Abstract: The primary component of the apparatus is a full port ball valve. One port of the valve is adapted to attach to the bonnet threads of a stop valve. A tubular chamber is attached to the other port of the ball valve with the axes of the ball valve body and chamber aligned with the axis of the stop valve. A cylindrical probe fits through the chamber and open ball valve with a seal between the probe and the free end of the chamber. The inserted end of the probe is adapted to engage splines on a valve stem assembly of a stop valve. A rod extends through the probe and seals prevent leakage through the probe around the rod. The inserted end of the rod is adapted to engage the threads in the end of the stop valve stem assembly. Once the probe and rod are inserted and the splines and threads in the stop valve stem assembly are engaged, the probe is rotated to remove the stem assembly from the stop valve. The probe is then retracted so that the stem is in the chamber and the ball valve is closed.