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. 



