Rounded Indications vs Pinhole on Weld Surface

[Hansac]

Is a pinhole considered a "rounded indication"?

As per ASME VIII Division 1 Mandatory Appendix 8:
"Rounded indications: any relevant indication (it means if its major dimension is greater than 1/16 (1.5 mm) ) shall be considered rejected if it is greater than 3/16 in (5 mm)"

As per ASME VIII Division 2 Part 7:
"(2) Relevant rounded indications greater than 5 mm (3/16 in.)"

Case: A tube-to-tubesheet weld failed during tubeside hydrotest and later discovered this failure was caused by a pinhole on the tube-to-tubesheet weldment. Fabricator argued that the pinhole was acceptable as per Code since the pinhole was very much less than 5 mm, which was why the NDT technician did not report this indications.

I argued that any surface openings has to be investigated and removed.

Appreciate your opinions on this.

 

Is a pinhole considered a "rounded indication"?

Not speaking as an inspector, but I would say the open indication qualifies as rounded if you can see the bottom of it. If you cannot, further exploration (or immediate remediation) is necessary.


"Everyone is entitled to their own opinions, but they are not entitled to their own facts."

 

[david339933]

Non rejectable indications shall be reported.

I argued that any surface openings has to be investigated and removed.

Not going to see much more than surface defects with this NDE.

 

[weldstan]

A pinhole is a rounded indication but need not be reported as such if <or= 1/16" diameterr. Since the joint failed hydro the NDE ispecyor should know that tube to tube sheet sigle pass fillet weld and seal weld joints are rather susceptible to leakage due to pinholes especially at the tie in location.

 

[weldstan]

I would add that in my engineering/purchasing specs, pin holes were not permitted on tube to tube sheet welds.

 

[JR97]

Appendix 8 paragraph 8.3(b) defines a rounded indication as an indication having a length to width ratio less than 3:1. Keep in mind Appendix 8 is PT criteria. The 1/16 and 3/16 dimensions mentioned are the size of the bleedout, not the size of the visible pinhole. If the pinhole has significant depth, the bleedout size will be quite a bit larger than the visible pinhole.

JR97

 

[DVWE]

Hansac,

Have a read of UW-38, and also, have your client read it.

The devil is in the details; she also wears prada.

 

[r6155]

The type of defect does not matter. All defects must be repaired and again undergo hydraulic testing.

Regards