ASME "U" on prefabricated vessels.

Question

ASME "U" on prefabricated vessels.

hwangbojin (Mechanical)

(OP)

20 Mar 04 08:26

Dear Experts and help me;

Generally,we have been requested to design and test the fuel natural gas pressure conditioning facilities in accordance with ASME VIII div 1.

Specifically,we have been requested to design and constructe the natural fuel gas knock drum and filter for separation of condensate and mechnical material (working pressure:60 bars, working temp 60 oC) but we have not been requested to design and construct natural fuel gas waterbath heater and strainer and condensate tank (W.P:60 bar,W.T:60 oC).

Now,we have already designed and fabricated on the shop holding ASME "U" stamp the natural fuel gas nock drum,filter and waterbath eater, strainer, condesate tank in accordance with ASME VIII Div. 1 without AI's ceterfication and involvement. And then, the client is requesting "U" stamp in accordance with ASME VIII div 1. And we are explaining to the client that "U" stamp is not requested from the client only requested design and fabrication in accordance with ASME VIII Div 1. But the client is interpretating that the design and construction and test in accordance with ASME VIII Div.1 meanns essentially the vessels with "U" stamped vessel.
Eventually our prefabricated vessels for fuel gas system rejected by client and our further work is still stopped.

Therefore we questionnaire the following 4 question.
Please advise it urgently so that we can proceed next step.

QUESTION 1 : is it correct client's interpretation (the vessel in accordance with ASME VII Div. 1 means of vessel
with "U" stamp essentially)?

QUESTION 2 : We understand that the boiler in accordance with ASME I have been interpretated the boiler(vessel) with "S" and/or "A" essentially. How about the vessel in accordance with ASME VIII Div 1?

QUESTION 3 : What is our best way to minimize our big impact to apply "U" stamp on prefabricated fuel gas vessel?

QUESTION 4 : Is there any special procedure to apply ASME VIII Div. 1 "U" stamp on prefabricated pressure vessel for natural fuel gas vessel?

QUESTION 5 : Is it not helpful to obtain "U" stamp from AI if fabrication of vessel is carried out on shop holding "U" stamp holding ?

Best Regards,

hwangbo-jin

metengr (Materials) · Answer 1 · 2004-03-20 12:33:25

If the Authorized Inspection Agency (AIA) will not certify the vessels for the client because they were not directly involved with in-process shop fabrication or hydrostatic testing nothing more can be done. These are code requirements. You should carefully review the clients purchase order contract documents to determine exact wording on how the pressure vessels were to be supplied to them. Your words above "design and fabrication" imply to me a pressure vessel that will be built in accordance with ASME Section VIII, and must be stamped.

We have on occasion requested components to be fabricated using ASME Section VIII, Div 1 construction guidelines. However, we made it clear in our contract documents (Purchase Order) that the vessels are exempt from a U stamp. When we purchase pressure vessels that require a U stamp because of Jurisdictional requirements, our contract Purchase Order states the vessels shall be designed, fabricated and stamped in accordance with ASME Section VIII, Div 1.

hwangbojin (Mechanical) · Answer 2 · 2004-03-20 12:49:03

Dear metenger;

Thank you very much for your advice.

Our subsupplier have determine to progress without stamp
due to installed of east asia that has no Jurisdictional
requirement and burdensome for inspection and maintenance.

If possible, please kindly advise the best way at the moment
to minimize our big impact.

Best regard

hwang-bo

metengr (Materials) · Answer 3 · 2004-03-20 14:34:04

hwangbojin;
If you subsupplier is making the vessel and there are no Jurisdictional rules regarding installation of the vessel, the U stamp is not really the issue unless your client's insurance company has requested that the vessel be code stamped after the order was placed to construct the vessel.

You must understand that the ASME code symbol is not something to be taken lightly. The shop which has the Code stamp must have a written Quality program and must adhere to it. As part of the Quality program, the Authorized Inspection Agency must be involved. I really have no advice to minimize your impact because the code rules must be followed, unless the client changes their mind and is willing to accept the vessels without a U stamp.

hwangbojin (Mechanical) · Answer 4 · 2004-03-22 07:51:49

Dear metengr;

Thank you very much for your help.
And the other expert informed that these components having the mixing and separating function should be treated as an
piping component, not as an vessel. Therefore stamp for piping components is not necessary. Also, the condensate tank and water bath heater shall be treated as just atmospheric tank due to operating pressure lower than 15 pia.Therefore stamp for condensate tank operating lower than 15 psi is not necessary.

regards

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ASME "U" on prefabricated vessels.