Ansi B31.3 Piping 1

[salohcin]

Normal practice is to radiograph pipe butt welds prior to hydrotesting. Is this a defined requirement as per Ansi B31.3 or is it as a general safety issue only?

 

[ApC2Kp]

salohcin,
If the piping is designed and installed per the ASME B31.3 Code, then there are examinations and leak tests required. For some other code besides B31.3 there may be other exam and test requirements. Most of the B31.3 fluid services will get a 5% random radiography of welds and a hydrostatic leak test. You want to do the radiography prior to hydro, so that any repairs to radiographed welds don't get you into another hydrotest of the complete piping system.
This is common sense, but the B31.3 Code states in Para.345.1 "Prior to initial operation, and AFTER (my caps) completion of the applicable examinations required by par. 341, each piping system shall be tested to ensure tightness. The test shall be a hydrostatic leak test in accordance with para. 345.4 except as provided herein."

 

[stanier]

Random radiography at 5% , if the welds are selected by the customer, basically means all welds will meet the code. The fabricator wouldnt want to repair a weld so would expect his welders to perform. Ergo its always good practice to select the welds for test yourself, else the fabricator will just show you the work of his top gun.

There are other methods of examination, dye penetrant, ultrasonic, magnetic particle etc. Dont forget the good lod visual examination of a weld. You can pick porosity, undercut etc from this alone. If you observe the welders preparing the weld, and every apss you will soon get to see which welds will be dodgy.

the highe rthe level of inspection the greater the cost but the better you will sleep at night.

 

[tickle]

I always ensure that the requirement for radiography/testing includes testing for welds done by each welder. If not I start asking questions.

 

[donf]

In defining the extent of examination required (for Normal Fluid Service), B31.3 341.4.1 (2) says "..... For welds, each welder's and welding operator's work shall be represented."

So not only is it good practice, it's required.

Donf

 

[Rolando68]

The specific requirment for RT is given in ASME B31.3 Paragraph 3.41.4.(b) which states: "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 production welding is included."

I will suggest you to read at least the whole paragraph 3.41.4

I hope this leads you on the right direction.