How long is the life of a spiral steel pipe ?
Spiral steel pipe itself has no life limit, and the service life is mainly related to the operating environment and production process. Spiral steel pipe operating environment is relatively poor In order to extend the service life, the outer wall and inner diameter of the steel pipe are preserved.
Anti-corrosion steel pipe refers to a steel pipe that has been treated by anti-corrosion technology and can effectively prevent or slow down the corrosion phenomenon caused by chemical or electrochemical reaction during transportation and use. The anti-corrosion steel pipe can effectively prevent or slow down the corrosion and prolong the service life of the steel pipe and reduce the running cost of the steel pipe.
The steel pipeline anti-corrosion layer with many domestic applications includes petroleum asphalt, PE jacket and PE foam jacket, epoxy coal tar pitch, coal tar enamel, epoxy powder and three-layer composite structure, and epoxy coal tar pitch cold-wrapped belt (PF type). , rubber-plastic epoxy coal tar cold tape (RPC type), etc., the most widely used pipe anti-corrosion methods are three-layer PE composite structure, single-layer powder epoxy, PF cold-wrapped tape, RPC-type cold Wrap.
1, petroleum asphalt, a wide range of raw materials, low prices. However, the working conditions are poor, the quality is difficult to guarantee, and the environmental pollution is serious.
2, epoxy coal tar pitch, easy to operate, but the cover layer curing time is long, affected by the environment, not suitable for field operations, difficult to construct below 10 °C.
3, epoxy powder anti-corrosion, using electrostatic spraying method, and the same material anti-corrosion tube body is well sintered, strong bonding, but the epoxy powder is poor in water resistance (high water absorption rate, reaching 0.83%), to the cathode Protection design brings certain difficulties. The requirements for on-site appliances are high, the operation is difficult, and the quality is difficult to control.
4,3PE heat-shrinkable material, pipeline anti-corrosion sealing, high mechanical strength, strong waterproof, stable quality, convenient construction, good applicability, no pollution to the environment. PE low water absorption (less than 0.01%), with epoxy High strength, low water absorption of PE and good softness of hot melt adhesive, etc., have high corrosion reliability, and the disadvantage is: compared with the cost of other filler materials, the cost is high.
5, PF type, RPC type cold-wrapped belt construction is simple and easy, the matching three types of molding glue, so that PF type epoxy coal tar pitch cold-wrapped belt can be constructed in any environment, any season, any temperature conditions.
As shown in Fig. 6, the cold-wound tape and the 3PE heat-shrinkable tape are characterized by being applicable to the main-layer anti-corrosion layer pipes of various materials, and the other methods are applicable to the main-purpose anti-corrosion layer pipes of the same or close to the material.
Secondly, with the development of some pipelines, it is also necessary to keep warm during the anti-corrosion. The oil is a very complicated mixture, which is easy to corrode the pipeline and anti-corrosion is necessary, but the refined oil pipeline also needs to be insulated in the case of anti-corrosion, in the northeast and winter, Thermal expansion and contraction will freeze the pipe and affect the stable supply.