. Locomotive engineering : a practical journal of railway motive power and rolling stock . artswe may add the vent ports M and / andthe passages H, L L and K. In charging up, the air comes in fromthe train pipe, takes the course indicatedby the arrows in Fig. i, and passes by thetriple piston through the feed groove B tothe auxiliary; it also charges chamber G,between the vent valve and triple pistons,through the very small port F, drilledthrough the vent valve piston. In the service application (Fig. 2) onlythe triple valve proper operates. The triplepiston moves to the left until it restsaga
. Locomotive engineering : a practical journal of railway motive power and rolling stock . artswe may add the vent ports M and / andthe passages H, L L and K. In charging up, the air comes in fromthe train pipe, takes the course indicatedby the arrows in Fig. i, and passes by thetriple piston through the feed groove B tothe auxiliary; it also charges chamber G,between the vent valve and triple pistons,through the very small port F, drilledthrough the vent valve piston. In the service application (Fig. 2) onlythe triple valve proper operates. The triplepiston moves to the left until it restsagainst, and forms an air-tight joint on,the leather gasket 133; then the exhaustvalve 38 is moved into a position coveringthe exhaust ports from the brake cylinderto the atmosphere, and the service port isuncovered by the graduating valve 48, sothat the auxiliary pressure may expandinto the brake cylinder and apply the make the triple operate in the service The moment the vent valve is moved awayfrom its seat train pipe pressure in a largevolume escapes to passage H, and rushesJ. TrainPipe or graduated application, a gradual reduc-tion in train pipe pressure is required. The quick-action parts of the triple areto be operated only in emergencies, andare added to the triple for the purpose ofgiving a quick serial application of thebrakes throughout a long train. If a quick, serial application of the brakeis desired, as in emergencies a quick re-duction in train pipe pressure must bemade, which will cause piston 128 to movevery quickly to the left, and thus, bycushioning and compressing the air inchamber G, which does not, on account ofthis quick movement, have time to escape,moves vent valve piston 129 to the left,mtil its stem strikes against the lever armof vent valve 71 and opens it, as in Fig. 3.[The engraving should show this valve 71wide open and free from its seat.—Ed.]The pressure that surrounds vent valve 71,and with the assistance of spring 132,holds it to its
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectrailroa, bookyear1892
