Why does the hydraulic pressure test pressure of external pressure vessels have nothing to do with the design temperature?
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The hydraulic test pressure of the external pressure vessel Pt=1.25P, why is it irrelevant to the design temperature? GB/T150 explanation, page P46, the internal pressure hydrostatic test of external pressure vessels is to check the sealing and defects that can easily expand into penetration. doubt: The tightness of the sealing structure: When the temperature is high, the sealing performance must change, maybe it is related to the temperature! Expand to penetrating defect: When the temperature is high, defects are more likely to expand. It depends on the temperature.
The purpose of the pressure test is to test that the internal defects of the equipment will not crack under the action of tensile stress, while the purpose of the pressure test of the external pressure equipment is to detect leaks and not to test the macroscopic stability of the equipment. Since the external pressure equipment is designed for stiffness rather than strength, and involves changes in its elastic modulus in the elastic state and the inelastic state, in order to avoid the trouble caused by changes in the E value, circumferential strain is used instead of circumferential stress to express the load-bearing level of its design state. From the circumferential strain formula, it can be seen that circumferential strain has nothing to do with the material temperature during the pressure test.
Since the deformation level has nothing to do with the test temperature, there is no need to adjust it according to temperature.
The purpose of hydrostatic testing of external pressure vessels is not to test the strength of the container, but to test the sealing of the container, so the influence of temperature is not considered.
This should be considered an authoritative answer.：
Standard Interpretation Instructions on External Pressure and Vacuum Container Pressure Test
I also want to know which book this is from