Abstract
With new advancements in the petroleum refining processes, the need for monitoring of corrosion on the new and old systems is also transforming. This paper describes the experience gained in monitoring of stagnant and low flow lines of a refinery in Kuwait After witnessing a failure in one of the de-salter relief lines of the crude distillation unit, a comprehensive plan was prepared to identify and address similar cases in the entire refinery which was a major challenge.
This paper describes the probable causes and the adopted remedies for the localized corrosion observed in the insulated de-salter relief line. Circumstantial evidence and failure morphology were studied in arriving at the root cause for this failure. Although, samples of the pipe showed signs of aggravated external corrosion at the failure location after removal of insulation, the reason assigned for the failure was due to under-deposit corrosion mainly on the pipe internal side.
Based on the findings and experience gained from the above case, an advanced Non Destructive Testing (NDT) e.g. Long-Range Ultrasonic Testing (LRUT), profile radiography etc. methodology for the monitoring of other stagnant and low-flow was prepared and is currently under implementation.
