ETL 1110-3-484
26 Sep 97
includes sprinkler, nozzle, detection, control, AFFF concentrate, proportioning, and etc. Include
detailed descriptions of sprinkler systems in terms of applicable sprinkler types, spacing
limitations, and etc. As applicable, include reference to other disciplines where related systems
are described. For example, refer to applicable civil site utility portions of the analysis for
description of water storage, distribution, and etc.
5.2 Water Supply/Demand Analysis. Hangar fire protection systems typically have high water
demands, in terms of water quantity and pressure. It is not unusual for such systems to have
water demands for sprinklers and nozzles in excess of 18925 L/min (5000 gpm) at pressures of
862 kPa (125 psi). To assure adequacy of water supply to meet such demands, the designer must
perform a detailed hydraulic analysis. This will compare the system demand with the supply and
identify system adjustments necessary to assure that all applicable design parameters will be met.
Include an exterior hose stream demand of 1893 L/min (500 gpm) where the water supply for the
building sprinklers and nozzles also supplies hydrants available for use by the fire department.
5.3 Hydraulic Calculations. Calculations in the absence of a specific design will constitute, at
best, rough approximations. While such approximations may suffice for the concept submittal,
subsequent submittals need to include calculations based upon an actual layout of discharge
devices and corresponding piping configuration.
5.3.1 Computer Software. Perform hangar fire protection system hydraulic calculations using
recognized fire protection software. The "HASS" (Hydraulic Analyzer of Sprinkler Systems) is a
recognized hydraulics program used by many contractors and fire protection design firms. This
program is taught in PROSPECT Course, "Fire Extinguishing System Design"and should be used
by Corps of Engineers offices performing or specifying fire protection systems for aircraft
hangars.
5.3.2 System Sketch. Include in the design analysis (not the contract drawings) a sketch
representative of the overall fire protection system. It should show all pipes and nodes in the
sprinkler, nozzle and underground water distribution systems. Assure that the sketch corresponds
to what is indicated on the project drawings as well as in the hydraulic calculations.
5.3.3 Hydraulic Reference Points. Identify all hydraulic reference points (nodes) in the piping
system being calculated. Include elevation and pressure at each node in the system. For
discharging nodes, indicate the k-factor and flow.
5.3.4 Pipe Segments. Identify all pipes in the system and indicate the two nodes to which each
pipe is connected. Include the diameter, length, number and type fittings, equivalent length,
friction loss per foot, flow, velocity, total friction loss in the pipe segment, Hazen-Williams
coefficient, and etc. As permitted by computer software used, label pipe segments as "strainer,"
B-3
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