Selection guide for Fire water: hydrant, sprinkler & fire pumps

Start from the occupancy, not from a favourite head. IS 15105 groups the risk as light, ordinary or high hazard. Light hazard (offices, hospitals, schools) typically uses a lighter design density and a smaller remote area than ordinary hazard (manufacturing, parking, retail). High hazard, including storage, needs the higher density and the matching orifice. The temperature rating follows the ceiling temperature: ordinary 68 °C or 79 °C unless the roof or a process is hotter. Keep the sprinkler type (pendent, upright, sidewall) matched to the ceiling and the obstruction. Heads and the 25 NB branch are counted per floor. The pump and the tank stay on the remote design area, not on the whole building area.

The jockey only makes up leakage. It must meet the duty flow and a head from the duty up to 15% above it. A pump that is far above the duty head is not a match. Where the catalogue has no fitting pump, the line stays price on request.