A53 welded pipe inspection items
The inspection items of A53 welded steel pipe include: surface defects, shape, size, weight, tensile test, flattening test, galvanized layer weight, galvanized layer uniformity, galvanized layer surface quality, galvanized layer adhesion, etc. Choose the appropriate inspection items according to your actual needs.
Project technical requirements
- Surface defects: The inner and outer surfaces of A53 ERW pipes should be smooth, and no folding, cracking, delamination, lap welding, arc breaking, burn-through and other defects whose depth exceeds the lower deviation of wall thickness after grinding are allowed. These defects should be completely removed, and the remaining wall thickness at the removal site should not be less than the minimum value allowed by the wall thickness deviation. Other local defects whose depth does not exceed the lower deviation of wall thickness are allowed.
- Tensile strength: The tensile strength of A53 steel pipes should not be less than 370MPa.
- Lower yield strength: The minimum stress of A53 steel pipe specimens during yielding, ignoring the initial transient effect, should not be less than 235MPa.
- Elongation after fracture: After the specified stress is removed, the ratio of elongation to the original gauge length of the A53 steel pipe sample should be no less than 15%.
- Flattening performance: When the distance between the two plates is 2/3 of the outer diameter of the A53 carbon steel pipe, cracks or cracks are not allowed at the weld. When the distance between the two plates is 1/3 of the outer diameter of the steel pipe, cracks or cracks are not allowed in other parts except the weld. Continue to flatten until the pipe wall fits. Delamination or metal overburning is not allowed during the entire flattening process.
- Galvanized layer weight: When measuring the zinc layer weight of the carbon steel A53 welded pipe, the total weight per unit area of the zinc layer on the inner and outer surfaces of the steel pipe should be no less than 300g/m².
- Uniformity of zinc layer: The A53 steel pipe sample does not appear red after being immersed in the copper sulfate solution for 5 consecutive times.
- Adhesion of zinc layer: After the A53 carbon steel pressure tested pipe has undergone the zinc layer adhesion test, the sample is not allowed to have zinc layer peeling.
- Surface quality of galvanized layer: The galvanized layer on the inner and outer surfaces of A53 steel pipe should be complete. No black spots or bubbles that are not coated with zinc are allowed. Small rough surfaces and local zinc nodules are allowed.
