Tank Container Operations: Risk Mitigation Strategies

Tank containers play a vital role in the global supply chain by safely transporting liquids, powders and gases. However, corrosion and pitting damage has increased in recent years, leading to safety issues and higher repair costs. This article summarises key risks for tank container operators and strategies to mitigate them.

Causes of Pitting Damage 

Pitting corrosion occurs when the protective passive layer on stainless steel is damaged, exposing the metal underneath to corrosion in an oxygen-deprived environment. Moisture ingress, product overheating, high ambient temperatures and delayed cleaning after discharge can all contribute to pitting. Proper compatibility assessment before transport and close operational control during transit are essential.

Inspecting and Repairing Damage 

When pitting is discovered, operators should first map its location, type and depth. Grinding and polishing can remove pits, but this process needs careful guidance. Advanced non-destructive testing methods like electromagnetic testing can accurately detect pits missed by visual inspections and guide repairs. Passivation treatments should follow to reinstate the passive protective layer.

Mitigation Strategies

• Conduct thorough product compatibility assessments before accepting cargoes
• Define and implement special handling requirements to control moisture, temperature etc.
• Select optimal routes to enable timely cleaning at discharge
• Upgrade component materials (e.g. foot valves) for better corrosion resistance
• Inspect tanks swiftly after discharge and initiate cleaning

With vigilance and adopting best practices, tank container operators can reduce safety hazards and costs related to pitting damage over their assets’ lifetime. New technologies for testing and material upgrades also show promise for further enhancing resilience.