RT4 for hydrogen?

[DavidCR]

I saw a pressure vessel used to conserve hydrogen (generated by a small electrolysis h2 generator) for an industrial process (to supply H2 for a H2 cooled generator in power plant). The U plate says MAWP 300psi@200F/ MDMT300psi@-20F, "FOR HYDROGEN" and RT4. The operation pressure is much lower than the MAWP.
Is it OK to use a pressure vessel(ASME VIII DIv 1) for hydrogen with RT4? I thought it should be highly inspected with RT1.

 

[marty007]

RT4 is a catch-all for anything not explicitly covered by RT1/RT2/RT3. You have to look through the U-1 form and likely the calculations for clarification on exactly what was done. They may have even done more x-ray inspection than is required by RT1 (or much less...).

 

[SnTMan]

Is it OK to use a pressure vessel(ASME VIII DIv 1) for hydrogen with RT4? I thought it should be highly inspected with RT1.

I don't recall that the Code requires any particular degree of RT for H2 service.

Regards,

Mike

The problem with sloppy work is that the supply FAR EXCEEDS the demand

 

[TGS4]

The Code is generally agnostic with respect to service. Personally, I would not purchase a vessel in hydrogen service (including a high partial pressure of hydrogen) that had many design details otherwise permitted by Div 1. It's the responsibility of the owner/purchaser to ensure that the vessel being purchased it suitable for the service.