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hydrostatic test duration for b31. 3 prefabricated spools
3

hydrostatic test duration for b31. 3 prefabricated spools

hydrostatic test duration for b31. 3 prefabricated spools

(OP)
Dear all,

Our company made an order for thousands of prefabricated pipe spools. The purchase order stipulates that the spools shall meet b31.3 criteria. The fabricator says he can only pressure test the spools for 1 minute as opposed to the requisite time of 10 minutes as per b31.3. Can this reduced test time be accepted ? Thanks.

RE: hydrostatic test duration for b31. 3 prefabricated spools

The owner has ultimate responsibility and may waive (or add) requirement in (to) B31.3.
Why cant he do a hydro for 10 minuten, but only for 60 seconde?

RE: hydrostatic test duration for b31. 3 prefabricated spools

(OP)
hi XL83NL,

The fabricator says he has a machine which can pressure test only one individual spool at a time and so 10 minutes per spool multiplied by thousands of spools will undoubtedly delay delivery time. He says 1 minute per spool is enough and still have b31.3 compliance. I don't know really.

RE: hydrostatic test duration for b31. 3 prefabricated spools

(OP)
So if a spool is pressure tested for 1 minute will it meet b31.3 requirements ??

RE: hydrostatic test duration for b31. 3 prefabricated spools

No, refer to para 345.2.2(a). Ten minutes.
However, the owner may waive that requirement. You then need his permission.

RE: hydrostatic test duration for b31. 3 prefabricated spools

Talk to the Owner's Inspector -- per B31.3 the Owner is required to have an Inspector. My usual take on "10 minutes" is that 10-minutes is up when I have laid hands on all welds and found them to be dry. So if the spools are fairly simple, and the Inspector is there for each hydro, 1 to 2 minutes seems to be a reasonable time; but it is up to the Inspector.

RE: hydrostatic test duration for b31. 3 prefabricated spools

(OP)
Thanks duwe 6,

I'm the owner and I'll be having a third party inspector assigned for this project. Yeah the spools are just a meter in length. I'm kinda leaning towards 1 to 2 minutes myself but my inspection team and my boss insist on the 10 minutes saying that's what the code says ! I mean in the here in field we test our pipelines for hours not 10 minutes due to extensive length and so if we extrapolate that for spools then 1 minute is enough. A leak should be instantaneous right and plus the weld joints will be right there in front of my TPI so he won't need a full 10 minutes to do a walk around.

RE: hydrostatic test duration for b31. 3 prefabricated spools

I think BOSS is the owner.

you must get smarter than the software you're using.

RE: hydrostatic test duration for b31. 3 prefabricated spools

Will you not be leak testing the completed piping systems? If you will be, that is when the 10 minutes applies. Note that "golden welds" do not apply to thousands of welds. Your boss may well be spending the company's money unwisely.

RE: hydrostatic test duration for b31. 3 prefabricated spools

(OP)
Yes the completed system will be leak tested in the field. The spools once they arrive will be part of the completed system. The purchase order for these spools mentions b31.3 our design engineer should have specified the holding time also but he didn't so now our division is left to enforce the purchase order my boss says wants to adhere to the purchase order religiously.

Even the design engineer says a spool on its own is not a piping component it is a piping system therefore 10 minutes per spool !!

And on a different note you can have more than one closure/golden weld.

RE: hydrostatic test duration for b31. 3 prefabricated spools

It is standard Engineering practice to specify B31.3 to a Pipe Fabrication shop for pipe systems designed, constructed and tested thereto but not to require hydrostatic testing of the spools. If it was not specifically stated in the P.O., if I were the Fab Shop Owner, I would back charge you big time based on customary practice and per 345.1, "each piping system shall be tested to ensure tighteness." A pipe spool is by no stretch of the imagination a piping system, especially when thousands of spools are involved.

And I do understand that there can be more than one closure weld.

RE: hydrostatic test duration for b31. 3 prefabricated spools

How many spools can you bolt or clamp together in one go to hydro? I've done this many times where you bolt up multiple spools just to hydro to reduce overall testing time as you have to allow for all the filling, draining venting, emptying etc as well as your 10 minutes per test and then just unbolt them all again to transport / fit in position. If they're only a metre long you should be able to get 10 or 20 or more bolted together in one go or even just join bolted spools together with a pressure hose. If you've got to bolt on two blank flanges for each one then it's just as fast if not faster to bolt spools together as you only need one bolt up per spool apart from the end spools.

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way

RE: hydrostatic test duration for b31. 3 prefabricated spools

(OP)
The spools are not flanged at the ends. They are made up of api 5l pipe pup pieces welded to b16.9 elbows mostly. The fabricator would like to avoid joining multiple spools together by welding just to leak test then cut them separate again to him it's a waste of material not to mention extra welding and cutting.

RE: hydrostatic test duration for b31. 3 prefabricated spools

unclebensrice,
You (or your boss)are about to make a huge mistake which will cost your project huge amounts of unnecessary time and money - purely because someone (specifically your design engineer) does not understand the applicable code.

"Even the design engineer says a spool on its own is not a piping component it is a piping system therefore 10 minutes per spool !!"


Here are some excerpts from B31.3

erection: the complete installation of a piping system in
the locations and on the supports designated by the
engineering design including any field assembly, fabrication,
examination, inspection, and testing of the system
as required by this Code.

piping components: mechanical elements suitable for joining
or assembly into pressure-tight fluid-containing piping
systems. Components include pipe, tubing, fittings,
flanges, gaskets, bolting, valves, and devices such as
expansion joints, flexible joints, pressure hoses, traps,
strainers, inline portions of instruments, and separators.

piping subassembly: a portion of a piping system that
consists of one or more piping components.

345.2.3 Special Provisions for Testing
(a) Piping Components and Subassemblies. Piping components
and subassemblies may be tested either separately
or as assembled piping.

Notice I have placed the emphasis on may


If you have gazzillions of dollars and a couple of years up your sleeve you may test each spool individually but the code does not require it and never has done.

Regards,
DD

RE: hydrostatic test duration for b31. 3 prefabricated spools

"The spools are not flanged at the ends.". So how exactly is the supplier pressure testing them? I agree with dekdee that these items are not a piping system and hence should not need individual test certs for each spool.

I am kind of intrigued to figure out what item needs "thousands" of small 1m long spool pieces pre-made.

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way

RE: hydrostatic test duration for b31. 3 prefabricated spools

(OP)
Hi guys,

First of all, a piping (sub)-assembly is not equivalent to a piping component. Please refer to the answer of question #1 of b31.3 interpretations volume 23.

Second, most of these spools consist of pipes with beveled ends welded to elbows with BW ends. They will be used for flowlines at road crossings.

Some spools have one or two flanged ends out of three ends and those spools are for tee branches to be used in the flow lines.

The order is for almost a thousand spools.

The hydrostatic test procedure is unclear. It says "the coupled system will be filled with water and then after the pressure is raised all connecting pipe excess those for pressure measurement shall be disconnected."

So what do you think now 1 min or 10 min :)

Thanks for all your valuable input fellows. Appreciate it.


RE: hydrostatic test duration for b31. 3 prefabricated spools

(OP)

Sorry for my above post I forgot to mention the interpretation number
It is Interpretation # 20-24, question #1 of b31.3 interpretations volume 23.

RE: hydrostatic test duration for b31. 3 prefabricated spools

Any assembly which is "plain end" is pointless to hydrotest for any duration, since it will need to be re-tested after the completion weld is done. The alternative is very careful NDE (plus a sensitive leakage test?) which may not be less effort than a hydrotest.

If the service is Category D (nonhazardous) per B31.3, the owner may elect to test the piping in service with the service fluid rather than hydrotesting, if I recall correctly.

Any spool terminating in nothing but flanged ends may either be hydrotested or pneumatically tested in a code-compliant way (10 min) now and then NOT re-tested post assembly, or it may be tested with the assembled system.

It is not necessary to re-hydrotest flanged spools which have been individually hydrotested, after the flanges have been bolted together, merely to test the integrity of the flanged joint. However, it is obviously prudent that these flanged joints be leak tested prior to being put into service. That leakage test has a different test design, different conditions, and totally different hazard profile than a hydrotest.

RE: hydrostatic test duration for b31. 3 prefabricated spools

unclebensrice,
I will try again.
It is quite clear a piping component and a piping subassembly are not the same as noted in my earlier post.
The interpretation you quoted is based on the 2002 edition.
The 2002 edition does not list piping subassembly in 300.2 Definitions and that would be why the query was submitted and interpretation raised (subsequently added for future editions).

You have a pipe (one component) and an elbow (another component) so they form a piping subassembly - which is then a portion of a piping system.

This is the definition of "piping system"
piping system: interconnected piping subject to the
same set or sets of design conditions

Is the pipeline running either side of the road crossing subject to the same set or sets of design conditions as the spool being used for the road crossing ?

Cheers,
DD

RE: hydrostatic test duration for b31. 3 prefabricated spools

(OP)
Hi gentlemen,

Just to answer the questions above :

- our service is normal fluid service not category D.
- the reason we request even flanged end spools to be hydrotested during their manufacturing even though we can just hydrotest the completed system once during field erection as per 345.2.3 is because we are purchasing these spools from abroad. We are not manufacturing them in house so it's kind of a precautionary measure. The purchase order asks for hydrotest.
- yes the the pipeline running either side of road crossing is same as the spools design code which is b31.3. 3.

Thanks again guys.

RE: hydrostatic test duration for b31. 3 prefabricated spools

you still need to ask how the supplier is intending to test open ended spools, especially those with elbows on. Straight pipe he might be able to clamp between moveable end stops like they do in the pipe mill, but once you've put an elbow on it you can't. I suspect he will be using plugs in which case I can't see how he can't couple up a load of spools at once and the hydro them all together?? BTW what is the hydro pressure / size of these "spools" Makes a difference to understand what we are talking about.

It could be that he can actually joint together spools by plugs and other devices and test more than one at once.

However when I saw the phrase - B31.3 designed for flow lines, with elbows in the line, I started to realise that things are not as they should be. B31.3 is designed for pipe inside plants, not flowlines.

1 minute or 10 minutes is in your hands as the owner / purchaser to waive or not as required. What you need from the fabricator is a written waiver request and then you can approve or not taking into account the consequences (time, cost etc) of your decision. Hand it to your "boss" to countersign whatever you decide.

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way

RE: hydrostatic test duration for b31. 3 prefabricated spools

Little Inch,
This is how the supplier intends to test

"The spools are not flanged at the ends. They are made up of api 5l pipe pup pieces welded to b16.9 elbows mostly. The fabricator would like to avoid joining multiple spools together by welding just to leak test then cut them separate again to him it's a waste of material not to mention extra welding and cutting."

This is why I have been going on and on about the ridiculous waste of time and money because someone doesn't understand what a piping system is.
It seems to be falling on deaf ears so I will give up,
Cheers,
DD

RE: hydrostatic test duration for b31. 3 prefabricated spools

Dekdee,

That is why the supplier doesn't want to weld lots of the spools together. I cab see his point. What I asked was how does he intend testing a spool with open end(s)?? Unless he puts something in the way the water will just shoot out the end no?? Perfectly reasonable question to me.

The current answer from uncle ben is "the coupled system will be filled with water and then after the pressure is raised". I'm asking how does he raise the pressure. If he can do it for one spool why can't he do it for 10 of them at the same time and then test 10 for 10 minutes instead of 1 for 1 minute each?? Then every one will be happy.

so far no answer.

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way

RE: hydrostatic test duration for b31. 3 prefabricated spools

unclebensrice,
Since the P.O. required the hydrotest strictly per B31.3 and the fabricator accepted the work without exception, he must comply. What he is asking may well be reasonable and will, more than likely, assure scheduled delivery. It is up to you as the Purchaser to weigh his request. If the pipe is ERW and its quality suspect, you should consider the request. If you suspect the fabricator's weld quality, you might consider a longer hold time to assure finding leaks from tight discontiuities. If you really suspect the fabricator's quality, you should not have awarded the Order or you should provide full time inspection if its price was low enough.

RE: hydrostatic test duration for b31. 3 prefabricated spools

(OP)
Hello gentlemen,

Apologies for this belated response it's the weekend here. So just to answer some of your questions again:

- I already asked the supplier to submit a more detailed procedure on pressure testing and whether he will be using end stops/plugs/weld to connect and seal off the ends and submit a brochure if he will be using a specialized pressuring device.

- we should be using api 1104 for pipelines I agree but they're using b31.3.for everything here perhaps because it's more stringent.

- fabricator submitted a written waiver request justifying his case by contrasting the little holding time needed for api 5l pipes and valves tested under api 598 to the extensive 10 min time needed for the spools.

- I know what a piping system is and that 345.1 is for piping systems and that testing the piping system in the field once is enough but like I said the purchase order states b31.3. 3 pressure testing and this is needed in our case because the spools are made abroad and we need a guarantee they're all good. Thanks for the patronizing tone on that one hehe.

- the spools will be made from seamless pipe.

- maybe this fabricator has one pressuring machine that's why he wants less time on the hydrotest.

Thanks again all of you guys for your time aND all your helpful comments.

RE: hydrostatic test duration for b31. 3 prefabricated spools

(OP)
Test pressure is 430 psi

RE: hydrostatic test duration for b31. 3 prefabricated spools

Gentlemen,

The code does not mandate shop hydrostatic testing of piping components nor piping subassemblies as is. hydrostatic testing of components is covered under relevant manufacturing standards.

"As a special case" in the event where the owner needs to hyrotest, 345.2.3 allowed under "special provisions" to (additionally) test individual component and subassemblies. In this case, the same should be additionally identified as a special requirement.





RE: hydrostatic test duration for b31. 3 prefabricated spools

(OP)
In one of the interpretations of the code,namely Interpretation 21-11, it says that a pressure test of less than 10 minutes by the pipe manufacturer will not satisfy b31.3 code requirements of paragraph 345.

Also the purchase order for these spool stipulates/additionally identifies b31.3 pressure testing so that's your special provisions clearly stated.

Thanks.

RE: hydrostatic test duration for b31. 3 prefabricated spools

If the 430 psi test pressure produces a stress across the circumferential welds < 20% of the SMYS and I suspect it's less than 15%, you are wasting time and money. The Supplier is simply looking at saving about 4 weeks time in testing and the costs thereof; however, exception was not taken to the P.O. requirements and you are justified in maintaining the original requirements.

RE: hydrostatic test duration for b31. 3 prefabricated spools

(OP)
The b31.3 code is a design code not a manufacturing code so its test pressures are are going to ve understandably much less than let's say api 5l. Even api 5l is at 60% or 70% SMYS. I think the intention of b31.3 pressure testing is to verify the workmanship or integrity of the weld not the strength ; that the welds don't leak and are free of discontinuities; kind of like what RT is to WPQs. The strength of the weld is verified through PQRs by the mechanical tests.

Thanks.

RE: hydrostatic test duration for b31. 3 prefabricated spools

Again, hydrotest on plain end pipe is a waste of time. What duration it is done for is not really worth worrying about, because you're going to have to re-test when the completion welds are done anyway. From a cost and quality perspective IMHO the bigger issue is the addition and removal of the cap they will probably weld onto the pipe to accomplish the test- unless they're planning to use an expanding plug in the end of the line to do so. That is probably fine with plain end pipe but how well is it going to work on elbows, as someone else has already queried? Surely any method they use to do this is going to take more than 10 minutes per spool to set up, so what's the dif between 1 and 10 minutes under test?!

RE: hydrostatic test duration for b31. 3 prefabricated spools

You are better off to re-negotiate that you will waive the hydrotests at the shop if they will assume responsibility for any defective welds that show up in the field. Then just back charge them for any bad welds that have to be fixed in the field. If there quality is good you both win.

Regards
Stonecold

RE: hydrostatic test duration for b31. 3 prefabricated spools

Our company made an order for thousands of prefabricated pipe spools. The purchase order stipulates that the spools shall meet b31.3 criteria. The fabricator says he can only pressure test the spools for 1 minute as opposed to the requisite time of 10 minutes as per b31.3. Can this reduced test time be accepted ? Thanks.
Just think this way also
“As during shut down the time is very short and so many loops having only one pipes ….during that time we don’t perform hydro test and do NDT for tie in joints .
Sometime loop is very small and we do NDT only for 2 or 3 joints …this time hydro may be waived by client or depend upon the situation at site.
This saves a lot of time also.
For doing of spool hydro test you can make a string and do partial welding which is is common practice to perform hydro….even ….this way we are doing old pipes hydro testing then why not for new pipe.
1 minute is not enough for any process pipe .”
Thanks & Regards,
Lalit Mohan Kothari
“Dreams and dedication makes powerful combination “
TUV NORD
https://www.google.co.in/?gws_rd=cr&ei=OhrBUpb...

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