Fuel Gas line recommissioning ?
Fuel Gas line recommissioning ?
(OP)
Hi everyone,
This is my first thread and hope to get some useful information.
I am working on a fuel gas line which has been isolated 4 years ago and we look for the possibility to re use it.
As you may imagine, there may be integrity issues and we will have to do some wall thickness checks.
Can somebody tell me if we have to re-do a hydotest, do a leak test of if the thickness control can be considered as sufficient ?
Are there indications in the b31.3 or fitness for service ? Thank you
Regards
Sam
This is my first thread and hope to get some useful information.
I am working on a fuel gas line which has been isolated 4 years ago and we look for the possibility to re use it.
As you may imagine, there may be integrity issues and we will have to do some wall thickness checks.
Can somebody tell me if we have to re-do a hydotest, do a leak test of if the thickness control can be considered as sufficient ?
Are there indications in the b31.3 or fitness for service ? Thank you
Regards
Sam





RE: Fuel Gas line recommissioning ?
RE: Fuel Gas line recommissioning ?
You have to remember that standards are NEVER a substitute for Engineering Judgement.
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.
RE: Fuel Gas line recommissioning ?
I'd look at the service (dry fuel gas, wet fuel gas, sour fuel gas, etc), how it was laid up (drained and blown dry, put under an N2 pad, just blinded off, etc), do some UT and perhaps drop a couple of spools if you have them at low points such as control valves to check for the internal condition. I'd then look at the UT results and see how much corrosion has occured relative to the amount of pipe needed to meet your design conditions and the original corrosion allowance.
If the line had been in service these past four years you wouldn't be looking at a full hydro again, you'd be depending on your NDE examinations by the inspectors. I'd be concentrating on seeing if there was something in the layup that could have resulted in high corrosion and therefore a hydrotest is a prudent precaution. Remember, if something goes wrong, those questions are going to be asked including why you didn't proceed with a hydrotest. Dead legs are a known location for corrosion problems.
RE: Fuel Gas line recommissioning ?
"People will work for you with blood and sweat and tears if they work for what they believe in......" - Simon Sinek
RE: Fuel Gas line recommissioning ?
RE: Fuel Gas line recommissioning ?
@David: That seems to be the optimal solution. I will gather the informations as suggested by TD2K and look for any portion of standards / Guidelines that may apply (even partially).
and, I like your signature :
"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.
@Simon: you are right, considering the current state of the line, hydrotest wouldn't be necessary, I believe. However, I would personally look to find a good reason not to do it rather than the opposite.
@austsa: well, as I wrote to Simon, you are right. I believe it's not necessary, however I prefer being sure and having my decision backed up. I will, as suggested by David, prepare a position paper and see if I can find something.
Thank you all for your help :)
RE: Fuel Gas line recommissioning ?
http://www.nfpa.org/aboutthecodes/AboutTheCodes.as...