Abstract:
The invention relates to a method for connecting two individual elements (4, 4') of a fluid transport pipe, each individual pipe element being made from metal alloy and being coated with an external insulating coating (6, 6') made from a thermoplastic material, except one end portion of the element that is not coated with the external insulating coating. The method comprises: a step of welding the two individual pipe elements which are placed end to end at the coating-free end portions thereof; a step of mechanically assembling at least two rigid shells (14, 16) to the coating-free end portions of the individual pipe elements, said rigid shells being made from a thermoplastic material; and a step of maintaining the shells leaktight relative to the external insulating coating of the two individual pipe elements, comprising positioning an annular sleeve (24) around the shells assembled mechanically to the coating-free end portions of the individual pipe elements, such as to cover the shells and a portion of the external insulating coating of the individual pipe elements, said sleeve being made from the same material as a constituent material of the external insulating coating of the individual pipe elements or from a thermoplastic material thermochemically compatible with same and being sealingly secured to the external insulating coating of the individual pipe elements by means of welding.
Abstract:
This invention concerns a method for joining or repairing a pipe system (1) that comprises a least two pipes (2) made of weldable plastic material comprising fitting a sleeve (5) made of weldable plastic material the distance between the two pipes (2), the sleeve (5) having a length A that exceeds the distance B between the mutually opposing pipes (2), such as to overlap each pipe end (2a, 2b) to a given extent C. The method has the working steps; placing an electrically conductive band (6) around one of the pipes (2), the band (6) having two ends (6a, 6b); connecting the band ends (6a, 6b)) to each other by placing the band ends (6a, 6b) overlapping each other; fitting the sleeve (5) over and against the pipe (2) and the band (6), and applying an electric current to the band (6) over a given period of time, thereby heating the band (6) to a determined temperature for a determined time and fusing the band (6) with the plastic surfaces of the pipe (2) and the sleeve (5) lying in abutment therewith to form a welding joint being fully executed around the pipe (2) and inside the sleeve (5). The invention also concerns an apparatus (12) to be used when working according to the method.
Abstract:
The present invention relates to a method of joining polymer coated steel pipes comprising the steps of - providing polymer coated pipe segments with an uncoated length on both ends of the segments; - welding the polymer coated pipe segments together; - applying a curable polymer (A) onto the uncoated length of the welded pipe segments to form an first coating layer; and - applying a polymer composition (B) onto the first coating layer to form a topcoat layer with a thickness of 0.5 to 10 mm, wherein the polymer composition (B) has a melt flow rate MFR 2 of 1.0 to 6.0 g/10 min, determined according to ISO 1133 at a temperature of 190°C under a load of 2.16 kg, and includes a base resin comprising (B-1) a non-elastomeric polyethylene in an amount of 60 to 85 wt% of the total polymer composition being produced in a process using a single-site catalyst, and (B-2) an elastomer comprising a copolymer of ethylene and at least one polar comonomer, wherein component (B-1) or components (B-1) and (B-2) have been grafted with an acid grafting agent and the use of polymer composition (B) as topcoat layer with a thickness of 0.5 to 10 mm in a coating of coated steel pipe field-joints, a method of coating a steel pipe and the use of polymer composition (B) for the coating of steel pipe joints or steel pipes.
Abstract:
An induction heating apparatus for use in pre-heating pipe joints. The induction heating apparatus comprises a frame for applying around the pipe joint, and an induction heating coil made from Litz cable wires.
Abstract:
A method of coating a field joint of a pipeline to accelerate the cycle time comprises positioning a mould tool around the field joint to define a mould cavity and injecting plastics material into the mould cavity through a plurality of gates in the mould tool, spaced along the mould cavity. The material is injected through different gates at different times as the mould cavity is filled, specifically through at least one first gate to advance a melt front within the mould cavity, and subsequently through at least one second gate spaced from the first gate, preferably when the melt front passes the second gate. First and second mould tools may be positioned successively around the field joint to create inner and outer coatings on the field joint. An insert may be positioned in the mould cavity to be embedded in the injected plastics material.
Abstract:
A method of coating a field joint of a pipeline to accelerate the cycle time comprises positioning a mould tool around the field joint to define a mould cavity and injecting plastics material into the mould cavity through a plurality of gates in the mould tool, spaced along the mould cavity. The material is injected through different gates at different times as the mould cavity is filled, specifically through at least one first gate to advance a melt front within the mould cavity, and subsequently through at least one second gate spaced from the first gate, preferably when the melt front passes the second gate. First and second mould tools may be positioned successively around the field joint to create inner and outer coatings on the field joint. An insert may be positioned in the mould cavity to be embedded in the injected plastics material.
Abstract:
A method of applying a heat-shrinkable sleeve (10) to a portion of a pipe (2) including the following steps: providing a pipe (2), arranging a heat-shrinkable sleeve (10) around a portion of the pipe (2), arranging a heat-delivery apparatus (12) around the pipe (2) in the region of the sleeve (10), the heat-delivery apparatus (12) including at least three heater devices (20) arranged at different positions along the axis of the pipe, such that a first heater device (20c) is positioned closer to the centre of the sleeve (10), in the axial direction, than second and third heater devices (20a, 20e), the second heater device (20a) is positioned in the region of a first end of the sleeve (10), and the third heater device (20e) is positioned in the region of a second end of the sleeve (10) opposite to the first end, and individually controlling each of the first, second and third heater devices (20a, 20c, 20e) to apply heat to the heat-shrinkable sleeve (10) wherein each heater device (20) is in the form of an infrared heater device.
Abstract:
A method of forming a protective coat (21) about a cutback (18) between pipes (3) forming part of an underwater pipeline (2) provides for laying a thermoplastic sheet (22; 42) on a supporting sheet (23; 27; 40); and winding the thermoplastic sheet (22; 42) and the supporting sheet (23; 27; 40) about the cutback (18) to join the thermoplastic sheet (22; 42) to the cutback (18). A method of forming a protective coat (21) about a cutback (18) between pipes (3) forming part of an underwater pipeline (2) provides for laying a thermoplastic sheet (22; 42) on a supporting sheet (23; 27; 40); and winding the thermoplastic sheet (22; 42) and the supporting sheet (23; 27; 40) about the cutback (18) to join the thermoplastic sheet (22; 42) to the cutback (18).
Abstract:
A me.tal pipe joint comprising a polymer coated pipe element (B, D, E, F) comprising on its outer surface a composite material, said material comprising a layer comprising an adhesive (G) and a layer comprising a wicking material (H), said adhesive compound layer contacting said polymer coating (D, E, F).
Abstract:
Method and apparatus for coating a pipe (2) or a pipe section with a layer of at least one polymer. The method comprises providing a pipe (2) or a pipe section having an outer surface defining the periphery of the pipe or pipe section; applying on the outer surface of the pipe or pipe section a layer of at least one polymer material in melt stage using a nozzle (3), which is mounted on a carriage capable of travelling along the periphery of the pipe (2) or pipe section; and moving the carriage along at least a part of the periphery during the application of the polymer material to form a layer on the surface of the pipe (2) or pipe section. The present invention is particularly useful for coating field joints in pipelines.