Locomotive appliances . Fig. Spring-Seat Valve. groove. These seats have greater contact surface,and by means of the central grooves have greaterresilient action, which permits them to shut tight andremain so. This novel characteristic prevents themfrom jamming when the valve is closed, and leavesthem free to accommodate themselves to any variationof temperature. When partially open, it is claimedthat the out-rushing steam or water does not abrade LOCOMOTIVE APPLIANCES. 373 their surfaces, as ordinarily happens with ordinaryvalves. THE HOMESTEAD STRAIGHT-WAY VALVE. This valve is so co
Locomotive appliances . Fig. Spring-Seat Valve. groove. These seats have greater contact surface,and by means of the central grooves have greaterresilient action, which permits them to shut tight andremain so. This novel characteristic prevents themfrom jamming when the valve is closed, and leavesthem free to accommodate themselves to any variationof temperature. When partially open, it is claimedthat the out-rushing steam or water does not abrade LOCOMOTIVE APPLIANCES. 373 their surfaces, as ordinarily happens with ordinaryvalves. THE HOMESTEAD STRAIGHT-WAY VALVE. This valve is so constructed that when it isclosed it is at the same time forced firmly toits seat. This result is secured by means ofthe traveling cam A through which the stem cam is prevented from turning with the stemby means of the lugs B, which move verticallyin slots. Supposing the valve to be open, thecam will be in the lower part of the chamber in. Fig 3Homestead Straight-Way Valve. which it is placed, and the plug will be free to be easilymoved. A quarter of a turn in the direction forclosing it causes the cam to rise and take a bearing onthe upper surface of the chamber, and the only effectof further effort to turn the stem in that direction is toforce the plug more firmly to its seat. A slight motionin the other direction immediately releases the camand the plug turns easily, being arrested at its properopen position by contact of the fingers o\ the cam atthe other end of its travel. E, />, D, are balancing-parts. This valve forms a very efficient blow off 374 LOCOMOTIVE APPLIANCES. valve where an automatic valve is not desirable (seechapter on Boiler Cleaners). STEAM CHEST VACUUM VALVES. The purpose of these valves is to permit air toenter the steam chest and thence the locomotivecylinder when the engine is drifting or running withsteam shut off. These valves are often termed relief valves, butshould more properly be know
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectlocomot, bookyear1901
