Oilfield safety is once again in the headlines and puts onboard fire safety deluge systems under scrutiny of the Health and Safety Executive.

It is imperative that the deluge system is allowed to discharge its water exactly where it may be required to fight fires. Unfortunately, this is not always the case.

On older assets, deluge systems were made of galvanised steel. The zinc has long gone since then, leaving mild steel pipes in regular contact with seawater. The results are huge and if left like that, heavy corrosion deposits would build up, until the deluge is either needed or tested. The size of the then dislodged corrosion product can block pipes and many deluge nozzles. In fact up to 85% of nozzles have been found to be impaired.

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

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