Patent ID: 8727315

Claim:
A wellbore ball valve, comprising: a ball having a flow bore therethrough; a first ball clamping assembly defining a first seat surface in contact with an exterior of the ball; a second ball clamping assembly defining a second, sealing seat surface in contact with and adapted to seal with the exterior of the ball, the second ball clamping assembly coupled to the first ball clamping assembly to clamp the ball between the first and second seat surfaces, the first ball clamping assembly adjustably coupled to the second ball clamping assembly, the second ball clamping assembly comprising: a seat ring holder; a seat ring carried by the seat ring holder and comprising the second, sealing seat surface; and a springing member between the seat ring and the seat ring holder springingly biasing the seat ring toward the ball, the seat ring holder having a shoulder that supports the seat ring against fully compressing the springing member, and a compression of the springing member is adjustable based on the adjustable coupling of the first ball clamping assembly to the second ball clamping assembly.