Patent ID: 6896297

Claim:
A gas service riser assembly comprising: an outer ductile pipe; a plastic pipe having open ends disposed within the outer ductile pipe and extending through one end thereof; a hollow rigid stiffener including a plurality of radial serrations having outwardly extending sharp points formed along the outside length thereof disposed within the interior of the upper open end portion of the plastic pipe within the outer ductile pipe, the stiffener including a flange at the upper end thereof above and adjacent to the plastic pipe that extends into close proximity with the outer pipe; a gasket positioned around the exterior of the plastic pipe adjacent to the stiffener; and a crimp formed in the outer ductile pipe adjacent to the gasket and the stiffener immediately below the flange of the stiffener whereby the outer ductile pipe is compressed against the gasket, the plastic pipe and the stiffener to thereby form a seal between the plastic pipe and the ductile outer pipe.