Shutoff valve

Abstract

A shutoff valve particularly suited for use with fluid pipelines such as natural gas mains or the like constructed from plastic which allows the valve to be selectively opened and closed from a remote location. The valve has a valve body which includes a mounting surface for mounting the valve to the pipeline. A first passageway extends through the valve body into communication with the mounting surface and a second passageway communicates with the first passageway intermediate the ends thereof. Fluid passing outwardly of the valve through the second passageway may be conveyed to the area of useful application. A punch arrangement is included in the first passageway which is conveniently used after valve installation to punch a hole in the side wall of the pipeline to provide fluid communication between the pipeline and valve. In one embodiment, a piston assembly is slidably received in the first passageway and selectively movable between a first normal position blocking such flow and a second open position allowing such flow. The piston assembly is moved from the first to the second position by fluid pressure introduced thereagainst from a remote source and is moved from the second back to the first position under the influence of a spring member. In another embodiment, the valve body includes a third passageway communicating with the first and second passageways. A piston assembly received in the third passageway is selectively movable between first open and second closed positions by external means to allow or prevent fluid flow through the valve as may be desired.