Anti-corrosion steel pipe refers to the anti-corrosion process processing, can effectively prevent or slow down in the transportation and use of chemical or electrochemical reactions occurring in the corrosion phenomenon of steel pipes. Anti-corrosion steel pipe can effectively prevent or slow down corrosion to extend the service life of steel pipe, reduce the operating costs of steel pipe.
Domestic application of more steel pipe anti-corrosion layer has petroleum asphalt, PE jacket and PE foam jacket, epoxy coal asphalt, coal tar enamel, epoxy powder and three-layer composite structure, epoxy coal asphalt cold wrapped tape (PF-type), rubber-plastic epoxy coal asphalt cold-wrapped tape (RPC-type), etc., and is currently promoting the use of the most widely used several types of pipeline anticorrosive way for the three-layer PE composite structure, a single layer of powdered epoxy, PF-type cold-wrapped tape, RPC type cold wrapped tape.
- Petroleum asphalt, raw materials, low prices. But poor labor conditions, quality is difficult to ensure, serious environmental pollution.
- Epoxy coal asphalt, easy to operate, but the cover layer curing time is long, affected by the environment, not suitable for field work, 10 ℃ below the difficult construction.
- Epoxy powder anticorrosion, using electrostatic spraying, with the same material anti-corrosion of the pipe body fusion is good, strong adhesion, but epoxy powder waterproofing is poor (high water absorption rate, up to 0.83%), to the cathodic protection design brings some difficulties. High requirements for field apparatus, difficult operation, quality is not easy to control.
- 3PE heat-shrinkable materials, pipeline anticorrosive sealing, high mechanical strength, waterproof, stable quality, convenient construction, good applicability, no pollution of the environment. low water absorption rate of PE (less than 0.01%), at the same time, with high strength of epoxy, low water absorption of PE and hot-melt adhesive softness, etc., has a high degree of anticorrosive reliability, the disadvantage: compared with the other mending material cost, high cost.
- PF-type, RPC-type cold wrapping tape construction is simple and easy, supporting the three types of stereotypes of adhesive, so that the PF-type epoxy-coal asphalt cold wrapping tape can be in any environment, any season, any temperature conditions of construction.
- Cold wrapping tape and 3PE heat shrinkable tape is characterized by: applicable to a variety of materials, the main body of the anti-corrosion layer pipeline, while the other way is applicable to the same or close to the material of the main body of the anti-corrosion layer pipeline.
Secondly, with the development of some pipelines in the anti-corrosion at the same time also need thermal insulation, oil is a very complex mixture, easy to corrode the pipeline, anti-corrosion is necessary, but the refined oil pipeline in the case of anti-corrosion also need to do thermal insulation, in the Northeast and in winter, the thermal expansion and contraction will be frozen and cracked pipeline, affecting the stability of supply.
