The working principle of 3PE anticorrosion steel pipe equipment

(1) Principle of surface treatment As mentioned before, the shot blasting machines and sandblasting equipment in the surface treatment system remove impurities from the steel pipe surface through mechanical impact and

friction. During the shot blasting process, under the action of the high - speed rotating impeller, the shot is propelled to hit the steel pipe surface at extremely high speed. Rust, oil stains,

and other impurities are peeled off by the impact force of the shot. At the same time, tiny pits are created on the steel pipe surface, forming a certain degree of roughness, which increases

the contact area between the coating and the steel pipe surface, thereby enhancing the adhesion of the coating. The sandblasting process is similar. Sand grains are ejected onto the steel

pipe surface at high speed under the action of compressed air to achieve the purpose of surface treatment. (2) Principle of heating and spraying The steel pipe heating system uses the principle of medium - frequency induction heating. It generates an alternating magnetic field through alternating current, causing induced current

to be generated inside the steel pipe, thus realizing rapid heating of the steel pipe. After the steel pipe is heated to an appropriate temperature, it enters the electrostatic spraying system.

During the electrostatic spraying process, the epoxy powder is charged under the action of a high - voltage electrostatic field. Since the steel pipe is grounded, the charged epoxy powder

is quickly adsorbed onto the steel pipe surface under the action of the electric field force. Meanwhile, the powder starts to melt under the high temperature of the steel pipe surface, forming

a uniform epoxy powder coating. This coating not only has excellent chemical corrosion resistance but also can form a strong chemical bond with the steel pipe surface, providing excellent

adhesion. (3) Principle of coating The adhesive extruder in the coating system extrudes the hot - melt adhesive onto the epoxy powder coating. The adhesive has good fluidity at high temperatures and can evenly cover

the surface of the epoxy powder coating. The molecules of the adhesive and the epoxy powder coating diffuse and cross - link with each other, forming a strong bonding force. Subsequently,

the polyethylene extruder melts the polyethylene particles and extrudes them through a specific die, winding them onto the surface of the adhesive layer. The polyethylene gradually solidifies

during the cooling process, forming a tough protective layer. The polyethylene layer not only has good mechanical properties, capable of resisting external mechanical impacts and abrasion,

but also has excellent weather resistance and water resistance, effectively protecting the steel pipe from external environmental erosion. (4) Principle of cooling and detection The water cooling system sprays and cools the coated steel pipe with circulating water, quickly solidifying the polyethylene layer and improving its hardness and wear resistance. During the

cooling process, water absorbs the heat from the steel pipe surface and carries the heat away through the circulation system. The detection system conducts real - time monitoring of various

quality indicators of the steel pipe throughout the entire production process. For example, the thickness gauge measures the thickness of the coating using principles such as electromagnetic

induction or ultrasonic. The adhesion testing equipment detects the adhesion strength between the coatings and between the coating and the steel pipe surface through methods such as

tension or peeling. The electrical performance testing equipment detects the insulation performance of the coating by applying voltage. These detection data are transmitted in real - time

to the electrical control system, compared with the preset standard values. Once an abnormality is detected, the electrical control system immediately takes corresponding measures to ensure

that the product quality meets the requirements.