Abstract: A pipe coupling for two pipe ends having the same inner diameter includes a first pipe coupling joining the pipe ends. The first pipe coupling is formed from a section of pipe having approximately the same inner diameter as the pipe ends and is split longitudinally. A second pipe coupling is clamped over the location of the junction between the pipe ends. The second pipe coupling is formed from a section of pipe having approximately the same inner diameter as the pipe ends and is split longitudinally. The split of the second pipe coupling is offset from the split of the first pipe coupling. The couplings may include an inner and an outer coupling, two outer couplings, or an inner coupling and two outer couplings. Each inner coupling have a strip of material removed along its longitudinal split so that it can be compressed to substantially close the gap at its split and inserted into a pipe end.

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.