Jessica Moncado - Petropiar Upgrader
As a case of study in this research is shown a coke drum that is operating since 2004 suffering several bulging and cracking at an early age. A bulge severity analysis was performed in 2015 finding high values of severity, in addition on June 2016 an ultrasonic test was made around the circumferential welds and several cracking was found. With the results of this inspection, a crack like flaws assessment was performed according to the API 579, establishing that a particular crack on the drum was already on its critical depth. Two months later during an operational window, that crack was re-inspected using ultrasonic testing and it was near to become a through wall crack. Due to this situation, a short-term plan was proposed, which consider putting an external weld overlay patch around the crack extension to arrest it, in order to prevent a not planned shutdown. The weld overlay was applied and the crack was contained successfully until today.