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)