FLOW CONTROL VALVE

摘要

The control valve described is a three-position valve that has been designed for use in decoking operations. The hollow body of the valve has been fitted with a sleeve that includes: a plurality of apertures adjacent the inlet of the valve that are arranged in communication with a first outlet; a second plurality of apertures that are spaced from the first apertures and arranged to be in communication with the second outlet of the valve; and, a plurality of relatively large perforations that extend through the sleeve and are located between the two sets of apertures and in communication with the first outlet. An elongated valve member is movably located within the sleeve. The valve member has a passageway extending therethrough so that when the valve member is in a first position, the fluid communicates from the inlet to the second outlet of the valve providing restricted flow permitting the pump connected therewith to continue to recirculate the fluid utilized in decoking through the second set of apertures. In a second position of the valve member, the decoking fluid flows through the first apertures purging and filling the decoking lines and simultaneously flowing through the valve member outwardly through the second set of apertures for recirculation as required. In the third position of the valve member, the perforations in the sleeve are open and the second set of apertures are closed so that substantially unrestricted flow is provided through the perforations to the first outlt from the valve to provide the necessary volume and pressure to perform the decoking operation.