Abstract: A fitting assembly for joining a double containment pipe (DCP), including primary and secondary pipes, to a double containment fitting, including primary and secondary fittings, wherein the secondary fitting has a larger diameter than the secondary pipe. A sealing reducer has a larger diameter end for fitting over the secondary fitting and a smaller diameter end for fitting over the secondary pipe. The sealing reducer is fit over the secondary pipe, the primaries of the DCP and double containment fitting are joined, and then the sealing reducer is positioned over the primary joint and its smaller and larger diameter ends sealed, either by adhesive or a combination of interlocking threaded fitting components and O-rings, to the ends of the secondary pipe and secondary fitting, respectively.

Abstract: Fiber-reinforced resin pipes and pipe fittings have a structural pipe wall formed from helically wound reinforcing fiber that is bonded together with a polymer resin. An intermediate layer is disposed around the structural pipe wall, and a fiber-reinforced layer is disposed around the intermediate layer. The intermediate layer is formed from material selected from the group consisting of impact attenuating and impact absorbing materials. The fiber-reinforced resin layer comprises layers of helically wound reinforcing fiber bonded together with a polymer resin. The materials selected to form the fiber-reinforced resin layer can be the same or different from that used to form the structural pipe wall. The pipe may comprise a single intermediate and fiber-reinforced layer disposed around the structural pipe wall, or may comprise an impact resistant jacket disposed around the structural pipe wall, wherein the jacket is made up of alternating intermediate and fiber-reinforced resin layers.