How to perform oil-free treatment for ball valves used with hydrogen?

Oil must be strictly avoided in hydrogen equipment. Hydrogen equipment generally requires degreasing before use (the internal surfaces must be thoroughly degreased using carbon tetrachloride). Equipment manufacturers usually subject the equipment to sandblasting treatment on both the inside and outside. Stainless steel is commonly used for valve bodies. Maybe reposting this will be useful. \"Construction Quality of Industrial Automation Instrumentation Projects\", 7.9 Degreasing; \"Code for Construction and Acceptance of Industrial Automation Instrumentation Projects\" GBJ 93-86, 9.1.1 Instruments, control valves, valves, and pipes that require degreasing must be subjected to such treatment in accordance with the design specifications. 9.1.2 The oil content in a clean, degreased organic solvent should not exceed 50 mg/L. Solvents with an oil content of 50–500 mg/L can be used for preliminary degreasing. Solvents with an oil content of more than 500 mg/L must undergo regeneration treatment to meet the required standards before they can be used. 9.1.3 Degreasing solvents can be selected according to the following principles: First, industrial dichloroethane, which is suitable for degreasing metal parts. II. Industrial carbon tetrachloride, suitable for degreasing ferrous metals, copper, and non-metallic parts. III. Trichloroethylene for industrial use, suitable for degreasing ferrous and non-ferrous metals. IV. Industrial alcohol (with a concentration of not less than 95.6%) is suitable for degreasing instruments, control valves, valves, and pipes where high standards are not required; it can also be used as an additional cleaning solution for parts that have been degreased. V. Concentrated nitric acid with a concentration of 98% is suitable for degreasing instruments, control valves, valves, and pipes whose working medium is concentrated nitric acid. VI. Alkaline degreasing solutions are suitable for degreasing components and pipes with simple shapes that are easy to clean. 9.1.4 Degreasing solvents must not be mixed with each other, nor must they come into contact with strong acids or strong bases. 9.1.5 When degreasing with carbon tetrachloride, dichloroethane, or trichloroethylene, the parts to be degreased must be dry and free of moisture. 9.1.6 Tools, measuring instruments, and equipment used for contacting degreased parts must be degreased in advance according to the same requirements as those applied to the degreased parts. 9.1.7 After degreasing, instruments, control valves, valves, and pipes must be stored in a sealed condition. It must be kept clean and free of oil during installation. 9.1.9 For instruments and pipelines that have passed the degreasing process, grease-free media must be used during pressure testing and instrument calibration. 9.1.10 Degreasing solvents must be stored properly. The defatted waste liquid should be disposed of properly. 9.2.5 When using the scrubbing method for degreasing, cotton yarn should not be used; instead, fabrics and silk from which fibers do not easily come loose should be employed. After degreasing, a thorough inspection is necessary; it is strictly prohibited for fibers to remain attached to the degreased surface. 9.3.1 After degreasing, instruments, control valves, valves, and pipes must pass inspection.

It’s the first time I’ve heard that valves on hydrogen pipelines need to be free of oil – does that mean hydrogen processing cannot involve any contact with oil? But oxygen valves indeed need to be free of oil. Hehe, maybe the original poster made a mistake. I would appreciate it if experienced sea travelers could confirm this, so as to avoid misleading anyone with what I’ve written or what was written above.

It seems that hydrogen valves do not require oil-free treatment, while oxygen valves do need degreasing treatment. However, hydrogen-related materials should be made of stainless steel, as hydrogen has a strong reducing property.

Reply to 3# donganhj Thank you! !