Remove 1-part of 3-part pressure vessel - Any special considered needed?
Remove 1-part of 3-part pressure vessel - Any special considered needed?
(OP)
So we have a 'distillation column' that is made up of 3 parts (top, middle, and bottom). The three parts are connected by flanges. All parts are manufactured to ASME VIII and share the same National Board number.
We want to run a test where we remove the bottom part and blank off the end of the middle part so we only have a top and middle.
My question is what additional work / testing would have to be done for the modification? Since all three pieces are under the same NB# and are all ASME vessels, can we do the modification and then do a pressure test (not a true hydrostatic pressure test but just enough to make sure that the flange is holding) and be okay or do we need to get a certified inspector in and have updates made to the NB records? Since it's all flanged and no welding/cutting/grinding type of work is needed, I didn't think much needed to be done, but we want to be careful.
We want to run a test where we remove the bottom part and blank off the end of the middle part so we only have a top and middle.
My question is what additional work / testing would have to be done for the modification? Since all three pieces are under the same NB# and are all ASME vessels, can we do the modification and then do a pressure test (not a true hydrostatic pressure test but just enough to make sure that the flange is holding) and be okay or do we need to get a certified inspector in and have updates made to the NB records? Since it's all flanged and no welding/cutting/grinding type of work is needed, I didn't think much needed to be done, but we want to be careful.





RE: Remove 1-part of 3-part pressure vessel - Any special considered needed?
If the flanges are not B16 type but are designed flanges, the new "cover flange" becomes a subcomponent of the "new" vessel. I'm not sure how it would be registered, or tested...
RE: Remove 1-part of 3-part pressure vessel - Any special considered needed?
Notice that) n most US states the Jurisdiction has to authorize the repairs or alterations of any boiler and p.v.
RE: Remove 1-part of 3-part pressure vessel - Any special considered needed?
RE: Remove 1-part of 3-part pressure vessel - Any special considered needed?
RE: Remove 1-part of 3-part pressure vessel - Any special considered needed?
RE: Remove 1-part of 3-part pressure vessel - Any special considered needed?
It shall be considered as Alteration as the overall length is changed that may affect the loading conditions. Refer 3.4.3(d)
Additional blank must be designed unless standard flange with suitable pressure temperature rating is used.
If the name plate was attached to the bottom part, it shall have to be transferred to another location
Discuss with your AI in details before proceeding.
Original vessel should have suitable markings on each part as required by UG-116(k)
RE: Remove 1-part of 3-part pressure vessel - Any special considered needed?
RE: Remove 1-part of 3-part pressure vessel - Any special considered needed?
RE: Remove 1-part of 3-part pressure vessel - Any special considered needed?
Why don't you tell us how big the whole vessel is and how big the individual parts are. What is the pressure rating of the three part vessel. Many people work on very large equipment where it would not be uncommon to invest thousands to get this done. Tell us what you have. What you are doing, and why you are doing it. What you hope to achieve. We might be able to help you a lot more.
Regards
StoneCold
RE: Remove 1-part of 3-part pressure vessel - Any special considered needed?
The entire vessel is 32in ID (which is why I'm thinking a slip blank may difficult) and about 42ft tall. The bottom section we want to take off is about 8.5ft long. The whole system is rated for 43.5 psig.
I hope this helps.
RE: Remove 1-part of 3-part pressure vessel - Any special considered needed?
RE: Remove 1-part of 3-part pressure vessel - Any special considered needed?
Indulge me for a moment. At my facility we had a column that was completely below the reactor that fed it. The vapor came off the top of the reactor and ran down the side of the column and entered just below the packing. Liquid was pumped from the bottom of the column back to the reactor. Due to the size we used a positive displacement pump that we adjusted the stroke on to keep the liquid pumped out.
You could do this many other ways, but instead of modifying the column you could just return the liquid to the reactor with a pump around loop.
Regards
StoneCold