Two-section type inter-anticorrosion-mouth-repair-free dead-mouth tie-in method for steel pipelines

Abstract

The invention relates to a two-stage method for connecting dead ends of steel pipelines without internal anti-corrosion. It includes the following steps: (1) Processing steps of connecting short pipes: (1) Cut two sections of short steel pipes according to the steel pipe specifications specified in the design; (2) Use a surfacing machine to circumferentially surfacing stainless steel materials on the inner wall of the pipe end; (3) Lathe Process the corrosion-resistant alloy pre-joining layer and the grooves at both ends of the short pipe; (2) On-site pipe dead end connection steps: Weld the unsurfacing end of the short pipe to the pipes at both ends; perform internal welding on the inner wall of the welding joint. After the anti-corrosion patching treatment, the same welding material as the pre-patching surfacing is used to weld the dead seam. The beneficial effects are: the present invention can eliminate the need for anti-corrosion patching within the dead end of the steel pipeline through two sections of pre-patched surfacing short pipes, solves the technical bottleneck of anti-corrosion patching within the dead end weld of the pipeline, and simplifies the connection of the dead end of the internal anti-corrosion pipeline. The first step of the process reduces the construction cost of dead-end joints of internal anti-corrosion steel pipes.

Description

technical field [0001] The invention relates to the field of steel pipelines, in particular to a two-stage steel pipeline-free internal anti-corrosion mending dead joint connection method. Background technique [0002] In order to avoid the corrosion of the conveying medium to the steel pipeline, it is necessary to carry out industrial anti-corrosion treatment on the inner wall of the steel pipe. Since the heat input of the pipeline welding will cause the damage of the anti-corrosion coating in the weld joint area, after the on-site welding construction, it is necessary to enter the interior of the pipeline manually or by equipment Anti-corrosion treatment is carried out on the inner wall of the welding joint. This process is called internal anti-corrosion repairing of the welding joint; pipeline welding joints that cannot be repaired internally by equipment or manually are called "pipeline dead joints"; [0003] Through pipe fittings such as elbows, tees or short pipes, or ...

AI Technical Summary

Problems solved by technology

[0006] The above invention adopts three prefabricated pup joints, and there are 4 welding seams in the on-site connection, two of which are stainless steel welding seams, which not only reduces the construction efficiency, but also increases the construction cost of the joint

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