Abstract: A method and apparatus for tensioning groups of studs to a predetermined strain. The method includes the steps of tensioning all of the studs simultaneously to a predetermined tension, tightening working nuts, releasing the tension on the studs, measuring the residual strain on the studs and determining for which studs the strain is outside a predetermined tolerance range, retensioning the studs to a tension greater than the predetermined tension, rotating the nuts for the studs which are outside the predetermined residual strain tolerance range in step by amounts and in directions corresponding to the amount and direction in which the strain deviates from the predetemined value and releasing the tension on the studs.

Abstract: A device for inserting and removing studs 16 from bores 19 in a workpiece, for example a nuclear reactor vessel, comprises manipulating devices 22 for operating on individual studs. Each device 22 is capable of tensioning a stud 16, slackening a working nut 17 on the stud, and subsequently removing the stud from the bore. A ring 92 has dogs 93 which can engage recesses in the working nut to interlock with the nut against relative rotation. Motors 100 are coupled to the ring 92 and operable to rotate the working nut. A top nut 51 is coupled to motor 100 which are operable to rotate the nut and screw it onto the stud 16. The top nut 51 together with other operating parts of the device can be raised and lowered on a tube 61 by means of a hydraulic actuator 65. A hydraulic load cell 52 is located between the top nut and a stool 53 which rests on the workpiece.

Abstract: A bolt comprises a tapered shank. The shank comprises an outer member with a cylindrical bore and an inner member with a cylindrical outer surface that is a close fit in the cylindrical bore. The inner member is secured to the outer member at the broader end of the shank and a screw thread is secured on a portion of the inner member projecting from the narrower end of the outer member, for receiving a nut which is used in tensioning the bolt into the workpiece.

Abstract: A hydraulic nut or washer or bolt head comprises piston means let into the recessed end-face of a body. Means for applying hydraulic pressure to a chamber or chambers behind the body are provided to urge the piston means in a direction which leads out of the end face. The piston means has an overall dimension in a first transverse direction which is less than the least possible overall dimension of an annular piston giving the same piston face area and having an overall dimension in another transverse direction, at right angles to the first, which is less than the least overall major dimension for a pair of opposed circular pistons giving the same piston face area. A sealing member comprising a layer of moulded deformable substantially incompressible material on a former is provided in the chamber to contain the hydraulic fluid.

Abstract: A method of joining pipes in which a sleeve is placed over the adjacent ends of the pipes so as to overlap each pipe. The sleeve fits with clearance around the pipe ends. The ends of the clearance space are closed by inflating hollow sealing rings and then epoxy resin is injected into the clearance space to fill the space. The pressure of the epoxy resin composition is then raised to a pressure substantially greater than atmospheric and the pressure is maintained until the resin composition is set.

Abstract: A sealing arrangement between rotary shafts and structure which surrounds them particularly propeller tailshafts and the stern boss of ships. The sealing arrangement comprises two rubbing seals mounted in series along the shaft between the shaft and structure which surrounds the shaft, with a void space between the seals. A drain conduit extends from the seals and a tun dish is located in the drain conduit to indicate the ingress of fluid into the void. The rubbing seals are formed by the opposite radial faces of an annular flange extending radially out from the shaft and by wear rings biased axially against the opposite sides of the flange.

Abstract: A method of forming a joint between a metal structural tubular member and a metal sleeve. The method comprises placing the sleeve around a part of the tubular member so that there is a space between the sleeve and the adjacent part of the tubular member, closing the ends of at least a part of the space between the tubular member and the sleeve, injecting a hardenable composition into the space between the closed ends and maintaining the pressure until set.The method can be used for joining together structural tubular members or for repairing a damaged structural member.

Abstract: A pipe coupling comprising a sleeve which is fitted over the adjacent ends of the pipe sections. The sleeve has sealing means for sealing the sleeve against the pipe and gripping means for gripping the pipe. The sealing means comprises an annular groove which accommodates an annular tire the interior of which communicates with the exterior of the sleeve through a bore in the wall of the sleeve. The gripping means comprises arcuate groove sections on the inside of the sleeve which accommodates a tubular member or members which communicate with the exterior through bores in the wall of the sleeve, and jaw sectors with teeth which bite into the outside of the pipe. The tubular member or members and the annular tire are filled with a hardenable composition and maintained under pressure until set to force the sealing member into sealing contact against the outer surface of the pipe and cause the gripping teeth to bite into the outer surface of the pipe.

Abstract: A method of joining pipes in which a sleeve is placed over the adjacent ends of the pipes so as to overlap each pipe. The sleeve fits with clearance around the pipe ends. The ends of the clearance space are closed by inflating hollow sealing rings and then epoxy resin is injected into the clearance space to fill the space. The pressure of the epoxy resin composition is then raised to a pressure substantially greater than atmospheric and the pressure is maintained until the resin composition is set.