The input strip package is placed on an external payoff which feeds via rollers into the main storage reels. The strip payoff section is the main magazine portion of the machine that stores and feeds the metal strip to the roll forming head. A series of forming rolls, mounted to the faceplate, progressively change the cross sectional shape. A set of winding rolls turn around the mandrel and interlocks this section into a helical pipe.

The strip armouring or carcass layer provides resistance from hydrostatic collapse, corrosion and erosion. It is also used as an impact or scuff resistant outer layer.