Fluid flow and pressure control valve

摘要

709,358. Valves. SHELL REFINING & MARKETING CO., Ltd. Sept. 4, 1952, No. 22277/52. Addition to 668,451. Class 135 A modification of the balanced valve of the parent Specification has the application of the pressure at the delivery point of a conduit (or a pressure proportional thereto) and of control pressure to the respective diaphragms or plungers 19, 20 reversed so that the diaphragm or plunger facing the valve seat 14 is exposed on one face to the control pressure in a chamber 27. The arrangement enables the valve to be used to open a bye-pass conduit from a main conduit upon cessation of flow in the latter, a chamber 25 being connected to the throat of a Venturi in a conduit connected in parallel with a portion of the main conduit which has a spring-loaded valve to ensure that a proportion of the flow takes place through the Venturi. Thus, the rise in pressure in the chamber 25 consequent upon cessation of flow through the Venturi causes the valve to open. A pipe 34 with a valve 32 enables any liquid which leaks past the piston 19 to be drained. As in the parent Specification the control pressure may be that of a spring. The seat 14 may, alternatively, lie in a plane normal to the direction of fluid flow.