Does shell thickness vary in ASME Sect VIII Div. 1 U-stamped Vessel ?
Does shell thickness vary in ASME Sect VIII Div. 1 U-stamped Vessel ?
(OP)
We are getting a process column designed. Our designer says that if opt for ASME U-stamp, the thickness of shell would increase & design calculations to be done again.
My Query:
1. Do all vessels, being designed & fabricated as per ASME Sect. VIII Div.1, need U-stamp ?
2. If yes, Does it cause a variation in Design calcualtions?
3. I believe that U-stamping governs the inspection clauses to be followed as per UG 91 to UG 97 of ASME Sect. VIII Div. 1 and do not affect the design calculations.
Forum may please opine ...!
My Query:
1. Do all vessels, being designed & fabricated as per ASME Sect. VIII Div.1, need U-stamp ?
2. If yes, Does it cause a variation in Design calcualtions?
3. I believe that U-stamping governs the inspection clauses to be followed as per UG 91 to UG 97 of ASME Sect. VIII Div. 1 and do not affect the design calculations.
Forum may please opine ...!





RE: Does shell thickness vary in ASME Sect VIII Div. 1 U-stamped Vessel ?
2. No, it does not cause any variation.
3. U-stamp confirms adherence to ASME code. It does not affect the design calculations.
Please note that the above applies in all developed countries who value safety of their own and others. Unfortunately, the world is full with shonky manufacturers prepared to take any necessary shortcuts to make it cheaper the manufacture, at the expense of safety of others. Don't buy anything made in China and sold 'guaranteed' to conform to ASME. I stopped trusting even Lloyds China, when the same person signed the test operator, the QA manager and the Lloyds certifying representative.
Cheers,
gr2vessels
RE: Does shell thickness vary in ASME Sect VIII Div. 1 U-stamped Vessel ?
RE: Does shell thickness vary in ASME Sect VIII Div. 1 U-stamped Vessel ?
The fear factor hitting to the roof is someone working for you who pretends to know everything, and gives you wrong information that leads you to make wrong decision or judgement. This is due to their lack of knowledge and experience. Ask your designer why he 'thinks' U-stamp will increase the thickness ? Ask him to prove it or where it is in the code. I have people working for me and when I see something weird, I ask what is their basis to prove their point.
"you think, I think" in pressure vessel battle field most of the time won't hold water. Anything has solid basis behind. It is just tremendious info there that no one knows all.
gr2vessels, you got lemon car. Sorry to hear you poor experience. We purchase vessels around the world. Malaysia could be worse than China. China has many good shops. Don't deny all.
RE: Does shell thickness vary in ASME Sect VIII Div. 1 U-stamped Vessel ?
Best regards,
gr2vessels
RE: Does shell thickness vary in ASME Sect VIII Div. 1 U-stamped Vessel ?
RE: Does shell thickness vary in ASME Sect VIII Div. 1 U-stamped Vessel ?
Something is fishy here.
What did your specification call for?
rmw
RE: Does shell thickness vary in ASME Sect VIII Div. 1 U-stamped Vessel ?
Guys... my concenr would be more clear now...!
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"UNQUOTE"
Dear ....
As per the trailing mail, both equipment are under the ‘U’ stamp. This will affect the following.
1.Due to the ASME documentation & various inspection stages,the delivery period may get extended by 3-4 months.
2.The cost of the equipment also may increase by 30 to 35%.
3.The thickness of the Vessel may increase due to various design factors & loads as per ASME Section.
So, we need to revise the whole design including equipment General drawing & enquiry specs. accordingly.
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How much justified their statement is?
RE: Does shell thickness vary in ASME Sect VIII Div. 1 U-stamped Vessel ?
ak1965, you are getting a lemon supplier. You will need to fight for it.
grevessels, your original reply regarding the design is 100% correct. I have nothing to against you. You misread what I wrote. I told ak1965 that his "designer" is lack of knowledge and experience, giving him wrong info (thk will increase, etc). I want ak1965 to ask his "designer" to prove it.
RE: Does shell thickness vary in ASME Sect VIII Div. 1 U-stamped Vessel ?
RE: Does shell thickness vary in ASME Sect VIII Div. 1 U-stamped Vessel ?
We have strongly asked our designer to clarify their version on the effects stated by them with U-stamp.
Lets wait what he replies.. i will share here...!
RE: Does shell thickness vary in ASME Sect VIII Div. 1 U-stamped Vessel ?
RE: Does shell thickness vary in ASME Sect VIII Div. 1 U-stamped Vessel ?
RE: Does shell thickness vary in ASME Sect VIII Div. 1 U-stamped Vessel ?
Sounds like you made a good deal with your AI. $450 total per vessel is really good price.
I thought AI is aupposed to come in take a look at some MTRs, drawings, review some RT films, witness hydrotest, review U-1 form and sign off. For a simple vessel, three visits may be enough. However I used to see AI bill four hours minimum per visit including driving time to and from the shop. That was many years ago.
On the other hand, if it costs shop $1000 for stamping, do you typically quote for the Buyer $1000 only? Just curious.
RE: Does shell thickness vary in ASME Sect VIII Div. 1 U-stamped Vessel ?
RE: Does shell thickness vary in ASME Sect VIII Div. 1 U-stamped Vessel ?
Or let me re-phrase my real question; when a vessel (for some reason) needs a new nameplate (e.g. the one already in place was of the wrong format), does the AI has to stamp every now to be attached nameplate? Or does the AI even not has to visit the shop when the nameplate is attached in the first place?
RE: Does shell thickness vary in ASME Sect VIII Div. 1 U-stamped Vessel ?
gr2vessels replied it well in the very 2nd post however later the post got diverted more towards to AI cost, which was informative as well.
The debate was a quality debate and gave us a nice conclusion well in-line to our thoughts about the issue.
Off-late, our designer also modified their original version & accepted that ASME U-stamp would not affect the delivery period & cost, if the vendor is ASME approved vendor.
RE: Does shell thickness vary in ASME Sect VIII Div. 1 U-stamped Vessel ?
If the vessel is designed to VIII there is no difference at all in the calculations/thickness between building it and building it code stamped (U-Stamped). The difference comes from the inspection/quality procedures to be done to the vessel and the items the Authrozied Inspector needs to look at.
Our company typically charges about $1500 more for a code stamp vessel, depending on the complexity and the information the AI needs to look over.
XL83NL, I believe you need to have an R stamp to do that, but I'm not positive. I know you can't touch any part of the vessel that is pressure containing after the AI has initially signed off on it. Therefore, if the nameplate is directly attached to the shell, you can not touch it, unless the plate itself is on a bracket. If the bracket is welded I think you may be able to replace the nameplate provided you inform the National Board.
RE: Does shell thickness vary in ASME Sect VIII Div. 1 U-stamped Vessel ?
RE: Does shell thickness vary in ASME Sect VIII Div. 1 U-stamped Vessel ?
RE: Does shell thickness vary in ASME Sect VIII Div. 1 U-stamped Vessel ?
RE: Does shell thickness vary in ASME Sect VIII Div. 1 U-stamped Vessel ?
RE: Does shell thickness vary in ASME Sect VIII Div. 1 U-stamped Vessel ?
If the vessel is not code, the HSB AI doesn't care at all. If the AI is a customer's AI just doing an inspection you would have to talk to your customer and that AI in regards to replacing a miss-print nameplate.
RE: Does shell thickness vary in ASME Sect VIII Div. 1 U-stamped Vessel ?
I suspect the vessel wont get the R-stamp, as we're EU-based, and will ship it to SA.
Second, I think the NPL's wont get changed