Are material and hardness tests required when installing stainless steel bolts?
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SH/T 3501 requires that: 5.5.4 For stainless steel and chromium-molybdenum alloy steel studs and nuts used in the pipelines specified below, verification tests on the content of their major alloying elements shall be carried out using spectral analysis; 5% of each batch shall be sampled, with a minimum of 10 pieces. a) Design pressure equal to or greater than 10 MPa ； b) Design temperature below -29℃ ； c) The design temperature is equal to or greater than 400°C. 5.5.5 Stainless steel and chromium-molybdenum alloy steel studs and nuts used for pipes with a design pressure of 10 MPa or higher shall be subjected to hardness testing; no less than 2 specimens per batch shall be inspected, and the hardness values shall fall within the range specified in the design documents or product standards. In the event of non-conformity, handle it in accordance with the provisions of Clause 5.1.12 of this standard. GB 50517 does not contain similar requirements regarding stainless steel materials. During the actual construction and installation processes, is it necessary to conduct material and hardness tests when installing stainless steel bolts?
According to the requirements of SH/T 3501, under specific conditions, material and hardness tests are required for stainless steel bolts during installation. These conditions apply to stainless steel and chromium-molybdenum alloy steel bolts and nuts used in pipes with a design pressure of 10 MPa or higher, and a design temperature of below -29°C or 400°C or higher. If your project meets these conditions, testing must be carried out in accordance with the standards. If this is not the case, or if the standard used is GB 50517 and such standard does not contain similar requirements, then material and hardness testing may not be mandatory; however, considering safety and engineering requirements, it is advisable to follow the relevant industry standards or the provisions specified in the design documents. .