Vessels experiencing scrubber corrosion issues
18-05-2021
It has been a year since the new IMO 2020 regulations were enforced leading more than 4.000 vessels to install an Exhaust Gas cleaning system, also know as a Scrubber. In that year we have experienced an increasing demand for repair and protection solutions for Scrubber systems on the market. What we see is both corrosion damage throughout the exhaust gas cleaning systems as well as a need for repair solutions on the GRE/GRP pipes transporting the wash water.
Scrubber Tower
The corrosion is catalyzed by the combination of SOx and other smoke particles, combined with the sulphuric acidic seawater and the water temperature.
This causes the highly corrosive cocktail to leave a trail of corrosion from its origin inside the scrubber tower and as far as along the outside of the hull.
The weakest link
When lower-grade steel is used, even as a small component, in an otherwise high-grade steel and stainless-steel system, this will become the weak link and causing serious corrosion, and in this case as fast as after only 3 months in operation.
By coating these elements using Wencons Protective Coatings we thereby separate the steel from the wash water and eliminate the issue.
Overboard outlets are often such a weak link.
Many of the cases we see, concerns failures of overboard outlets. When a new overboard outlet has to be installed we recommend a 600-micron layer of protective Wencon Hi-Temp Coating.
We have also seen cases where the corrosion had been discovered before the damage was too extensive, in these cases the outlet could be rebuilt and coated for future protection.
Overboard Hull protection
The hull is likewise exposed to the corrosive flow around the overboard outlets.
Shipowners are recommended to apply a protective coating in a 2 m diameter around the outlets, we recommend Wencon Hi-Temp Coating, which offers high resistance to the contents from the scrubber wash water.
After the application, the area is finished off with ship’s own paint and will provide increased corrosion protection.
GRE Scrubber Pipe Repair Kit
GRE pipes have proven the most resilient to the Scrubber wash water, but when they crack or disconnect because of pressure failures, or i.e., welding damage, a good and fast solution has been in high demand.
We have successfully supplied several hundred vessels with a specific GRE pipe repair kit, using our well-proven method of wrapping the section of damaged pipe with interchanging layers of fiber reinforcement tape and Wencon UW Coating.
The Wencon UW Coating makes it possible to start the application of the coating to the pipes when the area is still wet. This allows for the vessel to be back in operation 8-10 hrs. after the application has been completed.