1. All hydrogen valves are manufactured to meet low leakage requirements, in accordance with ISO 15848-2 standards (stem according to Class B, body seals <50ppmv), using low leakage packing.

2. The pressure testing duration for all valves is performed for twice the time required by API 598 or ISO 5208 standards. When conducting hydrostatic tests on austenitic stainless steel, the chloride ion content in the water must not exceed 100 PPM.

3. The S&P content of all carbon steel materials shall not exceed 0.02%. For welded ends, the carbon content of WCB and WCC materials shall not exceed 0.23%, and the carbon equivalent shall not exceed 0.43%.

4. For chromium-molybdenum steel materials, WC6, WC9, F11.1, and F22.1 are preferred. The carbon content shall not exceed 0.16%, and the S&P content shall not exceed 0.02%.

5. For stainless steel, materials containing stabilizing elements such as Nb and Ti are preferred. For forgings, F321 and F347 are used, while for castings, CF8C type can be selected. The chemical composition and mechanical properties of all materials must meet the requirements specified in the relevant standards.

6. All pressure-bearing components of the valves must undergo non-destructive testing. For components subjected to RT testing, the following requirements must be met: 

a. Porosity (A): No less than Grade II 

b. Slag inclusion (B): No less than Grade II 

c. Shrinkage (CA, CB, CC, CD): No less than Grade II 

d. Hot cracks and cold cracks (D, E): None 

e. Inclusions: None

7. All valve weld overlay sealing surfaces and welded areas must undergo PT testing, and no cracks are permitted in the test results.

8. For forged valves made of carbon steel and chromium-molybdenum steel, UT or MT testing may also be performed. The test results must meet the requirements of the relevant standards (MT in accordance with ASTM E709, UT in accordance with ASTM A388).

9. For casting repair welding: repair welding is not acceptable if the depth exceeds 20% of the wall thickness or 25 mm, or if the area exceeds 65 square centimeters.

10. The forging ratio for all forged valves must not be less than 3.

11. All non-machined surfaces of stainless steel valve castings and forgings must undergo pickling and passivation treatment.

12. All components must be thoroughly derusted and cleaned before assembly. Any parts that may come into contact with the medium are strictly prohibited from being assembled with grease, and no residual grease that cannot be removed is allowed (as a comprehensive degreasing process will be conducted after the pipeline installation is completed). For carbon steel and chromium-molybdenum steel valves, the application of anti-rust oil must be carefully controlled-apply only enough to prevent rust during transportation, avoiding excessive coating.

13. The exterior quality of all valves must comply with the requirements specified in MSS SP-55-2011, categories A and B of classes II-XII.

14. The wall thickness of all valves must meet the specified requirements for their respective valve types, such as API 600 gate valves, API 623 (BS 1873) globe valves, BS 1868 check valves, and API 602 forged steel gate and globe valves.

15. All hydrogen valve seats must adopt integrally welded or welded seat designs; threaded seats are not permitted. The bonnet seal must utilize integrally welded construction, and threaded bonnet seal seats are not allowed.

16. All swing check valves must use an internal structure; external structures are not permitted.

17. All hydrogen valves should also fully consider the issue of hydrogen embrittlement, and the materials must meet the technical requirements specified in NACE MR0103.

18. For valves designed according to API 600 / API 623 / BS 1868 / BS 1873 / API 602, the wall thickness and valve stem must meet the requirements specified in the relevant standards.

19. All other technical requirements shall be based on the customer's specifications in the order.