Abstract: A fusion bead testing device is provided for testing the strength of a fusion bead removed from a pipe joint. The testing device comprises a first pressing means for exerting a force against the fusion bead. If the fusion bead splits as a result of the applied force then the fusion bead fails a quality control test and the fusion bead and consequently the pipe joint from which the bead was removed are deemed too weak. The fusion bead testing apparatus comprises an automatic split detection device for detecting a split in the bead.

Abstract: A fusion bead testing device is provided for testing the strength of a fusion bead removed from a pipe joint. The testing device comprises a first pressing means for exerting a force against the fusion bead. If the fusion bead splits as a result of the applied force then the fusion bead fails a quality control test and the fusion bead and consequently the pipe joint from which the bead was removed are deemed too weak. The fusion bead testing apparatus comprises an automatic split detection device for detecting a split in the bead.

Abstract: A fusion bead testing device is provided for testing the strength of a fusion bead removed from a pipe joint. The testing device comprises a first pressing means for exerting a force against the fusion bead. If the fusion bead splits as a result of the applied force then the fusion bead fails a quality control test and the fusion bead and consequently the pipe joint from which the bead was removed are deemed too weak. The fusion bead testing apparatus comprises an automatic split detection device for detecting a split in the bead.

Abstract: Jointing systems for plastics pipes are known where electrofusion is employed to create a welded joint between two pipe ends. Conventional electrofusion units work well on pipes of small diameter, below 400mm, but with larger diameters difficulties arise. The invention seeks to overcome difficulties of joining large diameter pipes, an objective met by a jointing system comprising a strip of plastics material wound with a resistance wire, and a containment strip of a compatible plastics material. Both of the wound strip and the containment strip can have a tightening means such that with the wound strip wrapped around a pipe joint, and the containment strip wrapped around the wound strip, both can be tightened onto the pipe ends at the position of the joint. Once fusion has taken place, the wound strip and the containment strip are welded together onto the pipe ends to create a sealed joint in the form of a hoop of high strength.

Abstract: The invention relates to pipe clamps and is particularly concerned with equipment that combines ease of handling and transportation and which can ensure correct alignment of curved, polyethylene pipe ends and their presentation to an appropriate coupling means. This objective is met by a construction comprising first and second clamp means, said first clamp means being pivotally secured at or towards one end of an inflexible, extendible means, and said second clamp means being pivotally secured at or towards the opposite end of said extendible means, the free ends of the clamp means being detachably and pivotally secured to each other.

Abstract: The invention relates to electroweldable sockets. Previously the predominant method of manufacture has been by injection molding which while producing a socket of acceptable quality it is expensive and relatively slow.

Abstract: In an electron-fushion welding process a fault, e.g. due to incorrect assembly of the pipe joint components, is detected by sensing the welding current and emitting a signal to actuate an audible or visible alarm and/or to interrupt the welding process, if the welding current increases unexpectedly. A reference signal dependent upon the current dependent signal produced by the sensor and RMS to DC converter at a time t.sub.1 is held by a converter and is compared by a comparator with the current dependent signal transmitted through converter at subsequent intervals. So that the device does not react to transient current increase a delay arrangement delays the output signal for a given time.

Abstract: An electro-fusion fitting for coupling thermoplastic pipes incorporates a heating coil (2) and has a resistor (6) with a value chosen in accordance with the power to be supplied to the coil connected between a main terminal (4) and an auxiliary terminal (5). Control apparatus is adapted to sense the resistance value and supply electric current to the coil for a predetermined time set automatically according to the resistance value.