WO2015131910A1 - Large-aperture rapid non-return valves - Google Patents

Abstract

Large-aperture rapid non-return valves are used in particular in positive displacement pumps for imparting to the latter greater speed and an improved liquid-pumping rate whilst ensuring a reduced pressure differential, in particular during withdrawal, as well as in similar applications, and for preventing cavitation in the fluid-conveying lines. The method consists in covering the narrow apertures for the flow of liquid with sections of the valve disc or ring during closure, such that the width of the narrow apertures applies the dimensions of the disc or ring sections covering them (even if their thickness is greatly reduced) with a slight pressure differential, and thus produce a tight closure in the closure position. The reduced thickness of the disc or ring provides low inertia, to the benefit of the valve-reaction speed. The long edges surrounding the sections provide the liquid with a large flow area, even when the movement of the valve disc or ring is slight, far from the base thereof. The small movements provide low inertia and the large surface area decreases the loss in pressure of the flow through the large apertures in the open position.