Introduction to the advantages and disadvantages of spiral steel pipes

Spiral steel pipe is the strip or coil plate according to the spiral zigzag forming, with double-sided submerged arc active welding for the welding of the inner seam and the outer seam of the spiral steel pipe, because of the following reasons it can be widely used in water, electricity, chemical and other occupational production: only need to change the forming viewpoint, you can use the same width of strip steel to produce steel pipes of various calibers, easy to adjust. Because it is formed in successive zigzags, the length of the spiral tube is not constrained, and the length can be set arbitrarily.

The weld spiral shape is evenly distributed on the entire circumference of the spiral tube, so the scale accuracy of the spiral pipe is high and the strength is also strong. Easy to change the scale, suitable for small batches, a variety of spiral tube production. The weld of the spiral steel pipe is longer than the weld of the same standard straight seam pipe, and the spiral steel pipe receives greater pressure under the same standard wall thickness. The disadvantage of the weld of the spiral steel pipe is "oblique disadvantage".During use, the length of the equivalent defect in the main stress direction of the steel pipe, that is, the axis direction of the steel pipe, is smaller than that of the straight seam pipe; Secondly, because the pipeline steel is all rolled steel plates, the impact toughness has greater anisotropy, and the CVN value in the rolling direction can be 3 times higher than the CVN value perpendicular to the rolling direction.In order to get used to the needs of modern production, the steel structure workshop was invited to emerge, the steel structure workshop and the pre-component workshop have the following advantages, short production time, low production price, useful. The general steel structure workshop contains steel columns, steel beams, steel structure roots, steel roof trusses, steel roofs, steel pillars in previous years are used channel steel, in recent years people have found the defects of channel steel in construction, and gradually replaced channel steel with spiral steel pipes.

Production process

The raw materials are strip coil, welding wire flux. It must undergo strict physical and chemical testing before input.With steel head and tail butt, using single wire or double wire submerged arc welding, after coiling into steel pipe, automatic submerged arc welding repair welding is adopted.Before forming, the strip is leveled, trimmed, planed, cleaned and conveyed and bent.The electric contact pressure gauge is used to control both sides of the conveyor and press down the pressure of the cylinder to ensure the smooth conveying of the strip

Externally controlled or internally controlled roll formingThe weld gap control device is used to meet the weld requirements. Pipe diameter, misalignment and weld clearance are strictly controlledInternal welding and external welding adopt electric welding machine single wire and double wire submerged arc weldingAfter welding, it is automatically checked on the ultrasonic to ensure 100% weldingThe air plasma cutting machine is used to cut the steel pipe into a single piece, and put into production after strict inspectionsurface treatment; Cleaning, tool rust removal, pickling, projectile rust removal.