The invention provides improvements to electrofusion fitting methods that allow for continuity and repeatability of welds between an electrofusion fitting and a pipe lining (or stand-alone pipe). An electrofusion fitting for joining sections of lined pipe has heating elements configured to create at least one weld between the electrofusion fitting and a pipe lining, however prior to the weld step taking place the electrofusion fitting is heated and expands accordingly to ensure contact with the pipe lining. Preheating the electrofusion fitting also provides a predetermined starting temperature for the fitting and the lining which results in improved fusion cycle reliability. Furthermore, the need for clamps or support frames to support the electrofusion fitting in situ is removed, with corresponding reductions in cycle times, complexity, and hence cost.

The application relates to a method for producing a double-walled pipe (1) and a pipe (1) of this type, hating an outer pipe (3) which is press-fitted with an inner pipe (2) consisting of a corrosion-resistant alloy, wherein an adhesive (4) is inserted at least in regions between the outer pipe (3) and the inner pipe (2) wherein, after adhering the inner pipe (2) with the outer pipe (3), the inner pipe (2) and the adhesive layer (4) are removed at the pipe ends, and the inner side of the outer pipe (3) is plated via an integral connection with the inner pipe (2).

Enclosures are described that encapsulate or surround a joint between two or more elements, for example two pipes or a pipe and a valve. The enclosures prevent direct contact between the joint and the surrounding water, for example fresh or salt water, and prevent biofouling and corrosion of the joint. An enclosure encapsulates the joint and forms an enclosed space around the joint. Some or all of the enclosure includes a flexible material. The enclosed space is filled with a protective liquid that is retained in the enclosed space and that will be in direct contact with the joint. Due to the flexible nature of the flexible material, the pressure inside the enclosed space is maintained substantially equal to the exterior pressure outside the membrane.

An integrity monitoring system for a lined pipeline is provided far monitoring the integrity of a polymer liner in a host pipe. Methods and apparatus are described by which a lined pipeline is provided with such an integrity monitoring system. Sensor cable is able to bridge a joint between sections at lined pipe, for example by routing the sensor cable across the joint via a channel in an electrofusion fitting or by connecting successive lengths of sensor cable via pass-throughs in an electrofusion fitting. Advantageously, the sensor cable is disposed within a continuous annulus between linings and host pipes, and the continuous annulus is maintained across pipe joints using electrofusion fittings.

A method of manufacturing a Field Joint Coating (FJC) for a pipeline, the method comprising: providing a pipe section to be joined to a similar pipe section or free end of a pipeline, wherein each pipe section is provided with a coating comprising a thermal insulation layer over a length of the pipe section having a protruding section, wherein the end zones of each pipe section are free of thermal insulation, thereby allowing access to the ends of the pipe section and the pipeline to connect the pipe section with the free end of the pipeline, applying an anti-corrosion coating layer on a connection region of the joined ends of the pipe section and the pipeline, heating the protruding section and applying an intermediate coating layer of a thermoplastic material on the anti-corrosion coating layer and the protruding section, applying a thermal insulation layer on the intermediate coating layer.

An apparatus for heating an elongate tubular article, such as a heat shrinkable sleeve applied around a welded pipe joint during pipeline construction. The apparatus is in the form of a frame which can be disposed around the article, the frame having a heater device having both longitudinally disposed heating zones and radially disposed heating sectors, each of which can be independently controlled. Alternatively, or in combination, the apparatus can have an air circulation system. Also, a method for shrinking a heat shrinkable sleeve comprising use of said apparatus.

A method of coating a field joint and a coated field joint formed thereby. The field joint coating includes a first thermal insulation material injection molded over the uncoated field joint to form a first layer, and a second thermal insulation material injection molded over the first layer to form a second layer. The second material has a greater flexibility than the first material and a lower maximum operating temperature than the first material. In certain embodiments, the second material forms a significant part of the volume of the field joint coating.

A wrap tape cassette for a subsea pipeline repair or coating machine includes a drum for carrying a wrap tape wound on the drum. A housing defines an exit opening for the wrap tape to be dispensed from the drum onto a pipeline during a repair or coating operation. The drum may be mounted to the housing for rotational and longitudinal movement relative to the housing to dispense the wrap tape through the exit opening on being unwound from the drum. A leading end of the wrap tape may be attached to an anchor element that is arranged as a closure for the exit opening and, when moved from the exit opening, for attachment to a pipeline being repaired or coated.

A liner bridge for a lined pipeline has bores extending through a tubular wall and terminals fitted in the bores, each terminal being exposed to an inward side of the wall for conducting electricity to an electrofusion element. A sealing interface between each terminal and its surrounding bore has one or more projecting formations of the terminal and at least one complementary formation of the bore engaged with the or each of the projecting formations. The interface can also include a sealing mass in the bore.

Methods and apparatus for making lined pipelines in which pipes are joined together by attaching fittings at their ends and joining the fittings together. Within the joint there is a fit-up sleeve which forces liners against respective fittings and provides corresponding seals. Other seals can be provided by inserting sealing rings which force different portions of the liners against different portions of the fittings. The fit-up sleeve and sealing rings may force the liners against castellations which prevent movement of the liners. The fit-up sleeve may cooperate with insertion rims on the fittings to provide very accurate spacing, or touching edges which can be desirable if automatic welding is employed. The seals provided by the fit-up sleeve also eliminate backdraughts and assist welding operations. Furthermore, the fit-up sleeve permits pigging through the pipe joint and therefore along the length of the resulting lined pipeline. It is foreseen that the need for CRA components and CRA welding can be largely if not wholly dispensed with.