A case study: Reinforcement of a 48-in gas pipeline with a misaligned girth weld using a composite wrap

A case study of reinforcement of TD Williamson's (TDW) 48-in gas pipeline with a misaligned girth weld using a composite wrap is discussed. The engineers at TDW determined a composite sleeve design that included multiple layers of their composite system. This composite system uses a non-crimped carbon-fibre design to provide longitudinal and hoop strength to the pipeline. TDW proposed a finite-element analysis (FEA) to estimate the stresses in the pipe at the current operating condition of 940psi, at 1420psi before the composite sleeve was applied, and at 1420psi after the composite sleeve was applied at 940psi. Installation of the composite sleeve started with the excavation and cleaning of the pipeline's girth weld area. Epoxy putty with a high-compressive strength was applied to the girth weld area to fill large voids and create a smooth foundation for the composite sleeve. After the sleeve cured, the owner applied its standard pipeline topcoat over the sleeve and transitioned the topcoat into the existing topcoat on either side.