For spiral welded pipes and straight-seam welded pipes, GB/T9711-2017 shall be applied
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Hello, everyone! Has there been any change in the material selection for long-distance oil and gas pipelines since the issuance of GB/T9711-2017? For our project’s long-distance natural gas pipeline, which is 188 km long and operates at a design pressure of 6.3 MPa, spiral-welded steel pipes were used for the main pipeline. However, after the introduction of GB/T9711-2017, straight-seam welded pipes are now used for sections that need to pass through certain areas. Is this because of the high residual stress in spiral-welded pipes? Still in accordance with the requirement of the newly issued standards, I earnestly ask everyone for help in answering this!
Straight-seam resistance-welded steel pipes are mainly used in gas pipeline projects for pipes with a diameter of 150–400 mm in the pipeline sections. When using such steel pipes in areas that require passing through or crossing obstacles, the wall thickness can be increased. Domestically produced resistance-welded steel pipes can meet the supply requirements.
Is it because of the high residual stress in spiral welded pipes that terms like \"crossing\" are replaced with \"straight-seam welded pipes\"?
The data shows that the stress issue was not mentioned. Instead, it is possible to increase the wall thickness.
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