release of the brakes. To graduate the release of the brakes, the brake-pipe pressure should be increased just enough to move the main piston, slide valve, and graduating valve to release position, and the brake valve should then be returned to lap position, which will prevent any further increase in brake-pipe pressure. As the main piston and the slide and graduating valves have been moved to release position, brake-cylinder air 'escapes to the atmosphere through ports C, r, n, cavity w, port m, and the exhaust port p; but, as the increase in brake-pipe pressure has ceased on account of the brake valve being lapped and as air from the supplementary reservoir still flows through ports x and k into chamber R, the pressure on the auxiliary-reservoir side of piston 4 is increased sufficiently above that on the brake-pipe side to move piston 4 and graduating valve 7 to graduated- release lap position. In this position, piston 4 closes the feed- groove * and the graduating valve closes ports m, j, and k, on the back of the slide valve. This cuts off the flow of air from the brake pipe to the auxiliary reservoir through the feed-groove i and the port j and from the brake cylinder to the atmosphere through port m, as well as from the supple- mentary reservoir to the auxiliary reservoir through port k. In this way the brakes are only partly released, as only a portion of the brake-cylinder air is allowed to escape to the atmosphere. In releasing the brake, a series of such graduations may be made until the brake-pipe pressure has been restored to the pressure at which the auxiliary and supplementary-reservoir TRIPLE VALVES 221 pressures will equalize; then the brakes will fully release. The amount of reduction in brake-cylinder pressure for any given graduation depends on the amount of air pressure that is put into the brake pipe each time the brake valve is placed in release, or running, position during such manipulations. This will also determine the rate at which the brake is recharged. Emergency Position. — When a heavy and sudden reduction in brake-pipe pressure is made by the brake valve or in some other way, the triple valve moves into emergency position. The pressure in chamber H of the triple valve reduces suddenly and the greater auxiliary-reservoir pressure in chamber R causes piston 4 to move rapidly to the extreme left of its chamber, moving the slide valve and graduating valve with it. The graduating spring is compressed and the triple piston rests firmly against the cylinder-cap gasket 22. When the slide valve is in emergency position, the service ports do not register. ' The end of the slide valve uncovers port t in the slide-valve seat, which allows auxiliary -reservoir air to pass into the cham- ber above the emergency piston, forcing this piston down and thus unseating the emergency valve 10. This allows the air in chamber Y to escape to the brake cylinder; then brake-pipe air in passage a raises the check- valve 15 and flows into the brake cylinder in large volume through chambers Y and X and passage C. This produces a local reduction in brake-pipe pressure, which causes the next triple valve to operate quick- action, and so on throughout the train. At the same time port d in the slide valve registers with port c in the seat and allows air in the chamber back of the by-pass piston 25 to escape to the brake cylinder through ports c, d, n, r, and C. The pressure in the chamber back of the by-pass piston 25 will be considerably reduced and the by-pass piston will be moved backwards by the auxiliary -reservoir pressure in the chamber in front of it. This movement of the by-pass piston will unseat the by-pass valve 27 and thus connect the supplementary reservoir with the auxiliary reservoir through ports x, /, and g. This gives, in effect, an auxiliary-reservoir volume approxi- mately three times the size of the one that supplies air to the brake cylinder during a service application of the brake. 222 TRIPLE VALVES During an emergency application, communication between the auxiliary reservoir and the brake cylinder is established through port 5 in the slide valve and port r in the seat. Check- valve 15 will remain unseated until the brake-cylinder pressure is nearly equal to the brake-pipe pressure; the emer- gency valve 10 will be seated as the auxiliary and brake-cylinder pressures equalize; and the by-pass valve will remain unseated until the auxiliary-reservoir and brake-cylinder pressures are nearly equal to the pressure remaining in the supplementary reservoir. This action will result in a brake-cylinder pressure nearly equal to maximum brake-pipe pressure, and as cavity q in the slide valve is moved from over port r the safety valve is no longer connected to the brake cylinder; consequently, the high brake-cylinder pressure will be maintained until the brake is released in the usual manner. PASSENGER-BRAKE TEST Rack Tests. — In Pig. 1 are shown the results of standing train tests made with the high-speed and the LN equipments, JIO /S ZO 23 JO T/mc-Jecc/iate FIG. 1 Jff 4$ to determine the comparative time required to recharge the auxiliary reservoir after a 20-lb. service reduction has been made. The six-car trains carried 110-lb. brake-pipe pressure TRIPLE VALVES 223 and were equipped with old or high-speed, brake and new, or LN equipments. The brake-valve handle was placed in full release for 6 sec. and then returned to running position. The LN equipment required only 4.4 sec. to raise auxiliary-reservoir pressure to 105 Ib. pressure, whereas the high-speed brake equipment with P triple valves required 27 sec. The slow rate of charging with P triples is due to the fact that the rise in auxiliary pressure cannot exceed the rise in brake-pipe pres- sure. The rapid rise of auxiliary pressure with the LN equip- ment, shows the ability of this equipment to make a number of successive applications and releases with excessive .reduction of the resultant brake-cylinder pressure. 90 60 fff / / ,/Ve» /T?M ymer f / / — \f 0/Jt qu,p< nenf / u ( r\ / \40 JO 20 /0 f) 1 '\ f \ l\ i /< \ 1 \ \ 1 /,' \ I <~\ \ ] ' / /-•» i ; \\ 1 * \ / ; \ \ / / \ s i V \_, ^•J V_. ^r^. ^— - 3 l^-- -> FIG. 2 In Fig. 2 are shown the results of rack tests of the old, or high-speed, and new, or LN, equipments, with 110-lb. brake-pipe pressure. This chart shows the curves produced on the brake- cylinder cards by four 20-lb. service applications and releases and one emergency application made 15 sec. apart. With the LN equipment, the brake-cylinder pressure on the fourth appli- cation had only reduced 4 Ib.; with the old equipment, the brake-cylinder pressure dropped to 28 Ib. on the second appli- cation. This difference with the old equipment, was due to the brake-pipe charging to a higher pressure than the auxiliaries. The quick-recharge feature of the L triple valves overcame this. The curves also show that the cylinder pressure reached maximum pressure much sooner with the L triples than with 224 TRIPLE VALVES the P triples. This is due to the fact that brake-pipe and auxiliary pressures are practically balanced in the new equip- ment at the time of application so that the triple valve responds at once. With the P triples, the excess brake-pipe pressure had to be drawn off before the triples would respond to the reduction. In Fig. 3 are shown the results of rack tests of the old, or high-speed, and new, or LN, equipments, with 110 Ib. brake- pipe pressure, when emergency applications are made. These curves illustrate the high emergency and the retaining features of the LN equipment. This equipment gives a brake-cylinder pressure of 104 Ib. in about 4.5 sec. and maintains it constant too I j 4&r Cgu/l men, ~J~ __ j ~— -- — < OA/l q>u/f>. 770/rf ~~ -~^_ c 30 20 S) FIG. 3 throughout the stop; the old equipment gives a maximum of 83 Ib. in about 5 sec., but this pressure gradually decreases to 60 Ib. in about 45 sec.; the pressure though is maintained constant thereafter. For the same initial brake-pipe pressure, therefore, the LN equipment gives 21 Ib. higher maximum brake-cylinder pressure, and 32.5 Ib. average pressure for the first 45 sec. After 45 sec., the LN equipment gives 44 Ib. greater brake-cylinder pressure. This greater pressure through- out the stop is provided to compensate for the lowered coef- ficient of friction between the brake shoes and the wheels that results from the increased amount of work required from each brake shoe with the LN equipments. TRIPLE VALVES 225 In Fig. 4 are shown the pressures in the brake cylinder, brake-pipe, and auxiliary reservoir of an LN equipment that has 110 Ib. brake-pipe pressure, when a 30-lb. service reduction is followed by an emergency application and release. The curves show that it required about 6.5 sec. to make the 30-lb. brake-pipe reduction in this case. This reduced auxiliary ^^x^ ^Jerr/ce 4pp/fcafti -jj / / ffngn verrcp -7 7//J7/7 ffrafre Pi / / [ \ \Retear56 L1 * ' ' , i t i i i Vi-r- bri ' '3 L" ' ' '. w ' ' '. >.' * * J ^ ~^r~ ~^= ^^ ^ AuxHiar* ' Reserr Oir /^ ^ — ? j r /i? /^ 2d 2S JO 3$ 46 FIG. 4 pressure to 82 Ib. and gave a brake-cylinder pressure of over 60 Ib. After about 10.5 sec. from the beginning of the appli- cation, an emergency application was made reducing brake- pipe pressure to 0, and raising the brake-cylinder pressure to 104 Ib., but without further reducing auxiliary reservoir pres- sure; 20 sec. from the beginning of the application, a release 16 226 TRIPLE VALVES was made and in about 3 sec. the brake pipe and the auxiliary reservoir recharged to practically normal pressure. Standing Tests. — In Fig. 5 are shown the results of emer- gency applications made while the train is standing. The first car having the new, or LN, equipment used 90 Ib. brake- pipe pressure; the first car having the old equipment used 110 Ib. brake-pipe pressure. The chart shows that the new, or LN, equipment gave a greater emergency average brake- cylinder pressure for the stop than the old equipment though the latter carried 20 Ib. greater brake-pipe pressure. Running Tests. — The emergency application and retardation curves for two engines alone and ten cars alone in break-away tests, and for an entire train of two engines and ten cars are 80 -f, -^ » ^ ww: ~f ""-• --^c 0/cft quip, CW/7/ /o °O 3 /0 /5 20 2S JO J3 404* FIG. 5 shown in Fig. 6; the brake-pipe pressure was 110 Ib. One train equipped with the old, or high-speed, apparatus was stopped from a speed of 84.2 mi. per hr., and the other, equipped with the new, or LN, equipment, was stopped from a speed of 82 mi. per hr. Retardation curves 1 and 2 are for the high- speed equipment engines alone, and for the cars alone in a break-away test, the engine having been cut off at the point of brake application in each case. Retardation curve 3 is for the train entire, consisting of the two engines and the ten cars. For the LN equipment, 4 is the retardation curve for the engine alone, 5 the curve for the cars alone, and 6 the curve for the entire train. The curves show the difference in holding power of the engines and car brakes for both equipments; also, the TRIPLE VALVES 227 difference in holding power of the two types of brakes. The engines with the high-speed equipment, curve 1, passed the point at which the cars stopped, curve 2, at a speed of about 53 mi. per hr, and with a wrecking energy of 110,000 ft.-lb. per 1,000 Ib. of engines. The engines with the LN equipment, curve 4, passed the point at which the cars stopped, curve 5, at a speed of about 55 mi. per hr., and with a wrecking energy of 108,000 ft.-lb. per 1,000 Ib. of engines. This shows clearly SJSsfr * % S- •; k ^ *^ *» ^r \ X X ^x 5 ^ ,\ X X \ v;\ \ \ x. \ V' •^ ^ \ \ v>N \ t \t \f \ \ \ van W fj^» • Is 4 408//k ? 400 300 &oo 000 eooo 2*00 zaoe aeoo Jtfoo -tooc Ootonceinfrtt • PIG. 6 that the efficiency of the car brakes is much greater than that of the locomotive brake, due to the unbraked weight of the locomotive and to its relatively low per cent, of braking power. The train with the high-speed equipment, curve 3, passed the point at which the train with the LN equipment stopped, curve 6, at a speed of about 36.5 mi. per hr. and a wrecking energy of about 48,000 ft.-lb. per 1,000 Ib. of train. The comparative retardation curves for an eight-car train > when service applications are made, are shown in Fig. 7,. 228 TRIPLE VALVES The old, or high-speed, equipment train had a brake-pipe pressure of 110 Ib. and the new, or LN, equipment train, a brake-pipe pressure of 90 Ib. The old-equipment train was /000 D/sfance frtfeefy FIG. 7 stopped with two applications as will be seen by the cylinder- pressure diagrams; with the new equipment, the brake was first applied heavily and graduated off as the end of the stop was approached. The comparative retardation curves for an eight-car train, when emergency applications are made, are shown in Fig. 8. FIG. 8 The brake-pipe pressure was 90 Ib. and the total weight of the train was 532.5 T. The curves show that when the train equipped with the old, or high-speed, equipment passed the TRIPLE VALVES 229 point at which the new-equipment train had stopped, its speed was 32 mi. per hr. and it had a wrecking energy of 35,810,000 ft.-lb. It passed the point at which the new-, or LN-, equip- ment train stopped, 7.5 sec. before the new-equipment train reached that point. It was running at over 20 mi. per hr. and had a wrecking energy of over 14,000,000 ft.-lb. at the instant the new-equipment train stopped. It ran over 100 ft. after the other train stopped. The total work done, in foot-pounds per second, was 3,014.5 with the new brake and 2,442 with the old. The work per brake shoe was 27 ft.-T. per sec. with the new and 21 ft.-T. per sec. with the old. CLEANING TRIPLE VALVES Triple valves should be inspected and thoroughly cleaned at least once every 3 mo. The main piston and attached valves should be immersed in kerosene while cleaning the other parts. Remove and examine the emergency parts, then clean and replace them without oiling, as they are seldom used and the oil will only serve to collect dirt. The slide valve and main-piston chamber should be cleaned with kerosene and a piece of cloth, and care should be taken not to leave any lint clinging to the parts. All the grooves and ports should be thoroughly cleaned by means of a pointed, hardwood stick to remove the gum from the grooves. Give the triple-piston chamber and slide-valve seat a light coat of oil. Then remove the parts from the kerosene, and clean the slide valve and grad- uating valve. The main-piston packing ring should be worked around until all the dirt is removed from it; it should not be removed from the piston unless a new ring is to be applied. Care should be taken to wipe all parts perfectly dry before lubricating them, because, if any kerosene is left in the triple or on any of the parts, it will tend to destroy the lubricating qualities of the lubricant. Also, care should be taken not to apply too much oil or grease, as practical experience has shown this to be one of the chief causes for undesired quick action. The face of the slide valve and graduating valve and the main- piston packing ring should be lightly lubricated with oil 230 TRIPLE VALVES « tn g s I! CO CO fO CON 00 XXXXXX OM^JCOCOCD xxxx ooow XX XXXXX M §2 2^^ Jg i« r-< ,-H (N (N (N (N " k^ * CN^Ssooo (M iO O 05 O N CO lO COO ^ (£4 -H Q 4> T^ •ri J2 12 C3 +f *^ -S CH JH ^ U3 O ^ ll. O 0 O O O 23 .8.2 ° ^ w |J|«fe s ^ C'S mil mil co 8 & < 0 ll? il ^o ss^ss >C 03 »O O O »-i (M CO 0 O x3 I-. «3 3 of 4-> 0 w ^ i| III § •§ S2 B ^ o *3 1 "rt *» 1 HH O r| l|| o o 'I W HW ||l s I 1 1 11 •— ' ^ O co J3 3 " u 0 |_^^ o1 5*3. a Zr J 1 p TRIPLE VALVES 231 xxxxxxx o o IN ^ co oo xxxxxx oo o ~" ^?/. 0 F tO 15 SO 25 -3O 35 4 1 7trrre,inSfcon.e& I 1 O/<* \ 4 r9 SO/ /257 /$5O /79O /947 New \ 47/ ffTS 1/99 /454 /ff/9 Distance r'frFeef 0/d 47S •42S 356 293 24O \ 157 teO-66-3J83SC A/tiv +7/ 40S 3eo &SS /63 \f+3-fSf(\ FIG. 1 Comparative speed-time-retardation curves for an eight-car train, when emergency applications are made, are shown in TRIPLE VALVES 233 Fig. 1; the brake-pipe pressure was 90 Ib. These curves show the speed-time and speed-distance relations existing through- out the stop. A chart showing the progress of air-brake efficiency, as indi- cated by the comparative distances in which a train made up FIG. 2 of a locomotive and six cars has been stopped from a speed of 60 mi. per hr. for various types of equipment is given in Fig. 2. BRAKE-PIPE VENT VALVE The brake-pipe vent valve, here shown, is furnished when ordered with either ET or old automatic (schedule PL) tender- brake equipments. For a complete installation, a 10"X24" reservoir, Piece No. 3,091, is required, and with ET equip- ments, a brake-pipe air strainer with a }-in. side opening. The weight is 27 Ib. This valve is intended for use in place of the triple valve on tenders of engines that are to be used in double-heading or as helpers in a train. The vent valve requires a 10"X24" reservoir. As a vent valve is much less sensitive than a quick-action triple valve, this apparatus can be used wherever brake-pipe venting is desired, with 234 TRIPLE VALVES TRIPLE VALVES 235 entire freedom from undesired quick action. At the same time it insures the certainty of obtaining quick action through the entire train when desired. The piece number of the brake- pipe valve vent, complete, is 15,280. The piece and reference numbers of the various parts are given in accompanying list. Pc.No.Ref.No. 15,234 15,235 10,030 15,239 15,237 15,246 15,240 15,244 15,245 15,243 10,417 15,242 15,273 19,249 16,288 18,286 14,357 15,282 11,002 Name of Part Body, bushed. Cylinder cap. Piston ring. Piston, includes 4. Cylinder-cap gasket. Slide-valve spring. Slide valve. Check-valve cap. Check-valve spring. Check- valve, complete, includes 12 and 13. Rubber seat for check- valve. Check-valve guide. Pipe-bracket gasket. Pipe bracket, "complete, includes 16, 17, 18, and 19. Graduating sleeve. Graduating spring. Graduating-spring nut. Stud and nut. Bolt and nut, i in. X If in. DISTRIBUTING VALVES NO. 5 DISTRIBUTING VALVE The No. 5 distributing valve is a part of, and is regularly supplied with, the No. 5 ET locomotive brake equipment. An exterior view of the distributing valve and the reservoir is shown in Fig. 1; in Fig. 2 is shown a cross-section through the valve. The piece number of the valve, complete, with reservoir, is 13,017; without the reservoir, 13,018. The piece and reference numbers of the various parts are given in the accompanying list. PC. No. Ref. No. Name of Part 12,809 2 Body, bushed, includes Piece No. 3526. 14,283 3 Application-valve cover, includes Piece No. 1635. 6.268 4 Cover screw. 236 TRIPLE VALVES TRIPLE VALVES -9"- 237 FIG. 2 PC. No. Ref. No. Name of Part 10.918 5 Application valve. 14,281 6 Application-valve spring. 10,872 7 Application-cylinder cover. 10,836 8 Cylinder-cover bolt and nut. 10,870 9 Cylinder-cover gasket. 12,271 10 Application piston, includes 15. 10.914 11 Piston follower. 10,920 12 Packing-leather expander. 10,913 13 Packing leather. 10.915 14 Application-piston nut. 12,891 15 Application -piston packing ring. 10,917 16 Exhaust valve. 14,281 17 Exhaust -valve spring. 10.916 18 Application-valve pin. 10.919 19 Graduating stern. 1,523 20 Graduating spring. 9,283 21 Graduating-stem nut. 10,857 22 Upper cap nut. 12.348 23 Equalizing-cylinder cap. 10,836 24 Cylinder-cap bolt and nut. 238 TRIPLE VALVES PC. No. Ref. No. Name of Part 10,869 25 Cylinder-cap gasket. 13,021 26 Equalizing piston, includes 27. 10,032 27 Equalizing-piston packing ring. 12,589 28 Graduating valve. 12,887 29 Graduating-valve spring. 12,588 31 Equalizing slide valve. 17,237 32 Equalizing slide-valve spring. 12,586 33 Lower cap nut. 10,526 34 E-l safety valve, complete. 10,397 35 Double-chamber reservoir, complete, in-. eludes two of 37 and four of 36. 12,274 36 Reservoir stud and nut. 10,076 37 Reservoir drain plug. 3,526 Distributing-valve drain plug. 10,884 39 Application-valve cover gasket. 12,270 40 Application -piston cotter. 9,696 41 Distributing-valve gasket. 1,635 Pipe plug. NO. 6 DISTRIBUTING VALVE The No. 6 distributing valve with plain cylinder cap is a part of, and is regularly supplied with, No. 6 ET locomotive brake equipments. The quick-action cylinder cap is supplied only when specially ordered ; its weight, complete, with plain cap and reservoir, is 165 lb.; with quick-action cap and reservoir, 170 lb. The piece number of a No. 6 distributing valve, with plain cylinder cap, E-6 safety valve, and reservoir, complete, is 16,945; with quick-action cylinder cap, E-6 safety valve, and reservoir, complete, 16,946; with plain cylinder cap and E-6 safety valve, complete, without reservoir, 16,937; with quick- action cylinder cap and E-6 safety valve, complete, without reservoir, 16,938. The piece and reference numbers of the various parts are given in the accompanying list. In Fig. 3 is shown the arrangement of the valve and reservoir; in Fig. 4 is shown a cross-section through the valve; and in Fig. 5 is shown a section through the union stud, union nut, and union swivel. PC. No. Ref. No. Name of Part 19,338 2 Body, bushed. 16,521 3 Application-valve cover, includes 42 6,268 4 Cover screw. 16,940 5 Application valve. 14,281 6 Application-valve spring. 10,872 7 Application-cylinder cover. 10,836 8 Bolt and nut. TRIPLE VALVES 239 240 TRIPLE VALVES FIG. 4 PC. No. Ref. No. Name of Part 10,870 9 Cylinder-cover gasket. 16,939 10 Application piston, includes 15. 10.914 11 Piston follower. 10,920 12 Packing expander. 10,913 13 Packing leather. 10.915 14 Application-piston nut. 12,891 15 Application-piston ring. 16,479 16 Exhaust valve. 14,281 17 Exhaust-valve spring. 16,482 18 Application-valve pin. 10,919 19 Application graduating stem. 1,523 20 Application graduating spring. 9,283 21 Application graduating stern nut. 16,481 22 Upper cap nut. 18,650 Plain cylinder cap, complete, includes 23, 44, 45, and 46. 18,649 23 Plain cylinder cap. 10,836 24 Bolt and nut. 241 PIG. 5 TRIPLE VALVES PC. No. Ref. No. Name of Part i o. o. • ->rrER 16,491 25 Cylinder-cap gasket. 16,512 26 Equalizing piston, includes 27. 10,032 27 Equalizing-piston ring. 12,589 28 Graduating valve. 12,887 29 Graduating-valve spring. 18.601 31 Equalizing valve. 9,721 32 Equalizing-valve spring. 18.602 33 Lower cap nut. 15,890 34 E-6 safety valve, com- plete. 16,941 35 Double-chamber reservoir, complete, in- eludes two of 37 and four of 36. 12,274 36 Reservoir stud and nut. 10,076 37 Reservoir drain plug. 16,520 39 Application- valve-cover gasket. 12,270 40 Applicati9n-piston cotter. 16,943 41 Distributing- valve gasket. 6,753 42 Oil plug. 16,214 43 Strainer. 13,251 44 Graduating sleeve. 14,357 45 Cap nut for plain cylinder cap. 1,811 46 Graduating spring for equalizing piston. 1,635 J-in. pipe plug. 18,365 Distributing- valve union connection, com- plete, includes 202, 203, and 204. 18,364 202 Union stud. 15,292 203 Union nut. 18,363 204 Union swivel. No. 6 Distributing-Valve, Quick-Action Cylinder Cap. — The quick-action cylinder cap, shown in Fig. 6, is used with the No. 6 distributing valve for engines that are to be used in double-heading service, or as helpers in a train, and is fur- nished only when specially ordered. It weighs 12$ Ib. The piece number of the cylinder cap, complete, is 16,528; the piece and reference numbers of the various parts are given in the accompanying list. PC. No. Ref. No. Name of Part 16,936 47 Cylinder cap, bushed." 16.526 48 Emergency valve. 15.244 49 Check-valve cap nut. 16.527 50 Valve stem. 15.242 51 Check-valve guide. 10,417 52 Rubber seat for check- valve. 15.243 53 Check-valve, complete, includes 51 and 52. 15.245 54 Check-valve spring. 17 242 TRIPLE VALVES PC. No. Ref. No. Name of Part 1,811 55 Graduating spring. 16,524 56 Cap nut. 16,529 57 Emergency-valve spring. 17,605 58 Stop plug. Union T. — The union T, shown in Fig. 7, is used in the appli- cation cylinder pipe that connects the distributing valve with . the automatic and inde- pendent brake valves. The piece number of a 5-in. O. D. copper-pipe union T, complete, which includes 203, 204, and 205, is 18,366; 204 FIG. 6 2 0.0 Copper r/pe FIG. 7 the piece and reference numbers of the various parts are given in the accompanying list. PC. No. Ref. No. Name of Part 15,292 203 Union nut. 18,363 204 Union swivel. 18,362 205 Union T. NO. 6 E T LOCOMOTIVE BRAKE 243 NO. 6 ET LOCOMOTIVE BRAKE DEVELOPMENT OF ET BRAKE When the straight-air brake was first put into service, the locomotive was not fitted with brakes lest the drivers might slide and flatten. However, the desire for maximum braking power for the train soon led to the use of a tender brake and, later, to a brake on the drivers. After the auto- matic brake superseded the straight-air brake, a truck brake was added, thus completing the locomotive equipment. The next step was to equip the locomotive with a straight-air brake in combination with the regular automatic air brake, thus pro- viding the engineer with independent control of the locomotive brake, which greatly increased the flexibility and efficiency of the brake system as a whole. Although the combined straight-air and automatic brake greatly increased the flexibility of control of the engine brake, especially in switching and in handling slack in freight service, it increased considerably the number of pieces that went to make up a complete locomotive brake equipment. Then the duplex main-reservoir regulation, the double-pressure control, and the high-speed brake equipment added more apparatus to the equipment, making it still more cumbersome. In fact, from the very adoption of the automatic brake, all improve- ments were made by adding apparatus to the equipment existing at the time; consequently, as the improvements pro- gressed, the equipment became more and more complicated. With the increase in speed and weight of trains, the con- ditions of train service necessitated still further improve- ments in the brake system. It was apparent that to meet the requirements by the addition of the necessary apparatus to the brake system then in general use would make the system too cumbersome. This naturally led to the design of a locomotive brake equipment that would include in one apparatus all the desirable features of the existing brake system and eliminate many of the undesirable features, 244 NO. 6 ET LOCOMOTIVE BRAKE besides providing new features necessary to meet the require- ments of prevailing conditions of road service. This new brake system is known as the ET locomotive-brake equip- ment, the letters ET being an abbreviation for engine and tender. The ET locomotive brake equipment is adapted for all classes of engines and for all kinds of service, the only differ- ence in the equipment for locomotives of different size or for different service being in the size of the brake cylinders used. It was introduced in 1905, and was known as the No. 5 ET equipment. The No. 6 ET equipment is an improvement on the No. 5 ET equipment, as it accomplishes in a simpler manner all that the No. 5 ET equipment does, besides intro- ducing other features that experience with the No. 5 ET equip- ment has suggested. The ET brake equipment differs materially from the older form of locomotive brake equipment. It consists of less appa- ratus, as many of the valves are replaced by others of different construction, and the method of its operation is somewhat different. The same air pump, main reservoirs, duplex gauge, and brake cylinders, together with their apparatus for carrying the power to the brake shoes, are left in service, but the older forms of automatic brake valve, slide-valve, feed-valve, and duplex governor are replaced by new ones; also, the independ- ent brake valve takes the place of the older form of straight- air brake valve. The distributing valve replaces the triple valves, auxiliary reservoirs, and high-speed reducing valves formerly used on the engine and tender, and a new form of slide-valve feed-valve fitted with the regulating device adapted for a quick change of pressures takes the place of the reversing cock and duplex feed-valve. The reducing valve for the independent brake- valve also acts as a reducing valve for the air-signal system so that the style of reducing valve formerly used with the signal system is dispensed with. The double check-valves used with the combined automatic and straight-air brake are also dis- pensed with in the ET equipment. This new type of locomotive brake equipment can be applied to any locomotive, whether used in high-speed or NO. 6 ET LOCOMOTIVE BRAKE 245 ordinary passenger service, double-pressure-control service, freight service, or any kind of switching service. It has all the advantages of the older types of brake equipment and many other important advantages found by practical experi- ence to be necessary in modern locomotive brake service. The locomotive brakes can be applied with a graduated, a full-service, or an emergency application. They can be applied and released in conjunction with the brakes on the cars or independently of them, and they can be released either wholly or partly at the will of the engineer. Also, it is possible to release the train brakes and hold the locomotive brakes applied full force. When double-heading, the brake on either locomotive can be applied or released by the engineer on that engine without affecting any other brake. This is a valuable feature, because it permits the engine brake to be released in case the drivers slide and applied again as soon as the wheels begin to turn. The supply of air for the locomotive brake cylinders is taken direct from the main reservoir, and the distributing valve is designed so as to supply automatically brake-cylinder leakage, from the main reservoir, thus preventing the loco- motive brakes from leaking off as they do when the brake- cylinder supply is taken from the auxiliary reservoir. Neither the length of the brake-piston travel nor the brake- cylinder leakage affects the brake-cylinder pressure, and so long as the brake piston does not strike the non-pressure head of the cylinder or the brake rigging does not catch something that will prevent the power exerted on the piston from being transmitted to the brake shoes, the engine and tender brakes will be applied with the same pressure. If the brake is applied with the independent brake valve in order to prevent the engine from moving after being stopped, it will not leak off; and when standing on a down grade the locomotive brake can be applied independently to hold the train while the auxiliaries on the cars are being recharged. 246 NO, 6 E T LOCOMOTIVE BRAKE NO. 6 E T LOCOMOTIVE BRAKE 247 PIPING ARRANGEMENT AND EQUIPMENT The general arrangement of the various valves, pipes and pipe connections of the No. 6 ET equipment as applied to the locomotive is shown in the accompanying piping diagram. The discharge pipe conveys the compressed air from the air pump to the first main reservoir. The reservoir connecting pipe connects the two main reser- voirs. The main-reservoir pipe leads from the second main reser- voir and serves as a supply pipe to deliver full main-reservoir pressure to the automatic brake valve, the distributing valve, the B-6 feed- valve, the C-6 reducing valve, the maximum- pressure governor, and the red hand of the large air gauge. The main-reservoir cut-out cock is placed in the main-reser- voir pipe so that main-reservoir air can be shut off from the brake system when it is necessary to remove any of the apparatus while the brake system is charged. It contains a small bleed hole that allows the air to escape from the piping to the atmosphere when the cock is closed. The governor pipe H is connected to the main-reservoir side of the main-reservoir cut-out cock and leads to the maxi- mum-pressure head of the duplex governor, so that this head of the governor is always subjected to main-reservoir pressure regardless of whether the cock is opened or closed. The distributing-valve supply pipe E conveys main-reservoir air from the main-reservoir pipe to the distributing valve for use in the locomotive brake cylinders. The distributing-valve cut-out cock in pipe E is for the purpose of cutting off the supply of main-reservoir air from the dis- tributing valve when necessary. The pipe N leads from the main-reservoir pipe to the red hand of the large air gauge, which registers main-reservoir pressure. The brake pipe connects with the train brake pipe, so that it is in direct communication with all triple valves on the cars in the train. It connects with the automatic brake valve through the pipe O, and with the distributing valve through the pipe F. 248 NO. 6 ET LOCOMOTIVE BRAKE The double-heading cock (in the brake pipe just under the brake valve) is for the purpose of cutting out the automatic brake valve from the brake pipe on the following locomotive of a double-header. It is closed when its handle is parallel with, and open when its handle is at right angles to, the pipe. The by-pass for charging dead engine consists of a pipe leading from the brake pipe O to the main-reservoir pipe, together with a cut-out cock, a strainer, and a non-return check- valve. The purpose of this arrangement is to provide a means of supplying air for the distributing valve and brake cylinders of a dead engine (or one with a disabled air pump) from the supply in the brake pipe that is furnished by the other engine. When necessary to use the by-pass arrange- ment, the double-heading cock in the brake pipe must be closed and the cut-out cock in the by-pass pipe opened. When the by-pass arrangement is not in use, the cut-out cock in the by-pass pipe must be closed. The brake-cylinder pipe leads from the distributing valve to the driver and tender brake cylinders; also it connects with the engine-truck brake cylinder when the engine is provided with a truck brake. The driver, tender, and truck-brake cut-out cocks are for the purpose of cutting out their respective brakes in case the brake becomes disabled. The choke fittings in the tender and truck brake-cylinder pipe have a restricted opening that will allow air to pass to and from the engine-truck and tender-brake cylinders fast enough to operate their brakes properly; but if the hose con- nections to these cylinders should burst or become uncoupled, the choke fitting will restrict the flow of air so that the dis- tributing valve can hold the pressure up to the standard in the other brake cylinders; hence, the bursting of a tender- or truck-brake hose will not disable all the locomotive brakes during the stop. The B-6 feed-valve reduces the main-reservoir pressure to the standard desired for use in the train brake pipe. The C-6 reducing valve reduces the main-reservoir pressure to 45 Ib. for use in the independent brake valve and in the air-signal system. ATO. 6 ET LOCOMOTIVE BRAKE 249 The feed-valve pipe leads from the B-6 feed-valve to the pipe bracket of the automatic brake valve and conveys air at feed-valve pressure to the automatic brake valve. The excess-pressure governor pipe leads from the feed-valve pipe to the chamber above the diaphragm in the excess- pressure head of the duplex governor. The reducing-valve pipe conveys air at a pressure of 45 Ib. from the C-6 reducing valve to the independent brake valve and the air-signal pipe. A branch pipe leads from the reduc- ing-valve pipe to the combined strainer and check-valve through which air passes to the signal pipe. The gauge pipe L conveys air from the brake-cylinder pipe to the red hand of the small duplex gauge, which thus registers the pressure in the locomotive brake cylinders. The governor pipe K leads from the pipe bracket of the auto- matic brake valve to the chamber below the diaphragm in the excess-pressure head of the duplex governor. It supplies air at main-reservoir pressure to this chamber when the auto- matic brake valve is in release, running, or holding position. The gauge pipe U is connected to the brake pipe below the double-heading cock and leads to the black hand of the small duplex gauge. The black hand of this gauge therefore registers brake-pipe pressure at all times, whether the double- heading cock is open or closed. The equalizing-reservoir pipe connects chamber D of the automatic brake valve to the equalizing reservoir. The gauge pipe M leads from the equalizing-reservoir con- nection of the brake valve to the black hand of the large duplex gauge. The black hand of this gauge therefore registers equalizing-reservoir pressure at all times. The application-cylinder pipe connects the automatic and independent brake valves with the application cylinder of the distributing valve. The distributing-valve release pipe leads from the application- cylinder exhaust of the distributing valve to the independent brake valve. The release pipe extends from the automatic brake valve to the independent brake valve and connects the automatic brake valve with the application-cylinder exhaust port of the 250 NO. 6 ET LOCOMOTIVE BRAKE distributing-valve through the independent brake valve and the distributing- valve release pipe when the independent brake valve is in running position. The automatic brake valve is for the purpose of operating the locomotive and train brakes. The independent brake valve is for the purpose of operating the locomotive brakes only. The distributing valve controls the flow of air to and from the locomotive brake cylinders. It is the most important feature of the ET equipment and takes the place of the engine and tender triple valves, their auxiliary reservoirs, and the high- speed reducing valves used with the former type of locomo- tive brake. DESCRIPTION AND OPERATION DESCRIPTION OF VALVE The No. 6 distributing valve with its double-chamber reservoir is the most essential part of the ET equipment. This valve operates the locomotive brakes only. It takes FIG. 1 the place and performs all the functions of the triple valves, auxiliary reservoirs, double check-valves, and high-speed reducing valves used with the former types of locomotive NO. 6 E T LOCOMOTIVE BRAKE 251 brake. Fig. 1 shows the dividing line between the distribu- ting valve and its double-chamber reservoir. The distributing valve (the piece to the left) is directly connected to the double- chamber reservoir, and all the pipe connections, of which there are five, are made to the reservoir so that the distributing valve can be separated from its double-chamber reservoir without disturbing any of the pipe connections. Fig. 2 is a side view of the double-chamber reservoir sec- tioned in such a manner as to show the partition between the pressure chamber and the application chamber, as well as the relative sizes of these chambers. This view also shows the FIG. 2 ports MR, BP, and o, and' the core and drain plugs. The pressure chamber represents an auxiliary reservoir, and the application chamber, combined with the application cylinder of the distributing valve, represents a brake cylinder. These chambers have the relative proportions to each other of an auxiliary reservoir and its proper brake cylinder with 8 in. of piston travel; thus, when the pressure chamber is charged with air at 70 Ib. per sq. in., the same as that in the brake pipe and auxiliaries on the train, the volume of air therein will equalize in both chambers at 50 Ib., and in that propor- tion at every other auxiliary-reservoir pressure. The volume 252 NO. 6 ET LOCOMOTIVE BRAKE of the application cylinder of the distributing valve is included in the volume of the application chamber at all times except when the equalizing slide valve is in emergency position, at which time the equalizing valve closes communication between FIG. 3 the application cylinder and the application chamber. The volume of the equalizing-valve chamber in the distributing valve is included in the volume of the pressure chamber in all positions of the distributing valve. NO. 6 ET LOCOMOTIVE BRAKE 253 In Fig. 3 is shown a view of the distributing valve with the valve body sectioned vertically; all the movable parts of the valve are shown in place. Fig. 4 shows two views of the equalizing valve 81; Fig. 5, a view of the valve seat; and Fig. 6, a view of the graduating valve. As shown in Fig. 4, port z extends through the equalizing valve, and k, n, and q are cavities in the face of the valve. Port r extends through the valve, and port x leads from port r into the cavity q. Port 5 extends through the valve into a groove in the valve face, which is in two widths. In the valve seat, Fig. 5, port I leads to the safety valve; the ports h combine and connect with the appli- cation cylinder and with the application-cylinder pipe connec- tion 2\ port i leads to the distributing-valve release-pipe con- nection 4 5 and port w leads direct to the application chamber. In Fig. 7 are shown the exhaust - valve seat, with the ex- haust ports d and e that lead to the brake - cylinder ex- *o o «o O«> Oft Oft FIG. 5 FIG. 6 haust port of the distributing valve; the exhaust valve 16 and spring 1 7, the side of the valve being broken away to show the port /that extends through the valve ; the face of the application valve 5, showing its port a and the opening into which the pin 18 254 NO. 6 E T LOCOMOTIVE BRAKE fits ; and a view of the application- valve pin 1 8. This pin is made of steel and fits snugly in the opening 18 in the application -pis- ton stem. It extends upwards into the large round opening in the face of the application valve 5, and its function is to trans- mit the motion of the application piston 10 to the application FIG. 7 valve 5. It is grooved to receive the pin ab in the application piston and a similar pin in the opening in the application valve 5, so that the application valve cannot be put in wrong end to. Also, a view of the application piston 10 is shown. This piston controls the movement of the application valve 5 and the exhaust valve 16. It is moved back and forth by creating NO. 6 E T LOCOMOTIVE BRAKE 255 a difference of pressure on its two faces. In this view the stem is broken away so as to show the rivets a that secure the exhaust-valve yoke- / to the stem and the pin ab that fits in the groove in the -application- valve pin 18. The guide, or solid piston, ^7 around the stern just back of piston 10 fills the cylinder between the application-piston cylinder and the exhaust-valve bushing, so that it is nearly air-tight. This acts as a dashpot to make piston 10 move back and forth gradually and thus steadies the movement of the valves 5 and 16. The other figures show the application graduating stem 19 and spring 20, and the application graduating-stem nut 21. DUTY OF PARTS The duty of the equalizing piston 26 is to control the move- ment of the equalizing valve SI and the graduating valve 28, as well as to open and close the feed-groove r. It is caused to move by creating a difference of pressure on its two faces, the greater pressure moving it toward the lesser pressure. The equalizing valve 31 opens and closes communication between the pressure chamber, the application cylinder, and the application chamber, and between the application cylinder, the application chamber, and the distributing- valve exhaust. The equalizing valve is made shorter than the distance between the shoulders on the equalizing-piston stem, so that, when it is in service position, the piston can move the graduating valve far enough to open and close port z without moving the equali- zing valve. The graduating valve 28 opens and closes port z in the equalizing valve 31, and thus graduates the flow of air from the pressure chamber into the application cylinder when a graduated-service application is made with the automatic brake valve. The graduating valve also opens communica- tion between the application cylinder and the safety valve through ports r and s in the equalizing valve when in service position, and closes this communication when in service-lap position. The application piston 10 controls the movement of the application valve 5 and the exhaust valve 16. It is caused to move by increasing or decreasing the pressure in the application 256 NO. 6 E T LOCOMOTIVE BRAKE cylinder g above or below that in the exhaust-valve cham- ber. The application valve 5 controls or graduates' the flow of main-reservoir air from chamber a to the exhaust-valve chamber and the locomotive brake cylinders when the brakes are being applied by either the automatic or independent brake valves. The exhaust valve 16 opens and closes the brake-cylinder exhaust ports e and d. It is made shorter than the distance between the shoulders on the application-piston stem, so that when the exhaust valve is in lap position, piston 10 can move valve 5 far enough to open and close port b without disturbing the exhaust valve. The application-piston guide 47 is made nearly an air-tight fit in its bushing, so that in addition to acting as a guide for piston 10, it acts as a dash pot that assists in steadying the movement of the application piston and its slide valves 5 and 16. The application graduating stem 9 and spring 20 act as a cushion for piston 10 when it is moved to application position. They also assist the pressure in the exhaust-valve chamber in moving the application piston 10 back to lap position when the pressure in this chamber and that in the application cylinder are nearly equalized. The graduating stem 19 and its spring 20 are held in the stem of piston 10 by the nut 21. The stem 19 touches the cap nut 22 just as the piston 10 starts from lap to application position; thus, as piston 10 moves to application position, the spring 20 is compressed, and when the pressure in the exhaust-valve chamber becomes a trifle greater than that in the application cylinder, spring 20 will assist in moving piston 10 back to lap position. The equalizing-piston graduating sleeve 44 and spring 46 perform the same functions as the graduating stem and spring in a triple valve. They assist in preventing the equalizing piston from moving past service position during a service appli- cation on a short train, and also aid in starting the equalizing piston from emergency position. The application piston 10 is provided with a packing leather 13 and a packing-leather expander 12, as well as with a brass packing ring 15. These prevent air from leaking from the application cylinder g into the exhaust-valve chamber during an application of the brakes. NO. 6 E T LOCOMOTIVE BRAKE 257 The function of the application- valve pin 18 is to move the application valve 5 when piston 10 moves. The pin fits snugly in the stem of piston 10 and in valve 5; thus, piston 10 cannot move without moving valve 5. Whenever it becomes necessary to remove piston 10 from its cylinder, the applica- tion valve 5 and pin 18 must first be taken out. The upper, or application, piston of the distributing valve controls the movement of the supply and exhaust valves that control the brake-cylinder air supply during an application of the locomotive brakes and exhaust brake-cylinder air to the atmosphere during a release of the brakes. The lower, or equalizing, piston controls the movement of the equalizing and graduating valves. The equalizing piston, equalizing valve, and graduating valve operate the same as the triple piston, slide valve, and graduating valve of a triple valve. They con- trol the flow of air from the pressure chamber into the applica- tion cylinder and the application chamber during an automatic application of the brakes, and from the application cylinder and the application chamber to the distributing-valve exhaust when the brake is to be released by the automatic brake valve. The equalizing piston is operated by variations in brake-pipe pressure, and the application piston is operated by changes of pressure in the application cylinder or in the exhaust-valve chamber. With the ordinary automatic brake, the pressure in the brake cylinder depends on the amount of air the triple valve passes from the auxiliary reservoir into the brake cylinder; but with the ET equipment, the supply of air for the locomotive brake cylinders comes from the main reser- voir, and the pressure in the brake cylinders is determined by the pressure in the application cylinder of the distributing valve. With an automatic application, the pressure in the application cylinder depends on how much air the equalizing piston and its slide valves pass from the pressure chamber into the application cylinder. In another method of varying the pressure in the appli- cation cylinder to apply and release the locomotive brakes, no movement of the equalizing piston and its valves is required. This operation is performed by means of the independent brake valve. This brake valve can be operated to pass air 18 -*- 258 A70. 6 E T LOCOMOTIVE BRAKE from the reducing-valve pipe direct into the application cylinder or to discharge air from the application cylinder to the atmos- phere. This operates the application piston independently of the variation in brake-pipe pressure and applies or releases the locomotive brakes. Inasmuch as the supply of air for the brake cylinders is taken from the main reservoir direct and the operation of the application piston depends on the pressure in the application cylinder, as long as the pressure in the appli- cation cylinder is maintained, the same pressure will be main- tained in the brake cylinders, regardless of brake-cylinder leakage or variations in brake-piston travel. AUTOMATIC OPERATION OF DISTRIBUTING VALVE A conventional view of the distributing valve and its double- chamber reservoir is shown in the accompanying illustration. As the parts, ports, and cavities in the distributing valve are located so that they cannot be shown in a true sectional view, this conventional view has been prepared to help in the study of the operation of the valve. It shows the pressure and application chambers of the double-chamber reservoir as a part of the distributing valve and of a different shape from the original, being smaller in proportion to the size of the valve, but with the same relative proportion to each other. However, it must be borne in mind that conventional views are given in order to simplify the tracing of the air through the various ports, as well as to help explain the operation of the valve, rather than to show its actual construction and the proper location of the various ports. Automatic Charging Position. — When the distributing valve is charging, air from the main reservoir enters at MR, and passes into the application-valve chamber a. This supply of main- reservoir air is always present around the application valve 5, unless the main-reservoir cut-out cock or the distributing- valve cut-out cock is closed. When air is first admitted to the brake pipe, it enters the distributing valve at the brake-pipe connection and passes into chamber p. If the equalizing piston is not already in release position, the air entering chamber p will force it to release NO. 6 ET LOCOMOTIVE BRAKE 259 position; then all parts will assume the positions shown. The feed-groove v is opened by the piston 26, and air from chamber p will pass through it into the equalizing- valve chamber, thence through port o to the pressure chamber, until full brake-pipe pressure is obtained in this chamber. The feed-groove v is made of such a size that it will charge the pressure chamber at the same rate as the feed-groove in a triple valve will charge its auxiliary reservoir. 260 NO. 6 ET LOCOMOTIVE BRAKE Automatic Service Position. — When making an automatic service application of the brakes, brake-pipe pressure is reduced. This reduces the pressure in chamber p of the •distributing valve, and as the feed-groove is very small, the pressure in chamber p can reduce faster than the air can pass back through the feed-groove v. The greater pressure in the equalizing- valve chamber will then move the equalizing pis- ton 26 to the right. This movement cuts off communication between the equalizing-valve chamber and chamber p, by closing the feed-groove v. The graduating valve 28, which fits snugly between the shoulders on the piston stem, is also moved on the back of the equalizing valve so as to uncover the upper end of port z in the equalizing valve, and cavity t in the graduating valve 28 connects the ports r and 5 in the top of the equalizing valve. By this time, the shoulder on the end of the piston stem has engaged the equalizing valve, and a further movement of piston 26 carries the equalizing valve with it and all these parts will assume service position. When the valves are in this position, cavity k in the face of the equalizing valve is moved from over ports h and w, so that these ports are no longer connected with the exhaust port i. Cavity n in the face of the equalizing valve connects ports h and w in the valve seat, thus opening communication between the application cyl- inder and the application chamber; also, port r is moved over port h, and port 5 over port I. As ports r and 5 are con- nected through cavity t in the graduating valve 28, this opens communication between the application cylinder, the applica- tion chamber, and the safety valve. Port z in the equalizing valve registers with port h in the valve seat. This allows air from the equalizing- valve chamber and the pressure chamber to flow through ports z and h into passage h, thence to the application cylinder, and also through port h, cavity n, and port w into the application chamber. The equalizing piston stands against the graduating sleeve, but does not compress the graduating spring, because of its resistance and the fact that the slightly greater pressure in the equalizing- valve cham- ber is gradually reduced by the air passing through port z. If the pressure in the equalizing- valve chamber should be greatly in excess of the pressure in chamber p, the graduating spring NO. 6 ET LOCOMOTIVE BRAKE 261 would be compressed and the parts would assume emergency position. Air passing from the pressure chamber into the application cylinder builds up a pressure on the left side of the application piston 10, which forces this piston to the right. This movement of piston 10 also moves the application valve 5 and exhaust valve 16 over to the right. The graduating stem 19 strikes the cap nut, and the graduating spring 20 is compressed. When the exhaust valve 16 moves to the right, it first closes the exhaust ports e and d, and thus cuts off the brake cylinders from the exhaust port Ex and the atmosphere. Application valve 5 then connects chamber a with port b, and thus allows main-reser- voir air to flow from chamber a through port b into the exhaust- valve chamber, thence through port c to the brake cylinders. If the reduction in the brake-pipe pressure is not great enough to equalize the pressures in the application cylinder, the applica- tion chamber, and the pressure chamber, air from the equalizing- valve chamber will continue to flow through ports z and h until the pressure on the pressure-chamber side of the equalizing piston 26 is a trifle less than that remaining in chamber p and the brake pipe. The greater pressure in chamber p will then move the equalizing piston 26 and graduating valve 28 to the left, until the graduating valve closes the upper end of port z, stopping the flow of air from the pressure chamber to the application chamber and the application cylinder, thus pre- venting any further increase in application-cylinder pressure. The graduating valve has also closed the top end of port s and cut off communication between the application cylinder and the safety valve, so that if the safety valve leaks, the leak cannot reduce the pressure in the application cylinder. Air from chamber a will continue to flow to the exhaust-valve chamber and out through port c to the brake cylinders until the pressure in the exhaust-valve chamber slightly exceeds that in the application cylinder, when the greater pressure in the exhaust-valve chamber, assisted by the graduating spring 20 and stem 19, will move piston 10 to the left far enough to close port b and stop the flow of air from chamber a to the exhaust- valve chamber. This position, is called automatic service lap position. 262 NO. 6 ET LOCOMOTIVE BRAKE Automatic Release Position. — To release the locomotive brakes through the automatic brake valve, both the H-6 and S-6 brake valves must be in running position. When the auto- matic brake valve is placed in release position, air from the main reservoir passing into the brake pipe increases the brake- pipe pressure, which causes the triple valves on the cars to move to release position and release the train brakes. At the same time, the increase of brake-pipe pressure also increases the pressure in chamber p of the distributing valve above that in the equalizing- valve chamber, which forces the equalizing piston 26 to the left, carrying with it to release position the equalizing valve 31 and the graduating valve 28. When in this position, the equalizing piston 26 opens the feed-groove v, which allows air from chamber p to flow past piston 26 to the equalizing- valve chamber, and out through port and passage o into the pressure chamber, until the pressure equalizes on both sides of the equalizing piston 26. The graduating valve 28 has the top end of port z blanked, and communication between ports r and 5 is cut off. Cavity k in the equalizing valve con- nects ports h and w with the exhaust port i that leads to the distributing-valve release pipe, but as the automatic brake valve is in release position, its rotary valve closes the opening from the release pipe to the atmosphere and prevents the distributing valve from releasing the locomotive brakes. In order to connect the distributing-valve release pipe with the atmosphere and thus release the locomotive brakes with the automatic brake valve, the automatic brake valve must be moved to running position. This allows the air from the application cylinder and chamber to escape to the atmosphere through ports h and w, cavity k, and port i into the distributing- valve release pipe, thence through the S-6 brake valve into the release pipe and out to the atmosphere through the automatic brake valve. As the air in the application cylinder reduces, the greater pressure in the exhaust-valve chamber moves piston 10 to the left, carrying with it the application valve 5 and the exhaust valve 16. This movement of the application valve does not affect port b, but the exhaust valve 16 connects the brake cylinders with the atmosphere and brake-cylinder pres- sure exhausts through ports d and e, thus releasing the brake. NO. 6 ET LOCOMOTIVE BRAKE 263 To graduate the release of the locomotive brakes, through the automatic brake valve, the handle should be left in running position just long enough to reduce the application-cylinder pressure the desired amount, after which it should be moved to lap, holding, or release position. As the pressure in the applica- tion cylinder g reduces, the greater pressure in the exhaust- valve chamber will move piston 10 and valves 5 and 16 to the left and the exhaust valve 16 will allow brake-cylinder air to escape through ports d and e until the pressure in the exhaust- valve chamber is slightly less than that remaining in the appli- cation cylinder, when the greater pressure in the application cylinder will move piston 10 and valve 16 to the right and stop the flow of brake-cylinder air to the atmosphere. The equal- izing valve being in release position, the application chamber and the application cylinder are connected to the safety valve through ports h, s, and I. Automatic Emergency Position. — When a sudden and heavy reduction in brake-pipe pressure is made, it causes the distrib- uting valve to operate quick-action, and the movable parts will assume automatic emergency position. The pressure in chamber p of the distributing valve being suddenly reduced, the greater pressure in the equalizing- valve chamber quickly moves the equalizing piston 26 to the right with sufficient force to compress the graduating spring 46, thus allowing the equal- izing piston 26 to move its full stroke an d rest against the gasket 25. This movement carries the equalizing valve 31 with it to emergency position, port h in the equalizing-valve seat is uncovered, and air from the equalizing valve chamber passes through port h to passage h and the application cylinder. Cavity « in the equalizing valve is also moved away from port h, thus closing communication between the application cylin- der and the application chamber. Under these conditions, the pressure chamber has only the small volume of the application cylinder to fill, consequently the pressure chamber and the application cylinder will equalize quicker and at a much higher pressure than during a service application. The operation of the application piston 10, the application valve 5, and the exhaust valve 16 in emergency applications is the same as in service applications, except that they are moved to application 264 NO. 6 ET LOCOMOTIVE BRAKE position much quicker, and port b is opened wider than in ser- vice applications. When the pressure in the exhaust-valve chamber becomes equal to that in the application cylinder, the application piston will be moved to automatic emergency lap position. When the pressure chamber is charged to 70 lb., an emergency applica- tion will equalize the pressures in the pressure chamber and the application cylinder at about 65 lb., but when the automatic brake valve is in emergency position, air from the main reservoir will pass through a small port in the rotary valve and a port in its seat, into the application-cylinder pipe, thence to the appli- cation cylinder of the distributing valve, which raises the pres- sure therein above 65 lb. The amount of pressure that will be allowed to accumulate in the application cylinder will be deter- mined by the adjustment of the safety valve, to which it is connected. Main-reservoir air can pass through port n in the rotary valve of the automatic brake valve in about the same volume that it can pass to the safety valve through port x in the equalizing valve, so that a pressure of 68 lb. will be held in the application cylinder, as this is the pressure for which the safety valve is set. As the pressure in the brake cylinders is determined by the pressure in the application cylinder, also, 68 lb. will be obtained in them. This high brake-cylinder pres- sure will cause a shorter stop to be made than with a service application. In high-speed brake service, the operation of the distributing valve is exactly the same as in ordinary service, but with the high-speed brake service, the brake pipe being charged to a pressure of 110 lb. and the main-reservoir pressure being about 130 lb., an emergency application will raise the pressure in the application cylinder, and consequently in the brake cylinders to about 93 lb. In this case, however, the small port x in the equalizing valve will allow air to pass from the application cylinder to the safety valve a little faster than it can enter the application cylinder through the small port in the automatic brake valve, so that the safety valve will reduce the pressure in the application cylinder from 93 to 75 lb. in about the same time as the high-speed reducing valve will reduce the brake-cylinder pressure to 60 lb. NO. 6 ET LOCOMOTIVE BRAKE 265 When the application -cylinder pressure is reduced to 75 lb., a main-reservoir pressure of 130 lb. will force air into the applica- tion cylinder through the small port n in the rotary valve of the automatic brake valve as fast as it can escape from the applica- tion cylinder through the small port x in the equalizing valve, so that a pressure of 75 lb. will be maintained in the application cylinder and consequently in the locomotive-brake cylinders. When the equalizing piston 26 and valves 28 and 31 are in emergency position, and the application piston and valves 5 and 16 have moved to service position and then lapped the ports in the application-valve and exhaust-valve seats, the distributing valve is said to be in automatic emergency lap position. If the emergency application is caused by a burst hose, by the opening of a conductor's valve, or by the train parting, the automatic brake valve must be lapped to save main-reservoir air. Under these conditions the distributing valve will operate in the same manner as previously explained, but, since the auto- matic brake valve is not in emergency position, no main-reser- voir air will pass to the distributing valve through the applica- tion-cylinder pipe, therefore, the brake-cylinder pressure will not be as high as if the application were made by the automatic brake valve. In high-speed service carrying 110 lb. of brake- pipe pressure, the brake-cylinder pressure will be reduced to 68 lb., this being governed by the safety valve. If only 70 lb. of brake-pipe pressure is carried, the resulting brake-cylinder pressure will be but 50 lb. After a full-service application, if a greater brake-cylinder pressure is necessary, main-reservoir pressure may be conveyed to the application cylinder of the distributing valve by placing the automatic brake valve in emergency position. Automatic Release After an Emergency Application. — The automatic brake valve is operated in the same manner to release the brakes after an emergency application as after a service application, but the effect on the distributing valve is somewhat different. When the H-6 brake valve is placed in release position, the brake-pipe pressure in chamber p of the distributing valve is increased above that in the equalizing- valve chamber and the equalizing piston and the valves 28 and 266 NO. 6 E T LOCOMOTIVE BRAKE 81 are moved to release position. Cavity k in the equalizing valve 81 connects port h with ports w and i, which allows the pressure in the application cylinder to expand into the applica- tion chamber, and the pressure will quickly equalize at 15 Ib. This will cause the application piston 10 to reduce automatically the brake-cylinder pressure to the same amount, which will be retained as long as the automatic brake valve is in release position. To release the brake fully, the automatic brake valve must be placed in running position in order to connect the dis- tributing-valve release pipe with the atmosphere. INDEPENDENT OPERATION OF DISTRIBUTING VALVE Independent Application Position. — When the distributing valve is operated by means of the independent brake valve, piston 10 and valves 5 and 16 are the only parts that move. The equalizing piston 26 and its valves 28 and 31 are not influenced by the operation of the independent brake valve. When the independent brake valve is moved to either slow- application or quick-application position, air from the main reservoir, reduced to a pressure of 45 Ib. by the C-6 reducing valve, passes through the independent brake valve and applica- tion-cylinder pipe directly to the application cylinder of the distributing valve. This movement of the rotary valve of the independent brake valve also closes communication between the distributing-valve release pipe and the atmosphere, so that air from the application cylinder and chamber cannot escape through the distributing-valve exhaust port i. The pressure in the application cylinder forces the application piston 10 to the right to independent application position. The application valve 5 and the exhaust valve 16 will move with it, valve 16 will close the exhaust ports d and e, and valve 5 will then open port a to port b. Main-reservoir pressure from chamber a will pass through port b into the exhaust -valve chamber and out to the brake cylinders through port c until the pressure in the exhaust-valve chamber is a trifle more than that in the applica- tion cylinder, when the greater pressure in the exhaust -valve chamber assisted by the graduating spring SO will force piston 10 to the left until valve 5 closes port b. This position of the distributing valve is called independent lap position. NO. 6 E T LOCOMOTIVE BRAKE 267 A graduated independent application may be made by admitting a certain amount of pressure to chamber g in the distributing valve and then placing the independent brake valve in lap position, continuing this as often as desired until a full application is obtained. Each time the brake valve is lapped, the distributing valve will assume independent lap position. When a full independent application is obtained, there will be a pressure of 45 Ib. in the application cylinder and the locomo- tive brake cylinders, this being the pressure for which the C-6 reducing valve is set. When the equalizing valve SI and piston 26 are in release position, if the reducing valve is out of order or improperly adjusted, the safety valve will prevent the applica- tion-cylinder pressure rising above 68 Ib., the pressure for which it is set, provided the independent brake valve is in slow-appli- cation position; but if the independent brake valve is in quick- application position, the larger ports in the brake valve will supply air to the application cylinder faster than it can escape through the safety valve; consequently, the brake-cylinder pres- sure will be increased above the amount for which the safety valve is set. Independent Release Position. — If the equalizing piston 26 is in release position when the ^locomotive brakes are being released by means of the independent brake valve, the movable parts of the distributing valve will assume independent release position, which is exactly the same as when the brakes are released by the automatic brake valve. When the independent brake valve is moved to release position, it allows air to flow from the application chamber and cylinder to the atmosphere. The greater pressure in the exhaust-valve chamber then moves piston 10 to the left, carrying valves 5 and 16 with it. Valve 16 opens port d, and port /, through valve 16, registers with port e. This allows air from the exhaust-valve chamber and brake cylinders to escape to the atmosphere through the exhaust port Ex. When the equalizing piston of the distributing valve is in release position and the automatic brake valve is in running position, the locomotive brakes can be released by placing the independent brake valve in running position. Under these circumstances, application-cylinder and application-chamber air -268 NO. 6 ET LOCOMOTIVE BRAKE "will flow through ports h and w, cavity k, and port * into the distributing- valve release pipe, and then through the independ- ent brake valve into the release pipe and out to the atmosphere through the automatic brake valve. The locomotive brakes may be released by the independent brake valve after they have been applied in service or emergency by the automatic brake valve by moving the independent brake valve to release position. This allows the air in the application cylinder to escape through the application-cylinder pipe and the independent brake valve. However, if the auto- matic brake valve is in emergency position when releasing the locomotive brakes through the independent brake valve, it will be necessary to hold the independent brake valve in release position in order to prevent the brakes from reapplying, because, with the automatic brake valve in emergency position, main- reservoir air will be supplied to the application cylinder through the maintaining port n in the rotary valve of the automatic brake valve. To graduate the release of the locomotive brakes through the independent brake valve, the handle of this valve should be moved to full-release position (or to running position, if the automatic brake valve also is in running position) long enough to reduce the pressure in the application cylinder the desired amount, and then moved to lap position. As the pressure in the application cylinder and chamber is reduced, the greater pressure in the" exhaust-valve chamber will move the application piston 10 and exhaust valve 16 to the left and reduce the brake-cylinder pressure a trifle below the application- cylinder pressure, when the application piston 10 and the exhaust valve 16 will move to the right and close ports d and e and retain the remaining pressure in the locomotive-brake cylinders. PRESSURE-MAINTAINING FEATURE OF DISTRIBUTING VALVE The pressure-maintaining feature of the distributing valve is very valuable in connection with the ET equipment, for as long as there is air pressure in the application cylinder of the distributing valve, the same amount of pressure will be NO. 6 ET LOCOMOTIVE BRAKE 269 maintained in the locomotive-brake cylinders, regardless of the length of piston travel or the ordinary brake-cylinder leakage. This is due to the fact that the supply of air for the locomotive- brake cylinders is taken from the main reservoir, and when the application piston 10 is in service lap position, due to either an automatic or an independent application, a leak that reduces brake-cylinder pressure will also reduce the pressure in the exhaust-valve chamber of the distributing valve, which will cause the application piston 10 and valve 5 to be moved to the right by the greater pressure in the application cylinder. As the application valve 5 is moved to the right, it will open com- munication between chamber a and the brake cylinders through port b in the application-valve seat and allow main-reservoir air to pass to the locomotive-brake cylinders until the pressure in the exhaust-valve chamber, and consequently in the brake cylinders, is equal to that in the application cylinder, when the application piston 10 will move valve 5 to the left far enough to close port b. This action of the distributing valve will be repeated each time the leaks reduce brake-cylinder pressure below that in the application cylinder. It is possible for the leaks from the brake cylinder to cause the application piston 10 and valve 5 to be moved to the right just far enough to supply main-reservoir air to the brake cylinders through port b as fast as it can escape through the leaks, in which case piston 10 would not move valve 5 back to lap position until the brakes were released through the brake valves. If there are any leaks from the application cylinder of the distributing valve, this maintaining feature will be destroyed, because, with the brakes applied and the brake Valve in lap position, the leak will continue to reduce the pressure in the application cylinder. This will allow the greater pressure in the exhaust-valve chamber to move the application piston 10 and its valves to release position and exhaust brake-cylinder air. In such a case, however, it will be possible to hold on the brakes by placing the independent brake valve in slow-applica- tion position. Automatic Emergency Position With Quick-Action Cylinder Cap. — The valves in the quick-action cylinder cap do not operate during a service application, but when an automatic 2.70 NO. 6 E T LOCOMOTIVE BRAKE emergency application is made, they operate to vent some of the brake-pipe air to the locomotive-brake cylinders. The brake- pipe air vented to the locomotive brake cylinders by the quick- action cylinder cap does not give any higher brake-cylinder fr BraAe P//?e pressure, but causes a local reduction in brake-pipe pressure that insures the quick-action operation of the train brakes. The positions of the various parts, when the valve is in auto- matic emergency position, are as here shown. NO. 6 E T LOCOMOTIVE BRAKE 271 When a heavy and sudden brake-pipe reduction is made, piston 26 moves out quickly the full length of its cylinder. . The knob on the piston strikes the valve stem 50 and moves it over against the tension of the spring 55. As the emergency valve 48 fits snugly between the shoulders on the valve stem 50, it also moves to the right and uncovers port j in the valve seat. This allows brake-pipe air from chamber P to pass through port j to chamber X, which forces the check-valve 53 down against the resistance of spring 54- This allows brake-pipe air to flow to passage m in a large volume; it then passes through passage M to the chamber back of the application piston 10, and through port c into the brake cylinders. This makes a local reduction in brake-pipe pressure, which insures that the next distributing valve, or quick-action triple valve, will go into quick action. When the brake-cylinder and brake-pipe pressures have nearly equalized, spring 54 forces valve 53 back to its seat, so that no air can pass from the locomotive-brake cylinders into the brake pipe. When the brake-pipe pressure is increased sufficiently to force piston 26 back to release position, the grad- uating spring 55 forces the stem 50 and emergency valve 48 back to their normal positions. During this movement, valve 48 closes port j. CARE OF DISTRIBUTING VALVE In order that the distributing valve may work properly, the valves and pistons must be kept well lubricated and free from dirt. The distributing valve and its reservoir should be regularly drained and the pipe connections should be kept tight. If the distributing valve is to be repaired or cleaned and tested, it should be removed from the double-chamber reservoir; this is done by removing the nuts from the reservoir studs. As all the pipe connections are made to the double-chamber reservoir, removing the valve in this manner will not interfere with the pipe joints. If the gasket between the distributing valve and the reservoir becomes torn or injured while removing the valve, a new one must be supplied, as a very slight leak across this gasket, from one port to another, will interfere seriously with the operation of the valve. When the pipes are 272 PC PASSENGER-BRAKE EQUIPMENT first installed or when new ones are applied, they should be blown out with steam or compressed air before the valves are attached, to clear them of foreign matter. If the distributing valve becomes dry from lack of lubrication, or if it becomes corroded or very dirty, a greater difference of pressure will be required to overcome the excessive friction and to operate the movable parts. If the pipes and passages become corroded or very dirty, the engine brakes will not apply and release as promptly as when they are clean. If the engine brakes fail to apply when the brake system is fully charged and a 5-lb. service reduction is made, the trouble is most likely due to excessive friction in the working parts of the distributing valve, which should then be removed, cleaned, and lubricated. Sometimes the equalizing- piston packing ring sticks in its groove and prevents the equal- izing piston from being moved by variations in brake-pipe pressure. PC PASSENGER-BRAKE EQUIPMENT DEVELOPMENT OF EQUIPMENT The schedule PC equipment was designed especially for pas- senger-train service to control passenger cars weighing 130,000 Ib. or more. Passenger-brake cylinders had been increased from time to time as the increased weight of the cars demanded, until the 18-in. cylinder finally came into use. This brake cylinder pro- vided for cars of maximum weight up to 127,000 Ib. When cars of 150,000 Ib. or more were under construction, it became necessary either to use a 20-in. brake cylinder or to redesign the brake rigging so as to provide for a suitable brake for this service. A very serious objection to the use of a 20-in. cylin- der was the time necessary to apply the brake to its full capacity. At 80 mi. per hr., the speed is 116 ft. per sec.; and at 60 mi. per hr. it is 88 ft. per sec. A couple of seconds lost, therefore, means a couple of hundred feet passed over before the brake begins to be effective, thus greatly lengthening the P C PASSENGER-BRAKE EQUIPMENT 273 distance in which a stop could be made. Another objection to the use of a 20-in. cylinder is that on account of leakage the stop will be lengthened still more, it being impossible to obtain packing leathers large enough and of sufficient uni- formity to prevent excessive leakage. Then, too, the piston rods, drivers, etc. will be so large and heavy that they will take up too great a percentage of the power developed. The increased weight of the cars naturally brought increased length of trains, and the larger cylinders and greater train length mean that a much greater volume of air must be handled through the brake pipe. This would make the action of the brake on a train of cars with 20-in. cylinders so slow that it would be impossible to control the heavy cars with nearly the same effectiveness as is obtained with the brake used on lighter cars. Train Energy to Be Controlled. — The accompanying table has been compiled in order to give a clear idea of the tremendous amount of energy that the brake of a modern heavy passenger ENERGY OF TRAIN AT DIFFERENT SPEEDS Speed Miles per Hour Velocity Head Feet Energy per 1,000 Lb. of Weight Foot-Pounds Total Energy of Train Weighing 1,650,000 Lb. Foot-Pounds 10 20 30 40 50 60 70 3.55 14.20 31.95 56.80 88.75 127.80 173.95 3,550 14,200 31,950 56,800 88,750 127,800 173,950 5,857,500 23,430,000 52,717,500 93,720,000 146,437, 500 210,870,000 287,017,500 train has to destroy in stopping the train. The velocity head multiplied by the weight of the train, in pounds, will give the energy, in foot-pounds, for that speed. The third column of the table gives the energy of each 1,000 Ib. of train at the differ- ent speeds given in the first column. The rate of change of the energy of 1,000 Ib. of train with the increase in speed is indicated 19 274 PC PASSENGER-BRAKE EQUIPMENT by the curve in the accompanying chart, which was plotted from the values given in the third column of the table. Both the table and the curve show that the energy of each 1,000 Ib. of train is four times as great at 20 mi. per hr. as at 10 mi. per hr.; nine times as great at 30 mi. as at 10 mi. ; sixteen times as great at 40 mi.; twenty-five times as great at 50 mi.; thirty-six times as great at 60 mi. ; and forty-nine times as great at 70 mi. In I 8 $30 20000 4 e 8 1O 12 14 16OOOO Energy in Foot-Pounds per 1OOO Poundf of Train other words, at 70 mi. per hr., the brake has to do forty-nine times as much work to stop the train as it would at 10 mi. per hr. Suppose that a train weighs 1,650,000 Ib. Then, according to the fourth column of the table, the brake must destroy 5,857,500 ft.-lb. of energy in stopping the train at 10 mi. per hr. ; whereas, at 70 mi. per hr., it must destroy 287,017,500 ft.-lb. of energy, an amount sufficient to raise the entire train 174 ft. PC PASSENGER-BRAKE EQUIPMENT 276 vertically in the air. The magnitude of the energy that must be destroyed in stopping the train running at a speed of 70 mi. per hr. is too great to grasp without a special effort. But to give an idea of the magnitude, it may be said that if a person were to count 150 in each minute, or 90,000 in 10 hr., he would have to count 10 hr. a day at this rate for about 3,189 da., or every day for about 8| yr., to count the number of foot-pounds of energy to be destroyed in stopping the train running at a speed of 70 mi. per hr., or 287,017,500. This energy, if con- verted into heat, would produce 268,917 units of heat, an amount sufficient to raise 2,598 Ib. (311 gal.) of water from 70° F. to the boiling point, or to raise the temperature of 16 T. of iron 100° F. To destroy, within a distance of less than 1,200 ft. and with- out endangering the safety of the passengers and equipment, the enormous energy stored up in modern trains of heavy cars moving at high speeds, requires a brake of high maximum emergency stopping power; to perform the ordinary service functions and to provide the automatic safety and protective features necessary for a service of this kind, requires a very flexible and efficient service stopping power. It was to provide a brake that would fulfil these requirements that the PC pas- senger equipment was designed and introduced into service. FUNCTIONS AND FEATURES OF BRAKE In the PC passenger equipment, the triple valve is replaced by a valve known as a control valve, which performs several new functions in the manipulation of the brakes. The features of the brake, as well as its functions, are as follows: Graduated release and quick recharge, which are obtained in a manner similar to that of the type L triple valve. The emer- gency reservoir furnishes the air necessary, for obtaining the graduated release and for assisting in recharging. Certainty and uniformity of service action, which are obtained by so designing the parts of the control valve that the feed- grooves are closed on the slightest brake-pipe reduction. The design is such that the differential necessary to move the parts 276 PC PASSENGER-BRAKE EQUIPMENT to service position is then built up as the brake-pipe reduction progresses. Quick rise in brake-cylinder pressure, which is provided for by prompt movement of the parts of the control valve and by direct, unrestricted passages from the reservoirs to the brake cylinders during applications. Uniformity and maintenance of brake-cylinder pressure dur- ing service stops, which are provided for as in the distributing valve of the ET equipment. Predetermined limiting of the service braking power, which is freed by the equalization of the pressures in the application chamber and the pressure chamber of the control valve. This feature does away with the necessity of the safety-valve feature of the ET and other equipments. Automatic emergency application on depletion of brake-pipe pressure, which is insured automatically by the movement of the parts of the control valve to emergency position just as soon as the brake-pipe reduction becomes less than the pres- sure at which the pressure chamber and the reduction-limiting chamber equalize. Full emergency braking power at any time; the operation of the emergency and quick-action parts of the control valve is such as to give the full emergency braking power whenever the parts move to emergency position. The parts can be moved to emergency position at any time by making an emer- gency application either with the brake valve or the conductor's valve, or by other means; hence, full emergency braking power can be obtained at any time, even after a full service applica- tion has been made. Separate service and emergency features, thus giving the neces- sary flexibility for service applications without interfering in the slightest with the emergency features of the equipment. A law total leverage ratio and greater brake efficiency, due to the use of two brake cylinders on each car; also, this arrange- ment gives a higher service equalization pressure. Less tendency to undesired light applications of the brake, because the apparatus is less sensitive than others to the light fluctuations of brake-pipe pressure; this insures against brakes creeping on and dragging. PC PASSENGER-BRAKE EQUIPMENT 277 Maximum possible rate of rise of brake-pipe pressure, thus insuring greater certainty of all brakes releasing when a release is made. This is due to the fact that the brake pipe alone has to be charged by the air that flows through the brake valve; the pressure in the pressure chamber of the control valve is restored by air from the emergency reservoir, which raises the pressure at the same rate as brake-pipe pressure up to the point of equalization (about 5 Ib. less than normal brake- pipe pressure) of the emergency reservoir and the pressure chamber. After equalization, the reservoir and the pressure chamber are charged up to normal pressure from the brake pipe; this insures a rapid and certain release of all brakes and a rapid recharge and prompt response to succeeding reductions that may be made. Greatly increased sensitiveness to release, due to the fact that the rate of rise of brake-pipe pressure is much greater, because only enough air to charge the brake pipe must flow from the main reservoir through the brake valve to release the brake. Means of eliminating the graduated release feature during the transition period; if a PC equipment is used in a train of cars not so equipped, the graduated -release feature can be quickly and easily cut out. GENERAL ARRANGEMENT OF BRAKE Piping diagrams showing two methods of arrangement of the PC equipment are shown in Figs. 1 and 2. Fig. 1 shows the arrangement when the two brake cylinders point in opposite directions, whereas Fig. 2 shows the arrangement when the cylinders point in the same direction. The arrangement shown in Fig. 1 permits of a simpler arrangement of the hand-brake rigging; on the other hand, the arrangement shown in Fig. 2 brings, on some cars, the slack adjusters into a more conve- nient position. The choice of arrangements, therefore, depends largely on the construction of the underframing of the car and on the location of the apparatus under the car. Two brake cylinders are used on each car. The service cylinder is used in both service and emergency applications; 278 P C PASSENGER-BRAKE EQUIPMENT PC PASSENGER-BRAKE EQUIPMENT 279 $1 280 PC PASSENGER-BRAKE EQUIPMENT the emergency cylinder operates during an emergency applica- tion, but does not operate during a service application. Thus, in emergency applications, the maximum service braking power is doubled not by increased brake-cylinder pressure, as in the other equipments, but by the use of the second cylinder. Each cylinder is provided with a slack adjuster, and both adjusters are connected to the slack-adjuster hole in the serv- ice-brake cylinder; thus, they will operate simultaneously and take up the slack evenly in the two brake cylinders and in accordance with the requirements of the service cylinder. Two reservoirs are used with this equipment. The service reservoir supplies air to the service-brake cylinder; the emer- gency reservoir supplies air to the emergency cylinder during emergency applications; also, in service operations, it furnishes the air used in obtaining graduated release and quick recnarge of the equipment. A third reservoir, forming part of the con- trol valve, has three chambers called the pressure chamber, the application chamber, and the reduction-limiting chamber. NO. 3-E PASSENGER CONTROL VALVE The No. 3-E passenger control valve, superseding the No. 3-D control valve, is standard for and regularly furnished with PC (two-cylinder) schedules for very heavy passenger cars; i. e., PC-2-12, PC-2-14, PC-2-16, and PC-2-18. In Fig. 1 (a) is shown the release portion of this valve and in (fe), the applica- tion portion; the equalizing portion is shown in Fig. 2 and the emergency and quick-action portion in Fig. 3. The piece number of the control valve, complete, is 37,896. The piece and reference numbers of the various parts are given in the accompanying list. PC. No.Ref. No. Name of Part 32,873 Equalizing portion, complete. 32,143 Application portion, complete. 36,435 Emergency portion, complete. 35,598 Quick-action portion, complete. 37,849 2 Equalizing body, complete, includes one each of 19 and 37. 36,420 3 Release piston, complete, includes one of 9. 37,042 4 Release-slide valve. PC PASSENGER-BR.\KE EQUIPMENT 281 282 PC PASSENGER-BRAKE EQUIPMENT u I r < H A 4 i ft i i I PC PASSENGER-BRAKE EQUIPMENT 283 PC. No. 9.326 37,040 31,530 36,421 28,928 36,381 36,410 25,418 36,384 36,406 36,387 36,023 36,401 36,398 4,887 36,823 28,928 37,870 9,326 36,374 35,987 36,383 36,411 25,418 :w.S2i 1,523 :ii;!s3o 20,493 36,405 36,391 25,418 36,826 37,127 36,044 32,227 36,043 36,415 36,560 36,558 36,559 36,399 32,144 32,145 32,027 15,013 Ref. No. Name of Part 5 Release side-valve spring. 6 Release graduating valve. 7 Release graduating-valve spring. 8 Release-piston cap nut, for equalizing portion. 9 Release-piston ring. 10 Release-cylinder cap, bushed and plugged. 11 Release-cylinder-cap gasket. 12 Square head capscrew, i in.Xli in. 13 Release-piston graduating sleeve. 14 Release -piston graduating spring. 15 Release-piston graduating nut. 16 Check- valve. 17 Check- valve cap nut. 18 Release regulating cap. 19 Stud and nut for release regulating cap. 20 Equalizing piston, complete, includes one each of 21 and 32. 21 Equalizing-piston ring, large. 22 Equalizing slide valve. 23 Equalizing slide-valve spring. 24 Equalizing graduating valve. 25 Equalizing graduating-valve spring. 26 Large equalizing-cylinder cap, bushed and plugged. 27 Large equalizing-cylinder-cap gasket. 28 Square head capscrew, ^-in.Xli-in. 29 30 31 32 33 34 36 36 Equalizing-piston stop sleeve. Equalizing-piston stop spring. Equalizing-graduating nut. Equalizing-piston ring, small. • Small equalizing-cylinder cap. Gasket for small equalizing-cylinder cap. Square head capscrew, $-in. X 1 J-in. Cap nut for small equalizing - cylinder cap. Small equalizing-piston bush. Service-reservoir charging valve, complete. includes 39 and 40. 1-in. charging- valve piston ring. 1 J-in. charging-valve piston ring. Charging-valve seat. Charging-valve washer. Internal charging-valve nut. External charging-valve nut. Gasket for release regulating cap. Body, bushed. Piston, complete, includes 76, 78, 81, 82, 83, 84, and 85. Piston-stem, complete, includes 77. Piston ring, small. 284 PC PASSENGER-DRAKE EQUIPMENT PC. No. 31,558 30,603 28,928 31,429 31,491 31,529 31,440 12,270 32,030 33,556 32,031 14,281 32,032 36,810 36,395 36,384 36,406 36,387 32,033 32,044 24,496 36,457 36,762 10,030 36,686 32,045 36,458 36,460 36,459 36,462 18,286 25,418 32,106 31,928 36,049 9,753 1,791 28,912 1,737 1.794 1,715 36,051 36,080 27,195 25,598 25,597 36,053 25,418 Ref. No. Name of Part 78 Piston head, complete, includes 79 and 80. 79 Piston seal. 80 Piston ring, large. 81 Piston follower. 82 Piston-packing leather. 83 Piston-packing-leather expander. 84 Piston nut. 85 Piston cotter, ^-in.XU-in. 86 Exhaust valve. 87 Exhaust- valve spring. 88 Application valve. 89 Application-valve spring. 90 Application -piston holt. Spring box, complete, includes 91, 92, 93, and 94. 91 Spring box. 92 Piston-spring sleeve. 93 Piston spring. 94 Graduating nut. 95 Application-valve cover. 96 Application-valve cover gasket. 97 Square head capscrew for application-valve cover, |-in.X2Hn. 107 Body, bushed and plugged, includes 119. 108 Piston, complete, includes 109. Piston ring. Slide valve. Slide-valve spring. Small cylinder cap. Large cylinder cap. Small cylinder-cap gasket. Large cylinder-cap gasket. Piston spring. Square head capscrew, l-m.XH-m. Oval fillister head capscrew. Emergency-piston bush. Body, bushed and plugged. Piston, complete, includes 132. Piston ring. ick-action valve, includes 134 and 135 uick-action valve seat. uick-action valve nut. ick-action-valve spring. ick-action-valve cap nut. ick-action-valve cover, bushed. ick-action closing valve. ick-action closing-valve spring. over cap nut. Cover gasket. 143 Square head capscrew for cover, i-in.X li-in. PC PASSENCER-BR.4KE EQUIPMENT 285 PC. No. Ref. No. Name of Part 32,156 153 Reservoir, complete, includes four of 154, seven of 155, twelve of 156, six of Piece No. 1899. U-in. cap nut. Stud with hexagon nut 3f-in. long. Stud with hexagon nut 3 3 -in. long. 33.148 154 31,550 155 32,111 156 1,899 34,037 157 34,036 158 32,008 159 32,008 160 H-in. pipe plug. Emergency-cylinder gasket. Quick-action cylinder gasket. Large reservoir gasket. Equalizing-cylinder gasket. NO. 3-D PASSENGER CONTROL VALVE Emergency and Quick-Action Portions. — The No. 3-D pas- senger control valve differs from the No. 3-E control valve in having the emergency portion reversed in position as shown in the figure. Therefore, the piece numbers here given covering 286 PC PASSENGER-BRAKE EQUIPMENT the emergency portion, must be specified when ordering repair parts for the No. 3-D control valve, otherwise all repair parts for both valves are identical. Pe. No. Ref. No. Name of Part 32,458 107 Body, bushed and plugged, includes 119. 36,572 108 Piston, complete, includes 109 and 120. 10,030 103 Piston ring. 32,703 110 Slide valve. 32,045 111 Slide-valve spring. 32.151 112 Small cylinder cap. 32.152 113 Large cylinder cap. 32,080 114 Small cylinder -cap gasket. 32,079 115 Large cylinder-cap gasket. 1,745 116 Piston spring. 25,418 117 Square head capscrew for small cylin- der cap, i in. Xls in. - 32,106 118 Oval fillister head capscrew. 31,928 119 Emergency-piston bush. 36,569 120 Spring stem. CONSTRUCTION OF CONTROL VALVE The control valve takes the place of the triple valve of the older equipments, and, in a general way, corresponds to the FIG. 1 distributing valve of the ET equipment. The external con- struction of the control valve is shown in Pig. 1, which gives a PC PASSENGER-BRAKE EQUIPMENT 287 view of the right side of the valve, showing the lines of separa- tion of the equalizing portion. It will be observed that the application, quick-action, and emergency portions extend into the reservoir B when in place, so that when the control valve is assembled only the flanges of these portions are visible. 288 PC PASSENGER-BRAKE EQUIPMENT Compartment Reservoir. — Sectional views of the control valve are shown in Figs. 2 and 3 in order to illustrate how the reservoir is divided into compartments. Fig. 2 is a section taken lengthwise through the center line of the reservoir, and Fig. 3 a section taken crosswise of the reservoir on the line X Y, Fig. 2, the part to the right of the line being removed and the reservoir turned so as to show the section of the front portion FIG. 3 of the reservoir. It will be observed that there are three chambers or compartments in the reservoir. The application chamber X extends from the partition a, Fig. 2, forwards, and also on both sides of the reduction-limiting chamber Y, like a pair of saddle bags. There is a drain plug on each side of the compartment reservoir, so that each leg of P C PASSENGER-BRAKE EQUIPMENT 289 the application chamber can be drained. At 157, Fig. 3, is shown the emergency-cylinder gasket; at 158, the quick-action- cylinder gasket; at 159, Fig. 2, the large-reservoir gasket; and at 160, the equalizing-cylinder gasket. The functions of the application chamber are similar to those of the application chamber of the ET equipment. FIG. 4 The reduction-limiting chamber Y is the space contained within the inner reservoir wall b. The application portion of the control valve extends into this space, but it is not in any way open to chamber Y. The function of the reduction-limiting chamber is to limit the service braking power to a predeter- mined amount by maintaining the equalization of the pressure 20 290 PC PASSENGER-BRAKE EQUIPMENT and application chambers of the control valve. If, after equalization has taken place, a further brake-pipe reduction occurs, air is automatically vented from the pressure chamber into the reduction-limiting chamber, up to the point of equal- ization, fast enough to maintain the pressure-chamber pressure constant at the pressure of equalization. This, of course, maintains the application-chamber pressure constant, which Ex o © FIG. 5 FIG. 6 automatically maintains the brake-cylinder pressure constant. The capacities of the application and the pressure chambers are such that, with a 24-lb. reduction from 110 Ib. of brake-pipe pressure, they will equalize at 86 Ib.; from 70 Ib. of brake-pipe pressure, they will equalize at 54 Ib. with a 16-lb. reduction. In Fig. 2, the drain plug for the reduction-limiting chamber is shown at l5J^a. PC PASSENGER-BRAKE EQUIPMENT 291 The pressure chamber Z extends backwards from the partition a, Fig. 2, and surrounds the inner-reservoir wall b, as shown; the drain plug for this reservoir is numbered 154- Equalizing Portion. — The equalizing portion of the control valve consists of two parts, the release portion, and the equal- izing portion. The release cylinder is shown in section in Fig. 4. The release slide-valve seat is shown in Fig. 5. Port p leads to chamber P of the large emergency piston; port j, to chamber 5 of the small emergency piston; port e, to the direct and d( ;:© iT fv :?; R 'Li. 5 i j • i j i 1 *.: J ^ __ i 5) R FIG. 7 graduated release cap 18; ports £*, to the emergency-piston exhaust; port q, to the direct 'and graduated release cap; port I', to the application-chamber exhaust and to the direct and graduated-release cap; port I, to the application chamber; port r, to the quick-action closing valve; port c', to the emer- gency reservoir; and port i, to chamber F of the small equalizing piston. The release slide vak'e is shown in Figs. 6 and 7. Fig. 7 (a) is a sectional view; (b), a plan of the face of the valve; (c). 292 PC PASSENGER-BRAKE EQUIPMENT a plan of the top of the valve; ( and the emergency- piston exhaust Ex. This removes the pressure on the lower end of the small piston and makes the force of the pressure in chamber P greater than the force, in chamber R, that tends to move the emergency piston, so that the piston is held in the position shown. The reduction-limiting chamber F is connected to the atmos- phere through the port m, the cavity w in the slide valve 22, and the reduction -limiting chamber exhaust w. The application chamber X and the chamber C ahead of piston 78 are connected to the atmosphere through port /, port I in the release slide valve 4. port I', and the application - chamber exhaust. The service cylinder and chambers M and O are connected to the atmosphere through ports n, em, and en, chamber O, port k, and the service-cylinder exhaust. The emergency cylinder is connected to the atmosphere through port o, the cavity in the emergency slide valve, port o', and the emergency-cylinder exhaust Ex. The small cavity in the release 'graduating valve is con- nected to the atmosphere through port and cavity « in the slide valve 4 and the emergency-piston exhaust Ex. This relieves the face of the graduating valve of sufficient pressure to insure the graduating valve being held firmly on its seat under all conditions. Preliminary Service-Application Position. — A reduction in brake-pipe pressure lowers the pressure in chambers A and B below that in chambers D and E, thus tending to move both the pistons 20 and 3 forwards from release position. Piston 3 PC PASSENGER-BRAKE EQUIPMENT 303 'moves with a less differential pressure, however, owing to the fact that the chamber F at the small end of the piston 20 is open to the atmosphere in release position, thus reducing the area that chamber-!? pressure acts on. A greater reduction in brake-pipe pressure, therefore, is necessary to move piston 20 than to move piston 3, so that during a brake-pipe reduction piston 3 moves first. There is a small amount of space between the graduating valve and the release piston, and considerably more between the release slide valve and the release piston. When sufficient brake-pipe reduction is made to overcome the friction of the piston 3, the piston moves forwards, and when it strikes the graduating valve it moves that valve forwards, until, finally, it strikes against and moves the slide valve to the preliminary service position, and the parts assume this position only momentarily on their way to service position. In this position, the piston 3 has moved past the feed-groove s' and has come to rest against the release graduating sleeve 14, as shown. In moving the slide valve, port /, leading from the applica- tion chamber to the application-chamber exhaust, is closed. The reduction-limiting chamber F, the service cylinder, the emergency cylinder, and the chambers O and M are all still open to the atmosphere. The connection between chamber F and the atmosphere is now closed, and chamber F is connected through port * and port t of the release slide valve with cham- ber E, and thence through port h, check-valve 16b, and port /, with the pressure chamber Z, thus charging chamber F to pres- sure-chamber pressure and equalizing the pressures on the two faces of the small piston. Secondary Service-Application Position. — The instant that the pressures on the two faces of the small piston of the equal- izing valve are equalized, the pressure in chamber D exerts a force on piston 20 that is greater than that of the pressure in chamber A ; hence the equalizing valve is moved forwards toward service position. During this movement it momen- tarily assumes secondary service position. In this position, the shoulder on the end of the piston stem is just against the slide valve 22 ; also, port e of the slide valve registers with port c and the graduating valve uncovers port c in the top of the slide valve, 304 PC PASSENGER-BRAKE EQUIPMENT so that there is a momentary connection between the emergency reservoir and chamber D while the slide valve is moving past the secondary service position. The object of this is to charge chamber D from the emergency reservoir an amount sufficient to compensate for the increase in volume in chamber D as the piston 20 moves forwards to service position, and thus prevent a drop in chamber-/) pressure due to the increased volume. Also, momentary connection is made between chamber D and the pressure chamber Z through the groove d in the equal- izing-valve seat, port d in the valve face, the cavity dw in the graduating valve, and ports / in the slide valve and seat. This prevents chamber D from being highly overcharged and main- tains the pressures in chambers D and Z equal. The pressure in chamber E is maintained equal to the pressure in chamber Z through port /, check-valve 16b, and port h as the piston 3 moves forwards. In fact, during an application of the brakes, this connection practically makes chambers E and Z but one chamber in volume; that is, during a reduction the connection through the check- valve 16b maintains the pressure equal in the two chambers, so that to reduce the pressure in chamber E, the pressure in chamber Z must be reduced a like amount. Service Position. — The piston 20 moves forwards from sec- ondary service position to service position, where it is stopped by the equalizing graduating spring 30. In this position, port u connects chambers D and F, thus equalizing the pressures in the two chambers. The pressure chamber has a direct con- nection to chamber D by way of port / and a port through the equalizing slide valve 22. Also, it has an indirect connection with chamber D through the check-valve 16b, port h, chamber E, port t of the slide valve 4, and port i; port i divides, one branch leading to chamber F and the other to a port in the equalizing slide valve. These two paths make provision for a considerable volume of air to flow from the pressure chamber into chamber D. Pressure-chamber air, after flowing to chamber D, can pass through port I in the slide valve 22 and port / in the valve seat to chamber C ahead of the application piston 78, and to the application chamber X. The pressure thus admitted into chamber C moves piston 78 backwards to its application PC PASSENGER-BRAKE EQUIPMENT 305 position, compressing the application-piston spring 93. In this position, the exhaust valve closes the service-cylinder exhaust ports k. The port in the application slide valve is opened and permits air from the service reservoir to flow through port g and chamber N into chamber O, and through port n to the service-brake cylinder, applying the brake with the pressure developed by that cylinder. The pressure in chamber M is maintained equal to that in the service cylinder through the port en, the cavity in the emergency slide valve, and the port em. Air will continue to flow into the service cylinder and chamber M until the pressure becomes about equal to the application-chamber pressure on the other face of the piston 78, when the application-piston spring 93 returns the piston 78 and slide valve back to service lap position. This holds the brakes applied with a service-brake-cylinder pressure about equal to the pressure admitted to chamber C and the appli- cation chamber. The operation of the application portion of the control valve for all operations of this brake is exactly the same as the operation of the application portion of the distributing valve of the ET equipment. In service position, the emergency-brake cylinder and the reduction-limiting cham- ber are open to the atmosphere. Service Lap Position. — As there is direct connection between the chambers D, E, and Z in service position, it follows that any reduction of pressure in chamber D will produce a like pressure in chambers E and Z. When a brake-pipe reduction is made to apply the brake and the parts move to service position, air from chamber Z flows by way of chamber D into chamber C and chamber X. The air continues to flow from chamber D until the pressure is reduced sufficiently below brake-pipe pres- sure to overcome the resistance of the piston 20, when the equal- izing valve will be moved back to service lap position. It makes no difference in the operation of the control valve whether the piston S moves to lap position or not, because it is the equal- izing graduating valve that laps port /, thus stopping the flow of air into the application chamber X and holding the pressure that was built up in chamber C. The pressure in chamber C deter- mines the pressure in the brake cylinder, because brake-cylin- der pressure is automatically maintained equal to chamber-C 21 306 PC PASSENGER-BRAKE EQUIPMENT pressure by the application portion, as follows: Any reduc- tion in brake-cylinder pressure reduces chamber-O pressure and causes chamber-C pressure to force piston 78 backwards and open the port in the application valve. Air from the service reservoir, therefore, flows through chamber N into chamber O and the brake cylinder until chamber-O pressure is enough greater than chamber-C pressure to overcome the frictional resistance of the piston 78, when the application valve closes and cuts off the flow of air to the brake cylinder. The pressure- maintaining feature of the control valve is the same as that of the ET distributing valve. As will be noted, both chamber F and the emergency-brake cylinder are open to the atmosphere. Overreduction Position. — The pressures in chambers D and E cannot be reduced below the pressure of equalization of the pressure chamber and the application chamber, which is 86 Ib. from a brake-pipe pressure of 110 Ib. and 54 Ib. from a brake- pipe pressure of 70 Ib. If the brake-pipe pressure is reduced below the pressure of equalization — that is, if an overreduction is made — the equalizing piston will be moved by chamber-D pressure beyond its service position to the overreduction posi- tion. In this position, the equalizing piston 20 compresses the graduating spring 80 and bottoms against the equalizing-cylin- der cap gasket 27, Release piston 8 remains in service position owing to the higher resistance of the graduating spring 14, which is stronger than the spring 80. In moving forwards into overreduction position, slide valve 82 is moved so as to close, with port m of the seat, the port I leading to the application chamber and to port I of the slide valve. Port m leads to chamber F, so that on an overreduction the air from the pressure chamber flows into the overreduction chamber F instead of into chamber € and the application chamber. The pressure in chamber C is thus held constant at the pressure at which the pressure chamber and the appli- cation chamber equalized; hence, the service-brake-cylinder pressure is limited to this amount and maintained equal to it. The reduction-limiting chamber F is of such size that it will equalize with the pressure chamber at about 60 Ib. from a pressure-chamber pressure of 86 Ib., or at about 35 Ib. from a 70-lb. pressure-chamber pressure. PC PASSENGER-BRAKE EQUIPMENT 307 In the oven-eduction position, chambers C and X are con- nected through port /, ports / and y of slide valve 22, and port v of the seat with the chamber G above the service-reservoir charging valve. Also, pressure chamber Z is connected through port /, chamber D, ports c and » of the slide valve, and port x of the seat with the chamber K below the service-reservoir charging valve. The pressure in chamber C and, therefore, in chamber G is maintained constant; the pressure in chamber K reduces with the pressure-chamber reduction during an over- reduction, thus insuring that the service-reservoir charging valve will be held down on its seat. The service reservoir, the pressure of which is maintained about equal to chamber-C pressure by the pressure-maintaining feature of the application portion, is connected through port g with chamber H. Any slight leakage from the application chamber in this position of the control valve will be supplied from the service reservoir past the packing ring of the service- reservoir charging valve that separates chambers H and G. The capacity of the service reservoir is relatively large when compared with the capacity of the application chamber; there- fore, the pressure in the reservoir will be higher than that in chamber G when a leak develops. Reservoir air will thus leak past the piston-packing ring that separates chambers H and G and prevent any material drop in chamber-C and appli- cation-chamber pressure. Maintaining chamber-C pressure in this manner practically eliminates the possibility of the brakes gradually leaking off, due to application-chamber leak- age, because the pressure-maintaining feature of the control valve will automatically maintain brake-cylinder pressure equal to chamber-C pressure. Overreduction Lap Position. — When an overreduction is made, the piston 20 moves to overreduction position. This connects chamber D with chamber F, so that the pressure in chambers D, E, and Z gradually reduces by the air discharging into chamber F. When chamber- D pressure becomes enough less than chamber-A pressure for the latter to overcome the factional resistance of piston 20, the piston and the graduating valve 2^ will be moved back to oven-eduction lap position; that is, until the shoulder of the equalizing-piston stem strikes 308 P C PASSENGER-BRAKE EQUIPMENT against the slide valve 22. The graduating valve 24 will then cover or blank port / and thus close communication between the chambers F and Z. Each succeeding reduction, provided it does not produce equalization between chambers Y and Z, will cause piston 20 to move to overreduction position and, finally, back to overreduction lap position. Also, in this position, the graduating valve 24 blanks the port v leading to chamber K. Therefore, in case the brake is held applied in overreduction position for a sufficient length of time and the leakage from the application chamber is so great that sufficient service-reservoir air cannot leak past the piston-packing ring, from chamber H into chamber G, to supply it, the service-reservoir charging valve will finally be moved upwards, opening direct connection between the service reservoir and the application chamber through port g, chamber H, ports v and y, port / in slide valve 22, and port /. Should an overreduction reduce the brake-pipe pressure below the pressure of equalization of chambers Y and Z, quick-action will result. Preliminary Release Position. — In releasing brakes, a rise in brake-pipe pressure above the pressure in chambers D and E will cause the piston 20 to move toward release position. The equalizing piston 20 moves first, because the release piston and valves are designed so that they will require a greater differential pressure to move them than is necessary to move the equalizing piston and valves. When the equalizing slide valve 22 has been moved to preliminary release position, it is held momentarily with port z of the slide valve in register with port y of the seat. In this position, the pressure chamber Z is connected with chamber F by port /, ports w and i of the slide valve, and port i of the seat. Chamber-Z pressure in chamber F and the force of the equalizing-piston stop-spring 30 insure the slide valve 22 sufficient time in the preliminary release position to reduce chamber- £ pressure below that in the brake pipe by an amount that makes positive the return of piston 3 to release position. Chamber-E air exhausts through port y, port z of the slide valve, cavity dw of the graduating valve, and port w of the slide valve, to the reduction-limiting-chamber exhaust w. Secondary Release Position. — The reduction of chamber-^) pressure results in the release piston moving to release position PC PASSENGER-BRAKE EQUIPMENT 309 while the equalizing piston still momentarily remains in position with port z of the slide valve in register with port y of the seat. This position is called the secondary release position. With piston 3 in release position, chamber F is connected with the emergency-piston exhaust port Ex by port * and cavity i of the release slide valve. At the same time, the pressure chamber Z is connected to the same port * and chamber F by the port /, ports / and i in the slide valve 22, and port *. The exhaust of chamber-Z air through port i tends to maintain the pressure in chamber F temporarily while slide valve 4 is increasing the port opening from chamber F to the atmosphere to insure the exhaust from chamber E being held open until after the release piston is in release position. As the movement of the release slide valve toward release position increases the size of the opening of port *, the pressure in chamber F gradually decreases until it is low enough for the differential pressure acting on the piston 20 to start the piston toward release position. This movement of the slide valve 22 gradually restricts and, finally, closes port /, thereby stopping the flow of chamber-Z air into port i and chamber F. Chamber-/5" air then exhausts to the atmosphere, and the equalizing piston is moved to release position and held there. When the slide valve 4 assumes release position, and before the slide valve 22 moves to release position, a second passage is made for the exhaust of chamber- .E air to the atmosphere. In the release position of slide valve 4> port e of the slide valve registers with port e of the valve seat; therefore, cham- ber-E air can pass through the ports e, the cavity w of the slide valve, and the reduction-limiting-chamber exhaust w. This connection, like the connection between ports z and y, is but momentary and is simply a second, or additional, opening from chamber E to the atmosphere. It should be understood that a brake-pipe pressure of from 1J to 2 Ib. above that in the appli- cation chamber X is all that is necessary to move the parts through the momentary successive positions of preliminary and secondary release to release position. With release slide valve 4 in release position, chamber-C and application-chamber air exhaust to the atmosphere through the port /, ports / and I' in slide valve 22, and port /' in the 310 P C PASSENGER-BRAKE EQUIPMENT seat, to the application-chamber exhaust. As chamber-C pres- sure reduces, chamber-0 pressure forces piston 78 forwards to release position and exhausts the service-brake-cylinder air through port n, chamber O, port k, and the service-cylinder exhaust. The pressure in chamber M exhausts through the ports em and en into port n and thence to the atmosphere. Graduate d-Release Position. — With both piston 20 and piston 3 in release position, the control valve is said to be in graduated-release position, when the direct- and graduated- release cap 18 is turned, so as to cut in the graduated-release feature. If the cap 18 is turned into the position for direct release, the control valve is said to be in direct-release posi- tion. In both cases, the control valve is in release position, but the term graduated or direct is prefixed to show whether the cap 18 is turned so as to give a graduated or a direct release of the brake. The application chamber and chamber C are open to the atmosphere through ports I and V and the application-chamber exhausts. If it were not for the graduated-release feature, the release would be complete. However, the emergency reservoir is connected with chamber E through port c, ports c and e of the slide valve 22, port e, through the cap 18, port e, and port e of the slide valve 8, into chamber E. Before this connection was made, the chamber- £ pressure was reduced with the pressure- chamber pressure when the brake application was made. The emergency reservoir, on the other hand, is charged to normal brake-pipe pressure. Therefore, air from the reservoir will flow into chamber E, thence through port y, ports y and / of slide valve 22, and port / of the seat, to the pressure chamber Z. This pressure tends to increase the pressure in chambers E and Z at the same time that brake-pipe air is increasing chamber- B pressure. If chamber- .E pressure rises faster than chamber- .B pressure, the differential pressure thus created on piston 3 will tend to move the piston toward the graduated-release lap posi- tion, and either wholly or partly stop the flow of air from the application chamber to the atmosphere and from the emergency reservoir to chamber E. If brake-pipe pressure increases very slowly, the increase in differential pressure may be sufficiently rapid to cause the release piston and graduating valve to PC PASSENGER-BRAKE EQUIPMENT 311 graduate the release. If the rise in brake-pipe pressure is not slow enough to produce this action, the movement of piston 3 toward graduated-release lap position will be sufficient to restrict the flow of air from the emergency reservoir into chamber E to an extent sufficient to adjust the rate of rise of pressure in chamber E equal to the rate of rise of brake-pipe pressure in chamber B. In this case, the release of air from the application chamber and chamber C will be correspondingly prolonged. Whether the brake will be released completely or be gradu- ated off depends on whether chamber-C pressure is exhausted completely at one time or is exhausted by degrees, the pressure being partly exhausted and then held stationary for a time, this operation being repeated several times. The pressure in the reduction-limiting chamber and in chamber 5 below the emergency slide valve is completely exhausted when a release is made, regardless of whether the release is graduated or direct. Chamber E (and the pressure chamber) is connected to cham- ber K through the port y, ports y and x of slide valve 22, and port * in the valve seat, and emergency-reservoir air can pass to chamber G through port c, ports c and v of slide valve &&, and port v when slide valve 22 is moved to release position. Whether the service-reservoir charging valve will be operated and thus permit the service reservoir to be recharged will depend on the relative pressures in chambers G and K and the service reservoir. With the ordinary manipulation of the brake, the service-reservoir charging valve will not be operated, so that no air will pass from the emergency reservoir into the service reservoir; the pressure chamber, however, will be recharged with emergency-reservoir air to within 5 Ib. of the pressure in the emergency reservoir. The service-reservoir charging valve then opens and forms connection between the emergency reservoir and the service reservoir through chamber H, and the service and emergency reservoirs and the pressure chamber Z are all recharged to normal pressure by air from the brake pipe. In other words, in recharging the brake, first, the pressure chamber alone is recharged to within 5 Ib. of emergency-res- ervoir pressure by air from the emergency reservoir, during which time the brake pipe alone is being recharged from the 312 PC PASSENGER-BRAKE EQUIPMENT main-reservoir air supply through the brake valve. Connec- tion is then made between the service reservoir, the emergency reservoir, the pressure chamber, and the brake pipe, and the final stage of the recharging of all these parts is accomplished by air from the main reservoir passing through the brake valve. As main-reservoir air has the brake pipe alone to recharge during the first stage of the recharge, the rise in brake-pipe pressure is much more rapid than with the older types of brakes; hence, the release of the brakes throughout the length of the train is much more sure and positive than with the other types. Release Lap Position. — The release of the brake is accom- plished by placing the brake valve in release position so as to raise brake-pipe pressure, recharge the brake pipe, and move the pistons 20 and 3 to release position. If the handle of the brake valve is left in release position, the brake will release in one continuous exhaust of brake-cylinder air without any graduations of brake-cylinder pressure. On the other hand, if the brake valve is moved to release position for a time and is then moved to lap, only part of the brake-cylinder pressure will be exhausted, and by repeating the movement of the brake valve from release to lap positions the brake can be gradu- ated off. In graduating off the brake, while the brake pipe is recharging through the brake valve, the pressure chamber and chamber E are recharging with air from the emergency reser- voir. If, the brake-valve handle is moved to lap position when the brake pipe is only partly recharged, the continued flow of air from the emergency reservoir with chamber E will raise the pressure in chamber E above that in chamber B, which is now stationary, and cause the release piston 3 to move to graduated- release lap position. In this position, the shoulder of the stem of piston 3 is against the slide valve 4, the flow of air into cham- ber E ceases, and the graduating valve blanks port I and stops the exhaust of air from chamber C and the application chamber. This holds chamber-C pressure constant, and the application portion maintains brake-cylinder pressure constant and equal to chamber-C pressure. If the brake valve is again moved to release position and then back to lap position, piston 3 will be moved to release position and then back to rele&se lap position, PC PASSENGER-BRAKE EQUIPMENT 313 and this action will be repeated. The gradual release of the brake can be continued until the emergency reservoir and the pressure chamber equalize at a pressure about 5 Ib. below nor- mal brake-pipe pressure. Release Position — Charging Pressure Chamber and Emer- gency and Service Reservoirs. — The recharging of the pressure chamber to within 5 Ib. of brake-pipe pressure is accomplished with emergency-reservoir air. By the time this is accomplished the service-brake cylinder is entirely released, and the final stage of recharging the pressure chamber and the emergency and service reservoirs is accomplished by the use of air from the brake pipe. Direct- Release and Charging Position. — The direct-release position is the same as the graduated-release position, except that the direct and graduated-release cap 18 is turned to the position for the direct release of the brake. With cap 18 in this position, the brake cannot be graduated off. Changing the position of cap 18 cuts off the connection between the emergency reservoir and the application chamber and chamber E. During direct release, therefore, the cham- bers E and Z are recharged from the brake pipe through the feed-groove s' past the piston 3. There is direct connection between chambers E and Z through port y, ports y and / of slide valve 22, and port / of the valve seat. As chamber E charges from chamber B, chamber- E pressure cannot increase above chamber- B pressure; therefore, piston 3 cannot be moved to graduated lap position and the brake cannot be gradu- ated off. The chambers C and X are open to the atmosphere through port I, ports / and q of slide valve 4, port q, cap 18, port /', and the application-chamber exhaust. This affords an exhaust outlet for chamber X, which cannot be closed as long as the release slide valve 4 remains in release position. A second path from the application chamber to the exhaust leads through port /, port I in slide valve 4, cavity dw in the graduating valve 6, ports /' in the slide valve and seat, and the application-cham ber exhaust. It is possible, however, for this path to be partly restricted or, perhaps, entirely closed by the piston 3 moving the graduating valve 6 so as to close port / in the slide valve 4 314 PC PASSENGER-BRAKE EQUIPMENT partly or wholly. The first path, however, insures direct con- nection to the atmosphere. There are two outlets from the application chamber to the exhaust in direct-release position, while there is only one outlet when cap 18 is turned so as to give graduated release. The capacity of the release port, therefore, is greater for direct release than for graduated release, and thus gives a more rapid release with the direct-release adjustment, which is desirable. Quick- Action Valve Venting. — Either a brake-pipe reduction that is too fast or a reduction so heavy that it reduces brake- pipe pressure below the pressure of equalization of the pressure chamber and the reduction-limiting chambers will produce a differential pressure on pistons 3 and 20 that will move them to their emergency positions. With the slide valve 4 in emergency position, emergency- reservoir air passes through port c direct into chamber E, thence through port r to the space below the quick-action closing valve 139. Chamber T, above valve 139, is connected by port s with port o and the emergency-brake cylinder, which is con- nected to the atmosphere through port o, the cavity in the emergency slide valve, port o', and the emergency-cylinder exhaust; consequently, the quick-action clasing valve 139 is raised from its seat and emergency-reservoir air flows into the chamber W above the quick-action piston 131. This forces down piston 131 and opens the quick-action valve 133 against the brake-pipe pressure in the chamber V that vents brake-pipe air to the atmosphere through chamber V, port qx, and the quick-action exhaust, thereby producing a local drop in brake- pipe pressure that transmits the quick-action serially through- out the train. Air from the emergency cylinder, after flowing to chamber E, passes through port I direct to chamber C and the appli- cation chamber. This forces piston 78 back into application position, which closes the exhaust ports k and opens the appli- cation-valve port wide, thus allowing the service reservoir and the service-brake cylinder to equalize through port g, chambers N and O, and port n. The movement of the slide valve 4 to emergency position also opens the chamber P above the large emergency piston PC PASSENGER-BRAKE EQUIPMENT 315 108 to the atmosphere through port p and cavity * in slide valve 4- Emergency-reservoir pressure in chamber R forces the emergency piston 108 and the slide valve 110 to their emer- gency positions, thereby connecting the emergency-brake cyl- inder with the emergency reservoir through port c, chamber R, and port o and allowing the pressure to equalize in the cylin- der and reservoir; also, chamber R is connected to the service cylinder through port en and port n, thus allowing all the ser- vice- and emergency-brake cylinders and reservoirs to equalize with one another. Chamber M, behind piston 78, is connected to the atmosphere through ports em, the cavity in the emergency slide valve, port o', and the emergency-cylinder exhaust. This is done to assist the pressure in chamber C moving the piston 78 quickly and positively to emergency position. It will be noted that in emergency position the pressure chamber Z is connected to chambers D and E, and chamber D is connected to chamber Y. The purpose of this is to equalize the pressure in all the cham- bers and reservoirs and to insure sufficient pressure on all the slide valves and graduating valves to hold them to their seats. Quick- Action Valve Closed. — The closing of the quick-action valve 133, after making a local vent to the atmosphere to trans- mit quick action serially throughout the train, is accomplished as follows: As soon as quick action occurs, emergency-cylinder pressure and, therefore, chamber- T pressure, begins to rise, while the pressure in chamber W and the emergency reservoir begins to fall. When the pressures in chambers T and IV become nearly equal, the spring of valve 139 closes the valve and stops the flow of air into chamber W. The air thus trapped in chamber W escapes through the leakage hole Ih in the piston 131 to the atmosphere through port qx and the quick-action exhaust. This balances the pressure on the two faces of piston 131, and the spring of valve 133 and brake-pipe pressure closes the valve 133 and stops the escape of brake-pipe air to the atmosphere. If the brake-pipe pressure is entirely depleted, the spring of valve 133 will close the valve and thus insure against a loss of brake-pipe air when a release is made imme- diately after the quick-action application. 316 PC PASSENGER-BRAKE EQUIPMENT LUBRICATING THE CONTROL VALVE Equalizing Portion. — The equalizing portions of the control valve should be lubricated with a high grade of dry graphite (not flake graphite) of the highest obtainable fineness and purity. Oil should not be used for this purpose. A free use of oil should be made in "rubbing in" the bearing surfaces of the equalizing portion, but all oil, gum, or grease should be thor- oughly removed from the slide valves and seats before lubrica- ting them, as follows: Rub graphite on the face of the slide valves and their seats, on the face of the graduating valves and their seats, and on the upper portions of the bushings where the slide-valve springs bear. The graphite should be applied in such a way as to fill in the pores of the brass and leave a very thin, light coating on the seats. After lubricating the parts, care should be taken not to touch them with the hands, as moisture tends to remove the thin coating of graphite and thus destroy the lubrication. The graphite is best applied with a stick about 8 in. long, to one end of which is glued a small pad of chamois skin. The skin on the end of the stick is dipped in the graphite, and the graphite is rubbed on the surfaces to be lubricated. A few light blows of the chamois on the valve seats will leave sufficient loose graphite on them. After the pistons and slide valves are replaced in the equal- izing portion, they should be moved to release position so that a little oil may be rubbed on the piston bushings; the pistons should then be moved back and forth several times to make sure that the oil is evenly distributed on the bushing. Only a thin coating of oil should be used, and it should be well rubbed in so that there will be no free oil left on the parts after they have been oiled. Application Portion. — The application valve and seat and the exhaust valve and seat of the application portion of the control valve should be cleaned; then they should be rubbed in with oil, which should be thoroughly removed; and finally, they should be lubricated with graphite in the same manner as the slide valve and seats of the equalizing portion. During the time that the piston is removed, the cylinder should be PC PASSENGER-BRAKE EQUIPMENT 317 cleaned and the walls lightly lubricated with a good grade of valve oil. The piston and piston ring should be cleaned and the ring lubricated with a little valve oil of good quality, a few drops of the oil being applied to the packing leather. Emergency Portion. — To lubricate the emergency portion of the control valve, remove the parts and thoroughly clean the bearing surfaces; rub in the parts, using oil for the purpose, and thoroughly clean off all oil and grease; then lubricate the bearing surfaces with graphite. Remove the top cover and take out the loose-fitting cylinder bushing; lubricate the large piston with a few drops of a good grade of triple-valve oil and apply the slide valve to the portion; lubricate the stop-bushing for the small emergency bushing, applying a few drops of oil to its inner surface; then replace the bushing and bolt on the top cover. Move the slide valve to release position and apply a few drops of good triple-valve oil to the walls of the large cylinder bushing, and then move the piston back and forth several times to distribute the oil properly. Replace the large cover of the emergency portion. Quick-Action Portion. — Only the quick-action closing-valve piston 131 and the cylinder bushing of the quick-action portion require lubrication. Just a few drops of oil are sufficient; the piston, however, should be worked back and forth several times to distribute the oil properly and to make sure that it moves as freely as it should. 318 BRAKE CYLINDERS BRAKE CYLINDERS DRIVER-BRAKE CYLINDERS TYPE B DRIVER-BRAKE CYLINDERS In ordering brake cylinders or repair parts it is of the greatest importance to specify the proper piece number and name of the part wanted to insure correct understanding of order. The reference number, however, should not be given on the order. The driver-brake cylinders are furnished with outer and side 17 FIG. 1 flanges full unless the order specifies to the contrary. Either outer or side flanges will be removed when so specified on orders, in which case complete directions, with print showing exact dimensions desired, should accompany order. The piece num- bers of the type B driver-brake cylinders, complete, shown in Fig. 1, are given in the accompanying table. The reference numbers of the various parts are as follows: Ref. No. Name of Part 2 Cylinder body. 3 Piston and rod, includes 13 only. 4 Non-pressure head. 5 Pressure head. 6 Release spring. BRAKE CYLINDERS 319 PIECE NUMBERS OF TYPE B DRIVER-BRAKE CYLINDERS Cylinders Piece No. of Cyl. Com- plete Cylinders Piece No. of Cyl. Com- plete Dia. In. Stroke In. Type No. Dia. In. Stroke In. Type No. 6 8 8 8 10 10 10 10 8 6 7 12 6 8 10 12 48-B 33-B 11-B 43-B 51-B 55-B 35-B 99-B 8,618 1,148 1,134 6,236 9,687 1,115 1,120 1,101 12 12 12 14 14 16 16 8 10 12 10 12 10 12 13-B 15-B 39-B 21-B 42-B 101-B 47-B 7,318 7,339 7,378 7,203 7,260 22,038 7,447 Ref. No. Name of Part 7 Cylinder-head bolt and nut. 8 Cylinder gasket. 9 Push-rod holder. 10 Follower. 11 Packing leather. 12 Packing expander. 13 Follower stud and nut. 14 Push-rod with pin and cotter. 15 Oil plug. 16 Push-rod holder pin with cotter. 17 Push-rod pin, with cotter. TYPE C DRIVER-BRAKE CYLINDER^ The piece numbers of the type C driver-brake cylinders, complete, shown in Fig. 2, are as follows: PIECE NUMBERS OF TYPE C DRIVER-BRAKE CYLINDERS Cylinders Piece No. of Cylinders Piece No. of Dia. Stroke Type Cyl. Com- Dia. Stroke Type Cyl. Com- In. In. No. plete In. In. No. plete 8 6 33-C 1,207 12 g 13-C 1,169 8 7 11-C 4,847 12 10 15-C 1,175 10 10 10 6 8 10 30-C 55-C 35-C 1,192 1,198 1,184 12 14 14 12 10 12 39-C 21-C 49 C 1,179 1,258 1,265 10 12 99-C 1.204 320 BRAKE CYLINDERS FIG. 2 FIG. 3 The reference numbers of the various parts are as follows: Ref. No. Name of Part 2 Cylinder body. 3 Piston and rod, includes 9 only. 4 Non-pressure head. 5 Pressure head. 6 Push rod, with pin and cotter. 7 Cylinder-head bolt and nut. 8 Cylinder gasket. 9 Follower stud and nut. 10 Follower. 11 Packing leather. 12 Packing expander. 13 Oil plug. 14 Push-rod pin, with cotter. PUSH-DOWN TYPE DRIVER-BRAKE CYLINDERS The piece numbers of the push-down type of driver-brake cylinders, complete, shown in Fig. 3, are as follows: BRAKE CYLINDERS 321 PIECE NUMBERS OF PUSH-DOWN TYPE DRIVER- BRAKE CYLINDERS Cylinders Piece No. of Cyl. Com- plete Cylinders Piece No. of Cyl. Com- plete Dia. In. Stroke In. Type No. Dia. In. Stroke In. Type No. 6 6 8 8 10 10 10 6 8 6 7 6 8 10 66 48 33 11 30 55 35 2,529 1,972 1,358 1.311 1,333 1,339 1,342 10 12 12 12 14 14 12 8' 10 12 10 12 99 13 15 39 42 1,345 1,319 1,325 1,329 1,354 1,348 The reference numbers of the various parts are as follows: Ref. No. Name of Part 2 Cylinder body. 3 Piston and rod, includes 13 only. 4 Non-pressure head. 5 Pressure head. 6 Release spring. 7 Cylinder-head bolt and nut. 8 Cylinder gasket. 9 Crosshead. 10 Follower. 11 Packing leather. 12 Packing expander. 13 Follower stud and nut. 14 Oil plug. PISTON-ROD CROSSHEADS FOR DRIVER-BRAKE CYLINDERS In Fig. 4 are shown the cross-sections and plans and the piece numbers of the piston-rod crossheads that may be used with driver-brake cylinders. 322 (oTTo) BRAKE CYLINDERS 3OC; Pc.No.3743- Pc.No.j69i- (5 Q) Pc.No.j749- Pc.No.j76j. Pc.No.j76p. Pc.No.j77i. Pc.No.j6o6. Pc.No.j726. Pc.No.j728. 732. Pc.No.374O. Pc.No.3744- -"-x^-^ ; j |,Qt i Pc.No.j74S- Pc.No.j746V~Tc.No.j747- Pc.No.j776. Pc.No.j097. I! ' ^i ' I ( 1 i— i r-+ru, r— i-ru. /— l-n- _„ Pc.No.37JO. o o) Pc.No.j7ij. •pc.No.37+8. Pc.No.37 14. 1^"^ O ^ Pc.No.37SO i^O; Pc.No.j78i. Pc.No.j78j. Pc.No.j784. Pc.No.jjSj. fo Pc.No.j77a Pc.No.oo6*. •*\U/^ Pc.No.4624- Pc.No.j777. Pc.No.j782. ^ Pe.No.j8i6 Pc.No.37,6. n " /^^^ Pc.No.j78o. Pc.No.37oo. Pc.No3786. x^-/ Pc.No.38 1 8. Pc.No.37 1 7. ' — ^ (o o) Pc.No.37.8. Pcl.0,0. o)ES_« . Pc.No.j924. Pc.No.j926. Pc.No.j787. Pc.No.j925. Pc.No.j92;. Pc.No.j78,. Pc.No.gjo8. FIG. BRAKE CYLINDERS 323 ENGINE-TRUCK-BRAKE CYLINDERS A cross-section of the engine-truck-brake cylinders is here shown; the piece numbers of these cylinders are as follows: PIECE NUMBERS OF ENGINE TRUCK BRAKE CYLINDERS Cylinders Piece No. of Cyl. Com- plete Cylinders Piece No. of Cyl. Com- plete Dia. In. Stroke In. Type No. Dia. In. Stroke In. Type No. 6 8 8 10 8 7 12 8 48-D 11-D 43-D 55-D 9,729 1,963 1,964 1,969 10 10 12 12 10 12 8 12 35-D 99-D 13-D 39-D 1,968 1,970 7,551 17,244 The reference numbers of the various parts are as follows: Ref. No. Name of Part 2 Cylinder body. Piston and rod, includes 13 only. Pressure head, with lever bracket. Non-pressure head. Release sprng. Cylinder-head bolt and nut. Cylinder gasket. Push-rod holder. Follower. Packing leather. Packing expander. Follower stud and nut. Push rod, complete, includes 17. Oil plug. 324 BRAKE CYLINDERS Ref. No. Name of Part 16 Push-rod holder pin, with cotter. 17 Push-rod pin, with cotter. 18 Detachable lever bracket. 19 Lever-bracket bolt and nuts. Cylinders are not provided with bosses tapped for slack- adjuster connections unless so specified on orders. Should orders including truck-brake cylinders or cylinder heads also cover slack adjusters, detachable brackets will be omitted, and cylinders arranged for attachment of slack adjusters. TENDER-BRAKE CYLINDERS TYPE K CYLINDER Type K tender-brake cylinders are provided with detachable fulcrum and seat for type P or type H triple valve. These cylinders are not arranged for slack-adjuster connection, or for combined automatic and straight air, unless so specified on orders. The piece numbers of the cylinders complete and the piece and reference numbers of the various parts are given in the accompanying tables. TYPE L TENDER-BRAKE CYLINDER Type L tender-brake cylinders, Fig. 1, have a detachable fulcrum head; they are not arranged for slack-adjuster con- FIG. 1 nection unless so specified on orders. The piece numbers of the cylinder complete and the piece and reference numbers of the various parts are given in the accompanying table. BRAKE CYLINDERS 325 i M CO CN CO CM a 5 * I r-l r-l O5 CO rH t>- O CO_ (N 00 00 O ifj O "5 0 c-s b 8-a wd.?P •C C o) >, x ^ >, ra >> HH H H 326 CO I & BRAKE CYLINDERS l> >OC5C5t^« t^ coi-icococ O COOOCOt^ QOOt^-CMN^OOOOCQOCib-t t^O (N^O^O I-H l> t1* O O CO i— * 00 Is* J5 t^CO( X CO O JO 3 X X X O i-( »H >O C» O i-i >-i O >O •* • o ^ (N 1C CO l^ 00 O3 O *M (N CO rf i S :. ' .s.s^l loo"'"'0 . . ^ « cd .. .u 0,5^ go g .S BRAKE CYLINDERS 327 X 2 CN N ** in "** ^ ' CN lO OS"3 •* t- «O 1-1 IN O •* »O b- •«*< CO CC CO O OS »-l OJ OSOO OS O5 O O5 •* <-< <-< 1-1 1^ 00 CO CO (M i-4 1-4 \/ os coco wwqq»qqqq«H_t^-t^qqoo if I C CO CM 00 t» CO CO CO OS 00 CO O CO iO i-l ^ \S >sZ OS 1-H fH 1-H CO O O t— O O O O iH t— t> ^, ^ C• T1 ^ T¥ P °P ""• ^ P "£ ?5 «- ^ I^rH^rH^rH^rHrHO b X 2 -H-H .OrH'rH^.H-'H-rH'rH^w'WrH-rH-p" 00 O >O CO t- 00 O O rH (N CO •* >O :l :>. :a • • : I 'I * I :«j i ; Hi N -g w • ^9- • -d . -^13 • • :c rt • c * li P1A — I I :il«^"l5-i-- • ^ ^^ 328 BRAKE CYLINDERS All tender-brake-cylinder pressure heads with connection for quick-action triple valve are furnished as in Fig. 2, except that for ordinary equipments port c is not tapped, and bosses A and B not drilled. When ordering such pressure heads for the com- FIG. 2 bined automatic and straight-air brake equipment, schedule SWA-SWB , specify port c to be tapped for f -in. pipe and plugged, plug to be flush on cylinder side of head; also that either of bosses A or B should be drilled and tapped for Hn. pipe. BRAKE CYLINDERS 329 PASSENGER-BRAKE CYLINDERS TYPE M PASSENGER-BRAKE CYLINDER The type M passenger-brake cylinders, shown in Fig. 1, are used with standard (schedule PM) quick-action passenger-car FIG. 1 brake equipments, the seat on the pressure head being suitable for the type P triple valve. These cylinders, however, can be adapted to take the type L triple valve by use of filling blocks. 330 BRAKE CYLINDERS SI oooo«c OOCOCOOlN r-l C<1 CO Tt< »C CC I-H (N d HSHSHS.*. HO. " I— I CO Tfi 1C 1C l>- 00 0<~ « « 0 £ l-l CO Tt< 1C CO t^ 00 *5 I y?. os I os I S^feSs co co co co co « a I K *^ ^d ^O^^CO CO (N IM (N < xxxxxx Cylinders of 10 in. diameter or less are flat on top. The cylinders, end flanges and the walls of the body do not extend above the supporting flange. P-l triple valves are used for cylinders, 6 in.X12 in., 8 in. X12 in., and 10 in.X12 in.; P-2 triple valves are used for cylinders, 12 in.X12 in., 14 in. X12 in., and 16 in.X12 in. The dimensions and weights of the cylinders and their piece numbers and the piece and reference numbers of the vari- ous parts are given in the ac- companying tables. The slotted crosshead, Ref. No. 6, is used when the hand- brake rigging is designed to work in harmony with the air- brake system, an arrangement that is recommended for all con- ditions where it is practicable. Unless otherwise specified, the quick-action triple-valve head with slack-adjuster lug, with a detachable lever bracket is furnished on all orders for or including this part. This bracket can be easily removed to allow the application of the American automatic-slack ad- juster, thus obviating the neces- sity of changing the head. Should orders including cylin- ders or cylinder heads also cover slack adjusters, detachable brackets are not supplied. BRAKE CYLINDERS 331 5 ! " a CO BRAKE CYLINDERS OrHlO CD 00 CO CO 00 I-- £1 r-l rH ^H 00 1> CO 00 CO 00 .-I rH OOt^lN 1C (N t^- lO GO fO »C CO rJH O CO t- O N- CO CT> • t^OfH 00 CO'<*t>COCOCOCOOOCT)COOOCOOO'Or-l( T*i 1C CO TH l-H I-I i-HO r-1 GO »O -^ Tjl I-H O iH rH i-i CM O5 *O i— t i-H T^ T+^ 00 ^H (N IO O CO 1C t*» CD O5 *C 1C ^ 1>OCT) CO CD O t> 1-4 O rH r-l O rH CC GO C i-H 00 CO t— I IO Tt* CD t> 1C i-H *-H »™H rH »"- ' CO ^^ 00 i™< "^ ^ 00 Cl CD O C^ rf* 1C rH CO rH -^ 1>C Tt« T}< 1C 1C CD CD J> 00 O5 O ^ (N CO -^ 1C CD I> 00 O> O »-i (N BRAKE CYLINDERS TYPEN PASSENGER-BRAKE CYLINDERS The type N passenger-brake cylinders, shown here in cross- section, are used with the new (schedule LN) quick-action, quick-service, graduated-release, quick-recharge, high-emer- gency pressure, passenger-car brake equipments, the seat on the E — pressure head being suitable for the type L triple valve. Cylinders of 10 in. diameter or less are flat on top; end flanges and walls of body do not extend above supporting flange. The dimensions and weights of the cylinders and their piece and reference numbers of the various parts are given in the accom- panying tables. BRAKE CYLINDERS CO « a« o « ffi « 0 PQ ^ M ^^^^^^ £ »OCOt>OOO5O Q^ ^l«n|«>H»'> ,5 co -* i^ r^ I cocococo OS * XXXXXX X' O i-O CO M< N- CO N- • IN- CD (N GXNN-! 00 ilSSs 't'O.'*, lOi-Hi-H CO C)>-i 'CO"«H i-H COi-KN 00 N-ON-'*'* OCD^CO o_ i~ll-'5'~l'~l'~l >oco"co" co" i-Ti-T co"^ I-H "5 "5COCO1>00 II j'a' BRAKE CYLINDERS Tf 1C •«*! t* CO «O t>- O O5 ^ »O TJ< •* (N C ^•-lOOt^CO O O i— < O Is* r-T»- » • Iffllllli! .S-aa-a lOS-S-a-E-a^ I *^? It T^ • r- * — • T-" ^ o o^^^.a-.y.p> > o c-= carto«>>i-ii-iCa>a> C'7 x &,CX,fcp^OHHHJJO^.W o c-^.c.c.c 60"- . •US 8 i •^l* I JJS-S1 | Illl .5 Ifilll Blill •J rt'5)X.« U^ H "-S § IIH^BW S°"i^«2 Ililfl feilif 338 BRAKE CYLINDERS FREIGHT-BRAKE CYLINDERS TYPE C, 8"X12", FREIGHT-BRAKE CYLINDER AND RESERVOIR COMBINED Freight-brake cylinders are made in two styles, the type C in which the cylinder is secured to or combined with the auxiliary reservoir, and the type D in which the cylinder is detached from the reservoir. The type C brake apparatus, FIG. 1 shown in Fig. 1, is furnished, with schedules HC-812 or KC-812, for freight cars the light weight of which is not less than 22,000 nor greater than 37,000 Ib. The total leverage should never exceed 9 to 1. The piece number of the freight-brake cylinder and reservoir combined is 2,438; the piece and reference num- bers of the various parts are given in the accompanying list. PC. No. 1,216 1,246 1,217 2,305 1,142 1,144 1,145 1,110 1,147 4,883 4,887 2,439 1,004 * 2,427 4,904 4,889 lef. No. Name of Fart 2 Cylinder body, 8-in. X 12-in. 3 Piston and rod, includes 5 only. 4 Non-pressure head 5 Follower stud and nut. 6 Follower. 7 Packing leather. 8 Packing expander. 9 Release spring. 10 Cylinder gasket. 11 Cylinder-head bolt and nut. 12 Reservoir stud and nut. 13 Reservoir, includes 12, 14, and 16. 14 Drain plug. 15 Triple- valve gasket. 16 Reservoir tube. 17 Reservoir-cylinder bolt and nut. *Listed for convenience only, not included in Piece No. 2,438. BRAKE CYLINDERS 339 TYPE C, 10"X12", FREIGHT-BRAKE CYLINDER AND RESERVOIR COMBINED The type C brake apparatus, shown in Fig. 2, is furnished, with schedules HC-1,012 and KC-1,012, for freight cars the light weight of which exceeds 37,000 Ib. The total leverage FIG. 2 should never exceed 9 to 1. The piece number of the freight- brake cylinder and reservoir combined, is 23,733; the piece and reference numbers of the various parts are given in the accom- panying list. Pc.No.Ref.. 1,250 2 5,037 1,104 2,305 1,108 1,111 1,112 1.110 9 1,114 10 4,883 11 4,887 12 21.838 13 1,004 14 *4,886 15 4,906 16 4,889 17 ft>. Name of Part Cylinder body, 10 in.X 12 in. Piston and rod, includes 5 only. Non-pressure head. Follower stud and nut. Follower. Packing leather. Parking expander. Release spring. Cylinder gasket. Cylinder-head bolt and nut. Reservoir stud and nut. Reservoir, includes 12, 14, and 16. Drain plug. Triple-valve gasket. Reservoir tube. Reservoir-cylinder bolt and nut. *Listed for convenience only, not included in Piece No. 23,733. 340 BRAKE CYLINDERS TYPE D, 8"X12", FREIGHT-BRAKE CYLINDER AND RESERVOIR DETACHED The type D brake apparatus, shown in Fig. 3, is furnished, with schedules HD-812 or KD-812, for freight cars the light weight of which is not less than 22,000 nor greater than 37,000 lb., but the construction of which prevents the application of the type C brake. The total leverage should never exceed 9 to 1. The connection between the auxiliary reservoir and FIG. 3 brake cylinder should be as short as possible; if piping exceeds 8 or 10 ft., the braking effect is likely to be noticeably impaired. The piece number of the freight-brake cylinder, with plain pressure head, complete, is 2,447; of type D, freight auxiliary reservoir, complete, 2,445. The piece and reference numbers of the various parts are given in the accompanying list. PC. No. Ref. No. Name of Part 1.216 2 Cylinder body , 8 in. X 1 2 in. 1,246 3 Piston and rod, includes 5 only. 1.217 4 Non-pressure head. 2,305 5 Follower stud and nut. BRAKE CYLINDERS 341 PC. No. Ref.No. Name of Part ,142 6 Follower. ,144 7 Packing leather. ,145 8 Packing expander. ,110 9 Release spring. ,147 10 Cylinder gasket. 4,883 11 Cylinder-head bolt and nut. 4,887 12 Reservoir stud and nut. 2,445 13 Detached reservoir, includes 12, 14, and 16. 1,004 14 Drain plug. *2,427 15 Triple- valve gasket. 4,904 16 Reservoir tube. 2,448 18 Pressure head. 14 FIG. 4 TYPE D, 10"X12", FREIGHT-BRAKE CYLINDER AND RESERVOIR DETACHED The type D brake apparatus, shown in Fig. 4, is furnished, with schedules HD-1,012 or KD-1,012, for freight cars the *Listed for convenience only, not included in Piece No. 2,445. 342 BRAKE CYLINDERS light weight of which exceeds 37,000 lb., but the construction of which prevents the application of the type C brake. The total leverage should never exceed 9 to 1. The connection between the auxiliary reservoir and brake cylinder should be as short as possible; if piping exceeds 8 or 10 ft., the braking effect is likely to be noticeably impaired. The piece number of the freight-brake cylinder, with plain pressure head, com- plete, is 4,868; of type D freight auxiliary reservoir, complete, is 24,446. The piece and reference numbers of the various parts are given in the accompanying list. PC. No. Ref. No. Name of Part 1.250 2 Cylinder body, 10 in. X 12 in. 1.251 3 Piston and rod, includes 5 only. 1,104 4 Non-pressure head. 2,305 5 Follower stud and nut. 1,108 6 Follower. 1.111 7 Packing leather. 1.112 8 Packing expander. 1,110 9 Release spring. 1,114 10 Cylinder gasket. 4,883 11 Cylinder-head bolt and nut. 4,887 12 Reservoir stud and nut. 24,446 13 Detached reservoir, includes 12, 14, and 16. 1,004 14 Drain plug. *4,886 15 Triple-valve gasket. 4,906 16 Reservoir tube. 4,869 18 Pressure head. CLEANING THE BRAKE CYLINDER The non-pressure head and the piston should be removed from the brake cylinder and the cylinder cleaned with kerosene and waste to remove all the gum and dirt so that the walls will have a smooth surface. The leakage groove should be scraped out clean and the walls of the cylinder rubbed with waste saturated with kerosene. If there are any rough or rusty spots left, they should be smoothed with fine sandpaper; then all traces of the kerosene and dirt removed and the wall of the cylinder thoroughly covered with heavy grease provided for that purpose, rubbing it on well with the hand gives the best results. When cleaning the brake piston, take out the *Listed for convenience only, not included in Piece No. 24,446. BRAKE CYLINDERS 343 expander ring and clean the piston-packing leather by rubbing it with clean oily waste. If the leather is worn out or imper- fect in any way, replace it with a new one. The flesh side of the leather should be next to the cylinder walls, because it wears better and is not so apt to leak when put in this way. See that the follower head is in good condition and that the bolts are tight; also, that the piston rod is tight in the piston head. Soften the packing leather by working it with grease; put some grease in the expander-ring groove and replace the piston in the cylinder. To enter the piston properly, start it in edgewise, having the rod extended downwards at 45° with the cylinder; then slowly raise the piston while shoving the packing leather into the cylinder with the fingers. When it is entered, shove it back to position and turn the piston rod so that the expander-ring joint will be at the side of the cylin- der and away from the leakage groove; secure the non- pressure head. Also, see that the bolts that secure the brake cylinder to the car are tight. The brake may then be properly connected up, tested, and any rules and regulations regarding records, etc. complied with. CROSS-SECTIONAL AREA OF BRAKE CYLINDERS CROSS-SECTIONAL AREA OF CYLINDERS The accompanying table gives the cross-sectional areas for the standard sizes of brake cylinders. The calculation of the capacity of brake cylinders and reservoirs may be made by the following rule: Rule. — To find the cross-sectional area of a cylinder, in square inches, multiply the internal diameter, in inches, by the diameter and by .7854. EXAMPLE. — What is the cross-sectional area of a cylinder whose internal diameter is 10 in.? SOLUTION.— The area equals 10 X 10 X. 7854 = 78.54 sq in., call it 78* sq. in. Size of Cylinder Inches Area Square Inches 8 10 12 14 16 18 501 78 * 113 J54 201 254 i 344 BRAKE CYLINDERS CAPACITY OF CYLINDERS The capacity of a brake cylinder may be found by applying the following rule: Rule. — To find the capacity of a brake cylinder, in cubic inches, multiply the cross-sectional area of the cylinder, in square inches, by the piston travel, in inches. EXAMPLE. — What is the capacity of an 8-in. brake cylinder having an 8-in. piston travel? SOLUTION. — The area of the cylinder (from table) is 50 1 sq. in. The travel of the piston is 8 in. Hence, the capacity of the cylinder is 8X501 = 402 cu. in. The capacity of a brake cylinder is really greater than the amount calculated by this rule, for the reason that there is extra capacity that the rule does not take into consideration. CAPACITY OF AIR-BRAKE CYLINDERS Size of Cylinder Inches Piston Travel Inches Capacity Cubic Inches 8 10 12 14 16 18 8 8 8 8 8 8 450 675 950 1,280 1,650 2,085 In freight equipment, the capacity of the auxiliary tube and the cylinder clearance (the space between the brake-cylinder piston and the end of the auxiliary when the piston is in the position it assumes when the brake is released) is not consid- ered, while in passenger equipment, the capacity of the pas- sage in the brake-cylinder head and the cylinder clearance must be added to the cylinder capacity. Usually about 48 cu. in. is added to the calculated capacity of a brake cylinder to make up for the cylinder clearance, etc. In the accompanying table, the capacities of the standard brake cylinder are given, due allowance having been made for cylinder clearance, etc. BRAKE CYLINDERS 345 If the rule for the capacity of a cylinder is applied for a piston travel of 1 in., the number of cubic inches the capacity of a brake cylinder will change for each inch increase or decrease of piston travel, is numerically equal to the area of the cyl- inder. For example, the capacity of an 8-in. cylinder will change 50 j cu. in. for every 1 in. of change in the piston travel; that of a 10-in. cylinder will change 78j cu. in.; that of a 12-in. cylinder, 113 cu. in.; and so on. FORCE EXERTED IN BRAKE CYLINDER The total allowable braking force should not be exceeded when an emergency application of the brakes is made, since at such times it is especially important that no wheels slide, FORCE EXERTED IN BRAKE CYLINDER Size of Cylinder Inches Force Exerted With 50 Pounds Pressure Pounds With 60 Pounds Pressure Pounds 6 8 10 12 14 16 18 1,400 2,500 3,900 5,650 7,700 10,000 12,700 1,700 3,000 4,700 6,800 9,200 12.000 15,250 as a sliding wheel exerts but little retarding force. For this reason, the braking power is calculated on the assumption that, in an emergency application, 60 Ib. pressure is obtained in the brake cylinder with a quick-action brake, and 50 Ib. with a plain triple. The total force, in pounds, that a brake cylinder will develop when subjected to 50 and 60 Ib. pressure per sq. in. has been calculated for several sizes of cylinders; the results are given in the accompanying table. 346 BRAKE CYLINDERS The force exerted in a brake cylinder is found by multiplying the area of the piston, in square inches, by the pressure per square inch in the cylinder. Thus, if the piston has an area of 154 sq. in., it will develop a force of 154X50 = 7,700 Ib. under a 50-lb. pressure. The area of a piston may be found by multiplying the diameter of the piston, in inches, by the diameter and by 11, and dividing by 14. Thus, the area of a 10-in. piston is — = 78? sq. in. nearly. Another, and slightly more accurate, method of calculating the area of a piston is to multi- ply the diameter, in inches, by the diameter, and by .7854. FILLING BLOCKS When cars already equipped with the standard apparatus (schedule PM) are to be changed over to the new equipment (schedule LN) and when the foundation brake-gear design permits, it may be desirable to leave the old (type M) brake cylinder in position on the car instead of repla- cing it by a new (type N) cylinder. This can be accomplished by the use of a filling block, shown in the accompanying illustration, one face of which fits the seat on the brake cylinder, while the other face is a suitable seat for the triple valve to be used. When a filler block is used, an extra gasket suitable for the triple valve employed, is required. The piece numbers of the different filling blocks are: Filling block for changing from P-l to L-l triple valve, 9,361; filling block for changing from P-2 to L-2 triple valves, 9,357; filling block for changing from P-2 to L-3 triple valves, 13,006. COVER-PLATES When making the change from the standard (PM) to the new (LN) schedule, if it is found possible to leave the old (type M) brake cylinder in place on the car, but impracticable to use a filling block, the triple valve can be mounted on a BRAKE CYLINDERS 347 bracket and a suitable cover-plate, shown in the accompanying illustration, bolted to the triple-valve seat on the brake-cylinder head, making the necessary pipe connections from the cover- plate to the triple-valve bracket. The lower hole in the cover-plate connects to the brake cylinder, the upper one, at the center of the plate, to the aux- iliary reservoir. If it is preferred to connect the auxiliary reservoir direct to the triple-valve bracket, instead of retaining the old piping connecting the reservoir to the brake-cylinder head, this center hole can be plugged. The piece numbers of the different cover-plates are: Cover-plate for 6-in.f 8-in., or 10-in. type M brake cylinders, 9,235; cover-plate for 12-in., 14-in., or 16-in. type M brake-cylinders, 14,581. PRESSURE HEADS FOR TRUCK-AND TENDER-BRAKE CYLINDERS Name Piece No. Type Ref. No. Plain head for 6-in. cylinder 8,614 O 8-in. cylinder 1,136 O 10-in. cylinder 1,103 O 12-in. cylinder 3,981 O 14-in. cylinder 1,003 O 16-in. cylinder 1,071 O Plain head with lever-bracket lu%, bolts, and nuts for. 6-in. cylinder 4,938 P 8-in. cylinder 14,079 P 10-in. cylinder 14,084 P 12-in. tender cylinder 14, OSS P 12-in. truck cylinder 18,118 P 14-in. cylinder 14,091 P 16-in. cylinder 15,472 P Plain head with detachable bracket for. 6 in. cylinder 4,941 8-in. cylinder 11,502 10-in. cylinder 4,776 12-in. tender cylinder 4,777 12-in. truck cylinder 7,582 348 BRAKE CYLINDERS TABLE— (Continued) Name 14-in. cylinder 4,942 16-in. cylinder 4,913 Plain head u'ith connection for types H or P triple valves for 6-in. cylinder 4,944 8-in. cylinder 4,781 10-in. cylinder 4,779 12-in. cylinder 4,945 14-in. cylinder 4,946 16-in. cylinder 4,947 Head with lever-bracket lug, bolts, and nuts, and connection for types H and P triple valves for 6-in. cylinder 14,634 8-in. cylinder 14,611 10-in. cylinder 14,635 12-in. cylinder 15,293 14-in. cylinder 14,092 16-in. cylinder 24,767 Head with detachable bracket, and connec- tion for types H and P triple valves for 6-in. cylinder 10,151 8-in. cylinder 3,613 10-in. cylinder 4,761 12-in. cylinder 3,630 14-in. cylinder 8,617 16-in. cylinder 24,766 Detachable bracket complete, 6-in., 8-in., 10-in., and 12-in. cylinders... 10,878 Detachable bracket complete, 14-in. and 16-in. cylinders 10,820 Detachable bracket bolt and nuts, each 10,819 Detachable bracket, 6-in., 8-in., 10-in., and 12-in. cylinders, each 1,456 Detachable bracket, 14-in and 16-in. cylinders, each 4,010 Head with lever -bracket lug, bolts, and nuts, and connection for types H and P triple valves for use with combined automatic and straight - air brake, schedule SWBfor 8-in. cylinder 23,087 10-in. cylinder 10,947 12-in. cylinder 10,948 14-in. cylinder 10,949 16-in. cylinder 24.769 Piece No. AUXILIARY RESERVOIRS 349 AUXILIARY, SUPPLEMENTARY, AND EQUALIZING RESERVOIRS AUXILIARY RESERVOIRS The auxiliary reservoirs and brake cylinders with which they are used, according to the accompanying table, are so proportioned that an equalization pressure of 50 Ib. will, be obtained from 70 Ib. auxiliary-reservoir pressure with 8-in. piston travel for tender and passenger-car equipments, and with 6-in. piston travel for truck-brake equipments. Driver- brake equipment ordinarily includes two cylinders and one reservoir of sizes given in table. When a single 18-in. driver- brake cylinder is used, a 16"X42" auxiliary reservoir should be used instead of 16"X48". Standard freight-brake equip- ments include standard cast-iron auxiliary reservoirs, either detached or combined. Auxiliary reservoirs are tapped for j-in. pipe in one end; $-in. pipe in other end; and (for drain- age) in center of shell, J-in. pipe in reservoirs of 14-in. diam- eter or less, and j-in. pipe in reservoirs of 16-in. diameter or greater. SUPPLEMENTARY RESERVOIRS Supplementary reservoirs 16 in. in diameter or less are tapped for J-in. pipe in one end and $-in. pipe in other end; reservoirs over 16 in. in diameter are tapped for } in. pipe in both ends. For drainage in center of shell, reservoirs 14 in. in diameter and less are tapped for i-in. pipe and reservoirs of 16 in. in diameter or greater are tapped for i-in. pipe. When one supplementary reservoir per car is used, the sizes given in the accompanying table rhould be specified. If desirable or convenient, for any reason, two supplement- ary reservoirs may be used in which event two reservoirs of proper size, as indicated in the accompanying table, should be specified. 350 AUXILIARY, SUPPLEMENTARY, m (11^*0*0 .s .s ^ .s •§ •§ s g c n -^ ->j 8 8 -S ^ 00 O X O JS boO v w £ V—* ^ CO 00 O- CO i-i CT> O5 (N CO CO •* rf< •^QOOOOOCOOOOC'IM ^ 00 T}< T}( ** Cl CM (N W ?H C^ CN AND EQUALIZING RESERVOIRS 351 SIZE OF SUPPLEMENTARY RESERVOIR, WHEN ONE PER CAR IS USED | Used With Piece No. Size of Reservoir Inches Capacity of Reservoir Cubic Inches Weight of Reservoir Pounds L Triple Valves Passenger Car Cylinders Inches 3,091 14 X33 4,476 110 8 3,095 16 X33 5,724 145 10 13,220 16 X48 8,577 195 12 23,384 20iX36 10,158 205 14 23,385 20iX48 14,003 255 16 27,505 22*X54 18,967 410 18 SIZE OF SUPPLEMENTARY RESERVOIR WHEN TWO PER CAR ARE USED Used With Piece No. Size of Reservoir Inches Capacity of Reservoir Cubic Inches Weight of Reservoir Pounds L Triple Valves Passenger Car Cylinder Inches 3,092 "10 X33 2,145 60 8 3,093 12 X33 3,096 85 10 3,094 14 X33 4,476 110 12 3,095 16 X33 5,724 145 14 3,096 16 X42 7,436 175 16 23,384 201X36 10,158 205 18 EQUALIZING RESERVOIR The equalizing reservoir is used in connection with automatic brake valves. It is tapped for f-in. pipe and has a capacity of 812 cu. in. The piece number of the 10"X14$" equalizing reservoir is 4,884. 352 DRAIN COCKS RESERVOIR DRAIN COCKS I-IN., AUXILIARY-RESERVOIR, DRAIN COCKS The piece number of the J-in., auxiliary-reservoir, drain cock, shown in Fig. 1, is 2,101; its weight is 3 Ib. FIG. 1 FIG. 2 i-IN., MAIN-RESERVOIR, DRAIN COCKS The piece number of the i-in., main-reservoir, drain cock, shown in Fig. 2, is 7,716; its weight is 1$ Ib. The piece and reference numbers of the various parts are given in the accom- panying list. PC. No. Rff.No. 7,718 2 2,229 3 34,086 4 2,231 5 9,035 6 Name of Part Body. Key. Cap. Spring. Handle. RELEASE VALVES 353 RELEASE VALVES Auxiliary-reservoir release valves, or bleed cocks, as they are often called, are made in two types. The vertical type. Piece No. 2,416 and shown in Fig. 1, is regularly furnished as standard with full sets of freight- brake equipment; the horizontal type, Piece , No. 30,059 and shown r~l» — in Fig. 2, is furnished FiG. 1 only when specified and at an additional charge. The hori- zontal valve can be cleaned and repaired, or the internal parts may be replaced without remov- ing the valve from the auxiliary reservoir simply by removing the valve cap 24. The vertical valve weighs lj lb., whereas the horizontal valve weighs 2 1 lb. The piece and reference numbers of the various parts of the vertical release valve are given in the accompanying list. PC. No. Ref.No. Name of Part 2417 2,420 2,421 2,424 2.425 2,423 Cylinder, bushed. Stud. Vent valve, complete. Rubber seat. The piece and reference numbers of the various parts of the horizontal release valve are given in the accompany- ing list. 24 354 PRESSURE-RETAINING VALVES PC. No. Ref. No. Name of Part 30,093 23 Cylinder, bushed. 30,092 24 Valve cap. 2,421 25 Vent valve, complete. 2.424 26 Spring. 2.425 27 Handle. 2,423 28 Rubber seat. Operation of Release Valve. — The release valve is located on the auxiliary reservoir, and is used to reduce auxiliary- reservoir pressure in the event of a brake sticking, due to the triple valve not moving to release position. Also, the valve is used to relieve the auxiliary reservoir of pressure when a brake is cut out. In using the release valve to release a brake, the valve must be quickly opened its full amount and then closed the instant a blow is heard at the triple-valve exhaust port. PRESSURE-RETAINING VALVES PURPOSE OF RETAINING VALVES The pressure-retaining valve is included in all freight-brake •equipments, whether specified or not. It is furnished with passenger equipments, without extra charge, if specified on the order; it is not a part of the regular passenger schedule, however, and must be specified if desired. Care should be exercised to indicate the proper type of valve, depending on whether or not the car is of the vestibule type. It is located at the end of the car, within easy reach of the trainmen when the train is in motion, and is connected by a pipe with the exhaust port of the triple valve. Its purpose is to retard the discharge of air from, and retain a pres- sure of 15 Ib. in, the brake cylinder while the triple valve is in release position and the engineer is recharging the auxiliaries after a release on a grade, to be ready for another application of the brakes. PRESSURE-RETAINING VALVES 355 TYPE 15 RETAINING VALVE Five types of pressure-retaining valves are now in use: The type 15-O retainer, shown in Fig. 1, has a vent port &-in. in diameter and is used with 6-in., 8-inM and 10-in. brake cylin- ders; it weighs 4 Ib. The type 15-A retainer, shown in Fig. 2, has a vent port J-in. in diameter and is used with 12-in., 14-in., and 16-in. cylinders; it weighs 6§ Ib. This type differs slightly in form from the 15-O retainer, but the operation of the two is precisely the same. Type 15-B and type 15-C retaining valves shown in Fig. 3 (a) and (6), have adjustable handles for vestibule passengers cars having partitions 2J in. to 6 in. thick. The 15-B retainer is used with 6-in., 8-in., and 10-in. brake cylinders, and weighs 5$ Ib.; the 15-C, with 12-in., 14- in., and 16-in. cylin- ders, and weighs 8 Ib. The type 15-D re- tainer has three posi- tions of the handle: Straight down is release position; horizontal is FIG. 1 iap position and holds all brake-cylinder air; straight up is retaining position and holds 15 Ib. brake-cylinder pressure. It was used with driver- brake cylinders to hold 15 Ib. or all of the cylinder pressure; it weighed 5i Ib. But this valve is now obsolete, type 15-O and type 15-A being used when necessary to apply retaining valve to locomotives. The piece and reference numbers of the type 15-C, pressure- retaining valve and of the various parts are given in the accompanying list. PC. No. Ref. No. Name of Part 7,647 Type 15-C pressure-retaining valve, com- plete. 9,609 Body, complete, includes 5 to 14 inclusive. FIG. 2 356 PRESSURE-RETAINING VALVES FIG. 3 PC. No. Ref.No. Name of Part 7.645 2 Body, bushed. 2,457 3 Case. 2 458 4 Weight, complete. 7.672 5 Handle. 7.646 6 Cock key. 3,758 7 Cock cap. 7,679 8 Key spring. 7,671 9 Extension socket. 8,049 10 Extension-socket cotter. 7,674 11 Extension-socket sleeve. 7,676 12 Extension-socket sleeve pin. 7.673 13 Handle plate. 2,238 14 Handle pin. PRESSURE-RETAINING VALVES 357 The piece and reference numbers of type 15-D, pressure- retaining valve and of the various parts are given in the accom- panying list. Pc.No.Ref.No. Name of* Part 4.655 Type 15-D pressure-retaining valve, com- plete. 4,668 Body, complete, includes 5, 6, 7, and 8. 4.656 2 Body, bushed. 2.457 3 Case. 2.458 4 Weight, complete. 4,126 5 Handle. 3,762 6 Cock key. 3,758 7 Cock cap. 2,145 8 Key spring. The piece and reference numbers of type 15-O pressure- retaining valve and of its various parts are given in the accom- panying list. PC. No. Ref. No. Name of -Part 2.449 Type 15-O pressure-retaining valve, com- plete. 2.450 Body, complete, includes 5, 6, 7, and 8. 2,452 2 Body, bushed. 2.457 3 Case. 2.458 4 Weight, complete 2,105 5 Handle. 2,455 6 Cock key. 2,367 7 Cock cap. 2,231 8 Key spring. The piece and reference numbers of type 15- A pressure- retaining valve and of its various parts are given in the accom- panying list. Pc.'No. Ref. No. Name of Part 4.661 Type 15-A pressure retaining valve, com- plete. 4,670 Body, complete, includes 5, 6, 7, and 8. 4.662 2 Body, bushed: 2.457 3 Case. 2.458 4 Weight, complete. 4,415 5 Handle. 4,095 6 Cock key. 3,758 7 Cock tap. 2,145 8 Key spring. The piece and reference numbers of type 15-B pressure- retaining valve and of its various parts are given in the accom- panying list. 358 PRESSURE-RETAINING VALVES PC. No. Ref. No. Name of Part 7,813 Type 15-B pressure-retaining valve, com- plete. 9,602 Body, complete, includes 5 to 14 inclusive. 8,786 2 Body, bushed. 2.457 3 Case. 2.458 4 Weight, complete. 7.672 5 Handle. 7,812 6 Cock key. 2,367 7 Cock cap. 2,231 8 Key spring. 7,811 9 Extension socket. 8,049 10 Extension-socket cotter. 7,674 11 Extension-socket sleeve. 7,676 12 Extension-socket sleeve pin. 7.673 13 Handle plate. 2,238 14 Handle pin. OPERATION OF RETAINING VALVES With the retaining valve in release position, or straight down, the air that escapes from the exhaust port of the triple valve passes through the retainer pipe and out through the exhaust port without passing up into the valve case, thus giving a free exhaust for the air from the brake cylinder. If the handle is turned up to the horizontal, or retaining, position the free exhaust opening is closed and the air from the cylinder must then pass around the plug valve and up against the weight valve. This valve is held on its seat by the weight 4, which is heavy enough to hold the valve down against a pressure of 15 Ib. If the air coming from the brake cylinder has a pressure exceeding 15 lb.t it will raise the valve and pass up into the retainer case 8. It must then pass out through a small vent port, the diameter of which at its smallest part is & in. This retards the flow of air so that it takes about 20 to 25 sec. for the air to pass out of an 8-in. cylinder with 8-in. travel and reduce the pressure from 50 to 15 Ib.; thus, sufficient time is given for the auxiliaries to recharge from 50 to 70 Ib. before the pressure is reduced to 15 Ib. The brake-cylinder pressure reduces gradually during the recharging, and the retainer finally keeps 15 Ib. until the handle 5 is turned down to the vertical position, and opens the exhaust port. With larger cylinders, the use of this size retainer makes the time for PRESSURE-RETAINING VALVES 359 reducing the pressure from 50 to 15 Ib. proportionately longer. The small vent port chokes the discharge of air so that the weight 4 closes the weight valve at short intervals during the reduction. The restricted opening of the vent port is a valuable feature of this valve. HIGH- AND LOW-PRESSURE RETAINING VALVES The 15-30 pound, high- and low-pressure retaining valve, shown in Fig. 1, regulates the pressure at 15 and 30 Ib. It is FIG. 1 FIG. 2 used on 6-in., 8-in., and 10-in., brake cylinders and weighs 6J Ib. The piece and reference numbers of the valve and of its various parts are given in the accompanying list. PC. No. Ref. No. Name of Part 10,970 Type 15-30 pressure-retaining valve, com- plete. 10,973 Body, complete, includes 5, 6, 7, and 8. 10,972 2 Body, bushed. 10,977 3 Case. 11,756 1 Inside weight, complete. 360 PRESSURE-RETAINING VALVES PC. No. Ref. No. Name of Part 7,871 5 Handle. 7.870 6 Cock key. 7,875 7 Cock cap. 2,231 8 Key spring. 7.879 9 Weight-lifting rod. 10,976 10 Outside weight, complete. The 25-50 pound, high- and low-pressure retaining valve, shown in Fig. 2, regulates the pressure at 25 and 50 Ib. It is used on 6-in., 8-in., and 10-in. brake cylinders and weighs 7f Ib. The piece and reference numbers of the valve and of its various parts are given in the accompanying list. PC. No. Ref. No. Name of Part 7.880 Type 25-50 pressure-retaining valve, com- plete. 9.610 Body, complete, includes 5, 6, 7, and 8. 7.877 2 Body, bushed. 7.869 3 Case. 7.878 4 Inside weight, complete. 7.871 5 Handle. 7.870 6 Cock key. 7,875 7 Cock cap. 2,231 8 Key spring. 7.879 9 Weight-lifting rod. 9.611 10 Outside weight, complete. Operation. — This type of pressure-retaining valve operates like the older types, except that the weight can be increased so as to make it a two-pressure retainer. The weights 4 and 10 are equal. The weight 10 is cylindrical and surrounds the weight 4- It can be raised off of weight 4 or lowered on to it by turning the handle 5 to the proper position. With the handle straight down, the retainer is cut out of service. In this position the handle engages rod 9 and raises weight 10 off of weight 4 so as to reduce the wear of the valve seat. With the handle in its intermediate position, the weight 10 rests on the weight 4- This doubles the amount of retainer weight, so that the high pressure is retained, as the pressure must raise both weights to escape. With the handle horizontal, the weight 10 is raised off the weight 4 so that the weight 4 alone is in use; thus the low pressure is retained. SAFETY VALVES 361 SAFETY VALVES TYPES OF AIR-BRAKE SAFETY VALVES Pour types of air-brake safety valves are made; viz., E-l and E-6, which weigh 3 lb., and E-3 and E-7, which weigh 3i lb. While types E-l and E-3 are designed for air-brake service, they can be used for any service where a high-grade, air-pressure, safety valve is required. However, the ranges of pressures given must not be departed from as they cover the FIG. 1 FIG. 2 limits under which satisfactory operation can be obtained from the different springs. The pressure range for which the valve is adapted is now stamped on the hexagon portion of the body. The E-l safety valve, shown in Fig. 1, is suitable for general service where a high-grade, air-pressure, safety valve is required, except where it is necessary to have a close or adjust- able range between the opening and closing points of the safety valve, in which case the type E-3 should be used. 362 SAFETY VALVES The E-l safety valve, which has a range from 35 Ib. to 75 lb., Piece No. 10,526, is the valve most commonly used with driver- and tender-brake cylinders, in connection with schedules SWA, SWB, and U; on passenger cars temporarily used in trains equipped with high-speed brakes; and with No. 5 distributing valve. The E-3 safety valve, shown in Fig. 2, is provided with an adjustable exhaust regulating ring, by means of which the drop, or range between the opening and closing points of the safety valve, can be adjusted to any desired amount. It is, FIG. 3 PIG. 4 therefore, particularly adapted for use where it is desirable to keep this range at any given amount, large or small. The E-6 safety valve, shown in Fig. 3, is a special valve not used for general purposes. It is a part of and is regularly sup- plied with the No. 6 distributing valve. The E-7 safety valve, shown in Fig. 4, is a special valve, and not used for general purposes. It is a part of and is regu- larly supplied with type L triple valves. The piece and reference numbers of the different types of valves, and of the various parts of each, are given in the accom- panying lists. SAFETY VALVES PC. No. Ref. 28,487 18,598 10,526 24,106 24,107 24,108 10,528 9,029 10,524 10,523 18,286 18.414 1,498 3,639 24,112 13,434 9,030 24,109 24,110 12,705 24,111 15,494 26,079 12,795 9,029 10,524 10,523 24,113 24,112 13,434 24,114 12,490 26,078 6 9,030 7 12.797 8 12.798 9 TYPE E-l SAFETY VALVES No. Name of Part Type E-l safety valve, 5 Ib. to 25 lb., complete. Type E-l safety valve, 10 lb. to 40 lb.f complete. Type E-l safety valve, 35 lb. to 75 lb., complete. Type E-l safety valve, 60 lb. to 100 lb., complete. Type E-l safety valve, 80 lb. to 130 lb., complete. Type E-l safety valve, 110 lb. to 150 lb., complete. Body, bushed.. Cap nut. Valve. Valve stem. Spring, 5 lb. to 25 lb. Spring, 10 lb. to -10 lb. Spring, 35 lb. to 75 lb. Spring, 60 lb. to 100 lb. Spring, 80 lb. to 130 lb. Spring, llOlb. to 150 lb. Regulating nut. TYPE E-3 SAFETY VALVES Type E-3 safety valve, 50 lb. to 90 lb., complete. Type E-3 safety valve, 80 lb. to 130 lb., complete. Type E-3 safety valve, 110 lb. to 150 lb., complete. Type E-3 safety valve, 140 lb. to 225 lb., complete. Type E-3 safety valve, 210 lb. to 325 lb., complete. Type E-3 safety valve, 300 lb. to 400 lb. complete. Body, bushed. Cap nut. Valve. Valve stem. Spring, 50 lb. to 90 lb. Spring, 80 lb. to 130 lb. Spring, 110 lb. to 150 lb. Spring, 140 lb. to 225 lb. Spring, 210 lb. to 325 lb. Spring, 300 lb. to 400 lb. Regulating nut. Exhaust -regulating ring. Lock-ring. 4 SAFETY VALVES TYPE E-6 SAFETY VALVE PC. No. Ref. No. Name of Part 15,890 E-6 safety valve 50 Ib. to 90 lb., complete. 15.554 2 Body, bushed. 9,029 3 Cap nut. 10.524 4 Valve. 10.523 5 Valve stem. 24,113 6 Spring, 50 lb. to 90 lb. 16,087 7 Regulating nut. TYPE E-7 SAFETY VALVE PC. No. Ref. No. Name of Part 15,549 E-7 safety valve, 35 lb. to 75 lb., complete. 15,538 2 Body, bushed. 9,029 3 Cap nut. 10.524 4 Valve. 10,523 5 Valve stem. 1,498 6 Spring 35 lb. to 75 lb. 16,087 7 Regulating nut. 12.797 8 Exhaust -regulating ring. 12.798 9 Lock-ring. OPERATION OF SAFETY VALVES The construction of all four types of safety valves is prac. tically the same, except that the E-3 and E-7 valves have an exhaust-regulating ring 8 and lock-ring 9. The safety valve operates as follows: Air enters the safety valve and exerts an upward pressure on the under side of the valve 4- When the pressure underneath the valve slightly exceeds the tension of the adjusting spring 6, the valve 4 is raised, and as it rises, a larger area is exposed to the air pressure, which then causes it to move upwards quickly until the stem strikes the cap nut 3. During this movement, the upper end of the two vertical ports in the valve bushing are closed by the valve 4 and the horizontal ports in the bushing and the body 2 are opened. This allows air from the valve chamber to pass to the atmosphere, and as the pressure in this chamber decreases, the adjusting spring moves the valve 4 down toward its seat. During this movement, the horizontal ports are closed and the upper end of the vertical ports in the valve bushing are opened. This allows air from the valve chamber to pass into the chamber above valve 4, from which place it HIGH-SPEED REDUCING VALVE 365 can escape to the atmosphere through the vent ports in the valve body. The air from the valve chamber can pass into the upper chamber through the vertical ports in the bushing faster than the air can escape from this chamber to the atmos- phere through the vent ports. This causes a pressure to accumulate above valve 4 and assists the spring 6 in closing the valve with a pop action. The promptness with which valve 4 will close depends, to a certain extent, on the rate at which air can escape through the vent ports in the body 2 and the rate of discharge of air through these ports can be regulated by the exhaust-regulating ring 8, which is locked in position by the lock-ring 9. HIGH-SPEED REDUCING VALVE PIECE AND REFERENCE NUMBERS The high-speed reducing valve, shown in the accompanying illustration, is made in five sizes for use with 8-in., 10-in., 12-in., 14-in., and 16-in. brake cylinders, hence, care must be observed to use the proper size valve for the brake cylinder. The weight is 35 Ib. The piece and reference numbers of the different valves, and of the various parts of each, are given in the accompanying list. PC. No. Ref. No. Name of Part 4,128 High-speed reducing valve, complete, for 8-in. cylinder. 11,176 High-speed reducing valve, complete, for 10-in. cylinder. 3,712 High-speed reducing valve, complete, for 12-in. cylinder. 11,275 High-speed reducing valve, complete, for 14-in. cylinder. 3,711 High-speed reducing valve, complete, for 16-in. and 18-in. cylinder. PARTS COMMON TO ALL VALVES PC. No. Ref. No. Name of Part 2 Body, bushed. 2,402 3 Spring box, bushed. 2,392 4 Piston, includes 5. 366 HIGH-SPEED REDUCING VALVE HIGH-SPEED REDUCING VALVE 367 PC. No. Ref.No. Name of Part 10,030 5 Piston ring. 2,396 6 Piston stem. 2,397 7 Piston-stem nut. 8 Slide valve. 2,400 9 Slide-valve spring. 2,401 10 Cap nut. 2.406 11 Regulating spring. 2,407 12 Regulating nut. 7,094 13 Check-nut. 2,410 14 Union stud. 2,412 15 Union swivel. 1,749 16 Union nut. 2,411 17 Air strainer. 1,755 18 Union gasket. 5,198 19 Bolt and nut. 2,394 20 Piston seat. 2,395 21 Piston disk. 2,405 22 Spring abutment. 3,942 23 Cotter. 13,225 2,202 24 25 i-in. street L 1-in. pipe plug. PARTS NOT COMMON TO ALL VALVES, BUT TO BE ORDERED AS NOTED Ref. No. Name of Part Piece Number When Used With 8-In. Cyl. 10-In. Cyl. 12-In. Cyl. 14-In. Cyl. 16-In. and 18-In. Cyl. 2 8 Body Slide valve . . 4.124 4,125 11.124 4,125 3,349 3,351 11,128 11.129 3,346 3,347 OPERATION OF REDUCING VALVE The slide valve seat in the body bush has a long narrow port (which will be designated a) extending crosswise with the slide valve 8. The slide valve has a triangular-shaped port (which will be designated b) with its apex pointing toward the cap nut 10. In release position of the reducing valve, port b is above port a. 368 HIGH-SPEED REDUCING VALVE As long as the cylinder pressure remains less than 60 Ib. per sq. in., the reducing valve plays no part in an ordinary service application of the brake, the valve remaining in its normal position, with port a blanked. Suppose, that in making a service application, the brake-cylinder pressure should increase above 60 Ib.; the pressure above the piston 4 will be sufficient to compress the regulating spring, and the piston and slide valve will be forced downwards until the base, or largest part of port b, registers with port a. In this position, brake-cylinder air is free to flow to the atmosphere through the exhaust fitting 24 until the pressure is reduced to 60 Ib., when the regulating spring forces the piston and slide valve upwards into their normal positions again. The area of the opening through ports a and b in this position is such that air can discharge from the cylinder as fast as it enters through the service port in the slide valve of the triple. In an emergency application of the brake, air enters the brake cylinder from the train pipe and auxiliary reservoir in much greater volume than it could possibly escape through the ports a and b of the reducing valve; hence, piston 4 of the latter is forced downwards the full length of its stroke, and assumes a position such that the apex of the triangular port b registers with port a. In this position, the passage through ports a and b is small and air discharges quite slowly from the cylinder. As the pressure in the cylinder, and conse- quently above piston 4, gradually decreases, due to the dis- charge through ports a and b, the regulating spring gradually raises the piston and slide valve, and, as the slide valve is raised, the opening through ports a and b gradually increases; consequently, the discharge from the cylinder increases accord- ingly until the brake-cylinder pressure is reduced to a safe amount (60 Ib.), when the reducing valve assumes its normal position, covering the opening a so that no more air can escape from the brake cylinder until brakes are released. CENTRIFUGAL DIRT COLLECTORS 369 CENTRIFUGAL DIRT COLLECTORS The centrifugal dirt collector, which is shown in Fig. 1, supersedes the brake-pipe air strainer and is now regularly furnished as a part of the standard air-brake equip- ments. When included with full sets, no extra charge is made. The collector is made in three sizes, f-in., 1-in., and IJ-in. The f-in. collector, Piece No. 32,342, is used on locomotives; the 1-in., Piece No. 27,950, is used on pas- senger cars; and the li-in., Piece No. 31,802, is used on freight cars. The dimensions and weights are given in the accompanying table and piece FIG. 1 and reference numbers of the different sizes, and of the various parts of each, are given in the accompanying list. DIMENSIONS AND WEIGHTS OF CENTRIFUGAL DIRT COLLECTOR Size Inches Width Inches Length B Inches Length Inches Weight Pounds I 4i 7 8} 8J li 11 It «! 81 9 91 J-IN. CENTRIFUGAL DIRT COLLECTOR PC. No. Ref. No. Name of Part 32,342 J-in. centrifugal dirt collector, complete. 32,304 2 Body. 27,951 3 Deflector and special plug. 25 370 CENTRIFUGAL DIRT COLLECTORS I-IN. CENTRIFUGAL DIRT COLLECTOR PC. No. Ref. No. < Name of Part 27.950 1-in. centrifugal dirt collector, complete. 27,947 2 Body. 27.951 3 Deflector and special plug. H-IN CENTRIFUGAL DIRT COLLECTOR PC. No. Ref. No. Name of Part 31,802 Ij-in. centrifugal dirt collector, complete. 31,801 2 Body. 27,951 3 Deflector and special plug. With the brake-pipe strainer, there is a tendency for dirt and foreign matter to clog the strainer, thereby restricting the flow of air through it, which frequently results in imperfect FIG. 3 operation of the brakes; also, to clean the brake-pipe strainer, the pipe connections must be broken. With the centrifugal dirt collector no strainer is used; hence, the air passage through it remains free and unrestricted at all times. Dirt and foreign AIR STRAINERS 371 matter drop to the bottom of the chamber and can be quickly removed without disturbing any pipe connections. A good idea of the internal construction and the operation of the centrifugal dirt collector can be obtained from the horizontal section shown in Fig. 2. Air from the brake pipe, on its way to the triple valve, enters at A, passes through the passage ct into the chamber E, thence up passage /, and out at B. The air on its way through the passage c receives a whirling motion when it enters chamber E, which tends to cause any foreign matter in the air to be carried close to the walls of the chamber. Then, as the air is compelled to rise in order to escape through passage /, the foreign matter drops to the bottom of the collector whence it can be removed by unscrewing the special plug 3. In Fig. 3 is shown the application of centrifugal dirt collector to a car. AIR STRAINERS BRAKE-PIPE STRAINERS Two sizes of brake-pipe strainers, shown in Fig. 1, are made. The 1-in. strainer was formerly furnished with locomotive and passenger-car brake equip- ments. The IJ-in. was for- merly furnished with freight-car brake equipments, also with locomotive - brake equipments when li-in. brake pipe was spe- cified. To meet special conditions, a pattern is provided for a 1 1" X1J"X}" brake-pipe strainer, Piece No. 6,141, to avoid the cumbersome appearance of the standard IJ-in. strainer, Piece No. 2,151, if bushed. Piece No. 6,141 will be made up and sup- plied only as ordered and can be furnished with J-in. side open- ing bushed to Hn. (Piece No. 6,145) or to i-in. (Piece No. 11,496) if desired. Repair parts for these special strainers are the same as for the standard, except body, Piece No. 6,142, for 372 AIR STRAINERS the li"XlJ"Xi" strainer, arid bushings, }"Xi", Piece No. 9,332, and i"X|", Piece No. 10,089. If desired to have side opening bushed for smaller than 1-in. pipe, orders should so state and specify as follows: 1"X 1"X f " brake-pipe strainer, Piece No. 4,989; 1"X1"X?" brake-pipe strainer, Piece No. 2,179; or l"Xl"Xf" brake-pipe strainer, Piece No. 10,039. Repair parts for these strainers are the same as for the standard, except bushings, l"Xf", Piece No. 6,983, 1"X4", Piece No. 2,181, and 1"X|", Piece No. 10,045. The dimensions and weights of each size are given in the accompanying table; the piece and reference numbers of the strainers and their various parts are given in the accompanying lists. DIMENSIONS AND WEIGHTS OF BRAKE-PIPE STRAINERS Size Inches Length of A Inches Length of B Inches Length of C Inches Weight Pounds H 21 3} 4| 7| 1 2H si 4| 6 I-IN. BRAKE-PIPE STRAINERS PC. No. Ref. No. Name of Part 2,148 1"X 1"X 1" brake-pipe strainer, complete. 2, 180 2 1"X 1"X 1" strainer body, includes 6. 1,750 3 1-in. union swivel. 1,749 4 1-in. union nut. 1,755 5 1-in. union gasket. 2,150 6 Strainer. U-IN. PC. No. Ref. No. 2,151 2,182 2,155 2,154 2,183 2,153 BRAKE-PIPE STRAINERS Name of Part li"Xlj"Xlj" brake-pipe strainer, com- plete. H"X H"X 1 J" strainer body, includes 6. IJ-in. union swivel. IJ-in. union nut. li-in. union gasket. Strainer. 49»A49O U Ol/IctlilCl. Brake-Pipe Air Strainer With Special Union Nut and Swivel. In Fig. 2 is shown a brake-pipe air strainer with a special AIR STRAINERS 373 union nut and swivel; but this strainer is furnished on special order only. It weighs 8| Ib. The piece and reference numbers PlG. 2 of the strainer and its various parts are given in the accompany- ing list. PC. No. Ref. No. Name of Part 29,865 29,875 29,741 29,740 7,683 2,153 !J"Xli"XlJ" brake-pipe air strainer, complete. Strainer body, includes 6. IJ-in; union swivel. IJ-in. union nut. IJ-in. union gasket. Strainer. C STRAINER AND CHECK-VALVE The C strainer and check-valve, shown below, is now superseding the B-2 type. Type C-l-3-6 is used with schedule L air-signal equipment for locomotives having No. 6 ET brake equipment; it weighs 3} Ib. The piece and reference numbers 374 AIR STRAINERS of the strainer and its various parts are given in the accom- panying list. PC. No. Ref. No. Name of Part 24,899 C-l-3-6 strainer and check valve, complete. 25.908 2 Body, bushed. 14,661 3 Cap nut. 25.909 4 Check-valve. 25,921 5 3-lb. valve spring. 24,893 6 Valve cap. 1,044 7 Strainer (2 pieces) each. 8 Curled hair. 14,204 9 Union swivel. 2,165 10 Union nut. 2,204 1J Union gasket. 15,473 12 Choke plug with &-in. hole. 25,788 13 Leather seat. Type C-l-20-8 strainer and check-valve is used with dead engine fixtures, No. 6 ET equipment; it weighs 3J Ib. The piece and reference numbers of the strainer and its various parts are given in the accompanying list. PC. No. Ref. No. Name of Part 24,898 C-l-20-8 strainer and check valve, com- plete. 25.908 2 Body, bushed. 14,661 3 Cap nut. 25.909 4 Check-valve. 25,920 5 20-lb. valve spring. 24,893 6 Valve cap. 1,044 7 Strainer (2 pieces) each. 8 Curled hair. 14,294 9 Union swivel. 2,165 10 Union nut. 2.204 11 Union gasket 25,906 12 Choke plug with i-in. hole. 25,788 13 Leather seat. SIGNAL-PIPE STRAINER The signal-pipe strainer, shown herewith, is furnished with schedule K, passenger-car, air-signal equipments; it weighs 1$ Ib. The piece and reference numbers of the strainer and its parts are given in the accompanying list. AIR STRAINERS 375 PC. No. Ref. No. Name of Part 2,240 2,497 2 l"X i"X V signal pipe strain^. Strainer body, includes 6. complete. 2,166 3 !-in. union swivel. 2,165 4 -in. union nut. 2,204 5 -in. union gasket. 2,242 6 trainer. f-IN. AIR STRAINER The |-in. air strainer, shown below, is furnished with schedule J, locomotive air-signal equipments; it weighs 1| Ib. The piece and reference numbers of this strainer and its parts are given in the accompanying list. PC. No. Ref. No. Name of Part 3,272 3,273 1,044 3,274 f-in. air strainer, complete. Body. Strainer (2 pieces) , each. Cap. Curled hair. 376 CONDUCTOR'S VALVES 1-IN. BRANCH PIPE STRAINER The 1-in. air branch-pipe strainer, shown below, is used in connection with pipeless triple valves; it weighs If Ib. The piece and reference numbers of the strainer and its parts are given in the accompanying list. PC. No. Ref. No. Name of Part 9,523 9,522 2,411 1,749 1,750 1.755 1-in. branch pipe strainer, com- plete. Body. Strainer. 1-in. union nut. 1-in. union swivel. 1-in. union gasket. CONDUCTOR'S VALVES C-3 CONDUCTOR'S VALVE The C-3 conductor's valve, which is shown herewith and is tapped for f-in. pipe, is of the non-self-closing type; it is the standard valve furnished with all passenger-car brake equip- ments unless otherwise specified. Its weight is 4f Ib. The CONDUCTOR'S VALVES 377 piece and reference numbers of the valve and its parts are given in the accompanying list. PC. No. Ref. No. Name of Part 14,436 C-3 conductor's valve, complete. 14,428 2 Body. 2.143 3 Key. 2.144 4 Cap. 2.145 5 Key spring. 2,069 6 Key stop. 14.384 7 Key escutchdbn. 2,107 8 Handle. 2,147 9 Key nut. 14,716 10 Bolt and nut. iin.X3in. 14.385 11 Filler block. T B-3 CONDUCTOR'S VALVE The B-3 conductor's valve, which is shown herewith and is tapped for I -in. pipe, is of the non- self-closing poppet-valve type, which when opened, must be closed by hand. Its weight is 4 Ib. This valve is not standard, but will be supplied with passenger-car brake equipments when so specified on orders. The piece and reference num- bers of the valve and its parts are given in the accompanying list. PC. No. Ref. No. Name of Part 16,570 B-3 conductor's valve, complete. 16,499 2 Body. 16,514 3 Vent valve, complete, includes 4 and 5. 16,436 4 Rubber seat. 1.79-1 5 Valve nut. 7,448 6 Valve spring. 5,205 7 Cap. 378 CONDUCTOR'S VALVES PC. No. Re.f. No. Name of Part 13.574 8 Valve lever. 13.575 9 Operating lever. 13.576 10 Rivet. 2,958 11 Cotter. A-l CONDUCTOR'S VALVE The A-l conductor's valve, which is shown below and is tapped for f-in. pipe, is an old design of the self-closing type, and is no longer used except in special cases, It weighs 6 Ib. The piece and reference numbers of the valve and its parts are given in the accompanying list. Name of Part A-l Conduc- tor's valve, complete. Body.bush'd. Vent valve, complete, includes 4. Rubber seat. Valve spring. Upper cap. Lower cap. Extension stem. Lever, in- cludes ring. Lever braok't. Screen. OPERATION OF CONDUCTOR'S VALVE The conductor's valve is connected to the brake pipe by means of a branch pipe, and when open makes a direct passage from the brake pipe to the atmosphere. The valve is intended to be used only in case of emergency. It should be opened wide and held open until the train comes to a stop, for if allowed to close and the engineer's brake valve is in run- ning position, the brakes will be released again. HOSE, COUPLINGS, AND FITTINGS 379 HOSE, COUPLINGS, AND FITTINGS STANDARD FITTINGS The M. C. B. code of rules governing the condition of and repairs to freight cars for interchange traffic; and the appendix on same covering passenger cars (as revised June, 1911, and taking effect Sept. 1, 1911), make the 1|"X22" air-brake hose and coup- lings standard for both freight- and passenger-brake equipment, instead of the 1 \" X 22" hose and coupli ngs formerly standard. The interchange rules do not change the size of signal hose, the standard still being H"X22". The revised rules do not change hose for locomotives, which remain 1J"X 22", although l|"X22"hose and couplings may be used if desired. Hose couplings are designated by two letters and a figure, as FP-5. The first letter indicates the group of couplings that can be coupled together. That is, all couplings of group F will FIG. 1 1'P.PC FIG. 2 couple together, but they will not couple with those of group H. The second letter indicates the style of coupling, all P couplings 380 HOSE, COUPLINGS, AND FITTINGS being of the same style. The figure indicates the size of the hose or pipe, in quarters of an inch; a 5 hose is 5X i or IJ-in. hose; a 4 hose is a 1-in. hose. Nipples are designated by two dimensions, as If'Xli" nipple. The first dimension is the inside diameter of the hose for which the nipple is intended; the second dimension is the size of the pipe. A cross-section of hose, showing its construc- tion is shown in Fig. 1, in Fig. 2 is a diagrammatic view of the FP coupling. HOSE AND COUPLINGS HOSE AND FP-5 COUPLING The hose and FP-5 coupling is the standard for brake-pipe connection on freight cars; it is also furnished, when ordered, for locomotives having 1 J-in. piping. The piece and reference numbers are given in the accompanying list. PC. No. Ref. No. Name of Part 28,393 lf"X22" hose with FP-5 coupling and IJ-in. nipple, complete, per pair. 3,056 2 FP-5 hose coupling, complete, includes 3 per pair. 3,279 3 Hose-coupling gasket. 2.110 4 If'Xli" threaded hose nipple. 26,379 Galvanized annealed steel clamp, com- plete for l|-in. hose, includes 5 and 6. 26,378 5 Galvanized annealed steel clamp, only for If -in. hose. 4,866 6 Hose -clamp bolt and nut. 2.463 7 lf'X22" hose. HOSE AND FP-4 COUPLING The hose and FP-4 coupling is the standard for brake-pipe connection on passenger cars, and on locomotives having 1-in. piping. The piece and reference numbers are given in the accompanying list. PC. No. Ref. No. Name of Part 28,511 H"X22" hose with FP-4 coupling and IJ-in. nipple, complete, per pair. 3,058 2 FP-4 hose coupling, complete, includes 3, per pair. 3,279 3 Hose-coupling gasket. 2.111 4 1 i" X 1 i" threaded hose nipple. HOSE, COUPLINGS, AND FITTINGS 381 PC. No. Ref.No. Name of Part 28,222 Galvanized annealed steel clamp, com- plete for If-in. hose, includes 5 and 6. 28,221 5 Galvanized annealed steel clamp, only for li-in. hose. 4,866 6 Hose-clamp bolt and nut. 2,243 7 li"X22" hose. HOSE AND HP-4 COUPLING The hose and HP-4 coupling is the standard for signal-pipe connection on locomotives and cars; also for brake-cylinder connection between engine and tender with ET equipments and schedules SWA and SWB. The piece and reference num- bers are given in the accompanying list. PC. No. Ref. No. Name of Part 28,510 3,060 3.279 2,112 28,222 28,221 4,866 2,243 1|"X22" hose with HP-4 coupling and f-in. nipple, complete, per pair. HP-4 hose coupling, includes 3 per pair. Hose-coupling gasket. H"Xf" threaded hose nipple. Galvanized annealed steel clamp, complete for 1 J-in. hose, includes 5 and 6. Galvanized annealed steel clamp, only for IJ-in. hose. Hose -clamp bolt and nut. li"X22"hose. HOSE PROTECTING COUPLINGS The hose protecting coupling is absolutely interchangeable with the old coupling in every respect and is in fact identical except that the new type has a flexible bead, instead of the FIG. 3 ordinary bead, which is integral with the coupling casting. This flexible bead permits the disengagement of the couplings, when the cars are separated, before the pull is sufficient to 382 HOSE, COUPLINGS, AND FITTINGS damage the hose, the pull for the flexible- bead coupling being 50 Ib. as against approximately 250 Ib. for the rigid-bead coupling. This insures the parting of the flexible-bead coupling before the strain is sufficient to damage the hose. Couplings showing this bead are shown in Fig. 3. The piece number of the lf"X22" hose with hose protecting coupling, complete, is 32,015; that of hose protecting coupling, com- plete for lf"X22" hose, is 28,207. HOSE CONNECTIONS TRUCK-HOSE CONNECTION In Fig. 1 is shown the connection to engine-truck-brake cylinder, schedule D-2. The piece and reference numbers of the connection and its parts are given in the accompanying list. PC, No. 30,334 2,243 19,729 2,821 2.165 2,166 2,204 28,222 28,221 4,866 Ref. No. Name of Part 1 \" X 22" hose with union nipples for J-in. pipe. 2 1|"X22" hose. 1|"X 2 "union hose nipple, complete, in- cludes 3, 4, 5, and 6. 3 1 i" X 2" union hose nipple. 4 i-in. union nut. 5 |-in. union swivel. 6 |-in. union gasket. Galvanized annealed steel clamp, com- plete, for l|-in. hose, includes 7 and 8. 7 Galvanized annealed steel clamp, only for l|-in. hose. 8 Hose-clamp bolt and nut. HOSE, COUPLINGS, AND FITTINGS 383 ENGINE AND TENDER HOSE CONNECTION In Fig. 2 is shown an engine-and-tender-hose connection, that, while not standard, is furnished when specified with combined FIG. 2 automatic and straight-air brake, schedule SWB. The piece and reference numbers of the connection and its parts are given in the accompanying list. PC. No. Ref. No. Name of Part 30.626 lt*X36* hose with threaded and union nipples for f-in. pipe, complete. li»X36* hose. li'Xr union hose nipple, complete, includes 3, 4, 5, and 6. * union hose nipple. 4.893 21,394 2.114 3,306 3,307 3.308 28,222 28.221 4.866 2,112 f-in. union nut. ?-it 3 4 5 J-in. union swivel. 6 f-in. union gasket. Galvanized annealed steel clamp for IJ-in. hose, com- plete, includes 7 and 8. 7 Galvanzied annealed steel clamp, only for IJ-in. hose. 8 Hose-clamp bolt and nut. 9 IPX!* threaded hose nipple. FIG. 3 DUMMY COUPLINGS The new-style type F dummy coupling, shown in Fig. 3, is used with the FP-4 and FP-5 hose couplings, and the new-style type H dummy coupling is used with the HP-4 hose coupling. The new-style are now regularly furnished with all brake 384 HOSE, COUPLINGS, AND FITTINGS §| 'S 3 11 -ss /ijl ''t'''' ^ ,