Patent ID: 7975728

Claim:
A composite strip windable to form a helical pipe for transporting fluid, the composite strip comprising: an elongate plastic strip having a base portion, the base portion having a lower side defining an inner face and an upper side defining an outer face, the inner face having a substantially flat transverse cross-section; at least one lengthwise extending rib portion upstanding from the outer face of the base portion, the rib portion having a distal end remote from the base portion; an elongate inboard reinforcing member disposed within or adjacent to the base portion; an elongate outboard reinforcing member disposed within the distal end of the rib portion parallel to the inboard reinforcing member; and an elongate intermediate plastic web portion extending between the inboard and outboard reinforcing members, the web portion together with the inboard and outboard reinforcing members forming a composite rib portion, wherein, when wound into a helical pipe, the composite rib portion reinforces the pipe against radial crushing loads.