Abstract: A pipe joint which is made of a hollow body member having a passageway therethrough for receiving a pipe, a segmented gripper means positioned in a first circumferential tapered channel in the hollow body member and moveable axially within the passageway. The arrangement is such that, in use, when forces are applied tending to separate the pipe from the hollow body member the segmented gripper means can move axially along the tapered channel into gripping engagement with the pipe.

Abstract: An adjustable pipe bend which has at least two parts joined by flanges (10, 10a) which incorporate an electrical fusion element in the form of a plastic annular disc (15) with a heater wire (16) located at or adjacent both surfaces of the disc.A number of embodiments of the invention illustrate different adjustable bends, the arrangement being that the bend is adjusted to a required position and then the heater wire has a voltage applied to it to produce a heating current which causes the plastic annular disc and adjacent plastic faces of the flanges to melt sufficiently to cause fusion between the two parts of the pipe.

Abstract: A percussive-action mole 10 is energized by compressed air supplied through hollow rods 36 in a string 12 connected to the mole. A hydraulic motor 18 rotates the string and mole. The mole head 30 has a slant face 32 and a transverse permanent magnet 34. After each new rod is added to the string, the air is stopped to halt the mole which continues to be rotated. The field fluctuations from the magnet are detected by a magnetometer 24 using its probe at three positions 50, 52, 54 determiend by a triangular frame 22 placed flat on the ground. Calculations using the three readings each representing the distance of the magnet from the respective position on the frame enable the position and depth of the magnet to be determined. After completion, the passage 38 can be reamed to larger diameter to receive a gas pipe or other service.

Abstract: Members especially hollow members 10, 12 such as pipes and pipe fittings one member 12 of cross-linked polyethylene say and the other member 10 of medium density polyethylene say are joined by fusion using a butt fusion machine. End surfaces of the members are pressed at higher pressure against a hot plate 18 to upset only the medium density material to form beads 20, 22. No cross-linked material is upset to form beads. The pressure is reduced during a soak stage then the plate is removed and the surfaces are mutually engaged at the higher pressure. The beads formed are adjacent the interface between the members and both beads are offset towards the medium density material, member 10. Careful alignment will avoid faults caused when the beads do not cover exposed parts of end surfaces. Other materials include polypropylene, copolymer or monopolymer types. Natural gas distribution systems can be fabricated using the invention.

Abstract: First and second members (e.g. pipes, fittings) of cross-linked polyolefinic material such as polyethylene having a melt flow index (MFI) of zero are joined using a third member of polyolefinic material such as polyethylene having a higher MFI e.g. 0.3. The first member 10 and the third member gripped by clamps 18, 20 of a butt fusion machine are pressed against opposite faces of a heater plate which is then withdrawn and the members are pressed together by the clamps. Only the third member is upset to form beads 24, 26. Part of the third member is removed leaving a stub part 16. The second member is joined to the stub's face 36 using the heater plate. The part 16 is upset leaving a thin wafer 48. The two interfaces 30, 50 limit the growth of cracks in the wafer to prevent their propagation through the pipe thickness under hoop stress. The beads are preferably removed at each stage.

Abstract: A device for removing a weld bead from the external periphery of a plastic gas pipe.The device (FIG. 2) has a body 10 with an inclined reaction surface 13 and a blade 21. The blade 21 is engaged with a bead 22 and the portion 22a of the bead 22 which is lifted is gripped between a toothed wheel 17 and the inclined surface 21. As the wheel 17 is rotated by use of a lever 18 operating via a ratchet, the device is moved bodily around the circumference of a pipe 31 to remove the bead 22.Retractable and adjustable stabilising means 25, 28 etc. are provided and there is a hardened end portion 20 on the body 10 to enable the device to be hammered to engage the blade in the bead initially.

Abstract: A pipe scraper for scraping the end of a plastics pipe such as a plastics gas main or water main has a framework (10) in which is journaled a helically bladed rotary cutter (14) driven by means of a lever (17). On the shaft carrying the cutter is a pinion (16) which meshes with a larger pinion (19) driving a friction surface roller (21). The cutter is held in a Reed clamp and as the lever (17) is turned it rotates the helically bladed rotary cutter so as to scrape a low angle helical scrape approximating a longitudinal scrape. At the same time the rotation of the roller (21) causes the whole framework to rotate around the surface of the pipe so as to scrape the whole end peripheral surface.