Abstract: A method of monitoring the alignment of pipes to be welded end to end involves supporting a reference bar extending generally parallel to, and external of, the pipes so as to span a weld position of which the ends of two pipes are to be welded, performing measurements of perpendicular distance between the bar and each pipe at two predetermined distances from the end of each pipe, determining the thickness of the walls of the pipes, determining the slope of the exterior of each pipe with respect to the reference bar, calculating from the slopes the difference between the distances from the bar to the outer surface of each of the two pipes to the weld position, so as to provide a measure of the misalignment of the outer surface of the pipes at the weld position, differencing the wall thicknesses of the pipes to provide a wall thickness difference, and subtracting the wall thickness difference from the misalignment of the external walls of the pipe to determine the misalignment of the inner surfaces of the pipes

Abstract: A method for making an internal upset (20A) on metal drill pipe (10) having a transition section (24A) with a curved inner periphery (28A) of a concave curvature extending continuously between the central portion (12) of the pipe (10) and the increased thickness end section (22A) and formed from a radius (R2). An external upset (20) is first formed in forging steps as shown in FIGS. 2 and 4 by radially expanding and squeezing the end of pipe (10). Then the final forging step radially contracts the external upset (20) to form the internal upset (20A) as shown in FIGS. 3 and 5. The finished internal upset 20A as shown in FIG. 7 has a transition section 24A with an inner peripheral curved surface 28A formed from a radius (R2). The forging steps are performed with a single heating of the metal drill time in a minimum of time preferably within around one (1) minute but in any event less than around two (2) minutes.

Abstract: A pipeline is covered with a continuous wrapping sheet having heat-activatable adhesive on its inner side. The wrapping may be helically applied or may be heat shrunk to impart a circumferential stress conforming the wrapping tightly to the surface of the pipe. High frequency induction heating is applied to cause the adhesive to wet and bond to the pipe surface. The wrapping can be applied progressively and continuously along a pipeline excavated from the ground while the pipeline is in service. The product conveyed within the pipe assists in rapidly cooling the adhesive and wrapping sheet so that the pipe can be promptly relaid in the ground.

Abstract: An article, for example a pipe, has a first covering such as a polymer layer, and a second covering, such as a repair patch or a repair deposit of melt-on adhesive or a wrap or a sleeve protecting a welded joint between two lengths of such pipe. The second covering may have a functional coating on an underside which is applied on and is at least partially superimposed over the first covering. A cured deposit of thermoset resin is applied at least over the edges of the second covering, for example in the form of a fibrous tape impregnated with a curable resin composition, and bonds to the first and second coverings. The resin deposit provides the second covering with increased stability against displacement laterally of said first covering, for example as a result of soil stress.

Abstract: Heat-shrinkable cap comprising a heat-shrinkable tube sealed at one end by heat recovering that end of tube over a dimensionally stable, solid plug. The tube and plug are mutually weldable under heat, or are bonded together, thereby providing an air and water-tight seal at the sealed end. The open end of the cap may be internally coated with adhesive to provide an air and water-tight seal over an object such as a cable-end when the cap is heat recovered over said object.

Abstract: Surface anomalies on pipe are removed preparatory to corrosion coating. The removal is conducted by brushing with wire brush elements or Comax brush elements which may rotate about axes parallel to the pipe axis or substantially radially off the pipe. Both kinds of brush elements may be used in combination. Before subjecting the pipe to brushing, the surface is particulate blasted to remove ferric oxide and better expose surface anomolies. After wire brushing, the surface is again particulate blasted to provide an anchor pattern of indentations promoting adhesion of the coating.

Abstract: Surface anomalies on pipe are removed preparatory to corrosion coating. The removal is conducted by brushing with wire brush elements or COMAX brush elements which may rotate about axes parallel to the pipe axis or substantially radially off the pipe. Both kinds of brush elements may be used in combination. Before subjecting the pipe to brushing, the surface is particulate blasted to remove ferric oxide and better expose surface anomolies. After wire brushing, the surface is again particulate blasted to provide an anchor pattern of indentations promoting adhesion of the coating.

Abstract: A multiple layer wraparound sleeve having a heat shrinkable backing layer and at least one functional layer has the functional layer as a discrete sheet which is connected to one end of the backing layer, and is of at least sufficient length that, when the sleeve is wrapped around the pipe or other substrate at least twice, the functional layer sheet wraps around the substrate first with its ends overlapping and the backing layer wraps around the functional layer sheet with its ends overlapping. This allows wrappings of reduced thickness to be employed without problems of voids occurring between the functional layer and the substrate.

Abstract: The invention provides a composite protective coating applied to a steel pipe, the coating comprising an epoxy resin primer bonded to the outer surface of the pipe, a polyolefin outer sheath, and an interlayer consisting of a mixture of epoxy resin and polyolefin. The composition of the mixture forming the interlayer is graded throughout its thickness, being substantially all epoxy resin adjacent to the primer coating and substantially all polyolefin adjacent to the sheath.

Abstract: The invention relates to a method and apparatus for wrapping pipe with a cementatious material such as concrete. The material is conveyed to the pipe as a continuous strip provided with notches along one edge and complementary notches are formed at the other edge of the strip as the strip is wrapped spirally onto the pipe. The continuous strip is formed in a hopper having a number of sections of successively reduced widths and containing rollers by which successive superimposed layer portions of the strip are formed with reinforcing mesh embedded between successive layer portions.

Abstract: Two methods are provided for applying and forming a protective composite coating on a metallic substrate. In the first method, the substrate is heated to a temperature between about 175.degree. C. and 275.degree. C. and a powdered coating of epoxy resin between 100 and 400 microns thick is applied to the outer surface of the heated substrate. A premixed powder coating of epoxy resin and polyolefin is applied directly onto the epoxy resin coating, forming an interlayer of interspersed domains of epoxy and polyolefin between about 100 and 400 microns in thickness. On to this, powdered polyolefin is sprayed to produce a polyolefin sheath coating for the metallic substrate between 200 and 1000 microns in thickness. In the second embodiment of the method, the interlayer is formed by spraying pure epoxy resin powder and polyolefin powder from separate sources simultaneously onto the substrate. By these methods, a metallic substrate coated with a composite epoxy/polyolefin protective coating is produced.

Abstract: A longitudinally heat shrinkable closure sheet has a hold-down adhesive portion adjacent each longitudinal end for application on the exposed end portions a heat shrinkable wrap-around sleeve applied around a pipe or other article to be covered. Heat is applied to the closure sheet in order to weld the adhesive free portion of the underside of the closure sheet to the end portions of wrap-around sleeve. The initial shrinkage of the closure sheet between the hold-down adhesive portions draws it tightly into contact with the upper side of the end portions. Shearing forces are applied between the closure sheet and the end portions firstly as the closure sheet contracts relative to the end portions, and secondly, as the sleeve shrinks, develops hoop stress and stretches the closure sheet, and a high strength fusion bond is achieved between the closure sheet and sleeve.

Abstract: A heat shrinkable wrap-around sleeve comprises a heat shrinkable sheet with a heat stable strip welded on one end. The free end of the heat stable strip is overlapped on the outer side of the opposite end of the sheet and welded thereto by heating applied directly on the outer side. This allows a good quality welded connection to be formed without requiring the use of hold-down adhesives. The sleeve can be manufactured using induction welding or more preferably by heated wedged welding.

Abstract: A geophone is disclosed that has a cylindrical housing closed at one end by a bottom and at the other end by a top. A magnet assembly and a coil-mass are located in the housing. Springs support the coil-mass for axial movement relative to the magnet assembly along the longitudinal axis of the housing. A pair of coil terminals are mounted in the upper end of the coil-mass adjacent the top of the housing. A pair of eyelets extend through the top of the housing and outside geophone terminals are attached to and extend through the eyelets into the housing. A pair of pigtails connect the geophone terminals to the coil terminals.

Abstract: An intermediate weight member (10) having a variable cross-section or bending moment of inertia as a function of member length is disclosed. At one end of the member (10) a slip and elevator section (14) is provided. A partially grooved section (16) of a diameter greater than that of the slip and elevator section extends between the slip and elevator section (24) and the other end of the member (10). The partially grooved section (16) includes two variable depth grooved sections (18, 20) separated by an ungrooved section (22). The ungrooved section (22) includes hardbanding rings (26, 28). The spiral grooves (30A, 30B, 30C) of variable depth grooved section (18, 20) vary in depth as a function of member length such that the bending moment of inertia varies as a function of length from the slip and elevator section (14) to the lower end of the member (10).

Abstract: A method and apparatus are described, for extruding a thermoplastic protective jacket onto a steel pipe. The pipe is first coated with a layer of epoxy which is partly cured, and then is conveyed through a cross-head extruder where a layer of copolymer or other suitable adhesive is applied. The outermost thermoplastic jacket may be co-extruded with the adhesive layer or laid down onto the pipe as it passes through a second cross-head extruder. Radial pressure is applied to a band of surface about the jacketed pipe which has been cooled to a stage such that the outer surface of the thermoplastic is hardened while the inner portion thereof remains above the softening temperature, thereby achieving good adhesion of the jacket to the pipe, without dislocating or blemishing the thermoplastic protective jacket.

Abstract: A self-propelled pipe cleaning machine as disclosed for use in removal of deteriorated coatings, such as coal tar or tape, from pipelines and providing a degree of surface preparation suitable for recoating. The machine comprises a travelling frame for motion along the pipe and an oscillating carriage bearing a plurality of counter-rotating cylindrical cutting tools which are urged toward the pipe surface by constant-force pneumatic cylinders. Variation in the pressure of cutters against the pipe surface during oscillation of the cutter head is avoided by counterbalancing of the pivotally-mounted cutters and their associated drive means.

Abstract: An electrical connector is disclosed having an elongated conductor housing of non-conducting material with two electrical connector conductors embedded in and extending lengthwise of the housing. Each connector conductor has a socket at one end and a pin at the other. A sleeve of elastic material positioned on the housing so that a portion of the housing extends beyond the sleeve to serve as a male plug and a portion of the sleeve extends beyond the other end of the housing to combine with the housing to form a female plug. The sleeve has an integral elongated boot in the side through which a geophone cable extends. The conductors of the geophone cable are connected to the conductors embedded in the housing of the connector.

Abstract: In a concrete-wrapped pipe having an inner water-impermeable resinous coating, the concrete wrapping is formed with a continuous inner portion covering the resinous coating and a helically slotted outer portion, the helical slot extending at least to the depth of a mesh reinforcement embedded in the concrete. The structure is characterized by the fact that the inner portion of the concrete wrapping is formed with one or more helically extending zones of reduced compressive strength, radially aligned with the helical slot or slots in the outer portion. The helical configuration breaks the continuityof the concrete wrapping in the longitudinal direction of the pipe and, even with pipe of relatively large diameter, enables the wrapping to accommodate limited bending of the pipe.

Abstract: In a concrete-wrapped pipe having an inner water-impermeable resinous coating, the concrete wrapping is formed with a continuous inner portion covering the resinous coating and a helically slotted outer portion, the helical slot extending at least to the depth of a mesh reinforcement embedded in the concrete. The structure is characterized by the fact that the inner portion of the concrete wrapping is formed with one or more helically extending zones of reduced compressive strength, radially aligned with the helical slot or slots in the outer portion. The helical configuration breaks the continuity of the concrete wrapping in the longitudinal direction of the pipe and, even with pipe of relatively large diameter, enables the wrapping to accommodate limited bending of the pipe.