Patent ID: 6318400
Filing Date: 2001-11-20
Classification: G05D,Y10T

Abstract:
A low interflow hydraulic shuttle valve to direct fluid flow from two subsea control pods to a blow out preventer to actuate the preventer, comprising:a body having a pair of opposing coaxial supply ports, and a transverse function port, the supply ports in fluid communication with the subsea control pods and the function port in fluid communication with the blow out preventer;a first metal valve seat surrounding the first supply port and a second metal valve seat surrounding the second supply port, the valve seats being coaxially aligned on opposite sides of the body;an elongate shuttle coaxial with the metal valve seats and the supply ports slidably moving from sealing engagement with the first valve seat to sealing engagement with the second valve seat in response to fluid flow from the subsea control pods;said shuttle including a central flange with opposing sealing surfaces having opposing outward tapers to engage the valve seats, the shuttle further including opposing end portions, each with an axial bore and a plurality of perforations through the end portion to the bore; andeach of the opposing outward tapers of the sealing surfaces on the central flange of the shuttle adapted to alternatively contact the metal valve seats to progressively coin the valve seats and ensure a metal to metal seal between the tapers and the valve seats; anda circumferential chamfer adjacent each metal valve seat to create an obtuse metal point that will contact sealing surface,a displaced metal lip protruding from the chamfer, the lip being created by the progressive coining of the seat.