Downhole flapper valve

A valve for use in controlling flow in a fluid transmission conduit in a subterranean well, comprising:

• a valve flapper rotatable to open and close the bore of the fluid transmission conduit;
• a hinge on the valve flapper about which the valve flapper rotates;
• a valve housing;
• and a torsionally loaded spring engaging the valve flapper and extending circumferentially around at least a portion of the bore of the fluid transmission conduit and attached to the valve housing, the spring being loaded in torsion as the valve flapper rotates from the closed to the open position to exert a restoring force for rotating the valve flapper to the closed position.

In a valve for use in controlling flow in a fluid transmission conduit in a subterranean well:

• a valve housing having a bore therethrough;
• a valve flapper, means defining a hinge about which said valve flapper is rotatable between open and closed positions for controlling the flow in the fluid transmission conduit;
• the valve flapper having the configuration of a transverse section of an annular cylindrical member defined by an intersecting cylindrical surface having an axis perpendicular to the axis of the cylindrical member;
• a valve seat cooperating with the periphery of the valve flapper to hold pressure exerted on the upstream valve flapper face when the valve flapper is closed;
• an axially shiftable tubular actuating member engaging the periphery of the valve flapper to rotatably shift the valve actuating member from a closed to an open position;
• and a torsionally loaded spring engaging the valve flapper and extending circumferentially around at least a portion of the bore of the fluid transmission conduit and attached to the valve housing, the spring being loaded in torsion as the valve flapper rotates from the closed to the open position to exert a restoring force for rotating the valve flapper to the closed position, whereby the valve flapper configuration conforms to the exterior of the tubular actuating member when the valve flapper is open to increase the effective size of the valve housing bore relative to the outer diameter of the valve housing.

A valve for use in controlling flow in a fluid transmission conduit in a subterranean well, comprising:

• a valve flapper rotatable between open and closed positions for controlling the flow in the fluid transmission conduit;
• said valve flapper having a pair of co-axial hinge pins affixed thereto and defining the axis of rotation about which the valve flapper rotates;
• valve housing means surrounding the actuating means and the valve flapper and including a downstream housing member with seat means for engaging the valve flapper in the closed position and an upstream housing member;
• the upstream and downstream housing members being in abutting relationship with a recess being defined therebetween, said recess extending peripherally around said valve housing means;
• said flapper hinge pins being respectively retained between the upstream and downstream housing members and traversing said recess;
• and spring means disposed in said peripheral recess and affixed to said flapper hinge pins;
• said spring means being loaded in torsion as the valve flapper rotates from the closed to the open position to exert a restoring force for rotating the valve flapper to the closed position.