GB1096434A - Improvements in or relating to automatic regulating valves for fluid flow - Google Patents

Abstract

1,096,434. Valves. PLESSEY-UK Ltd. Jan. 20, 1965 [Jan. 24, 1964; April 15, 1964], Nos. 3145/64 and 15515/64. Heading F2V. A pressure-regulating valve comprises a sleeve 24 which slides within a valve housing 26 held by fins 27 in the fluid flow line. The upstream end of the sleeve 24 is formed with a perforated flange 31 joining the sleeve to a central portion 30, which slides on a hollow stem 29 of the valve housing. The downstream end of the portion 30 has an end 32 of greater diameter and abuts a collar 33 of the housing whilst the downstream end of the sleeve 24 is also of great diameter. A passage 36 is connected to atmosphere. To alter the fluid flow the sleeve 24 moves to and from its seat 22 under the action of the downstream pressure acting upon one side of the end 32 after passing through bore 28, with atmospheric pressure on the other side of the end 32 and a spring in opposition. Action of the upstream and downstream pressures on other parts of the movable sleeve 24 is otherwise balanced. In a modification the end 32 and the collar 33 are discarded whilst a fixed restrictor replaces the perforated flange 31 and a variable restrictor partly blocks the passage 36 to atmosphere. These restrictors are such that the flow therethrough is virtually always critical and movement of the sleeve 24 is achieved by the downstream pressure on the face 31, two springs and the pressure on the other side of the fixed restrictor opposing this. Grooved surfaces are provided in all cases to limit fluid leakage around the sleeve.