Large-diameter steel pipe is more than 1000MM OD steel pipe, steel pipe or solid steel ingot is made ​​of the capillary tube through the hole, then through the hot-rolled, cold rolled or cold call is made.

Large-diameter coated steel pipe is large diameter spiral welded pipe and high-frequency welded pipe made ​​of plastic coating on the basis of a maximum nozzle diameter of 1200mm, can be coated with polyvinyl chloride according to different needs (PVC), polyethylene (PE ), epoxy resin (EPOZY) and other various properties of plastic coating, good adhesion, corrosion resistance, and can be resistant to acid, alkali and other chemical corrosion, non-toxic, does not rust, wear and impact resistance, strong resistance to penetration, pipe surface is smooth, does not adhere to any substance that can reduce delivery time of resistance, increase traffic and transportation efficiency, reduce transport pressure loss. Coating solvent, no leakage of material, which does not pollute the transmission medium, in order to ensure fluid purity and health, in the range of -40 Ўж to +80 Ўж thermal cycling can be used interchangeably, not aging, no cracking, which can in cold areas such as the use of harsh environments.