Issues regarding the pressure for pneumatic testing under the new national standards
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Clause 9.1.4.d).2) of GB/T 20801.5-2020: \"Test pressure at which a circumferential or longitudinal stress exceeding 90% of the yield strength occurs at the test temperature (based on the minimum wall thickness).\\" ”How should this item be understood and calculated?
I haven’t studied this new standard in detail; a brief glance shows that it seems to be the formula for calculating the upper limit values for pressure tests as specified in DL/T 5054-2016. The circumferential stress may be determined using equation 3.3.3-3 from DL/T 5054-2016, while the longitudinal stress may be determined using equation 3.3.4 from the same standard. The allowable stress value for industrial pipelines is set at 20801, as the allowable stress values specified in the two standards differ.