166 



TRIPLE VALVES 



H-2 (H-49), QUICK-ACTION, FREIGHT, TRIPLE VALVE 



The H-2 (H-49), quick-action, freight, triple valve, shown in 

 Fig. 2, was used with 10-in. freight-car brake cylinders only; 

 it weighed 44 Ib. It has been quite generally superseded by 

 the K-2 quick-action, quick-service, uniform-release, and 

 uniform-recharge freight triple valve, which is regarded as 

 standard for this service. Though similar in appearance, 

 this valve differs essentially from other quick-action triple 

 valves, and should never be used except as specified. In 

 addition to being marked H-2 on the valve body, it may be 

 distinguished from the passenger triple valves, type P, by the 

 fact that it has two exhaust outlets (one of which is plugged) 

 and from the H-l 8-in. freight triple valve in having three 

 instead of two bolt holes in the back flange. The bore of its 

 slide-valve bush is If in. Fig. 

 3 shows two perspective views 

 of the slide valve 8. In or- 

 dering slide valve or gradua- 

 ting valve for the H-2 freight 

 triple valve, the order should 

 state clearly whether old- or 

 new-style parts are desired, 

 because these are not inter- 

 changeable. The new-style 

 (present standard) slide valve, 

 Piece No. 29,138, has straight 

 drill through longitudinal cen- 

 ter line of slide valve, for the 

 new (present standard) &-in. 

 graduating valve, Piece No. 29,139. The old-style slide valve, 

 Piece No. 1,769, has J-hi. drill with counter bore for the old- 

 style, graduating valve, Piece No. 1,732. The graduating 

 valves may be distinguished by the difference in diameter and 

 the fact that the old-style has a shoulder, whereas the new- 

 style has none. 



The piece number of the H-2 triple valve, complete, is 4,870; 

 the piece and reference numbers of the various parts are given 

 in the accompanying list. 



FIG. 3 



