A welding apparatus (1) for radio-frequency, RF, welding, comprises: a clamp (10) having two electrodes (100, 101; 100′, 101′) being movable with respect to one another for clamping one or more items (2; 2′) therebetween for a welding process; and an RF power supply (11) for providing an RF welding current to the electrodes (100, 101; 100′, 101′) of the clamp (10), the RF power supply being adapted to change the frequency of the RF welding current during the welding process.

This disclosure is directed to pipe fittings, systems, and methods. Specifically, this disclosure provides pipe fittings with pairs of circumferential sealing zones and a pressure-testing chamber between the sealing zones. This disclosure also provides pipe fittings with sensors for detecting a breach in one or more sealing zones. The disclosure also provides data trackers for collecting information about the pressure-testing chamber and/or breaches in the sealing zones. Finally, this disclosure provides a dormant power source that becomes powered upon an aqueous breach of one or more sealing zones.

A method of borehole pipe installation begins with unfinished stick pipes brought to the installation site and then machined or cut to form male and female ends. The pipe ends are then locked together to form a flush joint. The lock can be provided via a groove cut into one of the ends for receipt of a lock gasket, which secures and seals the joint when the pipes are pushed together, and prevents the pipes from being pulled apart. Alternatively, to the groove and lock gasket, the ends can be glued and screwed together, with the screws allowing the joined pipes to be pulled through the borehole before the glue is dry. The pipe joint has flush exterior and interior surfaces to minimize borehole clearance and maximize fluid flow through the pipe assembly.

A connection, and methods of making an using such a connection, the connection comprising a first layer; a second layer concentrically disposed about the first layer; and a laser-induced seal between portions of the first and second layers; wherein the laser-induced seal provides a fluid-tight engagement between the first and second layers. As to particular embodiments of the connection, the first layer can be incorporated into a first conduit and the second layer can be incorporated into a second conduit.

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.

Methods, apparatus or equipment and systems for lining conduits, e.g., preferably subterranean pipelines and passageways, such as sewers, with a liner impregnated with a curable resin in order to secure the conduit against ingress or egress of liquids.

A power convertor configured to output power to an electrofusion welding coupler for performing electrofusion welding. The power convertor comprises an array of connected DC to DC power convertor circuits. In use, the array of connected DC to DC power convertor circuits is configured to receive, at a first interface, power at a first voltage level from a battery and output power, at a second interface, at a second voltage level to provide power to electrofusion welding cable means. The DC to DC power convertors are arranged in a buck-boost configuration which can operate in a boost mode in which the first voltage level is less than the second voltage level and in a buck mode in which the first voltage level is greater than the second voltage level.

A coupling component having a first end and a second end, the fitting having a longitudinal axis between the first end and the second end, the first end of the component including a first tubular portion having a first internal diameter adapted to form a sliding fit with a first pipe section, and a first sealer adapted such that the first end can be sealed in use to the first pipe section; the second end having a second diameter or cross-sectional area which is larger than the first diameter and wherein the second end incorporates a flange, wherein at least part of the face of said flange is in a plane substantially non-perpendicular to, or offset from, the longitudinal axis of the component.

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.

Disclosed embodiments provide an electrofusion pipe coupler with mechanical support. The electrofusion pipe coupler comprises a coupler housing. A wire is configured and disposed within the housing. Electrodes are affixed to the coupler housing and in electrical contact with the wire. A threaded pattern is formed in an outer surface of the coupler housing. Gripping wedges are affixed to the coupler housing. Each gripping wedge extends from the coupler housing. A nut is attached to the coupler housing, engaging with the threaded pattern, and compressing the wedges against the connecting pipes. This serves to provide axial load transfer from the connecting pipes to the coupler housing via the wedges, thereby providing improved mechanical stability for such pipe assemblies.