GB190402977A - Improvements in and relating to Staem or other Fluid Pressure Reducing Valves - Google Patents

Abstract

2977. Graham, J., Graham, D. A., and Graham, A. Feb. 6. Reducing-valves; safety-valves.-The reducing- valve, shown in Figs. 1 and 2, comprises a valve a to the spindle of which is fitted the actuating- piston G, and a hood b for deflecting dirt into the lower part of the casing. The piston-chamber C is formed in the bottom cover of the casing. The piston G is subject to the fluid pressure in the inlet A<1> of the valve acting through the port H, pipe H<3>, and port H<2>, the pressure being controlled by a valve I. The valve I is held open by springs 0 against the closing action of a controlling- piston N which is subject to the pressure of fluid in the low-pressure side A<2> of the valve-casing, acting through a port H<1> open to the piston- chamber L under the valve I. The spindle K<1> of the controlling-piston N passes through a metal, india-rubber, or other diaphragm M. To prevent the chattering of the main valve, the seat may have a raised ring, tapered internally to cut off gradually in closing, or a similar ring may be attached to the underside of the valve, as shown in Fig. 2. In a modification, the piston-chamber C is formed in the casing, and the controlling-valve I is mounted in the top cover and operated by a fluid- actuated diaphragm. By reversing the ports of the controlling-valve, and arranging the spring to close this valve, the modification referred to above may be made to act as a "surplus steam valve" for passing surplus steam from a high-pressure boiler &c., into a low-pressure boiler &c., and for like purposes, instead of allowing it to escape to waste.