Abstract: A method of lining a pipeline 24 intended to carry gas, oil, water, sewage or chemicals in which a cross-linked polymeric liner pipe 10, which has been reduced from its original diameter to a lesser diameter or to a shape of reduced maximum dimension, is pulled through the pipeline 24. The lesser diameter is less than the least inner diameter of the pipeline 24. After the liner pipe 10 has been fully pulled through, the pipe liner 10 is heated by means of a source 60 of visible or infrared radiation forming part of a pig assembly 50 to cause it to revert to the pipeline. The pig assembly or assemblies are stationary at zones 70 where service connections are to be made. Subsequently, the remaining liner pipe 10 is reverted by pulling the source 60 through the liner pipe 10.

Abstract: A detector for detecting joints (5) in a cast iron gas main for instance comprises a sonde (1) having a central transmitting coil (2) and the two receiving coils (3, 4) spaced one on either side of the transmitting coil. At a joint, the gap (6) between the sections of pipe causes differential magnetic coupling between the pipe and the two receiving coils (3, 4). After a pulse of drive current from a control unit is applied to the transmitting coil, comparison by subtraction of voltages induced in the receiving coils and measurement of an appreciable voltage indicates that the sonde (1) is at a joint. In a second embodiment, the sonde (101) is provided with a sealing compound supply pipe (115) and nozzles (120) from which sealing compound can be sprayed into the joint on detection thereof.

Abstract: An oxygen sensor comprises a substrate 1 having two opposite faces, a first electrode layer 2 residing on one face of the substrate, an electrolyte 3 formed of a metal oxide oxygen ion conductor residing on the first electrode 2, a second electrode layer 4 residing on the electrolyte 3 wherein the electrodes 2 and 4 are formed of a material including a metal oxide oxygen ion conductor and a third electrode layer 6 residing on the other face of the substrate 1.

Abstract: A pipeline inspection vehicle comprises a body 18 an electromagnet 20 for generating magnetic flux, and two foil packs 24, 26 for conducting the flux into and out of the pipewall 10. An array of defect sensors is arranged around the body 18, each sensor being mounted on a respective assembly 28. Each assembly 28 comprises a steel sledge 40 which runs along the pipewall and which is secured to a sensor housing 42. A length of belting 44 is sandwiched between the two and end portions form a leading member 46 and a trailing member 48 linking the sledge to the vehicle. Each assembly 28 is positioned against a spring 64 which is also positioned against the vehicle. The assembly collapses out of the way when the vehicle traverses a sharp bend and the foil pack 24 is deflected to the right. The two members 46 and 48 both counteract the force of the spring 64 when the sledge crosses a void in the pipewall.

Abstract: A method is provided for replacing a length of a branch gas main 1 joined to a spine main 2 with a length of replacement main 7 having an outer diameter smaller than the inner diameter of the branch main. In the method access is gained to the bore of the branch main and one end of the replacement main 7 is fed along the branch main 1 via the access point and towards the spine main 2 until the branch main 1 has been replaced. During and after the feeding step gas is prevented from entering any clearance 20 between the mains 1 and 7 by means of a head 9 attached to the leading end of the main 7. After the feeding step a sealant 25 is injected into the branch main 1 to form a seal within the clearance 20.

Abstract: Apparatus for drying utensils comprises a chamber 1 and a gas-fired burner 20, such as a fully premixed burner, for firing into the chamber. Fans 30 blow air into the chamber and deflectors 31 direct air from the fans 30, via openings 43, to mix with the hot gaseous combustion products produced by the burner 20 to provide a hot mixture. A duct portion 7 directs the hot gaseous mixture from the chamber into a drying region 9 and over the utensils which pass through the drying region to be dried. The hot mixture is used to dry the utensils by direct contact.

Abstract: The system enables data from analogue state sensors S1 to S16, four of which may be direct frequency sensors, located in a ZONE 0 (1) environment, to be transmitted by a master transmitter 10 via a fibre optic data link 16 to a master receiver 14. The master receiver is located in a safe environment. The master transmitter comprises a power restrictor unit 18 which has for each data channel a power supply and also a power supply for the printed circuit-board (pcb) of the master transmitter. The master transmitter is located in a ZONE 1 environment. The analogue or state data are voltages which are converted by voltage-to-frequency converters mounted on the pcb and passed to the multiplexer of the master transmitter. The multiplexer feeds the fibre optic link and a demultiplexer at the master receiver reproduces the frequencies. The master receiver re-converts the frequencies to voltage signals.

Abstract: A coupler 10 consists of a length of cross-linked polyethylene pipe having a spiral groove 16 cut in its outer surface and another spiral groove cut in its inner surface. A heating element 18 is wound in the groove. The coupler is expanded mechanically so as to have an easy fit over the ends of polyethylene pipes 12, 14. The heater element 18 is energized and the coupler shrinks and forms fusion welded joints between itself and the pipes. No preparation of the pipe ends is necessary because the serrated inner surface cuts through the oxidized skin and bonds to material beneath the skin. The coupler is especially advantageous in large sizes of 500 mm or above. Instead of an electric heater, radiant energy, e.g. infra red or light is used to heat the coupler. For example, an array of reflector lamps can be used circumferentially located around the coupler.

Abstract: A method for abandoning a branch main 1 joined to a fluid-carrying spine main 2 comprises gaining access to the bore of the branch main 1 at an access point and then permanently blocking the bore of the branch main 1 at a blockage point closer to the junction then to the access point.

Abstract: The method and apparatus are useful in positioning components, for example two half shells of a clamp for a pipeline or other cylindrical member (10). One half-shell (12) is clamped by studs (56) to brackets (52) on a carriage (16) which can then traverse about the member (10) by engagement of sprockets (30, 28) with chains (18) encircling the member (10). A second half-shell is then lowered by crane onto the member (10). The two half shells are clamped together by studs and the brackets (52) released and swung clear. The apparatus can then be removed if desired. Drive to the carriage (16) is through a flexible shaft (70), gearbox (34) and sprockets (30) connected together by drive shaft (33). Wheels (26) roll on the member (10).

Abstract: A shower unit 1 comprises a mixing chamber 2 having an inlet 7 for hot water, an inlet 27 for cold water, a jet or nozzle 5 connected to the inlet 27 for causing the cold water and to entrain the hot water to form a mixture for discharge from the chamber 2 to a shower head or rose 6 which forms an integral part of the unit.

Abstract: A detector for detecting joints (5) in a cast iron gas main for instance comprises a sonde (1) having a central transmitting coil (2) and the two receiving coils (3, 4) spaced one on either side of the transmitting coil. At a joint, the gap (6) between the sections of pipe causes differential magnetic coupling between the pipe and the two receiving coils (3, 4). After a pulse of drive current from a control unit is applied to the transmitting coil, comparison by subtraction of voltages induced in the receiving coils and measurement of an appreciable voltage indicates that the sonde (1) is at a joint. In a second embodiment, the sonde (101) is provided with a sealing compound supply pipe (115) and nozzles (120) from which sealing compound can be sprayed into the joint on detection thereof.

Abstract: A sonar buoy 40 has narrow-beam sonar heads 80, 82 driven by a stepper motor 84. The heads produce sonar data for example accurately measuring the seabed. The buoy is handled by a crane wire 41 held taut by a float above the buoy and attached to a clump weight 46 resting on the seabed (although shown in retracted condition). A wire 50 runs from a winch 48 around pulleys 52 on the weight 46 and is connected to a lever 54 of a gimbal mechanism 56 which has two transducers 62, 70 giving measurements of the "X" position and the "Y" position of the buoy. A footage mechanism 76 is driven by the wire 41 and has a transducer giving a measurement of the heave position. A compass 88 and roll and pitch transducers at 86 give measurements of the heading position and the roll and pitch positions. The sonar data is compensated for the position of the buoy using a computer.

Abstract: A polyethylene pipe 10 is joined by a welded joint to a cross-linked polyethylene coupler 14 which has been expanded to make the coupler heat recoverable. Radiant energy (eg light in the visible spectrum or infra-red light) illuminates the outer surface of the coupler 14 supplied by an array of 15OW reflector lamps 20. The coupler 14 shrinks and is forced into engagement with the pipe 10 and the pipe 12 to join the pipes. A fusion welded joint is formed between the coupler 14 and each pipe, 10, 12. In an alternative a pipe is drawn down and inserted in an aperture through the wall of another pipe. A lamp is inserted in the drawn down pipe and the radiant energy causes the pipe to expand into engagement with the edge of the aperture and to be joined to it by a welded joint (FIG. 2).

Abstract: A method is provided for replacing a length of a branch gas main 1 joined to a spine main 2 with a length of replacement main 7 having an outer diameter smaller than the inner diameter of the branch main. In the method access is gained to the bore of the branch main and one end of the replacement main 7 is fed along the branch main 1 via the access point and towards the spine main 2 until the branch main 1 has been replaced. During and after the feeding step gas is prevented from entering any clearance 20 between the mains 1 and 7 by means of a head 9 attached to the leading end of the main 7. After the feeding step a sealant 25 is injected into the branch main 1 to form a seal within the clearance 20.

Abstract: A method is provided for replacing a length of a branch gas main 1 joined to a spine main 2 with a length of replacement main 7 having an outer diameter smaller than the inner diameter of the branch main. In the method access is gained to the bore of the branch main and one end of the replacement main 7 is fed along the branch main 1 via the access point and towards the spine main 2 until the branch main 1 has been replaced. During and after the feeding step gas is prevented from entering any clearance 20 between the mains 1 and 7 by means of a head 9 attached to the leading end of the main 7. After the feeding step a sealant 25 is injected into the branch main 1 to form a seal within the clearance 20.

Abstract: A vehicle 10 which inspects pipes 12 using flux-leakage has a flux generating electromagnet 14 and foils 18, 20 to transfer the flux to the pipewall 12. Sensors 22 detect flux forced to leak from the pipe by defects. The vehicle is required to pass 1-D bends as shown and has a swivel 40 having a load bar 48 on which there is a link 46 of a towing chain 26. On straight pipe the link 46 occupies a first position nearer to the axis 44. In a bend the swivel turns so that the link 46 can slide along the load bar 48 to a second position further from the axis 44. This reduces the angle which the chain 26 makes with the axis 44 and jamming of the vehicle 10 in the bend is avoided.

Abstract: An acoustic wave energy generator comprises a body having an internal gas-pressurisable first chamber 1 adjoining a second chamber 2 into which a liquid is introduced to cover a vibratable means 4 which may be a flexible diaphragm and is mounted on the second chamber so as to close an associated opening 5 in the second chamber. After the first chamber 1 is pressurised with a first gas a common closed opening between the chambers is opened to cause communication between the chambers 1,2 to permit a shock wave emanating from the first chamber to impinge on the liquid. As a result, the vibratable means 4 is caused to vibrate so as to produce acoustic wave energy in response to the impingement of the shock wave on the liquid. By using different liquids and/or different heights of liquids in the second chamber the generator may be tuned to provide acoustic wave energy with a relatively narrow chosen frequency range or within a chosen substantially single frequency.

Abstract: A die for reducing polyethylene pipe temporarily to enable it to be inserted in a pre-existing metal pipe is made of cast iron and has formations by which the die is splittable into two portions. The formations receive cylindrical bars which are squeezed together by a hydraulic squeeze off machine. Each formation is a U-shaped aperture with a saw cut extending from the base of the U into the ligament beneath the formation. The saw cut acts as a stress raiser. In a modification only one formation is provided. The die is made of grey cast iron or some other brittle material.

Abstract: A method for combined cycle electrical power generation comprises utilizing a coal hydrogenator 2 and a reactor 1 for producing from a methane-rich gas a hot crude hydrogen-containing gas which is fed directly (apart from an optional quenching stage) to the coal hydrogenator. The coal hydrogenator produces gaseous and liquid products which are combusted to drive a gas turbine 5 which drives an electrical generator 6. The hydrogenator also produces char which is combusted in a boiler 10 to form steam to drive a steam turbine 11 which, in turn, drives another electrical generator 12. Such direct use of the hot crude gas avoids having to preheat hydrogen-containing feed to the hydrogenator.