. Official proceedings . d open the serviceport. The quick service action at each K triple valve nuist waitlor sufficient brake pijX reduction to overcome the main >lide valvefriction. 51 The data of Fig. i taken from more than soo K triple valvesin service shows that the required reduction will vary throughwide limits. This delay in starting cjuick service at each valvegreatly retards the serial propagation of service application, espe-cially in long trains made up of modern cars which have a largebrake pipe volume. The opening of the K trii)le valve service and cpiick serviceports are pro
. Official proceedings . d open the serviceport. The quick service action at each K triple valve nuist waitlor sufficient brake pijX reduction to overcome the main >lide valvefriction. 51 The data of Fig. i taken from more than soo K triple valvesin service shows that the required reduction will vary throughwide limits. This delay in starting cjuick service at each valvegreatly retards the serial propagation of service application, espe-cially in long trains made up of modern cars which have a largebrake pipe volume. The opening of the K trii)le valve service and cpiick serviceports are proportioned from the start to full open position of theslide valve so that there is no position of the slide valve where theItrake pipe pressure can reduce faster than the auxiliary reservoirpressure. Otherwise this form of quick service w(juld he unstable. The proportioning of these port areas is based on minimumvolume per car and maximum leakage of the brake pipe. Under FIG. 7 - K TRIPLE VALVEQUICK SERVICE POSITION B. P,. A. R. these conditions the vigor and effectiveness of the quick service asa means for propagating the service brake action through a longtrain is a maximum. The modern trend tow^ards both largervolume and less leakage in the brake pipe has so reduced the ef-fectiveness of K equipment quick service that a full serviceapplication sometimes fails to propagate beyond the middle of along train of modern cars. Figures 8, 9 and 10 are simple diagrams of a triple valve inrelease position designed to show graphically the force which mustact to move a triple valve from release to application position. ?2 Figure 8 indicates the condition when the l)rake pi])e and auxiliaryreservoirs are charged to 70 pounds pressure. iMgure 9 shows the l)rake i)ipe i)ressure reduced 1 j/j poundsbelow the auxihary reservoir pressure. The K triple valve isdesigned to apply on this dififerential when its slide valve frictionis normal, llov^ever the data of Figure :? ])r()\es thai many
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Keywords: ., bookauthorrailwayc, bookcentury1900, bookdecade1900, bookyear1901
