UT TEST RESULTS AND FLAWS
UT TEST RESULTS AND FLAWS
(OP)
I AM WORKING ON PIPE LINE PROJECT 600 mm dia carbon steel pipe is being but welded .my problem is that we have to carry out 10% ut of weld .results show that 6 out of 10 welds are flawed our specifications suggest repair of flawed welds.i m insisting that test must be repeated with increased sample size however contractor is arguing that specification or any code(i-e api 1104) require only repair of joints
please guide me what is best for quality and safety
please guide me what is best for quality and safety





RE: UT TEST RESULTS AND FLAWS
B31.4 or or B31.8?
B31.4 says,
434.8.5 Required Inspection and Acceptance Criteria
(a) Required Inspection
(1) The quality of welding shall be checked by
visual inspection and supplemental nondestructive
methods or by removing completed welds as selected
and designated by the inspector for destructive testing.
(2) All welds shall be visually inspected.
(3) When the pipeline is to be operated at a hoop
stress of more than 20% of the specified minimum yield
strength of the pipe, the welds shall be inspected. A
minimum of 10% of the girth welds and 10% of the other
welds completed each day shall be randomly selected by
the operating company and nondestructively inspected.
The inspection of girth welds shall be by radiographic
or other accepted volumetric methods. Nonvolumetric
methods, such as dye penetrant or magnetic particle,
may be used for other welds. Each weld inspected shall
be inspected completely with the selected method. In
the following locations or conditions, all welds in the
pipe shall be completely inspected; however, if some of
the welds are inaccessible, a minimum of 90% of the
welds are to be inspected ....
You can find similar wordings in B31.8
you must get smarter than the software you're using.
RE: UT TEST RESULTS AND FLAWS
My favorite scheme of 'percentage testing' is what ASME B31.3 uses: Every welder's welds get tested, at an average rate of 5%. Any Reject requires two 'tracers' - testing of similar size welds, made during a similar time frame, by that same welder. If either of those tracers fail, two more tracers are taken [same method of selecting the welds]. If, out of those four 'tracer' tests two or more welds fail, then ALL that welder's welds are required to be either tested or completely cut out and replaced. Thus, the reason that your 'local contractor' is terrified to have any more welds tested. At a 60% Reject rate, I'd be scared too.
One of the most expensive things on a pie job are 'cheap' welders. Hire the best ones you can find, and don't allow them to have very many Rejects. Historically, the big [huge] contractors will allow one Repair per month and ZERO cut-outs* during the life of the job/contract.
*cut-out means a weld with sufficiently big or numerous defects that cutting it out instead of repairing the defect.
RE: UT TEST RESULTS AND FLAWS
you must get smarter than the software you're using.
RE: UT TEST RESULTS AND FLAWS
RE: UT TEST RESULTS AND FLAWS
Mike McCann, PE, SE (WA)
RE: UT TEST RESULTS AND FLAWS
I agree with the posts above.
My motto: Learn something new every day
Also: There's usually a good reason why everyone does it that way
RE: UT TEST RESULTS AND FLAWS
problem is according to our project specification contractor has to perform ut test of 10% of joints and 100 of tie joints ,bends,golden joints and if flaw is detected he will rectify the flaw .my opinion is what will be the condition of remaining 90% if flaw rate is such high as 60% .in this regard our design engineer who set the specifications is also supporting contractors opinion
RE: UT TEST RESULTS AND FLAWS
Go past him, go to the next higher levels.
RE: UT TEST RESULTS AND FLAWS
RE: UT TEST RESULTS AND FLAWS
RE: UT TEST RESULTS AND FLAWS
RE: UT TEST RESULTS AND FLAWS
Steve Jones
Corrosion Management Consultant
http://www.linkedin.com/pub/8/83b/b04
All answers are personal opinions only and are in no way connected with any employer.