1540 Ch 10 PowerPoint

1. Fire Protection Systems
Third Edition
Chapter 10 — Gaseous Agent Extinguishing Systems

2. Objectives
‣Describe the physical characteristics of carbon dioxide.
‣Describe the four application methods for delivery of carbon
dioxide.
‣Describe the physical characteristics of halogenated
hydrocarbons (halons).

3. Objectives
‣Explain the halon numbering identification system.
‣Describe the physical characteristics of halocarbons and inert
gases (clean agents).
‣Discuss the two categories of clean agents.

4. Objectives
‣Explain the difference between the two types of aerosol
generators.
‣Discuss the various acceptance and periodic inspections and
tests that are required to certify and maintain gaseous agent
extinguishing systems.

5. Introduction
‣New materials, machines, processes, and technologies created a
need for alternatives to water for extinguishing.
‣Gaseous extinguishing systems are effective in many situations
where water is not.
‣Carbon dioxide
‣Halogenated hydrocarbons
‣Halocarbons and inert gas

6. Carbon Dioxide
‣An odorless, colorless, noncombustible gas
‣Exists in the air at 380 parts per million
‣Can exist as gas, solid, or liquid
‣Liquid state best for suppression
‣Effective on Class A, B, and C type fires
‣Displaces and reduces the level of oxygen below the 15% of air
content that is necessary to sustain combustion

7. Carbon Dioxide Extinguishing Systems
‣Engineered systems that protect processes, equipment, items of
value/importance
‣Self-contained system using fixed nozzles, manual reels, or both
to deliver agent
‣Equipment requires listing or approval.

8. Carbon Dioxide Extinguishing Systems
‣When discharged, pressurized CO2 expands to gas vapor state:
‣Combines with moisture in air and forms a cloud that consumes
hazard
‣Helpful when another agent could be problematic or when there
are physical obstructions

9. Carbon Dioxide Extinguishing Systems
‣A few types of systems and methods exist.
‣Chosen based on hazard size and amount of agent needed
‣Many different nozzles are available to provide the correct
discharge velocity, flow rate, and discharge pattern.

10. Carbon Dioxide Extinguishing Systems
‣Discharge nozzles
‣Must be able to withstand fire’s
heat and discharge pressure of
CO2
‣Require blow-off caps or
frangible discs to manage
clogging
‣Require listing or approval
© A. Maurice Jones, Jr./Jones & Bartlett Learning

11. Carbon Dioxide Extinguishing Systems
‣Activation
‣Automatically with a detector,
or manually by a person
‣Warning signs must be
posted about dangers and
give emergency instruction.
‣Guidance on performing the
evaluation, design, and
installation of this type of system
is in NFPA 12.
© A. Maurice Jones, Jr./Jones & Bartlett
Learning.

12. Carbon Dioxide Extinguishing Systems
‣Low- and high-pressure storage
‣Low pressure stores CO2 at 300 psi; high pressure at 850 psi.
‣Both systems dispel gas without additional propellant.
‣System type is chosen based on hazard and amount of
CO2 needed.
‣Low-pressure systems may need refrigeration/heating
equipment to maintain CO2 at 0ºF.

13. Carbon Dioxide Extinguishing Systems
‣Low- and high-pressure storage (cont’d)
‣Low-pressure systems may use one large pressure container.
‣High-pressure systems can use multiple small cylinders
connected to a manifold.
Courtesy of American Fire Technologies. © A. Maurice Jones, Jr./Jones & Bartlett Learning.

14. Carbon Dioxide Extinguishing Systems
‣Delivery systems
‣Local application systems protect a specific area, piece of
equipment, process, or operation.
‣Total flooding systems protect enclosed hazards, rooms, and
areas, filling enclosure with gas.
‣Hand hose line system is manual system where individual
accesses hose, reel, and nozzle connected to fixed pipe CO2
supply.
‣Standpipe/mobile supply is a fixed local, total, or hand hose
system with no permanent CO2 supply.

15. Halogenated Agents
‣A mixture of carbon and one or more of fluorine, chlorine,
bromine, and iodine
‣Numbering system lists the number of atoms of each
element in the agent.
‣Halon 1211 and 1301 are used for fire protection.
‣Halon agents break down the reaction sequence of fire.
‣Disrupting the uninhibited combustion reaction that is the
basis of the fire tetrahedron
‣Effective for Class B and C type fires, and Class A to a degree

16. Halogenated Agents
‣Human exposure is fine, though not in high level or for long
duration.
‣Most systems have 4–7% concentration.
‣10% or higher is dangerous to humans.
‣Fire personnel should wear SCBA and take readings in
discharge areas.
‣Decomposition produces dangerous by-products.

17. Halon Extinguishing Systems
‣Can be pre-engineered or engineered and use many components
‣All equipment and components require listing and approval.

18. Halon Extinguishing Systems
‣Automatic detection and activation and manual control are
usually required.
‣Must also have emergency release by manual operation and
audible, visual, and olfactory warning devices
‣When activated, control head operates and valve head opens to
release gas to cylinders, flood piping, and reach nozzles

19. Halon Extinguishing Systems
‣If manual abort switch is installed,
must be in hazard area.
‣Substantial discharge must occur in
10 seconds.
‣Time delay allowed for
personnel to evacuate
‣Warning signs required
© A. Maurice Jones, Jr./Jones & Bartlett Learning

20. Halon Extinguishing Systems
‣Nozzle placement is critical to uniform delivery.
‣Pressurized nitrogen can be added.
‣Halon changes from liquid to vapor as it flows.
‣Discharges as cloud; when cloud dissipates, gas remains.
‣Once the hazard evaluation is done, there are engineering
considerations.
‣Size and number of cylinders and size of pipe
‣Nozzle and valve types

21. Halon Extinguishing Systems
‣NFPA 12A gives guidance on evaluation, design, and installation
of this type of system.
‣Referenced by NFPA 5000® and IBC®
‣NFPA 12B (Halon 1211) was discontinued.
‣NFPA 12A may also become obsolete.

22. Halon Extinguishing Systems
‣Halon delivery systems
‣Local application systems
protect specific area.
‣Discharge directly onto
hazard
‣Used in marine and aviation
applications
‣Total flooding systems protect
enclosed hazards by filling
them with halon.
‣Concentration level: 5–15%
by volume
‣Halon 1301 is usually the only
agent used for these systems.
© A. Maurice Jones, Jr./Jones & Bartlett
Learning

23. Clean Agents
‣Clean agents were developed to replace Halon 1301.
‣Effective on Class A, B, and C fires
‣Protect many high-value locations and items
‣Should not be used with reactive materials, materials with
own oxygen supply, certain peroxides and hydrazine

24. Clean Agents
‣ Human exposure is fine, though not in high level or for long
duration
‣ Clean agents fall into two categories:
‣ Halogen-based agents interrupt the fire’s chain reaction
and remove heat from reaction zone of flame.
‣ Inert agents reduce oxygen level in protected area.

25. Clean Agent Extinguishing Systems
‣NFPA 2001 gives guidance on evaluation, design, and installation
of this type of system.
‣Referenced by NFPA 5000® and IBC®
‣Additional standards:
‣UL 2127
‣UL 2166
‣ISO 14520-1

26. Clean Agent Extinguishing Systems
‣A complete hazard evaluation determines the appropriate size
and number of cylinders, pipe size, nozzle types, valve types,
and other supporting components such as detection and
activation equipment.
‣Pre-engineered or engineered self-contained systems that use a
number of different components
‣All equipment and components require listing and approval.
‣Specific to application

27. Clean Agent Extinguishing Systems
‣Activation
‣Automatic detection and activation and manual control
usually required
‣Must also have emergency release by manual operation and
audible, visual, and olfactory warning devices
‣If manual abort switch installed, must be in hazard area

28. Clean Agent Extinguishing Systems
‣When activated,
control head operates
and valve head opens
to release gas to
cylinders, flood
piping, and reach
nozzles.
© A. Maurice Jones, Jr./Jones & Bartlett
Learning
© A. Maurice Jones, Jr./Jones & Bartlett
Learning

29. Clean Agent Extinguishing Systems
‣Substantial discharge must occur
in 10 seconds for halocarbons and
60 seconds for inert agents.
‣Warning signs with emergency
information must be posted.
‣Nozzle placement is critical to
uniform delivery.
‣Clean agents can flood an area
and reach difficult places.
© A. Maurice Jones, Jr./Jones & Bartlett
Learning

30. Aerosol
‣Overview
‣NFPA 2010 adopted in 2006 to deal with evolving technology
of aerosol extinguishing agents.

31. Aerosol Extinguishing Systems
‣Alternative to clean agent and specialized water-based systems
‣Good for closed spaces and areas appropriate for total
flooding
‣As per NFPA 2010, this system is not well suited for:
‣Deep-seated fires
‣Chemicals subject to rapid oxidation
‣Reactive metals
‣Chemicals that undergo autothermal decomposition

32. Aerosol Extinguishing Systems
‣Condensed generators
‣Used in systems made up of
self-contained canisters in the
hazard area
‣When activated, an actuator
in the generators starts a
chemical reaction.
© A. Maurice Jones, Jr./Jones & Bartlett
Learning

33. Aerosol Extinguishing Systems
‣Dispersed generators
‣Already contain the chemical agent
‣Keep it pressurized by suspension in inert gas or halocarbon
‣When activated, pipes and nozzles distribute aerosol.

34. Approval and Periodic Inspection,
Testing, and Maintenance
‣Carbon dioxide
‣After installation, NFPA requires visual, operational, and
discharge inspections and tests.
‣Once operational, monthly visual inspections mandatory to
assess hazard changes, equipment damage, leaks
‣Weekly inspection of gauges on low-pressure systems to
ensure no decrease in liquid level
‣Semiannual inspection of high-pressure system tanks to
ensure no leakage

35. Approval and Periodic Inspection,
Testing, and Maintenance
‣Carbon dioxide (cont’d)
‣Annual actuation test of electronic components for both low-
and high-pressure systems
‣Hose systems inspected and pressure checked every 5 years
‣When system discharges, tanks require hydrostatic testing
before refilling.
‣If unused for 12 years, discharge and hydrostatic testing are
required.

36. Approval and Periodic Inspection,
Testing, and Maintenance
‣ Halon
‣ When new Halon 1301 system is installed, mechanical,
electrical, enclosure, and functional testing and inspection
are mandatory.
‣ Once operational, monthly visual inspections mandatory to
assess hazard changes, equipment damage, leaks
‣ Semiannual pressure checks to ensure pressure not lost

37. Approval and Periodic Inspection,
Testing, and Maintenance
‣Halon (cont’d)
‣Annual actuation test to ensure detection, alarm, and control
devices are operational
‣Annual inspection and pressure testing every 5 years for
hose systems

38. Approval and Periodic Inspection,
Testing, and Maintenance
‣Clean agents
‣Upon installation, same
procedures as halon
systems
‣Once operational, annual
visual inspections
‣Semiannual pressure loss
checks
‣Annual actuation test
‣Annual inspection and
pressure testing every 5
years for hose systems © A. Maurice Jones, Jr./Jones & Bartlett
Learning.
© A. Maurice Jones, Jr./Jones & Bartlett
Learning.

39. Approval and Periodic Inspection,
Testing, and Maintenance
‣Aerosol
‣Like other systems, acceptance inspection and testing and
periodic testing are mandatory.
‣30-day visual inspection and semiannual weighing
‣Enclosure and system components checked
‣System tested as specified by manufacturer