At a time when oilfield safety is again in the headlines, onboard fire safety deluge systems are coming under some scrutiny by the Health & Safety Executive. As you can imagine, it is imperative that the deluge system is allowed to discharge its water exactly where it may be required to fight fires. You may imagine this would always happen, but not so.

On older assets, deluge systems were fabricated from galvanised steel. The zinc has long since gone leaving mild steel pipe in regular contact with seawater. The results of this are major and if left heavy corrosion deposit build-up inside can occur, until the time comes when the deluge is either needed or tested and the corrosion falls off under the force of the water. The size of the dislodged corrosion product can block the pipe and many deluge nozzles – in fact up to 85% of nozzles have been found to be impaired.

A solution has been developed by Corrosion Solutions that is very safe and practical to implement. A mild organic acid (harmless to human skin and non-metallics) is used to fill each deluge system in turn (one at a time) and left usually 12 hours to soak. The solution is drained for re-use and the deluge system back flushed with seawater, removing up to 85% of the original corrosion product. The deluge system is then reinstated and tested.

The system is then fogged or flushed with a seawater compatible corrosion inhibitor. Both the rust remover and the corrosion inhibitor are from Cortec. The fogging process is carried out after every deluge use or 12 monthly and can help identify which, if any, nozzles may be blocked.

Corrosion Solutions can be contacted in Aberdeen, UK, on +44 1224 772694 or referencing DELUGE.