A. The working steel pipe adopts double-sided submerged arc spiral pipe. The tolerance and performance of the nominal diameter and outer diameter of the pipe should comply with GB/T9711-2017, and negative deviations are not allowed.
B. The material is Q235B, and the spiral welded steel pipe requires the use of coiled plates to manufacture welded steel pipes. Each pipe must be welded by the entire coiled plate, and two or more coiled plates must not be spliced together. The length of the steel pipe The length of each pipe is 12m, and the wall thickness of the pipe is required to have no difference.
C. Technical requirements for seamless steel pipes:
The size, shape, weight, allowable deviation, material, etc. of seamless steel pipes comply with the regulations of GB/T8163-2018. The material requires 20# steel.
D. The two ends of the steel pipe should be perpendicular to the axis of the steel pipe, the cut slope should not be greater than 5mm, and the height of the internal and external burrs should not be greater than 0.5mm.
E. Surface quality: According to the corresponding manufacturing method of the pipe, the inner and outer surfaces of the pipe should be smooth, and defects such as folding, fracture, delamination, lap welding, etc. are not allowed. Thickening of the weld wall thickness is allowed.
F. Working steel pipes should meet:
The surface of the working steel pipe should be pretreated to remove rust, rolling scales, grease, dust, paint, moisture or other contaminants. The rust removal level of the outer surface of the working steel pipe should meet the requirements of Sa2.5 in GB/T8923.1.
G. When the goods arrive, there are quality certification documents such as the steel pipe factory certificate, material list and inspection report (including hydrostatic test, ultrasonic and X-ray).
H. Lifespan: The expected lifespan of the insulation pipe at a continuous operating temperature of 130°C is not less than 30 years.
Execute in accordance with the current highest standards of the relevant industries in the country.
