Pressure energized pipeline plug

Abstract

A plugging apparatus is disclosed for plugging the bore of a pipe at a selected location and withstanding a pressure differential thereacross that may equal or exceed the designed working fluid pressure of the pipe and includes a body means adapted for insertion into the pipe bore and for axial movement within the pipe, the body means including an upstream pressure head having a selected projected area and support means (which can conveniently be pigging discs) attached to and cooperating with the body means for supporting the body means axially in the pipe during movement in the pipe. A pipe gripping means is carried by the body means, locking engagement with the inside surface of the pipe. A plurality of annular elastomeric sealing members having a selected annular area are circumferentially mounted on the body means. An actuating means, such as a hydraulic cylinder, is provided for actuating the pipe gripping means into locking engagement with the pipe and for applying an axial force to the compression sealing members for radially expanding the sealing members into engagement with the pipe wall. The ratio of the body means pressure head area to the sealing members annular area cooperates with the fluid differential pressure applied to the body means pressure head to convert said differential pressure into additional predetermined radial sealing pressure below the yield strength of the pipe.