A pipe clamp includes a deformable cylindrical sealing sleeve having a continuous side wall with a slotted opening extending 180 degrees around the circumference of the side wall adapted to receive a gate valve plate. The slotted opening has protruding lips bordered by clamping wedges. Clamps are provided for clamping the sealing sleeve to a pipe. Pressure members are provided. A clamping force with pressure members upon the clamping wedges to clamp the lips into a closed position thereby creating a fluid tight seal when the gate valve plate is removed.