TWO STAGE VALVE WITH CONICAL SEAT FOR FLOW SHUT-OFF AND SPOOL KNIFE EDGE FOR METERING FLOW CONTROL

摘要

A valve (100) comprises a barrel (104) having a central bore (110), an inlet (112), and an outlet (114, 116), and a spool (120) disposed for motion within the central bore, including a ball tip (128), a metering edge (130), and a bore (132). The spool is moveable between a closed position, wherein the ball tip engages a seat (142) to prevent fluid flow through the inlet and the metering edge is disposed in a lower chamber (148) of the central bore to prevent the fluid flow through the outlet, and an opened position, wherein the tip is spaced apart from the seat to permit fluid flow through the inlet and the spool bore into an upper chamber (154) of the central bore to equalize pressure on the spool, and the metering edge is disposed in a flow path of the outlet to permit fluid flow through the outlet.

主权项

1. A metering valve, comprising:
a barrel having a central bore, at least one inlet in flow communication with the central bore, and at least one outlet in flow communication with the central bore; and a spool disposed for reciprocal motion within the central bore of the barrel, the spool including a ball tip, a metering edge, and at least one bore extending from a first orifice to a second orifice; wherein the spool is moveable between a closed position, wherein the ball tip engages a conical seat formed in a wall of the barrel to prevent fluid flow between the at least one inlet and a lower chamber of the central bore and the metering edge is disposed in the lower chamber to prevent fluid flow between the lower chamber and the at least one outlet, and an opened position, wherein the ball tip is spaced apart from the conical seat to permit fluid flow between the inlet and the lower chamber and through the at least one bore of the spool into an upper chamber of the central bore to thereby equalize pressure of the fluid on the spool, and the metering edge is disposed in a flow path of the at least one outlet to permit fluid flow between the lower chamber and the at least one outlet.