Flexible pipe and process for production thereof
AssigneeEvonik Degussa GmbH
InventorsKarl Kuhmann, Andreas Dowe, Rainer Goering
Life of this patent
Estimating the term…
Abstract
The invention relates to a flexible tube of multilayer construction having unbonded layers, wherein at least one layer is formed in that a tape made of a plastic molding compound is spirally wound about a further inner layer, wherein the upper and lower layers of the tape are simultaneously or subsequently welded to each other at overlapping regions. The tube is particularly suitable for offshore application in oil and gas extraction
Claims20
A process for producing a flexible pipe of multilayer structure with unbonded layers effective for conveying a liquid or gas selected from the group consisting of crude oil, natural gas, methanol, and CO2 at a temperature of at least 130° C., the process comprising:
- forming a layer by winding a tape helically onto a more internal layer, and
- simultaneously or subsequently welding an upper sublayer of the tape and a lower sublayer of the tape to one another at an overlap region of no more than about 10% of the width of the tape via introduction of electromagnetic radiation,
- wherein the tape comprises a plastics molding composition based on olefinic polymer, polyamide, fluoropolymer, polyphenyl sulphone, polyarylene ether ketone, polyphenylene sulphide, or a polyarylene ether ketone/polyphenylene sulphide blend, the portions of the upper sublayer of the tape and the lower sublayer of the tape not welded to one another at the overlap region being no more than frictionally bonded together,
- wherein the electromagnetic radiation absorption properties of the tape differ across the width of the tape,
- when helically winding the tape, a more electromagnetic radiation absorbent width of the tape is covered by a more electromagnetic radiation transparent width of the tape, and
- at least two of the layers of the multilayer structure are not bonded directly or indirectly together.
A process for producing a flexible pipe of multilayer structure with unbonded layers effective for conveying a liquid or gas selected from the group consisting of crude oil, natural gas, methanol, and CO2 at a temperature of at least 130° C., the process comprising:
- simultaneously winding two layers of tape helically onto a more internal layer, the upper layer of tape being wound over the lower layer of tape, and
- simultaneously or subsequently welding the upper layer of tape and the lower layer of the tape to one another at an overlap region of no more than about 10% of the width of each tape via introduction of electromagnetic radiation,
- wherein each layer of tape comprises a plastics molding composition based on olefinic polymer, polyamide, fluoropolymer, polyphenyl sulphone, polyarylene ether ketone, polyphenylene sulphide, or a polyarylene ether ketone/polyphenylene sulphide blend, the portions of the upper layer of tape and the lower layer of tape not welded to one another at the overlap region being no more than frictionally bonded together,
- wherein the electromagnetic radiation absorption properties of the lower layer of tape are greater than the electromagnetic radiation absorption properties of the upper layer of tape and the electromagnetic radiation transparent properties of the lower layer of tape is less than the electromagnetic radiation transparent properties of the upper layer of tape, and
- at least two of the layers of the multilayer structure are not bonded directly or indirectly together.
Dependencies are inferred from the claim text.