Abstract: A method and apparatus for measuring the flow rate of a single phase fluid, particularly a gas, through a conduit. A pulse of tracer fluid is discharged or injected into a first fluid flowing through a conduit, the concentration of the tracer fluid is measured as a function of time at a downstream from where it is injected, and the flow rate of the first fluid is determined based on the concentration measurements. The concentration of tracer fluid is preferably sampled substantially continuously from when the tracer gas first passes the measuring point until substantially all of the tracer fluid has passed the measuring point and the sampled concentrations integrated. The concentration of tracer fluid is preferably determined by measuring the thermal conductivity of the mixture of the first fluid and tracer fluid which is dependent upon the concentration of the tracer fluid.

Abstract: A pitch sensor tool for a stem boring or drilling machine, for example a sub-surface directional drilling machine having a stem and a drilling head. The pitch sensor tool includes a generally cylindrical housing adapted to be mechanically coupled to the stem and to the drilling head, and a pitch sensing device disposed in or on the housing and adapted to transmit a reading of the second pitch of the pitch sensor tool. In one example, the pitch sensing device is housed in a compartment in the pitch sensor tool. A boring or drilling tool incorporates the pitch sensing tool and a drilling head, and a stem boring or drill machine incorporates the pitch sensing tool. By separating of the pitching sensing device from the rotating parts (i.e., drilling head or guide head) the pitch reading can be measured accurately and during a drilling procedure, as well as after it.

Abstract: A method and apparatus for determining the effective composition of a mixture of gases including a plurality of hydrocarbon gases, the method comprising selecting one or more effective hydrocarbons to represent the plurality of hydrocarbon gases in the gas mixture, the number of effective hydrocarbons being less than the number of hydrocarbon gases in the gas mixture whose composition is to be determined; measuring a number of characteristics of the gas mixture whose effective composition is to be determined, the number of characteristics to be measured being one less than the total number of components to be determined and determining the effective composition of the mixture of gases from the measurements of the characteristics of the gas mixture, a predetermined parameter dependent upon the characteristic measured and knowing that the sum of the components of the gas mixture equals 100%.

Abstract: A method for securing a branch assembly to a pipeline includes positioning a first containment ring surrounding an area from which the branch is to extend, positioning a first annular seal within the containment ring to provide a first ring/seal arrangement, positioning a second containment ring spaced from the first containment ring and first annular seal, positioning a second annular seal within the second containment ring to provide a second ring/seal arrangement, positioning the second part of the branch assembly onto the seals, and positioning a first part of the assembly on the pipe line and securing the first and second parts together so as to leave an annular gap between the first and second ring/seal arrangements and to provide an access point or vent in the second part communicating with the annular gap.

Abstract: A method and apparatus for obtaining information from a utility meter. A digital camera is used to take a digital image of information displayed on the utility meter. The digital image is passed to a computer that is arranged to extract information displayed on the utility meter from the image. The information may be used for a variety of purposes such as updating databases with details of utility meters and for billing purposes.

Abstract: A metal pipeline section that has a metal flange at one end is lined with a plastic liner such that some of the liner extends beyond the flange end of the pipeline section. An annular plastic member is electrofusion joined onto the outside of the portion of plastic liner which extends beyond the flange end of the pipeline section and any liner extending beyond the annular plastic member is trimmed off to make the liner flush with the annular plastic member. The annular plastic member is then positioned adjacent the annular plastic member of another similarly prepared pipeline section and a containment ring is secured around them to restrain any outward movement of the annular plastic members when the pipeline is in use. The metal flanges are secured to each other such that the annular plastic members are compressed between them to prevent leakage.

Abstract: A running fluid seal arrangement (10) includes a passage for receiving cable (12) with chambers (20,21 and 22). Water at a higher pressure than gas in main (11) is pumped via pump (26) into chamber (21) from a reservoir (27). A mixture of gas and water from the interface in the region of chamber (20) is passed to a sealed pressure vessel (28). Water therefrom can pass back to reservoir via float valve (29). Wiper seals (30,36 and 37) can also be provided.

Abstract: A method of controlling occurrence of slugging in a riser of a pipeline arrangement including a riser base and pipeline conveying a multiphase fluid system in which the gas phase may be natural gas. The upper end of riser is connected to a separator vessel. The gas phase of the multiphase fluid system is separated from the liquid phase so that the separated gas leaves through gas outlet pipe controlled by a first valve, and the liquid leaves through an outlet pipe controlled by a first valve. The first valve regulates the velocity of gas along the pipeline towards the riser. A pressure sensor observes the gas pressure in the riser base, and if the observed pressure exceeds a predetermined control pressure value a three term pressure indication control causes the first valve to be operated to pen to an extent that increases the gas outflow through the pipe, and thus increases the velocity of gas in the pipeline to avoid occurrence of severe slugging in the riser.

Abstract: A method and apparatus for synthesizing an approximation to a sine wave comprising generating a number of pulse width modulated signals, each having a predetermine duty cycle and being the same frequency as each other, from a clock signal. The generated pulse width modulated signals are then combined to produce an approximation to a sine wave having the same frequency as the pulse width modulated signals. The clock signal is provided by an oscillator arranged to produce clock signals over a continuous range of frequencies so that approximations to a sine wave can be produced over a continuous range of frequencies.

Abstract: A lining method for a host pipe (10) including lubrication of the host pipe prior to insertion of a thermoplastic liner (11) using tight fit techniques. After allowing the inserted liner to relax, the liner is partially pulled from within the host pipe using puller (20) and clamped with an internal clamp (30) to allow fitting of a special flange (40) to the liner (11) by butt fusion, for example. Threafter the liner is allowed to revert so as to abut a flange (12) fitted to the host pipe (10). The technique is repeated at the other pipe end.

Abstract: A method and apparatus for identifying the location of a gas leak source. The apparatus includes a gas detector for detecting the presence of gas and a wind direction indicator. The method traces a gas leak source location using the apparatus including the gas detector, arranged to detect the presence or absence of a gas, and the wind direction indicator.

Abstract: A water shut-off is provided in a hydrocarbon well by injecting a first chemical composition, effective as a relative permeability modifier polymer, into the hydrocarbon and a water zone of the well followed immediately by the injection of a second chemical composition, which forms a flow blocking polymer composition, into the zones and, after a shut-in period for reaction of the relative permeability modifier polymer, back producing the polymer compositions from they hydrocarbon zones to provide a path for the hydrocarbons from the zones while allowing the flow blocking polymer compositions to form the water shut-off in the water zones.

Abstract: A method and apparatus for determining the speed of sound in a gas. An acoustic transmitter is arranged to apply an acoustic signal to the interior of a resonator and an acoustic receiver is arranged to detect the amplitude of the acoustic signal in the interior of the resonator. A control means determines the speed of sound of gas within the resonator from the frequency of a detected non-radial resonant mode.

Abstract: A thermosyphon radiator comprising a sealed panel containing a reservoir of water in a lowermost part of the panel and a heating member, e.g. a hot water pipe, extending through the lowermost part of the panel, the member being at least partially immersed in the liquid.

Abstract: The process is characterised by sulfonating a partially brominated poly(phenylene oxide). The gas separation material so formed may be made into a membrane and is useful in separating component gases from a gas mixture.

Abstract: A coupling comprises a tubular insert (20), having an external shoulder (22) and external circumferential projections (26) separated by circumferential grooves (28, 30), and a tubular sleeve (14) having a largest internal diameter less than the external diameter of a pipe (10). The sleeve is advanced over the end (12) of the pipe and along the pipe away from the end. The pipe is constricted as the sleeve passes over it and then subsequently recovers to establish an end portion (18) which is unconstricted. The outside diameter of the insert is preferably not greater than the inner diameter of the pipe and the insert is inserted into the end portion of the pipe, the end of the pipe engaging the shoulder. The sleeve is then subjected to relative movement between said sleeve and said end until the end portion is gripped between the projections and the sleeve. The end of the sleeve preferably engages the shoulder (22). The coupling enables the pipe to be connected to other pipework.

Abstract: A pipeline cleaning arrangement that includes a cleaning pig with guide units at each end. A tow cable, via a cone, pulls the pig assembly in a forward direction. The tow cable then pulls the cone in a rearward direction. The pig is configured with two cleaning portions that separate in the forward direction to avoid debris collection and abut in the rearwards direction to collect pipeline debris and carry this to the entry point for removal via a suction tube.

Abstract: Determininig a frequency at which a resonator resonates comprising: driving an acoustic transmitter for applying an acoustic signal to the interior of a resonator by scanning through a first range of frequencies in substantially equidistant steps of a first size; detecting a signal from an acoustic receiver arranged to detect the amplitude of an acoustic signal within the resonator produced by driving the acoustic transmitter over the first range of frequencies; determining a frequency at which a maximum occurs in the detected signal for the first range of frequencies; driving the acoustic transmitter by scanning through a second range of frequencies containing the determined frequency from the first range of frequencies, the second range being smaller than the first range, and scanning through the second range of frequencies in substantially equidistant steps of a second size which is smaller than the steps of the first size; detecting a signal from the acoustic receiver produced by driving the acoustic tran

Abstract: A pipe threading arrangement includes a launch body (13) and a parachute (15) within tube (12). The parachute is launched into pipe (2) via slide valve (1) and brings with it a threading cable (19). At a remote location within the pipe (2) the parachute is stopped by a catch arm (8) with associated catch finger (5). The parachute is deflated and retrieved, together with the threading cable, via the slide valve into the catch body (4).

Abstract: Two outer steel pipes (16 and 16A) are each lined by corrosion resistant lining pipes (18 and 18A) of compressible plastics material which stop short of the ends (20, 20A) of the outer pipes to leave an annular recess or counterbore (24 and 24A) at each of those ends. A tubular bridging-member (2) of ductile, plastically deformable, corrosion resistant material, for example brass or stainless steel has two tubular end portions (4 and 6) extending in opposite directions from an intermediate tubular portion (8) having an outer diameter greater than that of the end portions (4 and 6) and an inner diameter greater than that of the said end portions. The end portions (4 and 6) are encircled by ribs (12). Initially the outer diameter of the end portions (4, 6) is less than that of the inner diameter of the lining pipes (18, 18A). Thus each lined pipe (16, 16A) can be fitted over the respective end portions (4 and 6) with the intermediate portion (8) occupying the combined counterbore (24, 24A).