An integrity monitoring system for a lined pipeline is provided for 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 of 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 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.

A joining sleeve configured to connect internal liners of two internally lined pipe sections across a welded pipe section joint and a method of use is disclosed. The joining sleeve comprises a sleeve body having a first end and a second end, the first and second ends configured to couple with opposing ends of first and second internal liners respectively. A collar is disposed around the outer surface of the sleeve body, the collar having a first retracted condition in which it has a first outer diameter, and a second expanded condition in which it has a second outer diameter, larger than the first outer diameter.

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.

A device internally insulating a welded pipeline joint between pipes having an internal protective coating, in a first variant, includes a power actuator having a cylindrical elastic working member for radial expansion when excess pressure occurs inside its cavity. A cylindrical casing of elastic anti-adhesive material arranged coaxially on the member exterior can have channels for exhausting air and supplying a compound. In a second variant, the device sleevelessly insulates an annular space. A casing made of an anti-adhesive material is centrally reinforced by an elastic cord. Using a cylindrical elastic anti-adhesive casing coaxially arranged on the exterior of a power actuator elastic working member forms an annular space in the weld zone either using a protective sleeve, or by a reinforced casing portion. A vacuum in the space is filled by a compound. The elastic anti-adhesive material allows easy removal of the casing from the hardened compound surface.

A method of joining together liner sections within a polymer-lined pipe energises an induction coil inside the pipe to spot-heat part of a circumferential interface between the liner sections. This melts and fuses the polymer material locally. The induction coil is then moved along the interface to heat other parts of the interface successively above the melting temperature. An apparatus for performing the method has a power supply for energising the induction coil and a drive system for moving the energised induction coil relative to a body of the apparatus. The apparatus may be configured as a carriage that is movable along the pipe.

A method for producing a steel underwater pipe for carrying a corrosive fluid, includes the successive steps: applying a layer of corrosion-resistant steel alloy on a terminal part of the internal wall of each pipe element from its end to be welded; the application of a plastic coating, on the internal wall of each pipe element; covering only a first part of the layer of metal alloy, a terminal part of the layer of metal ally on the side of the end to be welded of each pipe element not being covered by the plastic coating; the coaxial insertion and the crimping of a compression ring against the terminal part of the plastic coating; and the assembly by welding directly together the ends of two pipe elements by a corrosion-resistant steel alloy weld.

A connector for lined pipelines includes a tube having opposed male interface elements extending inwardly from respective ends of the tube. One or more circumferential permeable chokes project radially from each male interface element. The chokes minimise flow of oxidising fluid from the bore into the micro-annulus between the liner and the pipe while maximising flow of fluid from the micro-annulus into the bore in the event of catastrophic pressure drop in the bore. To maintain gaps between the tube ends and the pipe liners for fluid flow, shoulder formations extend circumferentially around the tube. The connector may be used in a joint arrangement where each liner includes a body, an end of lesser thickness and greater bore than the body that terminates short of an end of the pipe, an inner step between the body and the end, and an outer step between the end and the pipe.

An integrity monitoring system for a lined pipeline is provided for 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 pipeline construction usable for internally insulating a welded joint between pipes with an internal protective coating. A device for internally insulating a welded pipeline joint includes a sealing assembly including a cylindrical housing and a coaxially-fastened cylindrical working member that radially expands upon generation of excess pressure in a cavity thereof. Inside the housing are a sealing compound feed assembly, a dosing device formed by a piston assembly for sealing compound components, and a pneumatic control assembly. In the dosing device, working cavities for each component are connected to the feed assembly. The elastic working member has a conduit connected to the feed assembly for feeding sealing compound into an annular gap in a welded joint region, and a conduit for pumping air out of the gap. The pneumatic control assembly controls dosing device and feed assembly functioning and generates excess air pressure in the working member cavity.