Twentieth century handbook for steam engineers and electricians, with questions and answers; a practical nontechnical treatise on the care and management of steam engines, boilers and electric machinery (1922)
Swingle, Calvin Franklin, 1846- [from old catalog] · Chicago, F. J. Drake & company · leaf 151
thevalve its name, and it is sustained by the impact and re-action of the issuing steam, until the pressure has subsidedsufficiently to allow the spring to overcome these actions. A short space will be devoted to the consideration of thelover safety valve also, as it may be of interest to… … Fig. 5Gsquare feet of grate surface in the boiler, and the seats ofall such safety valves shall have an angle of inclination of45° to the center line of their axis/^ Boiler Setting and Equipment
