Double pipe welding method

Abstract

The invention discloses a welding method for a double-layered tube. The welding method comprises the following specific steps of preparing the double-layered tube, wherein the double-layered tube comprises an inner tube and an outer tube, the outer tube is sleeved with an outer tube sleeve, the inner tube comprises a left inner tube and a right inner tube, and the outer tube comprises a left outer tube and a right outer tube; attaching and aligning end faces of the left inner tube and the right inner tube, reserving a gap between the left outer tube and the right outer tube, moving the outer tube sleeve onto the left outer tube or the right outer tube, and exposing the gap between the left outer tube and the right outer tube; performing application for inspection before welding on the left inner tube and the right inner tube according to the butt welding requirement; welding a connected part of the left inner tube and the right inner tube; polishing and cleaning a weld joint of the welded inner tube; performing application for inspection before welding on the left outer tube and the right outer tube according to the overlap welding requirement; moving the outer tube sleeve to the outer side of the gap in the first step, and separately welding a connected part between the left outer tube and the outer tube sleeve as well as a connected part between the right outer tube and the outer tube sleeve; and separately polishing and cleaning a weld joint between the left outer tube and the outer tube sleeve as well as a weld joint between the right outer tube and the outer tube sleeve.

Description

technical field [0001] The invention relates to a marine double-layer pipe connection, in particular to a welding method for a double-layer pipe of a low-pressure gas pipe of a marine dual-fuel engine. Background technique [0002] At present, the connection between the outer pipes of low-pressure double-layer pipes at home and abroad mainly adopts the butt welding form, that is, the two pipe sections are directly butt welded. [0003] figure 1 As shown in , the double-layer pipe includes a double-layer outer pipe 100 and a double-layer inner pipe 200 , the double-layer outer pipe 100 is directly connected by a weld 400 , and the double-layer inner pipe 200 is directly connected by a weld 300 . [0004] However, in order to make the double-layer inner tube easy to weld, according to figure 2 As shown, a section of the outer tube 103 is generally cut out at the place corresponding to the weld seam 400 of the outer tube 100, and the outer tube 103 is cut into two in the axi...

AI Technical Summary

Problems solved by technology

[0009] In view of the above, the purpose of the present invention is to provide a welding method for double-layer pipes, which is used to solve the problems of difficult construction, slow construction progress and low pass rate of project inspection in the prior art

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