Repair-proof welded connection technology of inner walls of plastic-coated steel tubes

Abstract

The invention relates to the technical fields of metal surface anti-corrosion and pipe connection and discloses a repair-proof welded connection technology of the inner walls of plastic-coated steel tubes. The welded connection technology comprises the following steps: a. removing rust of the steel tubes; b. spraying metal coating at the ends of the steel tubes through thermal spraying; c. preparing thin-walled stainless steel jackets; d. installing the thin-walled stainless steel jackets in the steel tubes, performing tube expansion to ensure that the thin-walled stainless steel jackets are lined to the inner walls of the steel tubes; e. flanging the ends of the thin-walled stainless steel jackets according to the root shape of the steel tubes to form turnups; f. coating hierarchical coating on the outer walls of the steel tubes; g. transferring the steel tubes with the thin-walled stainless steel jackets to a site; h. welding the thin-walled stainless steel jackets by using stainless steel welding rods; i. welding the steel tubes by using carbon steel welding rods; j. repairing the hierarchical coating on the outer surface of the steel tubes and k. detecting. The invention avoids the repair of the inner wall of the steel tubes, eliminates corrosion blind spots, can not reduce the internal diameter of the steel tubes and flow rate and can greatly improve the installation efficiency of pipes.

Description

technical field [0001] The invention relates to the technical field of metal surface anticorrosion and pipeline connection, in particular to a repair-free welding connection process for the inner wall of a plastic-coated steel pipe. Background technique [0002] The key parts of the traditional plastic-coated steel pipe connection technology are generally welded and repaired to customize the inner or outer protrusion joints, which reduces the fluid section of the inner wall of the steel pipe, complicates the construction, and increases the cost, causing certain difficulties for the promotion and application of plastic-coated steel pipes. When the traditional plastic-coated steel pipes are butted, the joint head is too hot during the welding process, and the original coating is easy to decompose and carbonize at high temperatures, and for larger pipes, workers need to enter the pipe Repairs and touch-ups of coatings added to the workload; smaller pipes prevented workers from ...

AI Technical Summary

Problems solved by technology

[0002] The key parts of the traditional plastic-coated steel pipe connection technology are generally welded and repaired to customize the inner or outer protrusion joints, which reduces the fluid section of the inner wall of the steel pipe, complicates the construction, and increases the cost, which causes certain difficulties for the promotion and application of plastic-coated steel pipes.

When the traditional plastic-coated steel pipes are butted, the joint head is too hot during the welding process, and the original coating is easy to decompose and carbonize at high temperatures, and for larger pipes, workers need to enter the pipe Repairs and touch-ups of coatings increase the workload; smaller pipes prevent workers from accessing welding

At the same time, even if the inner wall of the pipeline repaired by manual welding is often the weak link in the whole steel pipe, it will easily cause hidden dangers after a long time

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