Hydraulic Analysis of Fire
Sprinkler and Hydrant Systems
The ACADS-BSG computer
program HYENA can be used to analyse automatic fire sprinkler systems with
a simple end, side or centre fed configuration or more complicated looped
and gridded systems. It may also be used to analyse fire hydrant and hose
reel installations or combined sprinkler, hydrant and/or hose reel systems
or any other systems where the discharges can be represented by a k factor
and minimum flow. With a given sized network the program performs a complete
hydraulic analysis determining the water flow in, and pressure drop though,
each pipe in the entered network taking account of all fittings entered
by the user.
Main Screen of HYENA
The main features
of the program are:-
- The program is
capable of analysing looped and gridded systems as well as the more
conventional tree configurations.
- The program can
be used to carry out a sprinkler system analysis in accordance with
NFPA, NZ4541, AS2118 or SSPC52 or to carry out an analysis of hydrant
systems with or without hoses or hose reels
- The piping system
can have up to 10 input points and `these can be modelled as a fixed
pressure, a town mains water supply or a pump
- The program can
work in a wide range of units including Metric and British or US and
uses the Hazen-Williams formula for the hydraulic analysis.
- The program operates
under WINDOWS and all input data is via a series of screens with numerous
features including drop down lists, selection lists, various sort options,
etc; to facilitate easy data input.
- All nodes that
are not nominated as discharges, or input points are automatically assigned
as reference nodes to save input, the user only having to assign elevations.
- Piping materials
complying with a wide range of codes are catered for including light
medium and heavy steel, cast ductile iron, and copper piping to Australian
or New Zealand Standards, and API piping codes, selected from a drop
- When pipe sizes
are entered as nominal sizes the program determines the actual I.D.
from data stored in the program for the different pipe materials. The
user can however add to this list by entering their own pipe materials
and associated internal diameters.
- On the Pipes entry
screen, columns can be sorted in ascending or descending order, particular
pipes or nodes can be found, and a global change check box allows global
changing of pipe diameters or lengths
The Pipes Data Entry Screen
- A wide range of
fittings are provided for with equivalent lengths stored in the program.
A facility is also provided for users to add to this with their own
fittings and associated equivalent lengths or to modify specific fittings
by entry of alternative equivalent lengths.
Booster pumps can be located anywhere in the network. Back flow preventers
can also be included and check valves can be made to restrict flow to
one direction in a given pipe.
The Fitting Selection Screen
- The program can
be used to determine the design point (required flow and head at the
input point) given the k factor and minimum discharge of each sprinkler
head or hose reel. Alternatively a pump or water supply characteristic,
or a fixed pressure can be entered for one or a number of input points,
and the program then determines the water flow from the discharging
heads or nozzles and the operating point on the entered water supply
or pump flow characteristic curve(s)
- Provision is made
for gridded layouts to be entered easily. This grid can contain one,
two or three main pipes with range pipes between and branches to the
left or right as required. Any number and arrangement of sprinklers
on the grid can be made operational and the program can find the least
favourable position of these operating heads across the grid if requested.
Nodes and pipes are automatically numbered when the grid facility is
used and various options are available for quickly
A Grid with two Main Pipes,
Ten Range Pipes and 14 Operating Sprinklers
- A graphical display
of the grid is provided and on this the user can elect to display pipe
numbers, node numbers, pipe diameters or lengths.
- In a Grid, sprinkler
elevations can be fixed at a given height, entered individually across
a grid row or entered as a single slope or pitched slope across the
grid row. These can be used in combination and row elevation are automatically
duplicated in subsequent rows up the grid until the next row elevation
- The grid commands
can be converted into the longhand detailed individual pipe and sprinkler
specification thereby enabling modifications to be made to the basic
- Range checks are
carried out on all input items as they are entered and rigorous cross
checks and other checks are made with a validation button that is red
when there are errors and green when there are no errors.
Setting the Elevation for
a Gridded System with Rising Main Pipes.
Selecting the Operating
Sprinklers in a Gridded System by Windowing the Required Heads
- The calculations
use a process of matrix inversion to solve the differential equations
for each loop in the system and this method is not only very fast but
also very reliable allowing very large systems to be analysed.
- The results include
a Summary of the flows and pressures for all discharges and for all
input points. This is followed by a detailed table of Pipe information
including the total equivalent length, pressure drop, etc., for every
pipe in the system and a detailed table of Node information. This includes
the pressure at each node and the flow if the node is a discharge or
input point. The total volume of the piping system in litres is also
- For design estimating
purposes the program can also determine quantities in the system including
pipe lengths and numbers of fittings categorised by pipe material type
The Summary Results