Hydro test & repairs

[airtight]

Hi, A few questions I hope can be answered. We have a U stamp vessel which needed some extra nozzles welded on. These were small 2" diameter 1" npt couplings.

We did the WPS, WPQR, WPQ etc. Got material certs for the couplings and involved Lloyds but only for the WPS / PQR.

We did not do any design calcs for couplings, and the only NDT was dp. Is that enough? Although the vessel is not being used in the USA I would appreciate finding out what is required to keep the vessel legal if it was being used in the USA.

Next question. It needs a hydro. Can ASME vessels that were made originally in the 1.5 x MAWP era now be hydroed to 1.3?

I believe that a pneumatic test can be done to 100% MAWP but I cannot understand what the benifit of this test would be. Perhaps someone could fill me in. Thanks.

 

[deanc]

This vessel is no longer usable in most US jurisdictions. The work needed to be performed by an "R" stamp holder to the requirments of the NBIC ANSI/NB-23.

http://www.nationalboard.org

All your questions can be answered at the above site.

 

[airtight]

Deanc - thanks for your reply. That was what I thought until an ABS inspector here told me differently, and I also thought if that was the case that would mean that the only vessels usable under US juristiction would be ASME U stamp ones, any BS5500 ones , or PD5500 would not be allowed?

Perhaps you could also tell me about the 1.3 MAWP hydro?

Thanks very much. Neville

 

[deanc]

Vessels may be built to other Codes but to be U stamped must also meet all of the ASME requirments. Sim.to PED in that a vessel can be be built to SecVIII with additional PED requirments. Clear as mud-yes?

The small fittings may be considered a repair or a alteration,depends on the sizes and the base metal thickness. If it is a repair it may be tested at the MAWP.
If it is an alteration it needs to be the original test pressure.

 

[JoeTank]

Airtight,

I see the (marine/ocean) behind your name and wonder if this may be a ship mount vessel. If so, then you may not have any specific jurisdictional rules. If it's land based, perhaps you could use API-510 if permitted by the jurisdiction. The work you describe and the tense you are using makes me wonder if this is work that is currently going on. If so, it may not be too late to keep the U-Stamp integrity. You may be able to salvage this thing yet.

With regards to the hydrotest, a vessel is to be tested per its original Code of construction or the Code under which it is re-rated. If it was orginally a 1.5 MAWP hydotest, then maintain that test criteria.

Regards,
Steve Braune

 

[deanc]

S Braune

Suggest you review the newest NBIC RC-2051 for repairs,RC-3031 for alterations. Then take a look at Apendix 6.

 

[airtight]

Ok, I spoke to ASME again today. They told me that it does not need the repair done by a R stamp holder to be allowed in the USA. I suppose that may be true as there arent many R holders compared to U holders. As clear as mud but ive got another telephone call scheduled with ASME tomorrow.

Anyway, the alteration has been done already, the hydro is geting done on monday, its getting shipped to Australia and then on to its final destination Nigeria. It wont matter what bits of paper it has when it gets to Nigeria, but I am primarily interested about the ASME stamps for future vessels that we send back to the USA...

 

[JoeTank]

deanc,
Thanks for the comment. I would go check those references right away, but newest NBIC is buried in my garage. I just changed jobs and have not uncovered all my good stuff yet. Could you give me a very quick sentence or two about the content of each reference.
I probably was not clear, but one of my questions to airtight was getting at the applicability of NBIC. NBIC is not a the only vessel maintenance Code for ASME Code stamped vessels in the US. API-510 is also applicable (to varying degrees) in a number of jurisdictions. I just wanted to alert him to that possiblity.
Thanks,
Steve Braune
Tank Industry Consultants

 

[deanc]

airtight

ASME handles new construction. It may not be simple,in the USA the Local Jurisdiction determines if the repair or alteration needs to be performed by a "R" stamp holder.

You really need to speak with the National Board and find out who to contact in each juridiction if you wish to ship in vessels. New or repaired.

Your couplings may be considered a "routine repair" and not an alteration depending on several factors.

 

[airtight]

Deanc: Ok, Im beginning to get it now. To change track a bit, would some jurisdictions allow a BS or PD5500 vessel in ? I presume this would be a question I would have to ask the National Board directly, I do find it quite difficult to get the correct information from these bodies sometimes.

 

[deanc]

airtight

The answer would be maybe. Depends on the laws in the location. You would need to contact the Jurisdictional Authority,who you can find thru the NB. They may be willing to issue a "state special".

This is the reason for the "U" stamp. This will get it done most of the time for a new vessel. Still depends on the jurisdiction. May be additional requirments in each location.

Other countries do the same for the "U" stamp. Canada requires a CRN. Australia needs a equivalent level of safety statement. You need to registered for PRC. etc,etc.

 

[airtight]

Thanks deanc. Over here in the UK and under the new PD, you can simply fabricate a pressure vessel to the relevant code ie 5500 , have the design and build + test overseen by a class society such as Lloyds or ABS etc, and thats it. Quite simple. Seems quite complicated in the USA!

 

[llpcode]

There are four concerns in this post:

1) Is the Lloyd's Surveyor an ASME Authorized Inspector (Most are not!)

2) Nozzles - The sizes mentioned (2 -1 inch) do not require calculations under ASME rules, but could under USCG rules.

3) Pressure test could be required by NBIC Rules, authorization by the ASME/NB Authorized Inspector to waive the pressure test is required.

4) ASME Section VIII - 1 (UG-99) did change the upper pressure test pressure, however, the rule of construciton of the vessel would govern the ASME Code inspector's decision on how to apply the NBIC rules.

 

[gpape]

The big difference between ASME and PED is the fact that PED is a "system" based standard and ASME is a stand alone that follows an idividual piece of equipment. PED requires assessment diagrams of the system to determine the Fluid Group and Category which then determines the level of inspection by the Notified Body. Each piece of equipment is then required to have an Application Card and Hazard Analysis. It can be built in accordance to any of the recognized codes (ie ASME, ADM, Stoomweezen) and their respective requirements. If a piece of equipment is removed from a system and is to be placed into another system, the whole process has to be redone.

And by the way, the last time I looked at putting equipment into Nigeria, they have their own rules and regulations the required a lot of paperwork and "money" in the right places.