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-in M 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 i a p 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 



