Spiral steel pipe is a spiral seam steel pipe made of strip steel coil as raw material, extruded at regular temperature and welded by automatic double-wire double-sided submerged arc welding process. Spiral steel pipe will be fed into the welded pipe unit, rolled by multiple rolls, the strip is gradually rolled up to form a circular billet with an opening gap, adjust the amount of squeeze rolls under pressure, so that the weld gap control in 1 ~ 3mm, and make the weld flush at both ends.
 
The first step is to check the spiral steel pipe, so that it is suitable for the construction of insulated steel pipe, a combination of various types of premises for steel pipe inspection.
 
The second step is to remove the embroidery on the steel pipe, the manipulation of certain special materials to understand the rust of the steel pipe profile, so that the steel pipe is not corrupted environment.
 
The third step is to wear pipe forming, after the rust and corrosion protection of steel pipe set in polyethylene casing; the fourth step is the head repair, the center of injection of polyurethane foam, so that it fills the empty space between the steel pipe and polyethylene casing, so that it becomes one; the last step is the product inspection, the construction of spiral steel pipe to achieve the product inspection, suitable for the sale of products, unsuitable products for new repair and improvement.
 
As long as the rust and corrosion resistant steel pipe set in the polyethylene casing, the center of the injection of polyurethane foam, so that it fills the empty space between the steel pipe and polyethylene casing, the ultimate steel pipe, casing, insulation layer constitutes a stable group, to achieve the results of anti-corrosion insulation, insulation steel pipe is composed.
 
Insulation steel pipe of such anti-corrosion insulation method can be crowded or buried in the open, all construction processes can be carried out in the field, easy to construct and manipulate, and is easy to be manipulated by the construction staff, the process is relatively simple.