Arc Strike on pressure vessel

[faiswish]

Hi brilliant guys,
Requires your help to sought out the problem, Welder has accendantly touched the heat treated vessel by air arc gouging of SA-517-F quenched and tempered steel and the gouged is deep about 10th of the base metal thickness. What would be the repair procedure, should I just blend it off and MPI if the thickness is not less than the required thickness and leave as it is, or by using the temper bead weld procedure fill up to the actual thickness.

Thank you!

 

[racookpe1978]

quenched and tempered, then arc-gouged 1/10 deep?

No. Definitely do NOT just blend the gouge out.

Length, width, depth of the gouge?
Show a photo>
Pressure, temperature, service life of the pressure vessel?
Wall thickness of the base metal at the gouge?

 

[metengr]

If the depth does not fall below minimum wall thickness, I would blend grind followed by wet fluorescent MT and portable hardness testing to ensure no softening in surrounding vessel base material.

If the gouge after blend grinding falls below minimum wall thickness, you can use Appendix 32 in Section VIII, Div 1 to evaluate a locally thinned area (LTA).

If the area needs to be weld repaired, you can do this in accordance with ASME Section VIII, Div 1 requirements. Temper bead is only an option if this vessel is in-service.

 

[EdStainless]

If you end up grinding this back you need to perform field metallography to assure that you have actually removed all of the damaged material. The change in microstructure and properties may go a lot deeper than the actual gouge.

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Plymouth Tube

 

[Cleandive]

Alternatively you may use UW 42 of ASME Sec VIII Div 1

UW-42 SURFACE WELD METAL BUILDUP
(a) Construction in which deposits of weld metal are applied to the surface of base metal for the purpose of restoring the thickness of the base metal for strength
consideration; shall be performed in accordance with the rules in (b) and (c).
(b) Procedure Qualification. A butt welding procedure qualification in accordance with provisions of Section IX shall be performed for the thickness of weld metal deposited, prior to production welding.
(c) Examination Requirements
(1) All weld metal buildup shall be examined over the full surface of the deposit by either magnetic particle examination to the requirements of Mandatory Appendix 6, or by liquid penetrant examination to the requirements of Mandatory Appendix 8.

 

[faiswish]

Hi racookpe1978,

This is in-service vessel removed from the service for the periodical inspection.
It is UHT horizontal highway LPG unit; thickness required .367", MDMT -20 F @ 250PSI, MAWP 250 PSI @ 115 F.
Two gouges 3/8" in dia .0360" deep and 3" apart on the mid section of the shell bottom half oriented about 7:OO.
Wall thickness of the base metal at the gouge .330"
Unfortunately I don't have the picture.

[li]I would like to go as "metengr" said this way it covers mechanical properties[/li].