Pre-treatment of straight seam steel pipes: non-destructive testing inside the welds Since the pipes are extra-large steel pipes in water supply projects, especially steel pipes with a thickness of t=30mm are used as pipe bridges, which not only bear internal water pressure but also bear the bending moment formed by the steel pipe’s own weight and water body, so the requirements for welding are particularly high. For large-diameter steel pipes with a thickness of t=30mm for pipe bridges, the longitudinal seams and circumferential seams belong to the first-class welds, and 100% X-ray film inspection and 100% wave flaw detection inspection are required; for buried steel pipes with a thickness of t=24mm, the longitudinal seams belong to the first-class welding, and 20% X-ray film inspections and 50% wave flaw detection inspections are required.
Uses of straight seam welded pipes: There are many types of straight seam welded pipes, according to their uses: general welded pipes, oxygen blown welded pipes, galvanized welded pipes, wire casings, idler pipes, metric welded pipes, automotive pipes, deep well pump pipes, transformer pipes, electric welding special-shaped pipes, electric welding thin-walled pipes.
General welded pipe: General welded pipe is used to convey low-pressure fluid. Made of Q235A, L245, Q235B steel.
Galvanized steel pipe: It is to coat the surface of the black pipe with a zinc layer. Divided into heat and cold. The hot zinc layer is thick, and the cold is cheap.
Oxygen-blowing welded pipe: generally small diameter welded steel pipe, commonly used for steelmaking oxygen blowing.
Wire casing: It is a pipe for a power distribution structure, which is an ordinary electric-welded carbon steel pipe.
Welded thin-walled tube: it is a small-caliber tube used for furniture and lamps.
Roller tube: The electric welded steel tube on the belt conveyor has the required ovality.
Transformer tube: It is an ordinary carbon steel pipe. Used in the manufacture of transformer heat pipes and other heat exchangers.
Post time: Jul-24-2023