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 superseded by D-5, E-6, or F-6 brake valve (the 1892 model) 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 



