Exploring cost-effective solutions to discharge pipe corrosion 

Most of the 5,000 exhaust gas cleaning systems installed in ships globally are open-loop scrubbers. Some of these systems have exhibited excessive corrosion in their discharge pipes. The issues with discharge pipe corrosion can occur in open-loop systems because of the sulphur oxides that are being carried in the discharge water. Exposed mild steel that is directly put in contact with high levels of this discharge water will suffer from accelerated and often aggressive corrosion. 

In some cases, this has led to leakages into the engineroom, forcing the vessel to stop the scrubber system entirely. Emergency repairs to the system can be costly. 

However, Wärtsilä Underwater Services in collaboration with AP Møller-Maersk has developed an innovative, cost-effective solution that can help shipowners avoid unnecessary and expensive emergency repairs (and the associated downtime). Veteran commercial diver and managing director of Wärtsilä Underwater Services, William Winters details how to address this problem, including the company’s newly developed pipe-in-pipe solution. 

“Maersk took it to the test and further drove the development of the solution for it to be executed on their fleet of vessels that use scrubbers,” said Mr Winters.