drilling for oil is a difficult thing in winter, the temperature is too low, ordinary steel pipe to transport trouble, so the general use of anti-corrosion pipe insulation, pipe insulation is a kind of corrosion resistance of steel, and has a good insulation performance, construction has been widely

pipeline corrosion reasons: 1, poor construction quality coating; 2, soil properties through lots of different pipes, easy to form an oxygen concentration cell, so that part of the pipe section appear localized corrosion; 3, anti-corrosion layer mending failure, a serious impact antiseptic quality;

acid or liquid flux never welded parts to penetrate in the galvanizing process, this liquid oozing after galvanizing, resulting in non-galvanized zinc or zinc dissolution.temperature difference caused by the uneven distribution of thickness, the thermal expansion or contraction caused not only plate