MXPA00003891A - Method for producing ends of metal of composite pipe lengths - Google Patents

Abstract

The invention relates to a method for producing ends of metal of composite pipes, comprising a casing pipe (1) of metal and a load carrying sheath (6, 7) of reinforced plastics, which sheath is produced in that the reinforcement is filled with polymer through injection under vacuum through injection pipes, said reinforcement comprises a first reinforcement layer (6) and a second reinforcement layer (7). To achieve the above-mentioned ends of metal the invention suggests that a sleeve (2) of the same thickness of material as the first reinforcement (6) is attached to the casing pipe (1) at both ends of said casing pipe, that the first reinforcement layer (6) is applied thereafter to the same thickness of material as the sleeves (2) over the whole length of the casing pipe, that a sheet metal strip (3) of preferably the same material as the casing pipe and with a greater width than the axial length of the sleeves is attached at the sleeves, respectively, and wound together with the second reinforcement layer (7) onto the sleeves as well as onto a part of the first reinforcement layer (6), the sheet metal strip having a step-like reduced thickness in the direction of its width to a depth corresponding to the thickness of material of the second reinforcement layer (7), so that said second reinforcement layer will be placed between the winding layers of the sheet metal strip, while the part of the sheet metal strips not being stepped will lie against each other, forming an end totally of metal at the pipe length, said pipe length being finished by injection in both reinforcement layers of a suitable resin.

Description

Method for the manufacture of metal tips of sections of composite pipe.

The present invention discloses a method for the fabrication of metal tips of sections of composite pipe, particularly those sections that include a metal casing and a shell of reinforced plastics, which is generated by the a - plication of reinforcement on said coating pipe and filling said coating with resin by vacuum injection by tubes or cannulas; said coating preferably comprises a first coating layer closer to the casing for the transmission of peripheral loads and a second reinforcing layer on the outside of the aforesaid reinforcement layer for the transmission of axial loads in the pipe. At present there are no known techniques for the manufacture of metal tips of said sections of composite pipe, which are intended to be subjected by known and certain techniques to form a pipe of great extension, said pipe must withstand high pressure and high temperature. The pipes are made REF .: 119473 for the production and transportation of natural gas and oil, for example. Therefore, the purpose of the invention is to propose a method for the manufacture of tips of metal tips - of sections of composite pipe, which can be joined by known and classified techniques, for example by welding or flange coupling. The purpose is achieved, according to the invention since sleeve preferably of the same metal as the casing and with the same thickness of the material of the first reinforcing layer is adhered to the casing at both ends of said casing, in where at least one of said liners is provided with axially arranged boreholes for the injection of tubes and vacuum connections, the first reinforcing layer is then applied to the same thickness of the liners over the total length of the liner pipe between the sleeves and placed successively at the same time said injection pipes in an arrangement parallel to the longitudinal axis of the casing, that a strip of metal sheet preferably of the same metal as the casing and wider than the length of the casings, is adhered to them respectively and applied together with the second reinforcing layer on the shirts, and on a part of the first reinforcing layer, the sheet metal strip having a reduced thickness by step in the direction of its width and at a depth equivalent to the thickness of the material of the second reinforcing layer, so that second layer of reinforcement will be placed between the rolled layers of the metal sheet strip, while the part of the rolled layers of the non-stepped strip will remain one over the other without reinforcement between them forming an end surface completely of metal in the section of the pipe, the section of the pipe being finished by injection of an appropriate polymer in both reinforcement layers. An unlimited example of the invention will be described below with reference to the accompanying drawings, in which fig. 1 shows a final view of a metal end of a composite pipe, fig. 2 shows a longitudinal section of a tip or section of metal attached to the composite pipe, and fig. 3 shows an enlarged longitudinal section of a metal strip with a reduced thickness by step, wherein a part of the second reinforcing layer is intended to be housed. According to the invention, the casing pipe 1, preferably made of stainless steel, is provided at both ends with a jacket 2 of the same material as the casing pipe; which shirt is adhered to it by pressure and welding or by brass welding. The connection between the jacket and the casing will have a tensile stress greater than that of the tube. Preferably, the sleeves 2 directly form part of the casing pipes 1. At least one of the sleeves is provided with axially arranged holes (not shown). Through some of these injection tubes provided with holes or cannulas, they are inserted. The remaining brakes are to be connected to a vacuum source (not marked). A reinforcement jacket 6, preferably in the form of a fabric, is wound in multiple wraps around the casing 1 between the casings 2, at the same time as injection pipes are placed in said reinforcement. Preferably, the injection pipes are pushed through the holes in the sleeve so deeply that the ends in the injection pipe are located close to the second sleeve and extend parallel to the longitudinal axis of the pipe. The first reinforcement 6 is wound to a predetermined thickness and the sleeves 2 must have the same thickness as that of the material, so that there is a smooth and flat transition section between the sleeves and the reinforcement. This first reinforcement is required only to transport the peripheral loads in the tube. A sheet of metal sheet 3, preferably of the same material as the coating pipe, which has a reduced thickness by step 4 along its entire length, is therefore adhered to the sleeves, respectively, preferably by welding in the longitudinal direction of the tube and, preferably, directly to the tips of said sleeves. However, the teal sheet strip 3 must be larger than the axial length of the sleeves. This step 4 is large enough to house a second reinforcing layer 7, which is used to transmit only axial forces in the tube and which extends between the strips 3. The metal strip is then rolled together with the second reinforcement 7, in such a way that the irreducible part 5 of the strip is wrapped on the sleeve 2, and the second reinforcement will be placed between the different rolled layers of the strip. When the second reinforcement 7 has finished being wrapped to the end of the metal strip it is still wound in at least one turn, after which the end of the strip is adhered, preferably by welding, to the underlying rolled layer . This is a consequence of the rolled layers of the second reinforcement 7 being surrounded by the rolled layers of the strip, and each fiber of said reinforcement will have a sufficiently large adhesion surface to produce a cutting force greater than the tensile force that it possesses. the fiber . During this wrapping operation of the strip 3 together with the second reinforcement 7 on the tube, the part with the step 4 of the strip and the part of the second reinforcement 7 covered by the part of the strip having the step, is bathed , in such a way that the polymer is distributed in liquid or powder form depending on which type of polymer provides the adhesion power. This means that if a plastic set by the heat is used, the total loss between the second reinforcement and the part of the metal strip that has the step will be complete, when the strip 3 and the second reinforcement 7 have finished being rolled up If a thermoplastic is used, said thermoplastic is heated after the second reinforcement and the metal foil strip have finished being rolled, mixed and left to solidify and thus allow the reinforcement to be held between the surfaces of the strip. Also in this case the bonding is complete. When the wrapping of the reinforcements 6, 7 and that of the sheet metal strip 3 has finished, the pipe is put into an appropriate mold (not indicated), which is raised essentially vertically and connected in its upper part. to an injection pump and a vacuum pump (not indicated), after which the injection of the polymer is carried out in the known manner. In this way a composite pipe with metal tips is obtained. The adhesion thereof in the axial direction is greater than the force equivalent to the total tension force of the laminate in the axial direction. This means that it is possible to join sections of composite pipe of the type mentioned above, in any known technique and by any classified technique, e.g. welding the tips, coupling flanges, etc. It should be mentioned that part 4 of the metal foil strips, which have a reduced thickness by step, can be provided with holes or can be perforated producing a rough surface which would increase the adhesion power between the polymer and the strip. In another type of composite pipes, which are not produced by the injection method mentioned above, but - which include metal casing and reinforced plating of reinforced plastics, which shell is preferably produced by prepregs and which the whole of its cross section in radial direction transmits at the same time both peripheral loads and axial loads in the shell; said strip of metal foil is adhered directly to the tips, respectively, of the casing without interlayer between them.

Claims (3)

2. A method for the fabrication of metal tips of composite pipe lengths, particularly those lengths that include a metal casing and a reinforcing plating of two reinforcing plastics, which shell is produced by the application of a reinforcement on the casing and filling said reinforcement with resin by means of vacuum injection by tubes or cannulas, said reinforcement preferably comprising a first reinforcing layer closer to the coating line for the transmission of peripheral loads and a second reinforcing layer on the outside of the reinforcing layer mentioned for the transmission of axial loads in the tube; characterized in that the jacket is preferably of the same metal as the casing and with the same thickness of material as the first reinforcing layer, is attached to the casing on both sides thereof, wherein at least one of said liners are provided with axially disposed holes for the injection of tubing and vacuum connections, that the first reinforcing layer is applied after the same thickness to the liners material along the casing between the liners and successively placing the injection tubes at the same time parallel to the longitudinal axis of the casing, as a metal sheet strip preferably of the same metal as the casing and wider than the axial length of the casings. is attached to said shirts, respectively, and wrapped together with the second reinforcing layer on the shirts, in addition to on a The first layer of reinforcement, the sheet metal strip has a reduced thickness by step in the direction of its width to a depth equivalent to the thickness of the material of the second layer of reinforcement, so that the second layer of reinforcement will be placed between the rolled layers of the strip, while the part of the rolled layers of the non-stepped sheet of metal sheet will remain one on top of the other without reinforcement between them, forming a surface entirely of metal in the section of the pipe, being finished the stretch by injection of an appropriate polymer into both reinforcement layers. 2. A method according to claim 1 characterized in that a polymer in the form of a liquid or powder is applied at the same time as the strip of metal sheet in the step and the second reinforcement are enwrapped on the section of the pipe towards the surfaces of the stepped part and the part of the second reinforcement, which is covered by said stepped part.
3. 3. A method according to claim 1, wherein the stepped portion of the metal strip is machined to achieve better adhesion. o or to a a r cac n e points and goal e sections of composite pipe. SUMMARY OF THE INVENTION The present invention describes a method for the manufacture of composite metal pipe tips, which comprises a metal casing pipe (1) and a reinforced plastics reinforcing shell, which is generated since the reinforcement is filled by a polymer by vacuum injection through injection tubes, said reinforcement includes a first reinforcing layer (6) and a second reinforcing layer (7). In order to achieve the aforementioned metal tips, the invention suggests that a jacket (2) of the same thickness of the material of the first reinforcement (6) is adhered to the casing (1) only a coating layer is applied next to the same thickness of the jacket (2), along the casing, than a strip of sheet metal (3) preferably of the same material as that of the casing and wider than the axial length of the casings, in addition to on a part of the first reinforcement layer (6), having a reduced thickness by slaving in the direction of its width to a depth equivalent to the thickness of the material of the second reinforcing layer (7), so that said second reinforcement layer will be placed between