composite strip windable to form helical pipe (embodiments), pipe produced by spiral winding of composite strip (embodiments) and method for producing spiral windable plastic PIPe with metal reinforcement (embodiments)

摘要

A composite strip (10) windable to form a helical pipe is disclosed. The composite strip (10) comprises: an elongate plastic strip (11) having a base portion (12) and at least one lengthwise extending rib portion (20) upstanding from the base portion (12); and an elongate reinforcing strip (30) extending lengthwise and supported laterally by the rib portion (20), the reinforcing strip (30) having a height to thickness ratio of at least three to ne and orientated substantially perpendicular to the base portion (12). When wound into a helical pipe, the reinforcing strip (30) reinforces the pipe against radial crushing loads. A bead (40) seals the reinforcing strip (30) from the environment. Desirably the composite strip (10) further comprises: a planar lamina (50) extending lengthwise and bonded to the base portion (12), the lamina (50) having a higher Youngs modulus and strength than those of the plastic strip (11). The lamina (50) greatly improves the pressure rating of a pipe wound from the strip (10).