Making Two Vessels From One - Code Issues?

[UW1981]

We have a situation where two vessels were made from a longer vessel. The original vessel was built in 1967 and was code stamped (we have the drawings). The vessel was cut in half and two vessel were constructed using new heads for each...both vessels were R stamped for the modification.

The question is...are both the newer vessels considered "code"....I believe they are since we have the pedigree information, though they may share the same National Board Number (ie, the number that was on the orignal vessel).

Any input/thoughts would be appreciated.

 

[CodeRef]

I am curious to know if this was R-Stamped as a Repair? (R-1) or an Alteration? (R-2)??

 

[UW1981]

I believe it was an alteration (R-2).

 

[metengr]

First off, only the one vessel could be stamped as an alteration because it bears the original ASME stamp and NB number.

The question is...are both the newer vessels considered "code"....I believe they are since we have the pedigree information, though they may share the same National Board Number (ie, the number that was on the orignal vessel).

Are you asking if both vessels are code or meet code requirements? The answer is one new vessel would have to be subjected to a review by the Jurisdiction because only one of the vessels has the original ASME Stamp and NB number, and now you have produced a second vessel that despite having traceability of material back to ASME B&PV Code, it would need to be either a State special or must be stamped by an ASME certificate holder as through the vessel was being fabricated like new.

 

[UW1981]

metengr - thanks for the response. We have folks that were on both sides of this fence. I think both vessel meet code requirements, but it seems to be a technical interpretation of the code as to whether both are now "code" vessels - whether both are "U-stamped". By the way, the original vessel was not assigned an NB number...for whatever that is worth.

Could I impose upon you to provide the reference, interpretation, logic that goes along with this conclusion (that only one maintains the U-stamp or "code")?

Again, many thanks.

 

[CodeRef]

Is the pressure vessel classified as a "Standard Pressure Vessel" or a "Non Standard Pressure Vessel" as defined by the Jurisdiction?

Definitions for these terms are usually stated in the Jurisdictional Code where the vessel is installed. By classifying the vessel in this way, it will point to a particular Construction Code. Construction Codes usually require identification measures such as a stamping or a namplate with a stamp. You now have two vessels but only one satisfies the definition of a "Standard Pressure Vessel" built to a Construction Code.

I am curious which Jurisdiction this is installed in. Call me Curious George.....

 

[UW1981]

CodeJackal,

This is all taking place in Texas....one of 17 states that have not "included by reference" the various pressure vessel codes (at least, last time I checked).

However, this application is subject to PSM as well as our own internal requirments. Our internal requirements restrict use of "non-code" pressure vessels...which I believe means vessels where we cannot confirm they were built to Section VIII code (ie, no data). Since we have all of the data for the original tank, as well as information relating to the alterations, both of these would appear to be "code vessels", although only one would have the original U-stamp. By the way, it does not appear our internal standards require a U-stamp....just that it was built to code (and we have the documentationto prove it).

Anyhow, I am a bit out of my depth here..

 

[CodeRef]

I did find an NBIC interpretation that asked if it was acceptable to utilize a part from one ASME stamped vessel for use on another ASME stamped vessel (as a part) and another inquiry asking if two vessels could be put together into one vessel, both were within the requirements, however, I did not find any inquiry asking to split one vessel into two.
As an AI, I have even signed an R-Form where the entire vessel with the exception of the manway and ASME Nameplate was replaced, all done under the R Program.

Perhaps the NBIC should address this issue for future inquiries.

Of course as you already explained, you would have to defend your position in a worst case scenario.

I would not be very accomodating if I was the AI signing the R-Form. I would definitely want to get my AIA's concurrence on anything like this before I signed the R Form.

 

[CodeRef]

Here is an example of a worst case scenario.

http://www.hss.energy.gov/CSA/csp/advisory/sad_2006-03.pdf

More here:

http://www.csb.gov/completed_investigations/docs/CSBMarcusOilCaseStudy.pdf

Keep this in mind too:
The accident referenced above could (and does) happen in states with boiler and pressure vessel laws, these laws are only as good as their enforcement.

 

[stanweld]

I had a similar proposal by an Owner a few years ago and consulted the National Board, whose response corresponded to metengr's. My original response to the Owner was also the same as metengr's.

 

[metengr]

UW1981;
After reading the above responses, maybe the best advice is to not pursue this because it will not work. The interpretations that CodeJackal mentions have to do with the concept of altering a vessel. This means that you can either remove material or add material to such an extent that only the nameplate remains with a piece of the original vessel material per the requirements in the NBIC for alterations.

The reverse cannot be applied to creating a second object that has no means of assuring compliance with the ASME B&PV Code via a nameplate. The reason is that this new vessel has not been stamped. End of story.

 

[JoeTank]

Technically speaking, isn't this situation just the flip side of what CodeJackal has mentioned. Of course, the NBIC doesn't address it as it's such a weird thing to do. But didn't they address the combining of vessel parts into one vessel after an inquiry was submitted? If done correctly, I see no rreason why something like this would not be in agreement with NBIC... aside from fact that they haven't addressed it yet. I believe the concept is sound, but outside the normal limits of NBIC. I wonder if anyone will ever ask the question of the NB?

Joe Tank

 

[deckie1026]

The ASME Code symbol "U" stamp can only be used once at the time of new construction. An NB R stamp holder may issue R-2's for these vessels with the concurence of the AIA.The original ASME "U" stamped data plate may remain on one vessel.

 

[metengr]

JoeTank;
I can tell you this, that the NBIC would probably not endorse this. Why? Because when the interpretation that CodeJackal mentions was discussed in our SC, a similar question was brought up and it was shot down in FLAMES. It will happen again. Plus, I would not support it.

 

[CodeRef]

As I stated

I would not be very accomodating if I was the AI signing the R-Form. I would definitely want to get my AIA's concurrence on anything like this before I signed the R Form.

It would not be my problem anymore than it would my AIA's problem.

 

[JoeTank]

metengr,
Why not cut the nameplate in half and place one part of it on each half of the vessel? Wouldn't that solve the U-stamp problem? Probably not, but this has been fun to mull over though.

Joe Tank

 

[decode]

INTERPRETATION BC-79-743 READS:

Question: May materials used in pressure vessels or piping systems which have been in service be reused for fabrication of pressure retaining parts for Section I, Section III, Section IV, or Section VIII vessels?

Reply: The Boiler and Pressure Vessel Code provides rules for the construction of new boilers and pressure vessels. Material used must be new material conforming to the Specifications permitted for use by the Section of the Code to which the boiler or pressure vessel is constructed. Used materials are not permitted.

MY HUMBLE OPINION IS THAT THIS IS THE CASE, A COUPLE OF NEW VESSELS ARE INTENDED TO BE PRODUCED USING REUSED PARTS, THIS IS NEITHER A REPAIR NOR AN ALTERATION.

ACCORDING TO ATTACHED INTERPRETATION THIS IS NOT PERMITTED.

DECODER.

 

[CodeRef]

decode,
You are correct, you cannot use used parts to construct a "new" pressure vessel. Your interpretation comes from the ASME Code which only governs "new" construction.

Subject to Jurisdictional and AI acceptance, you can use an assembly as a replacement part to repair/alter a vessel. See the following interpretation:

Interpretation: (NBIC) 95-15
Subject: R-307 Replacement of Pressure Parts, 1992 Edition with the 1994 Addenda

Question: Is it permissible to use an assembly from an in-service pressure vessel as a replacement part for the repair/alteration of a second vessel?

Reply: Yes, provided the intended repair/alteration has the concurrence of the jurisdiction and the Authorized Inspection Agency.

You can even use material from another vessel provided the material falls under the same Code of Construction and also subject to Jurisdictional and AI acceptance.
See the following interpretation:

Interpretation: (NBIC) 01-28
Subject: RC-1040, Materials, 2001 Edition with 2002 Addendum

Question: Is it prohibited to use material that has been previously in service for replacement material for a repair if that material otherwise conforms to the requirements of the original Code of Construction?

Reply: No, provided the use of the material has the concurrence of the Jurisdiction and the Authorized Inspection Agency.

I agree with metengr as far as ASME is concerned. There is only one pressure vessel with a stamp here. and should remain as one stamped vessel.

What is to prevent the R-Stamp from being applied to the other remaining part? I have been involved with R-Stamp repairs to other than ASME Stamped pressure retaining items. The real question is, which Code should be followed to satisfy the Jurisdiction, Insurance Company, and AI(AIA)?

Lots of questions come to mind...

 

[deckie1026]

DECODE, I would agree with you if this was new construction activity but this is not new construction in my opinion. This activity is post construction and the NBIC is the Code that is applicable.There is nothing in the NBIC that I can find that would specifically prohibit this situation. This is an alteration/rerating. An R-2 form is appropriate. These vessels have an equivalent level of safety as the "parent vessel" What are we worried about? Let's be pragmatic not dogmatic.
I am happy to see the owner of these vessels is at least thinking about these issues. As we all know Texas does not have pressure vessel law and from the jurisdictional perspective nothing needs to be done.

 

[metengr]

deckie1026;
I absolutely disagree with your line of thought. As an owner of boilers and pressure vessels I would never permit this activity in a code book like the NBIC because it could lead to unsafe vessel fabrication practices.

These vessels have an equivalent level of safety as the "parent vessel" What are we worried about? Let's be pragmatic not dogmatic.

How do I know that the second vessel is exactly duplicated without going back to the ASME Code and running calcs to verify the second vessel is a duplicate of the first? You cannot make that assumption, at least I wouldn't. This is why Jurisdictions have State specials for unstamped objects intended to be used in service.

Keep in mind the NBIC is written for all Users and knowing this would you let a dry cleaners or otjer user (like a school or business) simply have a NB certificate holder come in replicate another vessel or even small boiler because it saves cost?? Think about it.