Twentieth century hand-book for steam engineers and electricians, with questions and answers .. (1905)
Swingle, C. F. [from old catalog], Horstmann, Henry Charles, 1858- [from old catalog], Tousley, Victor Hugo, 1875- [from old catalog] · Chicago, F. J. Drake & co. · leaf 54
= 10 sq. in. Then 10 - .7854 =12.73 = square of diameter of valve. Extract the POP VALVE. square root of 12.73 and the result is 3.6 in, = diam-eter of valve. In practice a 4 in. valve would berequired. Fusible Plugs. A fusible plug should be inserted inthat part of the heating surface of a boiler… … INSIDE VIEW OF A POP SAFETY VALVE. about ij^ or 2 in. above the top row of tubes. In fire-box Doilers the plug can be put into the crown sheet 42 ENGINEERING directly over the fire. These plugs should be made ofbrass with hexagon heads and standard pipe threads,in sizes y2, ^, I in., or even larger…
