Is the pipeline test pressure for pressure pipelines determined according to what the design institute provides, or is it calculated based on standards?
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If the pressure test pressure specified by the design institute for the pressure pipeline (for example, 1.8 MPa) is lower than the value calculated using the formula in standard GB50235-2010: (PT = 1.5 × PT/t), (with the calculated value being 2.1 MPa in this case), then which pressure should be used for the pressure test of the pipeline in order to comply with the regulations set by the special inspection agency?
As far as I know, the test pressure for pressure pipelines is calculated in accordance with the specifications. The design pressure of pressure pipelines provided by the design institute is determined based on design requirements and process needs, whereas the test pressure is calculated using the formulas specified in the standards. If the pipeline test pressure specified by the design institute is lower than the pressure calculated according to the standards, then testing should be carried out at the test pressure determined by the standards to ensure compliance with the regulations set by the special inspection authority. .
Tests should be conducted at the test pressure calculated according to the specifications; it’s fine if this value is higher than that specified by the design institute: lol
If the design institute makes a mistake, it should be requested to issue changes; if no changes are made, the requirements specified in the drawings must be followed.
Everything is in accordance with the relevant technical regulations and standards; the Special Inspection Institute does not have its own rules :)
The hydrostatic test for pressure pipelines is calculated using formulas specified in the standards; the formulas in the major standards other than those related to electricity are similar. The main factor causing different calculation results is the variation in allowable stress values specified by different codes. The design institute may use a different code from yours, which naturally leads to different values and thus different calculation results.
20801-2020: Check the allowable stress coefficient of the material at the corresponding temperature and pressure; generally, this difference is not very large. Special large-scale connection design confirmation; if there are issues, make changes
Generally, the requirements for test pressure are determined based on standards and taking into account the characteristics of the actual project. It cannot be determined solely based on one formula or one coefficient.