FRNSW pump performance for high rise buildings
FRNSW requires any fire brigade booster assembly installed on a fire hydrant system serving a high-rise building to be commensurate with the design and its required fire brigade boost inlet pressure.
AS 2419.1–2005 Fire hydrant systems
Where a building has an effective height of more than 50 m, Clause 7.7 of the Standard requires a ‘fire brigade relay pump’ to be installed for the pressure zone/s above 50 m. For pressure zone/s located below 50 m height, the minimum boost inlet pressure applied by the fire brigade pumping appliance will be that required to provide 700 kPa to the applicable fire floor.
Note: The boost pressure signage for parts of the building below 50 m should identify the boost pressure value that provides 700 kPa at the hydraulically most disadvantaged fire hydrant outlet in the upper most pressure zone that is below 50 m.
For pressure zone/s above 50 m, the fire hydrant system pipework should be designed on the premise that the FRNSW pumping appliance will provide 950 kPa to the inlets of the fire brigade booster connection that is supplying the fixed on-site fire brigade relay pump. This input pressure should be used to size the relay pump so that it can deliver not less than 700 kPa to the hydraulically most disadvantaged fire hydrant outlet in each pressure zone above 50 m.
Note: The boost pressure signage for parts of the building above 50 m should identify a maximum boost pressure value of 950 kPa for input to the relay pump, which approximates 1,000 kPa output from a standard FRNSW pumper, less hose friction losses.
AS 2419.1:2021 Fire hydrant systems
Where a building has an effective height of not more than 135 m, the fire hydrant system (including pipework) is to be designed so that the pressure provided at the inlets of the fire brigade booster connection by a FRNSW pumping appliance will provide not less than 700 kPa at the hydraulically most disadvantaged fire hydrant outlet in each pressure zone. However, when the fire hydrant system is commissioned, the pressures detailed in Table 12.4.3 of the Standard may be applied.
Where a building has an effective height of more than 135 m, a performance solution must be developed in collaboration with FRNSW to ensure that the fire hydrant system facilitates the needs of the fire brigade.
Note: A PN 35 rated fire brigade booster connection with PN 40 high pressure Storz fittings is required for the high-rise ring main, particularly for redundancy during building construction.
Updated: 5th December 2024