Testing Weld Integrity for Butt-Weld Pipe Fittings

[jcash1]

I am designing a piping system for a hydraulic power unit (HPU). One leg consists of 3" S160 piping operating at 3,195 psi. Another is comprised of 1 1/2" XXS piping operating at 4,150 psi. Both legs incorporate A106 Gr. B pipe with full penetration butt-welded fittings (i.e. elbows, tees, caps, concentric reducers, weld neck flanges, & weld-o-lets). I do not have a specific code to go by as far as testing procedures for the integrity of the welds. I was wondering what the best method of testing would be for this situation (e.g. UT, X-ray, magnetic particle, 1.5 times pressure test, etc). Any help would be much appreciated.

 

[metengr]

Why don't you use ASME B31.3 Process Piping for guidance? At these pressures and for butt welded connecitons I would perform radiographic testing (x-ray) of a select group of welds followed by hydrostatic testing after all piping is assembled.

 

[jcash1]

Thanks. Which code would better pertain to this application, ASME B31.1 or B31.3?

 

[metengr]

Well, if you read the Introduction, B31.1 is Power Piping, and deals with piping design/fabrication in steam plants. The Process Piping is probably more applicable for your situation because it has a section devoted to high pressure piping (see Chapter IX).

 

[Zapster]

X-ray weld inspection for B31.3 will be required to be in accordance with BPV code, Section V, Article 2.

You may want to consider using API 1104 for weld inspection criteria.