PIPELINE FIELD JOINT COATING FOR WET INSULATION WITH IMPROVED ADHESION

摘要

Bond strength is improved between a polyurethane joint infill material and the dissimilar polymer materials of the parent coating at a pipeline field joint in a wet insulation coating for a pipeline. Heat is introduced in addition to the flame or corona heating used in normal bonding, and as a result, the bond strength is improved. The injected liquid polyurethane of the infill meets the heat treated surface and fully wets the treated surface out prior to the surface losing the added heat.