Incident XX-026 Severe corrosion NH3 transfer line

The Incident:
Severe corrosion of a carbon steel liquid ammonia transfer line to jetty. This line is intermittent in operation with operating temperatures varying between -33 degC and ambient temperatures.


The Cause:
Corrosion under insulation, not proper insulation.

The Consequences:
Potential ammonia leaks, which are not easy to be detected as line can be long (this case 1900 m)
Many repairs needed and complete replacement was required after some 20 years.

The Lessons Learned:
Perform regular corrosion inspections
Assure proper insulation
Install an ammonia leak detection

THE CAUSE OF CORROSION MAY BE DUE TO NOT PROPER INSULATION AND WHEN COLD AMMONIA SUPPLY FROM THIS LINE OUT SIDE MOISTURE CONDENSED ON IT .MOISTURE CONTAINS SOME SEA WATER VAPOURS ALSO.