Fire main pressure
With the two pumps simultaneously delivering through nozzles , the quantity of water, through any adjacent hydrants, the following minimum pressures are to be maintained at all hydrants:
- vessels of 6,000 gross tonnage and upwards: 0.27 N/mm2 (40 psi)
- vessels of 1,000 gross tonnage and upwards, but under 6,000 gross tonnage: 0.25 N/mm2 (37 psi)