GB706777A - Improvements in manostat - Google Patents

Abstract

706,777. Fluid-actuated valves. EMIL GREINER CO. Feb. 19, 1951 [Sept. 1, 1950], No. 4034/51. Class 135 A fluid-pressure operated valve comprises a body 7, Fig. 1, e.g. of transparent material, containing liquid 11 on which floats a bell 10 carrying a closure member 24 at its top, a tubular member 13 extending into the body and having an orifice 12 co-acting with the closure member, a tube 22 for guiding the bell, connections 19, 20 for the tubular member and the space above the ball respectively, and a branch 28 from the connection 20 to the interior of the bell. The member 13 is adjustable to vary the setting of the valve. The connections 19, 20 lead respectively to a source of vacuum and a system in which the vacuum is to be maintained constant. A cock 35 in the branch permits a desired control pressure to be locked in the bell which then controls the orifice 12. In a modification for controlling a positive pressure, the connection 19 leads to exhaust and a restricted continuous supply of fluid is admitted to the system. The valve then exhausts the fluid to hold the system pressure constant. In another arrangement, the differential pressure across an orifice 38, Fig. 3, is applied to opposite sides of the bell which controls the exhaust of pressure fluid to maintain the differential constant, positive pressure being supplied through a needle valve 37. In a modification of Fig. 3, the connection 19 leads to a vacuum source, and the direction of flow through the orifice is reversed. In yet another arrangement, the end of member 13 is fitted with a nozzle 45, Fig. 6, containing a closure member 42 seating on a ring 43 and being operated by the bell to control the supply of pressure fluid from connection 19 to connection 20.