Augmenting Fire Standpipe Systems
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Transcript Augmenting Fire Standpipe Systems
Augmenting Fire
Standpipe Systems
Importance of
To provide independent and
redundant primary or secondary
water supply.
Floor outlets eliminate the need
to stretch hose lines from the
pumper to the upper floors or
deep inside a larger area building.
Principles
To properly supply a standpipe
system, the following principles
are involved;
Nozzle pressure and friction loss in the
attack line,
Head pressure due to elevation,
Friction loss in the system,
Friction loss in the supply line from the
pumper to the FDC.
FD Operational Variations
Fire Department Variations:
Attack and Supply lines;
Some FD’s use a smooth bore or a
combination (fog & straight stream) nozzle
with 1 ½”, 1 ¾”, or 2” hose with lengths up to
150’,
Some FD’s use 150’-200’ of 2 ½” hose with
a smooth bore or a combination nozzle,
Some FD’s use a short length of 3” hose off
the outlet, then connect a gated wye,
Different strokes for different folks
Some FD’s use 50’ of 2 ½” hose to a gated
wye, supplying two 100’ lengths of 1 ½” – 2”
hose with combination nozzles,
One large metropolitan FD use 3 ½” hose
with 3” couplings to supply the FDC,
Some FD’s use LDH with Storz couplings to
supply the FDC or as a temporary backup for
the system,
Storz
Connections
LDH used as replacement to system
Reasons for use:
1.Damaged, inoperable
or defective standpipe
system.
2. Pressure Restricting
Valves or Pressure
Reducing Valves (PRV’s)
that cannot be
overridden.
3. Heavy volume of fire
requiring greater fire
flow.
Hypothetical Situation
Scenario
Fire is on the eighth floor of a high rise.
For the purpose of this presentation, we
will assume the use of 200 ‘ of 2 ½” hose for
the attack line, with a 1 1/8” smooth bore
nozzle.
Supply to the FDC is two individual 50’
lengths of 2 ½” hose.
Hydraulics
Attack Line using a Smooth
Bore 1 1/8” nozzle with 50 psi
nozzle pressure.
Formula: GPM= 29.7*(D2)*Sqrt of the Nozzle
Pressure.
29.7*1.265652*7.0710678= 265.8 (266 GPM)
Friction loss in attack line of
200’ of 2 ½” hose:
Formula per 100’: FL= C*Q2 / 10000
2 * 2662 /10000 = 14.1512 * 2 =
28.3024
Friction Loss 200” 2 ½” hose= 28 psi
Elevation (head pressure):
5 psi per floor * 8 floors =
Elevation = 40 psi.
Friction loss in the standpipe
system:
Friction loss in system = 25 psi.
Note: With the various size of riser pipes, (4”, 5”, 6”) it is a
generally accepted practice to use 25 psi friction loss in the
system to make it easier to calculate desired engine pump
pressure.
Friction loss in two individual 50’
lengths of 2 ½” hose supply line;
Formula per 50’: FL = C*Q2 / 2 / 10000
2* 133/2/10000 = 1.7689
Friction Loss in Supply line = 2 psi
Calculations
Nozzle Pressure (50 psi nozzle)
Friction loss in attack line
Elevation
Friction loss in standpipe system
Friction loss in supply line
Total
50 psi
28 psi
40 psi
25 psi
2 psi
145 psi
Engine Pump Pressure = 145 psi
General Operations
To ensure adequate water:
Supply the system from two pumpers, if
possible,
If the system has interconnected standpipe
FDC, supply them both,
If only one FDC present, supply 1st floor
hose outlet with additional line,
If building is equipped with a separate
sprinkler and a standpipe system FDC, supply
the standpipe first.
Supply the Standpipe 1st
If the standpipe is equipped with
pressure-reducing hose valves, the valve
acts as a check valve, prohibiting pumping
into the system when the valve is open,
A supplementary single-inlet FDC or hose
valve with female threads at an accessible
location on the standpipe allows pumping
into that system.
Operations
Engine Co. Chauffer
Test the hydrant before connecting, let
Engine Officer and/or IC, know if the hydrant
is not operational, thereby causing a delay in
supply,
Try to keep supply line to FDC not more
than 100 feet,
Remove kinks and sharp bends,
Supply the FDC with the largest available
hose,
Increase pump pressure slowly to avoid
pressure surges at the nozzle.
Use at least two supply lines to FDC if;
more than one attack line being used
from the standpipe or,
indications from attack crew not enough
water volume or pressure.
Use the floor outlet(s) to supply the system
if;
leak in the piping at any point below
grade allowing water to drain off,
foreign matter pushed in the FDC,
FDC inoperative.
FD Connection
FDC
Safety consideration:
Do not put your hands in the FDC to clear
debris out, because it may have the presence
of:
broken glass,
sharp metal,
used drug needles.
Cans, bottles, balls,
metals and drug
needles have been
shoved into FDC
Difficulties may be encountered with FD
connections.
These difficulties may include:
missing caps,
defective or incompatible threads,
debris stuffed into the connection,
tight caps,
female swivels out-of-round,
frozen female swivels,
and clappers either broken or jammed
open.
Many FDC’s are equipped with either
metallic or plastic vandal proof caps,
these caps are usually attached with
screw eyes placed over the pin lugs on the
female swivel,
both metal and plastic caps are removed
by striking the center of the cap with a tool,
caps can also be removed by prying one
of the screw eyes off the pin lug.
Some FD’s use security caps, responding via
mutual aid, without the key, you will not be
able to remove the cap……..
therefore, you will have
to supply the system
through floor outlets.
Knox
registered FD ‘s
should request
extra keys for
their mutual aid
departments
FDC Plug
Key
Summary
Test hydrant before committing,
Use largest adaptable hose to supply system,
Don’t put your hands into FDC,
If FDC is inoperative, don’t waste time, supply
system thru floor outlet(s),
If supplying floor outlet(s), remember proper
fittings,
If your FD has security caps/plugs, make sure
responding FD’s have keys provided to them.
Prepared by Thomas Bartsch
Chief Fire Inspector (ret)