Gate Valve Modification

I gonna to do some modification on gate valves and I'd like to have information about a suitable handbook for the calculation of the minimum wall thickness required and other specification necessary for the final design approval.
What is the standard on which your valve is designed? The information you have provided is insuffiecient for a practical suggestion.
My Valves should be designed on API6/API2 standard. They was designed to work in high H2S concentration and at 10k psi. I can not add more details cause I inherited them whitout the right documentation.


From the original1Gate valve
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