. Railway master mechanic [microform] . ffler to a locomotive valvedoes not materially alter the constant or discharge. Thereis but 2% difference between tests No. I) and No. 13, (5th) Diregarding the rather unsatisfactory 1 ^ in. and•! in. locomotive valve tests, the different sixes of valtested show a variation in the constant when plotted togiven lifts of about 4%. (6th) There is a slight uniform decrease of the constantwhen increasing the valve lifts. The variations indicated in the last two conditionsare not large enough, however, to materially impair the valueof a single constant obtaine
. Railway master mechanic [microform] . ffler to a locomotive valvedoes not materially alter the constant or discharge. Thereis but 2% difference between tests No. I) and No. 13, (5th) Diregarding the rather unsatisfactory 1 ^ in. and•! in. locomotive valve tests, the different sixes of valtested show a variation in the constant when plotted togiven lifts of about 4%. (6th) There is a slight uniform decrease of the constantwhen increasing the valve lifts. The variations indicated in the last two conditionsare not large enough, however, to materially impair the valueof a single constant obtained by averaging the constants ofall the 24 tests given. The selection of such a constant isobviously in accord with the other four conditions men-tioned. This average constant is , giving as the formula(E = x ax P). Its theoretical value for the standard ori-fice of Napiers formula is , of which the above is92^%. To make this formula more generally serviceable, itshould be expressed in terms of the valve diameter and lift,. Lift Apparatus Rigged for Locomotive Test at Burnside Shops,111. Cent. Ry. and can be still further simplified in its application by ex-pressing the term E (steam discharged or boiler evaporationper hour) in terms of the boiler heating surface or gratearea. For the almost universal 45 degree seat the effectivedischarge area is, with a slight approximation (Lxsine 45xirxD), in which L equals the valve lift vertically ininches, and D the valve diameter in inches. Substitutingthis in the above formula gives E = x L x sine 45xtxD x P, or E = x L x D x P. The slight mathematical approximation referred to con-sists in multiplying the (Lxsine 45) by (t D), instead ofby the exact value (txD plus [^L). To find directly theeffect of this approximation upon the above constant, thevalues for E, L, D, and P from the tests have been substi-tuted into the above formula and the average constant re-determined, which is The average lift of all t
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