Plastic-coated steel pipes, also known as plastic-coated pipes, steel-plastic composite pipes, and plastic-coated composite steel pipes, are based on steel pipes. A layer of plastic anti-corrosion layer or plastic anti-corrosion layer is fused to the inner surface of the steel pipe (bottom pipe) through spraying, rolling, dipping, and suction processes. A steel-plastic composite steel pipe with a plastic anti-corrosion layer fused to the inner and outer surfaces.
Plastic-coated steel pipes use ordinary carbon steel pipes as the base pipe, and the inner and outer walls of the pipe are coated with thermoplastics with excellent chemical stability. It is a special chemical composite pipe that has been treated with anti-corrosion technology. It can effectively prevent the acid and alkali salts contained in the chemical fluid medium from corroding the pipe. In the past, chemical pipes could not withstand corrosion, so the pipes had to be replaced every year. Later maintenance costs are very high. This product improves its shortcomings and increases the service life to 20 years. Generally, there are more chemical pipelines buried underground. The previous pipelines cannot withstand such harsh usage environments as buried underground, so the chemical industry of previous generations has accelerated The aging of pipelines may even lead to leakage. Plastic-coated steel pipes for the chemical industry have changed this situation. Therefore, they are also known by more and more chemical plants and have become a popular pipeline material in the chemical industry.
Advantages of plastic-coated steel pipes:
1. Hygienic, non-toxic, no scale accumulation, no breeding of microorganisms, ensuring fluid quality
2. Resistant to chemical corrosion, soil and marine biological corrosion, and cathodic stripping resistance
3． The installation process is mature, convenient, and fast, and the connection is the same as that of ordinary galvanized pipes.
4． Good weather resistance, suitable for harsh environments such as deserts and saline-alkali
5. Smooth pipe wall, improved conveying efficiency, and long service life
Key points for construction and installation of plastic-coated steel pipes
1. It should be implemented by the “Technical Regulations for Plastic Coated Composite Pipe Engineering for Building Water Supply” CECS125:2001.
2. The following construction machines should be used for plastic-coated steel pipes:
(1) Cutting should be done with a metal saw;
(2) A special rolling groove machine should be used for grooving;
(3) The bent pipe should be cold-bent using a pipe bending machine;
(4) An electric threading machine should be used to process pipe threads;
(5) Files should be used for deburring and rounding corners of plastic-coated steel pipe ports;
(6) A small brush or toothbrush should be used to apply high-strength inorganic solvent liquid epoxy resin coating.
3. The construction procedures of plastic-coated steel pipes should meet the following requirements:
(1) Plastic-coated steel pipes should not be buried in reinforced concrete structural layers;
(2) Welding is prohibited during the installation of plastic-coated steel pipes;
(3) The installation of plastic-coated steel pipes should be gradually connected from large diameter to small diameter, and the pipe openings should be blocked in time;
(4) Throwing and violent impact of plastic-coated steel pipes are strictly prohibited during transportation, loading and unloading, and construction on construction sites;
(5) When installing plastic-coated steel pipes, if the pipe diameter is not larger than DN50, a pipe bending machine can be used for cold bending, but the bending radius of curvature shall not be less than 8 times the pipe diameter, and the bending angle shall not be greater than 10°.
Installation method of plastic coated steel pipe
1. Pipe cutting: Calculate the pipe size and use a special pipe-cutting tool to cut the pipe to the required length. When cutting, the pipe end should be kept perpendicular to the axis of the stainless steel pipe.
2. Cleaning and gluing: Clean the socket of the stainless steel pipe fittings and the end of the thin-walled stainless steel pipe. Foreign matter such as water and oil is strictly prohibited. Then apply anaerobic glue evenly from 5mm from the end of the steel pipe to the marked line.
3. Insert the steel pipe: Insert the stainless steel water pipe into the bottom of the pipe fitting socket and rotate it once to ensure that the glue adheres evenly.
4. Crimping: Place the steel pipe into the clamping mold of the crimping tool, and then press it.
Post time: Jan-10-2024