All,
We still have debate internally how to classify a vessel as hydrogen service. If it is classify as "hydrogen service " the cost associated with it is huge by applying the requirements from vesselfab in the following link.
API 941 Nelson curves tells what material to be selected or whether PWHT is required or not. It does not define in what condition the vessel must be designed for 'hydrogen service" such that what vesselfab said in the above thread shall be applied to avoid hydrogen induced cracking.
I used to see some companies define HPP >=100 psia as hydrogen service without considering temp. But someone says only temp above such and such that the vessel to be designed for hydrohgen service.
Here are tow real vessels I have (1) 200 psia HPP at 350F, and (2) 2500 psia HPP at 350F. Per Nelson cure, regular CS without PWHT is good. (PWHT for thickness per code for sure will be applied). But do I need to consider both vessels are in "hydrogen service" and apply costly features as vesselfab mentioned, integral nozzles, full penetration welds, , PWHT (even it is not require der Nelson curve), etc ?
The key issue is: how do you define "hydrogen service" in your company so a vessel must be designed and paid extra $$ for it.
We still have debate internally how to classify a vessel as hydrogen service. If it is classify as "hydrogen service " the cost associated with it is huge by applying the requirements from vesselfab in the following link.
API 941 Nelson curves tells what material to be selected or whether PWHT is required or not. It does not define in what condition the vessel must be designed for 'hydrogen service" such that what vesselfab said in the above thread shall be applied to avoid hydrogen induced cracking.
I used to see some companies define HPP >=100 psia as hydrogen service without considering temp. But someone says only temp above such and such that the vessel to be designed for hydrohgen service.
Here are tow real vessels I have (1) 200 psia HPP at 350F, and (2) 2500 psia HPP at 350F. Per Nelson cure, regular CS without PWHT is good. (PWHT for thickness per code for sure will be applied). But do I need to consider both vessels are in "hydrogen service" and apply costly features as vesselfab mentioned, integral nozzles, full penetration welds, , PWHT (even it is not require der Nelson curve), etc ?
The key issue is: how do you define "hydrogen service" in your company so a vessel must be designed and paid extra $$ for it.
