A ball valve includes a first ball clamping assembly that defines a first seat surface in contact with an exterior of the ball. A second ball clamping assembly defines a second, sealing seat surface in contact with and adapted to seal with the exterior of the ball. The second ball clamping assembly is coupled to the first ball clamping assembly to clamp the ball between the first and second seat surfaces. The second ball clamping assembly includes a seat ring holder and a seat ring carried by the seat ring holder. The seat ring of the second ball clamping assembly has a sealing seat surface. A springing member is provided between the seat ring and the seat ring holder and springingly biases the seat ring toward the ball. The seat ring holder has a shoulder that supports the seat ring against fully compressing the springing member.