Multiwall pipe lip seal joint

摘要

An elastomeric lip seal joint for sealing the inner liner and grout layers when joining two sections of multiwall pipe having an outer steel casing and an inner liner. The ring-shaped lip seal joint comprises a gasket with insulating material completely covering its outer surface. The insulating material is capable of shielding the gasket from the heat produced when the sections of outer steel casing are welded together. The use of the lip seal joint simplifies the process of joining sections of multiwall pipe. Each side of the lip seal joint is inserted into one of the annular voids at each end of the pipe, thereby sealing the inner liner and grout. A single circumferential weld then joins the outer steel casing. The gasket remains intact during the welding process due to the presence of the insulating material.