Abstract: A gas sensor for use in monitoring gases such as H2S, NO2 or SO2 comprises a film or layer of non-protonated polyaniline as the gas sensing material.

Abstract: An arrangement is proposed for a system with at least two molten carbonate or solid oxide fuel cell stacks (1, 2, 3). The cathode flows (14) of these stacks are connected in series while the anode flows (25) are in parallel. All stacks have an internal reforming device for a hydrocarbon fuel. Anode gas is recycled (24) from the stack outlets to the inlets. The invention allows the stacks to be of the same design and this reduces manufacturing costs. The cathode streams between the stacks are cooled by, for example, adding streams of cool air (15) to them. The cathode inlet temperatures can, therefore, be controlled by relatively inexpensive low temperature air valves. The invention allows the system to be designed with few heat exchangers, if any. The per pass utilization of all the oxidant streams and fuel streams are low. The efficiency of the system is typically 4-5 percentage points higher than that of equivalent conventional systems.

Abstract: An arrangement is proposed for a system with at least two molten carbonate or solid oxide fuel cell stacks (1, 2, 3). The cathode flows (14) of these stacks are connected in series while the anode flows (25) are in parallel. All stacks have an internal reforming device for a hydrocarbon fuel. Anode gas is recycled (24) from the stack outlets to the inlets. The invention allows the stacks to be of the same design and this reduces manufacturing costs. The cathode streams between the stacks are cooled by, for example, adding streams of cool air (15) to them. The cathode inlet temperatures can, therefore, be controlled by relatively inexpensive low temperature air valves. The invention allows the system to be designed with few heat exchangers, if any. The per pass utilization of all the oxidant streams and fuel streams are low. The efficiency of the system is typically 4-5 percentage points higher than that of equivalent conventional systems.

Abstract: A method of lining installed pipework which includes the steps of taking a length of liner pipe made from a memory retaining plastics material of external diameter greater than the internal diameter of the pipework to be lined, drawing the liner pipe through a swaging die which is attached directly or indirectly to the pipe to be lined using pulling means under tension attached to the leading end of the liner pipe and threaded through the pipework to reduce the external diameter of the liner pipe by up to 15%, the tension applied by the pulling means being such as partially to restrain the radial expansion of the outer surface of the liner pipe after its emergence from the die, drawing the liner pipe after its emergence from the die, drawing the liner pipe through the installed pipework with its outer diameter reduced to and/or maintained at a dimension less than that of the inner diameter of the pipework and thereafter allowing the liner pipe to expand within the pipework by relaxation of the said tension fo

Abstract: An anaerobically curable composition for use in sealing gas pipeline leaks, comprising an anaerobically curable base preparation and a filler, wherein the filler is a metal-containing filler having a substantially metal free barrier coat.

Abstract: An in-pipe vehicle for carrying out at least one operation in a pipeline. The vehicle comprises a train of modules 11-16 interlinked by suspension units 17 to allow serpentine movement through pipe bends. The vehicle train has its own internal power supply and drive mechanism in respective modules. A detector module 14 determines the presence of a service junction and a manipulative module 13 allows the vehicle to be temporarily wedged in the pipeline whilst providing rotational movement to facilitate the desired operation at the junction. This can include drilling and welding of a service pipe to the main using appropriate modules.

Abstract: Apparatus is provided for introducing sealant into a clearance between a replacement pipe and an existing pipe within which in use the replacement pipe is located. The apparatus includes a nose-cone having a tubular body for connection to the upstream end of the replacement pipe, a frangible member in the form of a pop-out plug; pierceable metal foil; plastic film or membrane to seal the bore of the tubular body and at least one non return valve in the form of an elastic ring, rubber O-ring or plug and spring assembly to permit the flow of sealant from the bore of the body into the clearance by way of the wall of the body but to resist return-flow from the clearance into the bore.

Abstract: A process for preparing a porous amorphous silica-alumina refractory oxide is described in which a source of silica, such as tetra ethyl ortho silicate, in a non-aqueous solvent, such as an alcohol, is hydrolysed by adding an aqueous solution containing aluminum ions, in particular a solution of aluminum nitrate, thereby to form a sol and calcining the sol at, for example, 200.degree. C. to 600.degree. C. The product, which may have a microporous or mesoporous structure, is useful in the separation of fluids, especially the separation of carbon dioxide from natural gas.

Abstract: A flame support 20 has a plurality of discrete regions 22 through which fuel/air mixture can pass by means of burner ports 13 which extend through the support to a multiplicity of openings 25 at the flame supporting side 24. The support 20 comprises barriers 21/26 which extend between and separate the discrete regions 22. The barriers serve to prevent the passage of fuel/air mixture from upstream of the support to the downstream side 24 of the support in a region between the discrete regions. In burners provided with such a flame support, the likelihood of resonant combustion noise occurring has been found to be reduced.

Abstract: A frame for supporting a sign comprises three members which are interconnectable in such a way as to form a three-sided figure with one side forming a base and at least one of the other sides forming a mounting for the sign, each member being in the form of a hoop of tubular section.

Abstract: A meter to measure the volumetric flow rate of a liquid, for example water, is formed with a pipe forming a liquid flow path containing a low power electrical heater. A first temperature sensor measures the temperature T of the liquid adjacent to an upstream end of the heater and a second temperature sensor measures the temperature T.sub.2 of the liquid adjacent to a downstream end of the heater. The heater adds heat power of a value P to the liquid. A control arrangement comprising a computer means calculates the flow rate Q using the expression ##EQU1## where ST.sub.1 and DT.sub.1 are respectively the specific heat capacity of the liquid and the density of the liquid at the temperature T.sub.1 measured by the first sensor.

Abstract: A carburetor (2) to supply a mixture of fuel gas and combustion air to a reciprocating internal combustion engine. The carburetor has a venturi (4) and a throttle (10) including a throttle valve (24). A tear-drop shaped obstruction (36) is mounted in the venturi throat (18) on diametrically opposed radial arms (66). The narrowest part of the tubular gap (46) between the walls of venturi (4) and the obstruction (36) is at gap (48). A continuous slot (50) in the throat wall (18) encircles the obstruction and opens into gap (48). Another continuous slot (70) encircling the obstruction (36) is formed therein and also opens into the gap (48). Fuel gas is supplied to the slots (50 and 70) through passages (52, 74 and 72).

Abstract: A heat meter for measuring the amount of heat consumed in a region. A heat exchanger is supplied with heated fluid through an inlet pipe which carries temperature sensors for sending signals to a control. The control also receives signals from a temperature sensor in an outlet pipe carrying fluid away from the region. A low power electric heater is mounted between the sensors to add a known amount of heat to the fluid. The control calculates the heat power consumed in the region based on the temperature difference across the regions and the temperature difference across the region and the temperature difference across the heater.

Abstract: An in-pipe vehicle for carrying out at least one operation in a pipeline. The vehicle comprises a train of modules 11-16 interlinked by suspension units 17 to allow serpentine movement through pipe bends. The vehicle train has its own internal power supply and drive mechanism in respective modules. A detector module 14 determines the presence of a service junction and a manipulative module 13 allows the vehicle to be temporarily wedged in the pipeline whilst providing rotational movement to facilitate the desired operation at the junction. This can include drilling and welding of a service pipe to the main using appropriate modules.

Abstract: A method for blocking the bore of a pipe comprising moving an inflatable bag along the bore of the pipe from an access point in the pipe to a point where the bore is to be blocked, inflating the bag until it engages the internal wall of the pipe or main and causing the bag to maintain its inflated condition. Where an expandable foam is used.

Abstract: A process for preparing a porous amorphous silica-alumina refractory oxide is described in which a source of silica, such as tetra ethyl ortho silicate, in a non-aqueous solvent, such as an alcohol, is hydrolysed by adding an aqueous solution containing aluminum ions, in particular a solution of aluminum nitrate, thereby to form a sol and calcining the sol at, for example, 200.degree. C. to 600.degree. C. The product, which may have a microporous or mesoporous structure, is useful in the separation of fluids, especially the separation of carbon dioxide from natural gas.

Abstract: A method is provided for replacing an existing service pipe carrying fluid to an outlet within a property with a replacement service pipe. In the method the outlet is disconnected within the property from the existing service pipe in such a way that both during and after disconnection fluid is prevented from escaping into the property. A desired length of replacement service pipe is then fed into the existing service pipe in such a way that during and after the feeding step fluid is prevented from escaping into the property. The outlet is then connected to the outlet end of the replacement pipe 2 in such a way that during the connection fluid is prevented from escaping into the property and after the connection step fluid is allowed to pass to the outlet solely by way of the replacement pipe.

Abstract: A method and apparatus for lining a pipe with a polymer liner in which the liner is pulled through a die to reduce the liner's diameter and through the pipe and on removal of the pulling load, allowing the liner to revert to at least the minimum internal diameter of the pipe, wherein the liner has a maximum diameter before entering the die and a minimum diameter in the die. The die having an aperture which is symmetrical with respect to a central, longitudinal axis and comprising in the direction that the liner is passed an entry, a throat and an exit. The diameter of the aperture decreasing over the entry to a minimum to the throat and increasing over the exit. The entry of the die, when viewed in a sectional plane extending longitudinally of the liner and containing the axis, is convex over substantially an entire axial length between where the liner first contacts the die and the throat, wherein the liner substantially continuously engages the die over substantially the entire axial length.

Abstract: A method for guiding a device in a required direction along the interior of a pipe, the method comprising removably mounting the device on a curved guide, lowering the device and the guide through a hole bored in the wall of the pipe to gain access to the interior of the pipe with the guide arranged to curve in the required direction in which the device is to move along the pipe and moving the device off the guide in the required direction.

Abstract: An electrofusion coupler is slid over one of two thermoplastic pipes, each having a layer or layers of reinforcing fibers between the center of the wall of the pipe and the outside surface of the pipe. The end surfaces are trimmed in a butt fusion machine and the resulting end surfaces are forced against a heater plate. The plate is removed and the end surfaces are forced together. Internal and external beads involving inward and outward flow of material result, the outward flow ensures that there is at the welded joint an inner layer which is free from reinforcement fibers. The external bead is removed and the coupler is slid over the butt fused welded joint and energized to cause it to become fusion welded to the outside of the pipe.