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Product Name: spiral welded pipe for heat supply
Standard: CJT 3022-1993
Steel grade: Q235B
Specifications: 820 x 12 x 12000mm
Outer diameter deviation: tube body is less than or equal to 0.75%D; pipe ends are less than or equal to 0.50%D or 3.5mm, take a small value.
The thickness deviation is less than or equal to 0.1t.
Ellipticity: the maximum outer diameter is less than 1%D, and the minimum outer diameter is less than 1%D in the 1000mm length range of the pipe ends.
Length deviation: +/- 50mm;
Straightness: the full length of the steel pipe is less than 0.2%L.
Slant: less than 2mm;
Groove angle: 30 degree -35 degrees;
Blunt edge: 1.6 + /-0.8mm;
Outer weld height: less than 4.0mm;
Internal weld height: less than 4.0mm;
The hydrostatic test pressure is more than 4.1MPa, the time of stabilizing is more than 20s.
NDT: 100% weld length RT.