Spiral steel pipe

Spiral steel pipe is a spiral seam steel pipe made of strip steel coil as raw material, often warm extruded and welded by automatic double wire double-sided submerged arc welding process. The spiral steel pipe sends the strip steel to the welding pipe unit, and the strip steel is rolled by multiple rolls. The strip steel is gradually rolled up to form a circular tube blank with an open gap. Adjust the reduction of the extrusion roll to control the weld gap at 1~3mm, and make both ends of the weld crater flush .

Advantages of spiral welded pipe:(1) Steel pipes of different diameters can be produced using strip steel of the same width, and

steel pipes of large diameter can be produced from narrow strip steel.

(2) Under the same pressure conditions, the stress of the

spiral welded seam is smaller than that of the straight seam, which is 75% to 90% of that of the straight seam welded pipe, so it can withstand greater pressure. Compared with the straight seam welded pipe of the same outer diameter, the wall thickness can be reduced by 10% to 25% under the same pressure.

(3) The size is accurate, the general diameter tolerance does not exceed 0.12%, the deflection is less than 1/2000, and the ovality is less than 1%. Generally, the sizing and straightening process can be omitted.

(4) Continuous production is possible. In theory, long steel pipes can be produced, with small head and tail loss, and can

increase the metal utilization rate by 6% to 8%.

(5) The equipment is light in weight and low initial investment. It can be made into a trailer-type mobile unit to directly produce welded pipes at the construction site where the pipeline is laid