yes Dlew, you might want to extend inspection to welds in similar service /material /system to look for welding defects.
Have you already identified that there was some design /construction /welding deficiency?

Yes. If you have confirmed or strongly suspect Amine Stress Corrosion Cracking (ASCC) in piping after many years of trouble-free operation, the investigation should extend beyond the affected line. ASCC is often a plant-wide degradation mechanism rather than an isolated piping problem.

Yes there are changes in component /bellow OD and they are considered especially when:
Bellows are installed inside sleeves or guides.
There is insulation clearance.
Bellows are inside pressure vessel annular spaces.
External covers or shrouds are very close to the convolutions.

P5 is considered a very important Cr-Mo alloy for high-temperature piping. It fills the gap between carbon steel (which lacks adequate high-temperature performance) and higher-alloy Cr-Mo materials such as P9 (9Cr-1Mo) or P91 (9Cr-1Mo-V-Nb), which are chosen when even greater creep strength and ...

We have checklists available to perform this however not directly in system.
Even for MOC system, process workflow is all in SAP but not with the review & working lists.

For a PSV that has now shown this behavior three times. You must focus on gathering actual lift data like date /time of each lift, process conditions, flare header pressure (if connected to flare).
Trend simultaneously the PSV inlet pressure, flare header pressure, compressor /pump status, control ...

Yes that says all.

arcpro wrote: 19 Jun 2026, 11:08 This guide should cover all.
Metal_Dusting_Guide.png

Existence of thermal stresses is normally overlooked.
Examples include steam tracing، cyclic startup/shutdown, hot process line connected to colder branch, differential expansion between header and branch.
Repeated thermal cycles can cause thermal fatigue cracking, low-cycle fatigue, crack ...

The sound type itself can help.
Check if that is not rattling or metallic and instead humming, whistling or a low-frequency one.
This can be due to some high gas velocity passing through vane opening, support beams, nozzles.
And you may end up finding that nothing is mechanically damaged.

The fastest UDC damage usually occurs when MULTIPLE factors overlap simultaneously like there are deposits present, intermittent water, low flow/stagnation, oxygen ingress, chloride concentration, transient operations etc.
That combination can produce extremely rapid localized attack even while bulk ...