Is it acceptable for a company to nominate ASME B31.3 as the design and fabrication code for a piping system and then specify less than 5% for the minimum RT requirements.?
The majority of the piping will be classified as Normal Fluid Service Piping,
Thanks and regards,
Ballbearing

Ballbearing,

Yes, it could acceptable to replace RT by UT, or by in-process examination:

(1) Not less than 5% of circumferential butt and
miter groove welds shall be examined fully by random
radiography in accordance with para. 344.5 or by random
ultrasonic examination in accordance with para.
344.6. The welds to be examined shall be selected to
ensure that the work product of each welder or welding
operator doing the productionwelding is included. They
shall also be selected to maximize coverage of intersections
with longitudinal joints. When a circumferential
weld with an intersecting longitudinal weld(s) is examined,
at least the adjacent 38 mm (11⁄2 in.) of each intersecting
weld shall be examined. In-process examination
in accordance with para. 344.7 may be substituted for
all or part of the radiographic or ultrasonic examination
on a weld-for-weld basis if specified in the engineering
design or specifically authorized by the Inspector.

Hello Dr Koelbl,
My apologies for not responding sooner.
The reason was I have only just finished on the project that was the reason for my initial question.
The company in question stated that in some cases for B31.3 NFS there would be 4% RT and in others 2% RT with this percentage being relaxed further if results were acceptable.
This does not comply with the minimum 5% required by the code.
There was no substitution with UT or "In Process Examination" as you noted.
Can the company still claim to have designed and fabricated to ASME B31.3 if this is the case ?
Regards,
BB

Hi, Ballbearing,

what are you doing when the cops pull you over for speeding: you claim that it was not that fast, that you did not see the signs, the car is new to you, at home the limit is higher and so on, right?

I would kindly ask the manufacturer for the paragraph allowing such reduction, after asking them if it is a Category "D", or "M" or maybe "cyclic service", which is also important.

And by the way, it is not 5%RT, it is 5% of all welds, per welder.
If you have 10 welds, welded by two welders, 5 each, you got to RT 2 complete welds, which is 20%!!! rather than 5!
Now do the same for 2 welds, 1 from each welder, and you end up with 100%.
i just like simple math.

DK

Thanks you for the post.
Hi guys, Im a newbie. Nice to join this forum.

__________________