Plastic coated composite steel pipe

Specification: ФDN100-ФDN1800

Standard: "Plastic-coated Composite Steel Pipe for Water Supply" CJ/T120-2016

Plastic-coated composite steel pipe is a new type of pipeline material newly developed in China. It adopts a composite structure of reinforced welded steel pipe or seamless pressure-bearing steel pipe with a plastic protective layer inside and outside, which overcomes the easy rust and corrosion of the steel pipe itself. High pollution, low strength and easy deformation of plastic pipes, it integrates the common advantages of steel pipes and plastic products, and is an environmentally friendly product promoted and used by the country. Plastic-coated composite steel pipe is a layer of polyethylene (PE) resin, ethylene-acrylic acid copolymer (EAA), epoxy (EP) powder, non-toxic polypropylene (PP) or non-toxic polypropylene (PP) with a thickness of 0.5 to 1.0mm melted on the inner wall of the steel pipe. The steel-plastic composite pipe composed of non-toxic polyvinyl chloride (PVC) and other organic substances, not only has the advantages of high strength, easy connection, and resistance to water impact of steel pipes, but also overcomes the corrosion, pollution, fouling and fouling of steel pipes when exposed to water. Plastic pipes have disadvantages such as low strength and poor fire-fighting performance, and their design life can reach 50 years. The main disadvantage is that it is not allowed to be bent during installation, and during thermal processing and electric welding cutting, the cutting surface should be brushed with the non-toxic normal temperature curing glue provided by the manufacturer.

Production Process

Plastic coated composite steel pipe is divided into: hot dipping process, internal and external spraying process, rotomolding process, curtain coating process, suction coating process, fusion winding process, etc.

1. Hot dipping adopts: fluidized bed dipping, one-time film forming method. Also known as the first generation of anti-corrosion plastic coated steel pipe, inner and outer polyethylene.

2. Internal and external spraying process: using electrostatic adsorption theory, pre-treatment of steel pipe, spraying polyethylene or epoxy resin powder with spray gun. Also known as the second generation of anti-corrosion plastic coated steel pipe, internal and external epoxy composite steel pipe.

3. Flow coating process: also known as the curtain method, which is coated on the outer wall of the heated steel pipe through a sieve filled with powder by means of flow coating.

This process can produce outer polyethylene inner epoxy composite steel pipe. Also known as the third generation anti-corrosion of plastic coated steel pipe.

4. Fusion winding process: using the hot fusion winding method, the 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 epoxy/extrusion Polyethylene structure protective layer.

This process can produce outer three-layer structure polyethylene inner fusion bonded epoxy composite steel pipe. Also known as the fourth generation anti-corrosion of plastic coated steel pipe.