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. 



