Pressure Vessel modification

[pamc21]

All,

I am working in the Biopharma field in ireland. I am involved in a project where we are reusing pressure vessels that were manufactured in circa 1993. They are 10,000 L Vw.

We are having difficulties in designing our CIP process as the nozzles on the vessel are not of hygienic standard that is available now.
They do not not meet the L/D less than or equal to 2 requirements. The necks are too tall protruding up from the vessel and we are not getting any coverage/impact via our sprayballs on certain nozzles even after completing a 3D sprayball map.

One solution is to modify the vessel by cutting out the nozzles and replacing with ASME ferrules while re certifying the vessel.
Has anyone come across a similar issue and do they know if this is possible? Concern would be purging vessels also around producing documentation from 1993 to meet PED requirements.

Thanks

 

[mk3223]

It's a potential issue to any Manufacturer to re-certify a non-standard vessel. IMO, it could be simple and less trouble to buy a new Coded compliant vessel.

 

[MJCronin]

I agree with the above post and feel that you may be trying to convert a sow's ear into a silk purse.

The purchase of new ASME biopharma grade vessels may be the cheaper choice in the long run as there is an assurance that the CIP requirements will be met and there will not be any project delays due to contamination.

Cutting out multiple nozzles, replacement, recertification and retesting means you are only salvaging the shell and support stand.

Please post pictures of the vessels or design drawings .... this would help us with our responses.

MJCronin
Sr. Process Engineer

 

[LittleInch]

You really need to talk to the certifying authority and the first thing will be to see if your documentation is sufficient. You may just have a lump of scrap metal.

What was the original design code? ASME or BS5500 or something else?
Then you can discuss changes and how they would be certified.

If the necks are too long, can't you just cut them down and re-weld the flange?

I didn't fully understand the "ASME ferrule" bit. Any details?

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[jari001]

It would help to know what parts of the vessel are inside the rated boundary, so some pictures/details would help. I think it will be worth your time to have a qualified and experienced inspector come evaluate your situation, but depending on how your Quality and Validation view welding on an existing vessel, it might be less headache to just get a new vessel.

 

[bimr]

The vessels are already 25 years old. It is time to think about replacement anyway.