METHOD AND VALVE FOR CONTROLLING FLUID FLOW, AND METHOD OF SERVICING VALVE

摘要

A gate valve for controlling fluid flow through a housing is disclosed. The gate valve includes a frusto-conical shaped internal cavity having a fluid inlet and a fluid outlet formed in the wall thereof. Fluid flow through the cavity (from inlet to outlet) is transverse to the direction of the taper of the frusto-conical cavity. A gate including a frusto-conical portion is disposed within the housing. The frusto-conical portion of the gate may be moved transversely through the fluid flow passing from the internal cavity inlet to the outlet. The frusto-conical portion of the gate is adapted to seat against the frusto-conical shaped internal cavity to block fluid flow there through. The gate does not contact the seat until the point at which all fluid flow is shut off. This reduces wear on the gate and the seat and promotes laminar flow through the valve during the process of closing the valve.