In the field of industrial production, there are various types of ND steel pipes, which are mainly divided into four categories: prefabricated direct-buried insulating pipes, prefabricated direct-selling insulating pipes, winding glass cylinders and prefabricated direct-buried high-temperature insulating steam pipes due to different production processes and materials. These four categories are very professional, and ordinary people do not clear up what each category looks like. Today, let's get to know what the four specific characteristics and divisions are. １，预制直埋式保温管（塑料外壳，又称氰聚乙烯塑料，黑色外套，黄夹克，高密度聚乙烯外护层ＰＵ管）的特点：与传统的地埋式保温材料，聚乙烯外护管相比，具有机械强度高，耐冲击，耐环境应力开裂，耐腐蚀，耐低温，易焊接，施工简单，使用寿命长，可防水，防潮有效服务３０－５０年的生活，通常持续到１２０度工作摄氏度。
1. Prefabricated direct-buried insulation pipe (plastic shell, also known as cyanide polyethylene plastic, black coat, yellow jacket, high-density polyethylene outer protective layer PU pipe) features: compared with traditional buried insulation material, polyethylene outer protective pipe, it has high mechanical strength, impact resistance, environmental stress cracking resistance, corrosion resistance, low temperature resistance, easy welding, simple construction, long service life, can be used. Waterproof, moisture-proof and effective service for 30-50 years of life, usually lasting to 120 degrees Celsius.
2, steel prefabricated directly buried insulation pipes are made: steel is the medium between the conveying steel pipe and the steel tube filled with aluminum silicate cotton. The anticorrosive coating is a kind of steel pipe, and can also be filled with silicon calcium tiles and polyurethane foam. Buried steel pipe (sleeve steel) technology is a waterproof, leak-proof, impermeable, pressure-resistant and closed burial technology. Features: Safe operation for a long time to create the largest, waterproof sealing performance is the best, pipeline corrosion protection to ensure long life, energy saving is obvious.
3. Wrapped FRP: The direct buried insulation pipe is increased by FRP? Strong resin winding, it has high mechanical strength and excellent corrosion resistance. It can protect pipes and can be installed and used in transportation without external factors.
4. Prefabricated directly buried high temperature adiabatic steam pipe, suitable for conveying pressure of 2.5 MPa and temperature of 130-350 degrees Celsius of steam pipe.