Abstract: A double containment fitting for use with a double containment pipe having an inner carrier pipe and an outer containment pipe. The fitting includes an inner containment member having a pair of open ends and a pair of centering spiders, each spider adhesively engaged with the exterior of the inner containment member near an end of the inner containment member. An outer containment member has a pair of open ends, each open end including a first portion having an inner radius larger than the exterior radius of the centering spider and a second portion adjacent the first portion having an inner radius less than the exterior radius of the centering spider, providing a shoulder for abutting an edge of the centering spider.

Abstract: A process to install an interlocking union for joining a first double containment pipe having a first carrier pipe within a first containment pipe to a second double containment pipe having a second carrier pipe within a second containment pipe. The process includes slipping a first locking ring into position over the outside diameter of the first carrier pipe to stop against the first containment pipe. A carrier coupling is adhesively bonded to the first carrier pipe stopping against the first locking ring. Thereafter, a second locking ring is slipped into position over the second carrier pipe stopping against the second containment pipe. The carrier coupling is adhesively bonded to the second carrier pipe stopping against the second locking ring. Finally, a containment coupling is bonded to the first containment pipe and to the second containment pipe.

Abstract: A containment interlocking union for use with a containment pipe which encloses a carrier pipe. The containment interlocking union is placed in position around a coupling in the carrier pipe. The interlocking union includes a first joint member and a second joint member positioned circumferentially adjacent to each other and coupled to the containment pipe. The first joint member comprises a first coupling portion of a major radius sealably engaging an outer circumferential surface of an end of the double containment pipe, a pair of second coupling portions of a minor radius adjacent the first coupling portion providing a pair of flanges abutting the ends of the carrier pipe coupling providing longitudinal support of the carrier pipe coupling, and a third coupling portion of an intermediate radius adjacent the second coupling portion.