In-service Inspection of Welds in Atmospheric Ammonia Storage Tanks

摘要

Traditional intrusive inspection of ammonia storage tanks requires decommissioning of the tank,rncostly downtime and oxygen ingress inside the tank. This paper summarizes Yara’s non-intrusiverninspection process including the description of a novel technique for in-service inspection of doublernwall ammonia storage tanks. This novel inspection technique consists in an inspection robot equippedrnwith ultrasonic probes. The robot is deployed through the manhole of the outer tank into the externalrnsurface of the inner tank shell. Remotely controlled, it scans the inner tank welds looking for cracks.