API Publ 2376:1998 pdf download.Prepared for the Health and Environmental Affairs Department
by the Finance, Accounting and Statistics Department.
The pipe nipwred as a result of being subjected to excessively high temperature and not being properly depressured. per emergency procedures. Cause for the excessive temperature was a very high rapid temperature excursion4 which started in catalyst bed 4 of Reactor 3 in Stage 2 of the hydrocracker. Although. no single or conclusive cause for the emperature excursion could be determined after the explosion, all possible causes for the temperature excursion were identified. Possible reasons identified for the temperature excursion include: spontaneous formation of a “hot spot” in bed 4; the flow characteristics of fluids in bed 4; or the possibility of uneven liquid distribution within the bed.
A contributing cause for the pipe rupture was that the operators did not depressure the unit as specified in emergency procedures for safely controlling temperature excursions. Reasons for the operators not depressuring the unit include: the incident occurred very rapidly and was Outside previous experiences; they did not believe the control room temperature indicators; and they were confused and distracted by process information which was inconsistent with past temperature excursion experiences.
Corrective actions were identified to respond to the possible causes for the reactor emperarure excursion. These actions include installation of new controls which will automatically depressure the unit in the event of a future high temperature excursion, and retraining of operations personnel.
API Publ 2376:1998 pdf download
