US Patent 7395695 Apparatus for testing lengths of pipe

A pipe testing apparatus includes a mandrel adapted for insertion within the pipe and two sealing devices connected to the mandrel and adapted to seal opposite ends of the pipe to create an annular space between the mandrel, the pipe, and the sealing devices. The apparatus further includes one or more ports for filling the annular space with a pressurized fluid and a pressure gauge for monitoring the pressure within the annular space. At least one of the sealing devices includes a combination of a sealing ring and a force applying ring, which forces the sealing ring to bear against one end of the pipe to from a seal. The mandrel is provided with stops for preventing the at least one sealing device from moving axially away from the pipe.