Hydrant type Fire Protection System essentially consists of a large network of hydrant valves – both indoor & outdoor. The hydrant network is divided into different ring mains, each serving various parts of the entire plant. All ring mains shall be suitably interconnected. The ring mains shall be provided with adequate number of isolating valves with valve chambers to obtain the best possible pressure at the seat of a fire. This will also enable isolation of any damaged portion of the network when required. The hydrant mains shall be buried piping, with external hydrants and risers for various areas & building.
The hydrant network in the entire plant shall be sized and analyzed to ensure that about 7.0 bar (g) pressure is available at the hydraulically remotest point (as per OISD) in the system with the hydrant pump discharging at rated head and capacity. The velocity in the hydrant main shall not exceed 5 m/s.
Each riser in the building is be provided with an Air Release valve at the highest point and a drain valve at the lower most point.
The working pressure of entire firefighting system should be maintained at 8.8 bar (g). All Firefighting system components and systems shall be designed for 1.3 times of working pressure and the hydraulic test pressure shall be 1.5 times of design pressure.
