Anti-corrosion painting material treatment method for pipeline external surface

Abstract

The present invention discloses modern pipe outer anticorrosion spraying method. The pipe outer anticorrosion spraying process includes the following steps: processor-treatment of steel pipe, preheating steel pipe, spraying one layer of thermosol in the thickness of 0.1-0.2 mm, spraying polyethylene layer of 1-5 mm thickness, curing and leveling for 20-35 min, discharging from furnace and cooling. The present invention is suitable for the surface anticorrosion treatment of conveying pipe for petroleum, natural gas, chemical material, etc.

Description

technical field [0001] The invention relates to an anti-corrosion treatment method for pipes, more specifically, relates to a surface anti-corrosion treatment method for pipes used in oil, natural gas, chemical industry and other transportation pipelines. Background technique [0002] At present, it is mainly used in the surface anticorrosion treatment of oil, natural gas, chemical and other pipelines, using the treatment method of winding three layers of polyethylene. Wrapped three-layer structure polyethylene (referred to as: coated 3PE) was first used in Europe and Canada in the 1980s, and then extended to the world. It has been used in China since the mid-1990s. The coated 3PE anti-corrosion layer has good anti-corrosion performance and tough and durable performance. Now the extrusion lateral winding process is usually used. This process has disadvantages: [0003] 1. The combination of three different families of materials presents a risk of delamination [0004] The...

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Problems solved by technology

[0003] 1. The combination of three different families of materials presents a risk of delamination

[0004] The 3PE anti-corrosion layer is composed of bottom epoxy powder, middle layer adhesive and surface layer polyethylene. There are obvious interfaces between the three different families of materials. The process parameters are not adjusted properly during production, and there is a danger of delamination when air enters during coating. Delamination will cause peeling, and it is not easy to find, but it is often easy to find clues (such as warped edges) at the end of the pipe

[0005] 2. The thinning of the outer anti-corrosion layer of the weld cannot be eliminated

[0006] When the adhesive and polyethylene extruded from the 3PE anti-corrosion layer are wound sideways, due to the action of the pressure roller, the anti-corrosion layer will inevitably be thinned outside the weld protrusion, and the thinning amount can reach 20-30% of the anti-corrosion layer , the problem of uneven thickness of the anti-corrosion layer of a pipe is difficult to solve

For example, in order to ensure the thickness of the outer anti-corrosion layer of the weld, it is often necessary to thicken the thickness of the anti-corrosion layer of the pipe body, resulting in waste of materials and increased costs.

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