Pressure relief valve

Abstract

A pressure relief valve particularly suitable for fluid compressors includes a valve seat and a flexible valve closure element cooperating therewith. The closure element, formed from a single sheet of spring steel or similar flexible material, includes a planar portion normally overlying the valve seat to keep the valve closed, and a pair of flexible arms joined at one edge of the planar portion and extending around either side of the planar portion and beyond the opposite edge. In position, the remote ends of the arms are fastened to the supporting structure in a plane common with the valve seat, with the planar portion overlaying the valve seat and closing the valve orifice. Upon application of fluid pressure from the valve orifice to the underside of the planar portion of the valve closure, the planar portion lifts off the valve seat and the combined flexing of the planar portion with respect to the valve arms and the arms with respect to the supporting surface enable the planar portion to lift off the opening perpendicular to the direction of flow of fluid and parallel to the valve seat without additional valve guides. This provides maximum fluid flow for the amount of opening and reliable and long-lived operation. In a practical embodiment, the valve seat is provided by the end face of a tubular section forming the orifice to minimize pressure drop across the valve and the seat is notched to permit by-pass flow to occur with the valve in the closed position to facilitate opening of the valve. Spring means, which may be adjustable, are provided to control the pressure required to open the valve and limit stop means restrict the maximum opening of the valve closure to establish a maximum pressure for the compressor with which it is used and to prevent vibration of the valve closure.