Re: PWHT on a live Fuel Gas Line

From: <elie>
Date: Sat Jan 27 2007 - 11:37:00 EST

Yes, it is.

  1. UT exisiting pipeline for actual wall thickness
  2. Obtain the allowable stress for the material of construction of the pipeline from B31.3 table A1 at the PWHT temperature
  3. Calculate the design pressure (p1) of the existing pipeline under above conditions.
  4. Read the section titled "Welding criteria permit safe and effective pipeline repair" in the Pipeline Rules Of Thumb Handbook to find out the relationship between gas velocity, remaining wall thickness, welding voltage etc. Good Luck.

   Please understand that welding on a live line is a huge responsibity and may kill people. I am not getting paid for this advise, therefore I am in now way should be held liable for your decision. I do consultant work for living, if you need a stamped SOW, we can do it.

   Regards,
Elie AlTawil
Sr. Engineer >20 years
Denver, Colorado.

dd jdh <saduemk@yahoo.co.in> wrote:

           hi every one,

I have a 42" Split Tee Hot Tapping connection on a 550 psig design pressure 200 deg F design temp. petroleum fuel gas line.But the split Tee provided is of 30mm.Ofcourse should go for PWHT.

Is this feasible on a live fuel gas line or whether there will be any other alternative.

Thanks in advance,

regards,

Sadanandan.M.K
PE,
Middle East



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Received on Sat Jan 27 11:37:00 2007

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