Full Scheme (For general information of the tenderer)
1 (One) No. Fire Pump Hydrant 1 (one) No. jocky pump ( each electric motor driven) and 1 (one) no. Diesel Engine driven Fire Pump shall be installed in the pump room, pumping water from the underground water tank. The common outlets of fire pump delivery system shall cater to the following:
At the top of each Wet Riser an Air Vessel assembly with Air Relief Valve, a Drain-valve, pressure gauge etc shall be provided to take care of pressure surges and also for letting out entrapped air in the system.
Fire Hydrant System & Sprinkler System
Water supply header and main pipe up to hydrant valve/landing valves shall be kept pressurised by the jockey pump which shall start automatically on receiving the impulse from the pressure switch in case of any pressure drop in the header. It shall stop at a preset pressure as soon as pressure builds up in the header.
For smaller fires, first aid hose reel would be used; while hydrant valve would be used for bigger fires. In the event of fire out break, opening of hydrant valve/hose reel will result in fall of pressure in the header and electric motor driven fire pump shall come into operation automatically through the impulse from the pressure switch. The fire pump shall be stopped manually only. In case the electric driven main fire pump fails to start; the diesel engine driven pump shall come into action automatically on further fall of pressure and receiving impulse from pressure switch.
The setting of the pressure switches shall be done keeping the above sequence in consideration.