US Patent 9316322 Split seat shear valve

A gate valve has a gate valve seat for sealing a valve body to a gate of the gate valve. The valve seat extends from a flow passage of the valve body into a cavity of the valve body parallel to an axis of the flow passage. The cavity is perpendicular to the flow passage, and the gate is disposed within the cavity. The valve seat has a tubular body having a face for contact with a gate, and an end opposite the face adjacent to and in contact with the valve body. The valve seat also includes a sleeve positioned on an inner diameter of the tubular body, the sleeve adapted to receive a shear force for shearing a member extending through the flow passage, the inner sleeve having an adjustable length.