MECHANICAL BI-DIRECTIONAL ISOLATION VALVE

摘要

A valve (20) having a sealing surface that is rotated 90 degrees on axial floating hinge assemblies (72) is provided. A sleeve (52) moves into position to protect the valve mechanism when the valve is in an open position. A sleeve locks the valve sealing element in place in either a closed or open position. The valve may be used during drilling of wells to prevent flow into the casing (14) when the drill pipe (15) and bit (16) are raised above the valve.