Painting before Hydrotesting 1

[Angsi2]

Can piping be painted before hydrotest? ASME B31.3 does not address this but as a good engineering/fabrication measure the oil and gas/petrochemical industries require that the hydrotest take place prior to painting.

I have a contractor who has accidentally painted his spools, assembled all of them (large bore spools) awaiting hydrotesting. To take it apart after hydrotesting could be costly to him and he is asking for a one time concession. I believe it was a honest mistake.

Besides increasing the hydrotest duration, are there any other supplmentary tests that can be requested to compensate for any 'masking' role that the paint dft might play during hydrotest?

Any input will be appreciated.

 

[zdas04]

I do it all the time on gathering systems. Generally we clean up right behind the lowering-in crew and part of clean up is usually painting dog legs. I've had jobs where the pipe was painted 3-4 months prior to hydrotesting.

David Simpson, PE
MuleShoe Engineering

"Belief" is the acceptance of an hypotheses in the absence of data.
"Prejudice" is having an opinion not supported by the preponderance of the data.
"Knowledge" is only found through the accumulation and analysis of data.

 

[pennpiper]

Lets bring some reality to this situation.
You are NOT talking about ALL the piping on a Project when you ask this question.
a.) Stainless Steel Lines are normally NOT painted. So deduct the SS lines.
b.) Certain other Alloy lines are also NOT painted. So deduct these lines.
c.) High temperature Insulated lines are NOT painted. So deduct these lines.
d.) Low temperature/Cryogenic insulated lines are NOT painted. So deduct these lines.
e.) 2" and smaller screwed and socket-weld field fabricated lines will also be split by Insulated & uninsulated lines. So deduct a percentage of these.
f.) 3" and larger Shop Fabricated Carbon Steel and Alloy lines can have the weld lanes taped off before shop painting.

What you are left with is a much smaller number of lines to consider for painting before or after hydro-test. When you work the problem through and find the realistic number you should be able to answer your own question.



prognosis: Lead or Lag

 

[Kiwi2671]

Angsi2,
Painting of welds prior to hydrotest is allowed as per B31.3.
345.3.1
"All joints may be primed and painted prior to leak testing unless a sensitive leak test is required."
Unless the requirement to not paint prior to hydrotest is in your specifications or contract documents there is no need for a concession as the welds are code compliant.
A bit of a concern your engineers and your contractor have not bothered to look very hard in the code,
Regards,
Kiwi

 

[Angsi2]

Thanks all.

Kiwi2671: The referenced project engineering standards (not ASME Codes) requires welds not be painted prior to testing however. This is where the snag is.

Pennpiper: Vendor was asking for a one time concession for one preassembled spool section, not for the entire plant.

 

[BigInch]

Then don't take a bite of that apple. You must pass it on to the client for their resolution and approval. Remember what happened to Snow White.

"People will work for you with blood and sweat and tears if they work for what they believe in......" - Simon Sinek

 

[Angsi2]

Of course BigInch, just wanted to understand the industries' position on this before approaching Client, so that we have some 'valuable' input into his decision making. I think we all should, instead of just sliding the responsibility onto someone else.

So far, it seems like there is a general acceptance to the practise of hyrotesting painted spools. So BigInch, I can now advise my Client appropriately i.e. maybe we can actually grant the vendor/contractor one time concession? Hope you can see what I am trying to getting at.

Anyways guys, thanks alot.

 

[Latexman]

Please let us know the outcome and the client's rationale. Thanks!

Good luck,
Latexman

 

[gr2vessels]

Angsi2,
The hydrotest is an integrity test, not a fine leak test for hydrogen confinement. This is the test for the strength of the individual pipe welds and of the entire system. If the paint thickness is holding your piping together, then God save the people working on that site.
You could however, impose somne restrictions on a few welds (critical welds at bends or highly stressed areas and request removal of paint on those areas for the hydrotest).
Remember, the code cannot cover all areas of engineering and the codes are every year improved by innovative engineers with bright ideas to make them safer, better engineereed, cheaper. Use your best enguineering judgement to prove your worth and keep everyone safe.
Remember, the Client has hired you as the expert in the trade. They can read the code just as well you can, so they need someone telling them the work is safe in the spirit of the code.
Give kiwi another star!
Cheers,
gr2vessels

 

[sentjoh]

Hydro testing is often part of more NDE inspection and not to mentions visual examination. In my experience it’s more or less subject to time pressure, especially in shut-downs, whether an asset-owner allows it.

@ pennpiper. A lot of SS system are coating to protect against SCC


Regards,

Johan Sentjens

http://www.linkedin.com/in/johansentjens

 

[BigInch]

senthoh, I think he knows that. He's been doing this for longer than you've been born.
Pennpiper said "normally". That doesn't mean every time.
You said "a lot". That doesn't mean all, and it doesn't mean none.
Seems like you said the same thing that PennPiper did, just more than two months late and
in a confrontational manner. Everybody was pretty happy with the end of the discussion for more than two months now.
What's your point? Or was that it?
BTW I don't understand why you would want to buy SS, if you have to coat the pipe anyway.
No. That's OK. Don't tell me why.

Independent events are seldomly independent.

 

[sentjoh]

BigInch,
Can you please explain me your offensive attitude. This discussion is still open and the person on behalf you seem to react clearly mentions "Any input will be appreciated." I merely share my experience which judging by your reply doesn’t qualify in eyes.
I assume you’re not familiar with Stress Cracking Corrosion (SCC) on SS piping/equipment, often occurring under insulation by leachable chlorides. And protected by either wrapping in Alu foil of finished with coatings. It’s in the (petro)chemical industry a well known and documented phenomenon. And standards like NACE SP0198 or EFC 55 CUI guideline mention above type of solutions.


Regards,

Johan Sentjens

http://www.linkedin.com/in/johansentjens

 

[BigInch]

I simply meant that I don't think PennPiper needed the lesson and
that Angsi2 hasn't even mentioned he is working with any kind of SS at all, so
I am still wondering what your point is. Who here is using SS?

BTW It's probably better not to make any assumptions about what I do, or don't know. If you want to know, just ask me.

Independent events are seldomly independent.