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.
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
Why cant he do a hydro for 10 minuten, but only for 60 seconde?
RE: hydrostatic test duration for b31. 3 prefabricated spools
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
RE: hydrostatic test duration for b31. 3 prefabricated spools
However, the owner may waive that requirement. You then need his permission.
RE: hydrostatic test duration for b31. 3 prefabricated spools
RE: hydrostatic test duration for b31. 3 prefabricated spools
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
you must get smarter than the software you're using.
RE: hydrostatic test duration for b31. 3 prefabricated spools
RE: hydrostatic test duration for b31. 3 prefabricated spools
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
And I do understand that there can be more than one closure weld.
RE: hydrostatic test duration for b31. 3 prefabricated 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
RE: hydrostatic test duration for b31. 3 prefabricated spools
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
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
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
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
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
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
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
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
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
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
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
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
RE: hydrostatic test duration for b31. 3 prefabricated spools
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
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
RE: hydrostatic test duration for b31. 3 prefabricated spools
Thanks.
RE: hydrostatic test duration for b31. 3 prefabricated spools
RE: hydrostatic test duration for b31. 3 prefabricated spools
Regards
Stonecold
RE: hydrostatic test duration for b31. 3 prefabricated spools
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
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