It is clear that discharge time of a deluge system is of critical importance in its operation, especially if it works in conjunction with a firewater ringmain. In the case of offshore firewater systems, the sequence leading up to the last nozzles discharging water is complex. Hitherto the estimation of the discharge time has not been possible and it has not been a requirement of the NFPA rules.
This document shows that it is now possible to estimate the discharge time, even in the case of an offshore firewater system. In this case we will assume that an elastomeric deluge valve is used. Similar principles apply with ‘clack’ shut type of deluge valves.