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 



