An apparatus for sealing an open end of a pipe includes an external clamp for frictionally being secured to the exterior surface of the pipe and an internal clamp for frictionally being secured to the interior surface of the pipe. A sealing plate, connected to one or both of the clamps seals the open end of the pipe. The apparatus further includes a means for pressurizing the interior of the pipe. A method of sealing and pressurizing the pipe is also provided.