Fire Hydrant Wet Riser System

Were risers are a form of internal hydrant for the fireman to use and are always pressurized with water. Wet risers are only required for buildings where the topmost floor is higher than 30.5 meters above the fire appliance access level.

Wet riser system comprises duty fire pump with standby pump discharging into a 150mm diameter riser pipe with landing valves at each floor and to which canvas hose with nozzles cab be connected to direct the water jet at the fire. A jockey pump is usually provided to maintain system pressure. For high rise buildings, each stage of the wet riser should not exceed 70.15 meters.