The technical specifications of galvanized pipe are as follows:
1, Galvanized steel pipe, the surface should be straight and smooth, there should be no cracks, scarring, delamination, dislocation, hard bend, burr, indentation and deep scribing.
2, Grades and chemical composition of galvanized steel pipe should be consistent with the provisions of GB 3092 black pipe steel grades and chemical composition.
3, The pipe wall should be marked marked material manufacturing standards and manufacturers.
4, The chemical composition of the content of the following requirements: carbon 0.14-0.22%; manganese 0.3-0.65%; phosphorus is not more than 0.045%; sulfur is not more than 0.05%.
5, The quality of galvanized steel pipe should be consistent with the "carbon structural steel" (GB / T700) in the Q235-A steel and JGJ130-2001 provisions.
6, Nominal diameter of not more than 50mm galvanized steel pipe should be cold bending test. Bending angle of 90 °, bending radius of 8 times the outer diameter. The test without filler, the sample should be placed in the weld bead bending direction of the outer or upper part. After the test, there should be no cracks on the specimen and peeling of the zinc layer.
7, Hydrostatic test should be carried out in the black tube, eddy current testing can also be used instead of hydrostatic test. Test pressure or eddy current test specimen size should be consistent with the provisions of GB 3092.
