PetroStreet

A lot many learnings from the incident.
Steam service resulting in BLEVE from oxygen pitting corrosion impacting a repair location not complying with standard repair & inspection requirements.
Thought, would interest many.
We planned a separate session with our Inspection & Maintenance teams to discuss this incident. Participating engineers contributed on how such scenarios can be avoided. How the triggers can be picked up early as we identified the equipment at our location prone to oxygen pitting corrosion in steam generation.

https://www.csb.gov/assets/1/6/loy_lang ... _final.pdf

How well the cause has been pointed towards:

"The CSB determined that the cause of the explosion was deficiencies in Loy-Lange’s operations, policies, and
process safety practices that failed to prevent or mitigate chronic corrosion in its Semi-Closed Receiver and
Kickham Boiler and Engineering’s performance of an inadequate repair to the SCR in 2012 that left damaged
material in place. Contributing to the incident was the City of St. Louis’s missed opportunities to identify and
ensure the inspection of the SCR, Arise’s acceptance of and failure to detect Kickham’s inadequate repair, and
gaps in Arise’s and the National Board of Boiler and Pressure Vessel Inspectors’ repair inspection requirements."

The type of repair was approved by the repair inspector, who documented the 2012 repair as a code-compliant, permanent repair after witnessing the hydrostatic pressure test. The inspector accepted the repair by signing the associated repair documentation (Page 73).

Here, I could clearly observe that no matter what but an ITP having a Company Inspection personnel must also be involved.
And if it is not someone from Inspection, maintenance should get their best supervisor step forward to check or at least have the affected part inspected himself along with AI. Inspection & maintenance personnel working at the facility without a doubt have more information on the asset they have been inspecting & maintaining however when an AI is linked for such repair job, total responsibility of assessment and ensuring that correct recommendations are provided and implemented is with AI. Less frequent I have seen in my experience as well that when an AI is present at site, our own personnel cut in to verify things.
So just a thought here that plant personnel should be the people overlooking, assessing, and auditing the whole process of critical repairs of assets irrespective of an AI doing his job as per his own responsibility.