Pipelines reinforced by wrapping with steel strips - has wrapping tension equalised to avoid pipe distortion by simultaneous winding of two spaced sections

摘要

Several strips, or wires, are wrapped round a long cylindrical body, such as, a pipe. The winding is simultaneously undertaken in opposite directions in two spaced zones. Thus, at least two strips or wires, are wrapped in each zone, so that the resulting tension forces are zero. In each zone, the strips, or wires, are pref. applied in pairs at diametrically opposed locations, the two wires in each pair being exposed to the same tension. The wrapping can be carried out on site, e.g. immersed pipes can be butt welded together on a pontoon and then wrapped continuously. Due to the balanced tension forces, the risk of pipe distortion during wrapping is eliminated and it is no longer necessary to hold the pipes in a jig.