Day 2
FM Global Property Loss Prevention
Seminar II
Mumbai, India
So far yesterday
Covered hazards relating to plastics in
construction and not to take test results at
face value. Half the battle is won if building is
non-combustible, i.e. passive protection is
always better
Looked at Fuel Safety Controls to ensure your
process using heat transfer operations do not
result in an explosion
Discussed basics of sprinkler systems and
installation, including sizing of pumps and tanks
Spoke about maintenance and testing of fire
protection
Some good questions were raised, continue the
questions
Kindly complete the
seminar evaluation
forms for yesterday
Special Protection Systems
Objectives
Recognize some hazards which need special
protection systems.
Describe the operation of each of the
Special Protection Systems.
Recommend the appropriate Special
Protection System for a given hazard in
accordance with FM Global Property Loss
Prevention Data Sheet.
Trivia Question
Q:
What is special protection?
A:
All fire protection systems other than
automatic sprinkler systems
Definition:
Special Protection Systems are used to
extinguish or control fires in:
high value occupancies;
high hazard areas;
areas where water would cause
contamination and/or excessive damage;
situations where rapid knockdown is
important to lessen damage;
Type of Special Protection Systems
FM Approved Special Protection Systems:
Carbon Dioxide Systems
Clean Agent Fire Extinguishing Systems
Dry Chemical Systems
Foam Systems
Air Foam Systems
Water Mist Systems
Advantages of Special Protection
9 Direct application - specific to hazard
9 Limits production downtime to...time to replace
agent and clean up
9 Less damage from fire AND extinguishing
medium
9 Detector activated - often more rapid
detection and suppression
9 Various choice of systems for specific
applications.
Disadvantages of Special Protection
More readily compromised by occupancy
deficiencies or changes: Managing Change!!!
Area/volume limited.
More complicated maintenance
Limited supply of agent maybe one chance to
extinguish fire.
Delay in restoring protection - Temporary
measures needed
More costly than simple sprinkler systems.
Trivia Question
Q:
What is the maintenance guidelines
for special protection systems?
A: FM Global Loss Prevention Data Sheet 4-0
series;
Cross reference to NFPA Guidelines
Manufacturers instructions
Local Authorities Having Jurisdiction.
(e.g. Fire Department)
Carbon Dioxide (CO2)
Properties
Liquefied gas under its own vapor pressure
Electrically non-conductive gas
Leaves no residue
Vapor density 150% ! air
settles in low spots (drains, pits,
trenches)
Low Pressure CO2 System
Stored in insulated
tanks
refrigerated to -18C
(0F)
pressures around 2068
kPa (300 psi).
These are normally used
for larger installations
protecting larger
volumes, measured in
hundreds or thousands
of cubic meters, or
duration of application.
High Pressure CO2 System
Stored in steel cylinders
at ambient temperature
and at pressures around
59 bar (850 psi).
These are more commonly
found in smaller
installations, up to several
cubic meters.
Individual cylinders having
a standard weight capacity
of 2.3 to 54.4 kg (5 to 120
lb)
Note two banks of CO2 as
connected reserve with changeover.
Total Flooding Application CO2 System
Total Flooding: Electrical Room
Local Application CO2 System
CO2
discharged
only on
the dip tank
and drain
board.
Local Application- Diptank
Local Application - Printing Press
Limitations/Concerns of CO2 Systems
Life safety concerns
Possible suffocation
Reduced visibility
Pre-discharge alarm and time delay required for evacuation
Thermal shock potential.
Static electricity can be generated
Leaking gas, room integrity
Cannot protect reactive metals and nitrocellulose
materials
Full discharge test to confirm design application
Trivia Question
Q:
What is the white stuff seen during a
discharge?
A:
Ice, the expansion of carbon dioxide
discharge is so cold that the moisture in the
air becomes ice crystals.
Clean Agent Systems (Halon Alternatives)
What is a clean agent?
A volatile liquid or gaseous fire extinguishing
agent that is
electrically non-conductive
does not leave a residue upon evaporation.
Clean agent classifications
Halocarbons
Inert Gases, i.e. mixtures of naturally
occurring gases which suppress combustion
FM Approved Extinguishing Agent
These agents are listed in
National Fire Protection Association: NFPA
2001, Standard on Clean Agent Fire
Extinguishing Systems
United States Environmental Protection Agency
(EPA) Significant New Alternatives Policy
(SNAP) Program, subject to any SNAP
Narrowed Use Limits and other restrictions
Extinguishing agents listed to date:
CEA-410 (Perfluorobutane)
FE-13 (Trifluoromethane)
FE-241 (Chlorotetrafluoroethane)
FE-227 (1,1,1,2,3,3,3-Heptafluoropropane)
FM-200 (1, 1, 1, 2, 3, 3, 3-Heptafluoropropane)
FM Approved Clean Agent Systems
FM Approved Clean Agent Extinguishing Systems:
Halocarbons
FM 200,
FE-13,
FE-241
Inert Gases
Inergen
Argonite
Clean Agent Extinguishing
Reduces the oxygen level
to a point where
combustion cannot be
supported.
Some cooling of the fire.
Currently recognized for
total flooding applications
only.
Design - Clean Agent Systems
Acceptable design concentration
Typical electrical/electronic
equipment areas (Class C), having
little or no ordinary combustibles
present.
7% FM-200 (HFC-227ea) held for 10 minute
12-14 % oxygen concentration (approximately 3343% inert gas concentration) held for 10 minutes
18 % FE-13 (HFC-23) held for 10 minutes
Class B fuel (flammable liquid
hazard) should be the extinguishing
concentration as determined by the
cup burner test method
Limitations Clean Agent Systems
Enclosure integrity procedure (i.e., door fan
test)
Accidental system discharges difficult to
replace
Venting to prevent enclosure over
pressurization.
Conduct complete system component
functional tests
Pneumatically or Hydrostatically test all
piping
Conduct a flow test using nitrogen or an inert
gas on the piping network
Weekly Inspection and Maintenance
Nozzles/discharge devices are clear and in
proper position
Operating controls are properly set; i.e
switched on!!
System components not damaged
Liquid level gauges.
Semi-annual Inspection and Maintenance
Check weight and pressure of containers.
Determine if loss is due to discharging or a
leaky container.
Replace or replenish containers if
pressure loss 10% or
weight loss 25%
High-Pressure Cylinders.
Continuously in service without discharging is
permitted to be retained in service for a
maximum of 12 years
At the end of 12 years, they should be
discharged and retested (hydrostatic test)
before being returned to service.
Comparison of the Gases
Carbon
Dioxide
FE13
Agronite
Inergen
FM200
Chemical
Properties
& Names
CO2
Trifluoromethane
HFC-23
50% Ar
50% N2
IG55
50% N2,
42% Ar 8%
CO2
IG541
Heptafluoro
-propane
HCFC227ea
Gas type
CO2
HFC
Inert
Inert
HFC
Typical
design*
50%
18%
35%
40%
7%
Cylinder
storage
pressure
(Bar)
52
41
155 to 310
150 or 200
10 to 41
Cylinder
storage
phase
Liquid /
Vapor
Liquid
Gas
Gas
Liquid
* Typical design effective concentration to electrical room
Comparison of the Gases
Cylinder
storage
space
Carbon
Dioxide
FE13
Agronite
Inergen
FM200
Large
Small
Large
Large
Small
Installation
cost*
Suppressant
refill cost*
* per cu m protected space. Total flooding system
Trivia Question
Q:
Under what terms was the use of Halon being
limited?
A:
The Montreal Protocol on Substances That
Deplete the Ozone Layer, an international
agreement designed to protect the stratospheric
ozone layer. The treaty was originally signed in
1987 and substantially amended in 1990 and 1992.
Before that, the Vienna Convention for the
Protection of the Ozone Layer (1985), outlines the
adverse effects of ozone depletion, established
the framework under which the Montreal Protocol
was negotiated.
Dry Chemical Systems
Dry chemical extinguishing systems are very
finely ground powder of
sodium bicarbonate (most common)
potassium bicarbonate,
potassium chloride
monoammonium phosphate
Other ingredients to keep it free-flowing and
to resist the caking effect of moisture.
Dry chemical systems:
Gas cartridge
Stored pressure.
Dry Chemical Systems
A container of
expellant gas,
when released by
automatic or
manual means,
pressurizes a
container of dry
chemical.
Dry Chemical Systems
Dry Chemical System Limitations
Dry chemical systems are used primarily for
extinguishing fires in flammable liquids.
They are not recommended for fires involving
delicate electrical equipment
Suitable for fires in hot oils and asphalt since
they will not cause serious boilovers.
Cleanup and disposal.
Trivia Question
Q:
What was the common use of sodium
bicarbonate?
A:
Baking
Foam Systems
High, medium and low expansion foam
systems are covered in FM Global Loss
Prevention Data Sheet
DS 4-3N Medium and High Expansion Foam
DS 4-7N Low Expansion Foam
Cross reference to
NFPA 11 Standard for Low-, Medium-, and
High-Expansion Foam
NFPA 11A Standard for Medium- and HighExpansion Foam Systems
How Foam Systems Work
Foam lower in density
than flammable liquid
so it floats on top
Forms cohesive
floating blanket which
Excludes air
Cools the fuel
Suppression
How AFFF & Alcohol Resistant Foams work.
High Expansion Foam Discharge
High Expansion Foam Discharge
Portable Supply Expansion Foam
Standpipe Foam System
Hose Line System
Bladder Type Foam Storage Tank
Horizontal
and
Vertical Bladder Tanks
Bladder Type Storage and Discharge
Foam System Limitations
Not to be used on energized electrical
equipment (foams electrically conductive).
Not effective for three dimensional flammable
liquid fires (low expansion foams)
Determine the percent of a foam concentrate
with discharge and measurement.
Refractive Index Method.
Conductivity Method.
Cleanup and disposal.
Specific Maintenance for Foam Systems
Weekly
Pumps/tanks/lines
for leaks or damage
Manual shutoff
valves
positioned/locked
Central panel lights
operating
Supervised
functions checked
for proper operation
Annual
Thorough inspection
and proper operation
by inspector/
authorized person
Send concentrate
sample to
manufacturer
After any use
Thoroughly flush
system
Water Mist Extinguishes or Controls
It reaches fire by
Direct impingement &
cooling
Entrainment in the supply
of combustion air to the
fire.
Converting to vapor mist
(1700/1 expansion
factor)
Flame cooling
Fuel wetting
Displacement of O2
air
fuel
air
Evaluation of Water Mist System
No general design method is recognized.
Performance objectives need to be proven by
fire test
for the hazard
in the configuration for the hazard
types of fire scenarios expected.
DS 4-2 and Appendices
NFPA 750.
Discharge test
Water Mist System
Application of Water Mist System
FM Approval testing is directed at specific
hazards such as
combustion turbine enclosures,
special hazard machinery spaces,
wet benches,
light hazard occupancies
continuous board presses.
Systems that have been Approved for
protection of a specific hazard may be used for
protection of other hazards provided hazards
are similar.
Trivia Question
Q:
What is the FM Global Approval Standard
for Water-Mist Systems?
A:
Approval Standard 5560 Approval
Standard for Water-Mist Systems
Detection and Actuation Devices
All the above system needs an
effective detection and actuation system.
Trivia Question
Q:
What would happen to the Special
Protection System if the controller is
unable to trigger the actuation system?
A:
If the actuator is an electro-mechanical
releasing device, and there is a mechanical
release, the special protection can be
discharge manually.
Should the system be just an electrical
system without any other mechanical means
for release, then you are reliant on the
sprinkler system!
Summary
We just covered hazards and occupancies
where Special Protection Systems may prove
most effective.
Sprinkler system is still recommended as they
are more reliable and has longer period of
application.
Maintenance of these systems are crucial for
their reliability.
Questions ?
