Patent ID: 7942422
Filing Date: 2011-05-17
Classification: F16L

Abstract:
1. A ring-shaped member for use in joining lengths of multiwall pipe to form pipeline systems for transporting pipeline fluids, each length having two ends, a steel outer casing, an inner liner having a uniform outer diameter, and an annulus holding a grout layer, the annulus having a height between the outer casing and the inner liner and an annular void having a width at each of the ends, the member comprising: an elastomeric gasket having an outer surface and an inner surface; insulating material dimensioned to completely cover the outer surface of the gasket; and means for affixing the insulating material to the outer surface of the gasket; the member having a first side and a second side and a uniform inner diameter corresponding to the uniform outer diameter of the inner liner and further having a height corresponding to the height of the annulus and a width equal to twice the width of the annular void at each of the ends of the lengths of pipe, the member being fabricated so that the first side fits into the annular void at the end of a first length of multiwall pipe and the second side fits into the annular void at the end of a second length of multiwall pipe, thereby sealing the inner liner at the ends of the first length of pipe and the second length of pipe, the member being completely enclosed by abutting ends of the outer casing and the inner liner.