Material analysis of 3PE anti-corrosive steel pipe
3PE anticorrosive steel pipe base material includes seamless steel pipe, spiral steel pipe and straight seam steel pipe. The three-layer structure polyethylene (3PE) anticorrosive coating has been widely used in the petroleum pipeline industry due to its good corrosion resistance, water vapor permeability resistance, and mechanical properties.
Introduction to the anti-corrosion layer of 3PE anti-corrosion steel pipe
3PE anti-corrosion steel pipe-an anti-corrosion layer is crucial to the life of buried pipelines. Some pipes of the same material are buried in the ground for decades without corrosion, and some leak in several years. It is because they use different outer coatings.
3PE anti-corrosion generally consists of 3 layers of structure:
First layer of epoxy powder (FBE> 100um)
Second layer of adhesive (AD) 170 ～ 250um
The third layer of polyethylene (PE) 2.5 ～ 3.7mm
In the actual operation, the three materials are mixed into a whole, and after processing, it is firmly combined with the steel pipe to form an excellent anticorrosive layer. Its processing methods are generally divided into two types: winding type and round mold coating type.
Advantages of 3PE anti-corrosive steel pipe anti-corrosive layer
The coating of 3PE anti-corrosion steel pipe is an epoxy powder anti-corrosion coating which is in contact with the bottom layer and the surface of the steel pipe. The middle layer is a copolymerized adhesive with branch structure functional groups. The top layer is a high-density polyethylene anticorrosive coating. 3PE anti-corrosion steel pipe coating (three-layer polyethylene anti-corrosion coating) is a new type of anti-corrosion produced by skillfully combining 2PE anti-corrosion coating in Europe and epoxy powder anti-corrosion steel pipe coating (FBE) widely used in North America Steel tube coating. It has been recognized and used worldwide for more than a decade.
3PE anti-corrosion steel pipe inspection process
First, inspect the anti-corrosion steel pipe, and comprehensively inspect the steel pipe to meet the conditions for making insulated steel pipes. Check the steel pipe for corrosion, check and remove the embroidery on the steel pipe. The next step is to put the steel pipe after derusting and anticorrosion in a polyethylene casing to form a pipe. However, after the head is repaired, polyurethane foam is injected into it, and the gap must be fully filled to make it fully filled. Inspection of anti-corrosion steel pipes, and inspection of finished products of finished insulated steel pipes.
Before the 3PE anti-corrosive steel pipe base material is subjected to anticorrosive treatment, it is necessary to inspect and record the steel pipe entering the pipe entry platform, perform shot blasting and rust removal on the outer surface of the steel pipe, and then check whether the cleanliness of the outer surface of the steel pipe and the depth of the anchor pattern meet the requirements. Non-compliant grinding with hand wheel qualified, winding tape on the tube end, dust treatment, intermediate frequency heating to the required temperature, epoxy powder spraying, winding on the adhesive extruder side, entanglement on the PE extruder side, anti-corrosion The pipes are water-cooled, the qualified products are spray-labeled, and the lower pipe platforms and stacks are ready for shipment.
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