Classification and production process of coated steel pipe

classification of coated steel pipes
coating raw materials for coated steel pipes include epoxy resin (epoxy powder) and polyethylene coating materials. the inner wall of the pipeline is coated with epoxy powder thermal fusion, and the outer wall of the pipeline is generally anti-corrosion with epoxy powder or polyethylene. epoxy powder is a kind of thermosetting coating. the steel pipe is first subjected to shot blasting and de-rusting treatment, then heated at medium frequency, and then electrostatic spraying technology is used to spray epoxy powder on the surface of the pipe to cure and form a coating.

1. according to the difference of coating raw materials, including inner and outer coated steel pipes, outer galvanized inner coated steel pipes, inner epoxy outer polyethylene anti-corrosion steel pipes, tpep anti-corrosion steel pipes, etc.
2. according to the purpose, it includes coated steel pipes for fire protection, coated steel pipes for mining, coated steel pipes for water supply and drainage, coated steel pipes for tap water supply, and coated steel pipes for cable protection.
3. divided according to the installation method, including overhead coated steel pipes, municipal pipe gallery coated steel pipes, and buried coated steel pipes.
4. divided according to the connection method, including coated steel pipes connected by screws, coated steel pipes connected by clamp grooves, coated steel pipes connected by flanges, coated steel pipes by bimetallic welding, and coated steel pipes by flexible sockets.

customers can choose different coated steel pipes according to different uses, anti-corrosion level requirements, and connection methods of the pipes.

the production process of coated steel pipe
(1) internal and external spraying process: using electrostatic adsorption theory, through pre-treatment of steel pipes, spray polyethylene or epoxy resin powder with a spray gun. also known as the second-generation anti-corrosion coated steel pipe, epoxy composite steel pipe inside and outside.
(2) curtain coating process: also known as the curtain method, it is coated on the outer wall of the heated steel pipe using curtain coating through a sieve filled with powder.
(3) melting and winding process: using the hot melting and winding method, hot melt adhesive and polyethylene are wound on the heated steel pipe in the form of an extruder, and react to form a three-layer structure. the full name is fusion bonded epoxy/extrusion plastic polyethylene structural protective layer.
(4) hot dipping adopts fluidized bed dipping, a one-time film-forming method. also known as the first generation of anti-corrosion coated steel pipes, polyethylene inside and outside.
(5) coated steel pipes are divided into a hot dip molding process, internal and external spraying process, rotational molding process, shower coating process, suction coating process, fusion winding process, etc.