To make the molded straight seam welded steel pipe seam and gas shielded welding (MAG) for continuous welding; internal welding: the use of longitudinal multi-wire submerged arc welding (up to four wires) on the inside of the straight seam welded steel pipe; external welding: the use of longitudinal multi-wire submerged arc welding on the outside of the straight submerged arc welded steel pipe; ultrasonic inspection Ⅰ: inside and outside of the welded straight seam weld and weld on both sides of the base material 100% of the inspection X-ray inspection Ⅰ: on the inside and outside of the weld and weld on both sides of the base material Inspection X-ray inspection Ⅰ: 100% of the internal and external welds X-ray industrial television inspection, using image processing system to ensure the sensitivity of the flaw detection; Expansion: submerged arc welded straight seam steel pipe full length of the expansion in order to improve the dimensional accuracy of the steel pipe, and to improve the distribution of internal stress in the steel pipe Hydraulic test: in the hydraulic testing machine after the expansion of the steel pipe for the test one by one in order to ensure that the steel pipe to meet the standard test Pressure, the machine has automatic recording and storage function.
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