Abstract: Method of lining a tubular structure with a plastics liner pipe comprising the steps of: —temporarily reducing an outside diameter of the liner pipe by passing the liner pipe through a roller system; —cooling the liner pipe once its outside diameter has been reduced and applying a thermal restraint; —transporting the liner pipe to an installation site remote from the roller system; —removing said thermal restraint; and —installing the liner pipe in said tubular structure at said installation site.

Abstract: Method of lining a tubular structure with a plastics liner pipe comprising the steps of:—temporarily reducing an outside diameter of the liner pipe by passing the liner pipe through a roller system;—cooling the liner pipe once its outside diameter has been reduced and applying a thermal restraint;—transporting the liner pipe to an installation site remote from the roller system;—removing said thermal restraint; and—installing the liner pipe in said tubular structure at said installation site.

Abstract: An adaptor assembly to be fitted onto a service pipe comprising a host pipe lined with a lining pipe is provided. The adaptor assembly includes a body to seal with the host pipe, a bore extending along a longitudinal axis of said body, and a compression element mountable on and displaceable relative to the body. The adaptor assembly includes an axially translatable piston, an annular flange protruding into said bore, and a grip ring disposable between said piston and said flange and having an inner radial surface to grip an outer radial surface of the lining pipe. A slip spacer is disposable between the compression element and the piston to transmit axial load but substantially prevent transmission of torque therebetween. The compression element is moveable to axially displace the piston causing the grip ring to bear against the inclined annular flange and grip radially inwardly against the outer radial surface.

Abstract: A plastics pipe which comprises an inner core and an outer removable skin layer bonded thereto, the outer removable skin layer comprising a polymeric material, chosen for its physical and mechanical properties, and an adhesion-modifying additive, the adhesion-modifying additive being present in the skin layer in an amount such that the adhesion of the skin layer to the inner core is sufficient to prevent substantial undesired relative movement between the skin layer and the core during installation, but insufficient to prevent the outer skin layer from being cleanly removed by peeling, at least at the ends of the pipe, and insufficient to cause a substantial reduction in the impact strength of the inner core.

Abstract: An adaptor assembly to be fitted onto a service pipe comprising a host pipe lined with lining pipe is provided. The adaptor assembly includes a body to seal with the host pipe, a bore extending along a longitudinal axis of said body, and a compression element mountable on and axially and displaceable relative to the body. The adaptor assembly includes an axially translatable piston, an annular flange protruding into said bore, and a grip ring disposable between said piston and said flange and having an inner radial surface an outer radial surface of the lining pipe. A slip spacer is disposable between the compression element and the piston to transmit axial load prevent transmission of torque. The compression element is moveable to axially displace the piston causing the grip ring to bear against the inclined annular flange and grip radially inwardly against the outer radial surface.

Abstract: A moulded electrofusion fitting for connection to a plastics pipeline comprises a hollow body formed with a tubular opening that has a longitudinal axis and is adapted to receive and end of the pipeline as a close sliding fit. An electrofusion element is formed in the internal surface in the opening, spaced from its end. Fingers are on the end of the opening, circumferentially spaced around the opening and separated by slots between them. Cam surfaces in the form of ribs are defined on the fingers, and a grip ring is received on the fingers and includes wedge elements in the form of grooves. These are adapted to fit the ribs so that, when a pipeline is inserted in the opening and the grip ring is rotated about said axis, the ribs and grooves engage to press the fingers radially inwardly against the reaction of the grip ring, whereby said pipe is gripped by said grip ring and centralized in the opening.

Abstract: A method for the production of a plastics pipe (9) comprising an inner core and an outer removable skin bonded thereto, which method comprises co-extruding molten polymeric materials forming the inner core and the outer removable skin layer from one or more extruder dies, bringing the polymeric materials together and allowing them to solidify, and conditioning the solidified polymeric materials at a temperature and for a time sufficient to influence the adhesion of the outer skin layer to the inner core, such that on cooling the adhesion of the outer skin layer to the inner core is sufficient to prevent substantial undesired relative movement between the skin layer and the core during installation of the pipe (9), but insufficient to prevent the outer skin layer from being clearly removed by peeling, at least at the ends of the pipe (9), and insufficient to cause a substantial reduction in the impact strength of the inner core.

Abstract: A tapping tee assembly (10) comprises an integrally moulded saddle (12), body (14) and socket (16). The tapping tee assembly can be mounted on a pipeline thereby enabling a cutter to travel through the body of the fitting in order to cut a hole in the pipeline. The saddle (12) is provided with a saddle-shaped electrofusion element mat (18) and the socket (16), which is integral with the body (14) and in fluid connection with the axial bore (20) of the body, is provided with a second electrofusion element (22). The electrofusion elements (22,30) are connected by an integrated anvil-shaped connector (26) and connecting pin (28) such that both electrofusion elements (22,30) can be energized simultaneously using two electrical terminals (24,38), and the device can be manufactured with relative ease.

Abstract: A tapping tee assembly (10) comprises an integrally moulded saddle (12), body (14) and socket (16). The tapping tee assembly can be mounted on a pipeline thereby enabling a cutter to travel through the body of the fitting in order to cut a hole in the pipeline. The saddle (12) is provided with a saddle-shaped electrofusion element mat (18) and the socket (16), which is integral with the body (14) and in fluid connection with the axial bore (20) of the body, is provided with a second electrofusion element (22). The electrofusion elements (22,30) are connected by an integrated anvil-shaped connector (26) and connecting pin (28) such that both electrofusion elements (22,30) can be energised simultaneously using two electrical terminals (24,38), and the device can be manufactured with relative ease.

Abstract: A moulded electrofusion fitting (10) for connection to a plastics pipeline, comprises a hollow body (16) formed with a tubular opening that has a longitudinal axis (82) and is adapted to receive an end of the pipeline as a close sliding fit. An electrofusion element (22) is formed in the internal surface (52c) in the opening, spaced from its end (52b). Fingers (52) are on the end of the opening, circumferentially spaced around the opening and separated by slots (53) between them. Cam surfaces in the form of ribs (60) are defined on the fingers, and a grip ring (50) is received on the fingers and includes wedge elements in the form of grooves (62). These are adapted to fit the ribs so that, when a pipeline is inserted in the opening and the grip ring is rotated about said axis, the ribs and grooves engage to press the fingers radially inwardly against the reaction of the grip ring whereby, said pipe is gripped by said grip ring and centralised in the opening.