A system for combating fires inside the building that uses down comer mains with an internal diameter of at least 100 mm, terrace pumps, gate valves, non-return valves, and landing valves on each level and landing, connected to the terrace tank. Additionally, it is equipped with ground-level inlet connections and a roof-level air release valve so that it can be charged with water by pumping from fire service equipment.
Depending on the area and height of the structures, the wet-riser system should consist of a pipe or a number of pipes. With branch pipes, landing valves, hose reels, hoses, etc. at every floor level. a provision for a pressure differential switch to activate the pump immediately as soon as water is pulled from hydrant landing valves, producing a drop in pressure, making water under pressure available for functioning hydrants, hose reels, etc. A backup pump is also built into the system, which will start working automatically if the primary power source fails.
Underground, at ground level, or at a higher level should be provided water reservoirs to supply the fire hydrant system. It is a horizontal pipeline that is joined to an underground water tank via a 63 mm-diameter outlet. Courtyard hydrants are required to have stand posts, per the quantity schedule. For the hydrants to operate quickly there should be a sufficient supply of hydrant accessories, such as hydrant standpipes, hydrant key and bar suction collecting heads, delivery hoses, branch pipes, and nozzles, etc.