Twentieth century hand-book for steam engineers and electricians with questions and answers; a practical non-technical treatise .. (1913)
Swingle, Calvin Franklin, 1846- [from old catalog] · Chicago, F. J. Drake & company · leaf 148
modern pop valve is generally re-liable, but, like everything else, if it is allowed to standidle too long it is likely to become rusty and stick. There-fore it should be allowed to blow off at.least once or twicea week in order to keep it in good condition. Most pop valves for stationary boilers… … ---d Fig. 55 The ratio of safety valve area to that of grate surface is,for the old style lever and weight valve, 1 sq. in. of valvearea for each 2 sq. ft. of grate surface, and for pop valves1 sq. in. of valve area for each 3 sq. ft. of grate surface. Each boiler in a battery should have its own…
