The anti-corrosion layers of
steel pipelines that are widely used in China include petroleum asphalt, PE jacket and PE foam jacket, epoxy coal tar pitch, coal tar enamel paint, epoxy powder and three-layer composite structure, epoxy coal tar pitch cold wrap tape (PF type), rubber and plastic epoxy coal tar pitch cold wrapping tape (RPC type), etc. Currently, the most widely used pipeline anticorrosion methods are three-layer PE composite structure, single-layer powder epoxy, PF-type cold wrapping tape, and RPC-type cold wrapping tape. Tape.
Petroleum asphalt has a wide range of raw materials and low prices. But the working conditions are poor, the quality is difficult to guarantee, and the environmental pollution is serious.
Epoxy coal tar pitch is easy to operate, but the covering layer takes a long time to cure and is greatly affected by the environment. It is not suitable for fieldwork, and it is difficult to construct at temperatures below 10°C.
Epoxy powder anti-corrosion, using electrostatic spraying method, good fusion with the anti-corrosion pipe body of the same material, strong adhesion, but epoxy powder water resistance is poor (high water absorption rate, up to 0.83%), for cathodic protection design brings some difficulties. The on-site equipment has high requirements, the operation is difficult, and the quality is not easy to control.
3PE heat-shrinkable material, strong pipeline anti-corrosion sealing, high mechanical strength, strong waterproof, stable quality, convenient construction, good applicability, and does not pollute the environment. PE has low water absorption (less than 0.01%), high epoxy strength, low water absorption of PE, good softness of hot melt adhesive, etc., and high anti-corrosion reliability. The disadvantage is: compared with other sealing materials, costly.
The construction of PF-type and RPC-type cold wrapping tape is simple and easy, and the matching three kinds of setting glue make PF-type epoxy coal tar pitch cold wrapping tape suitable for construction under any environment, any season, and any temperature condition.
The characteristics of cold-wound tape and 3PE heat-shrinkable tape are: it is suitable for main anti-corrosion layer pipelines of various materials, while other methods are suitable for main body anti-corrosion layer pipelines of the same or similar materials.
