Module-6-Design-of-Clean-Agent.pdf

Module 6
CLEAN AGENT
FIRE SUPPRESSION SYSTEM
WHAT IS CLEAN AGENT SUPRESSION SYSTEM
MANUAL DESIGN PROCEDURES
GOVERNING CODES AND STANDARDS IN THE DESIGN
TYPES OF CLEAN AGENT AND ITS ADVANTAGES
CONSIDERATIONS IN CLEAN AGENT SELECTION
COMPONENTS OF CASS

NFPA 2001 defines Clean Agent as an electrically
nonconductive, volatile or gaseous fire extinguishant that
does not leave a residue upon evaporation.
Using water to extinguish a fire is not applicable for critical assets such as IT
systems, data storage rooms and manufacturing equipments, or irreplaceable
items like customer/client records, intellectual property, art, antiques and
artifacts.
Novec 1230, FM-200 and Argonite are the preferred Clean Agent fire
suppression systems of Approved Protection Systems.
There are 3 ways clean agents extinguish a fire:
1. Reduction of heat (FM-200, Novec 1230)
2. Reduction or isolation of oxygen (Argonite)
3. Inhibiting the chain reaction of the above
components (FM-200)

Clean Agent Benefits
Fast
Clean Agent systems reach extinguishing levels in 10seconds or less!
Effective
Clean Agents are designed to control and extinguish a fire in its incipient
stage – before it has a chance to spread. Clean Agents are electrically non-
conductive and non-corrosive, and there will be no damage to electronics
and delicate mechanical devices.
Safe
Clean Agents are designed to provides a wide margin of human safety – they
are safe to use where people are present.
Clean
Clean Agents rapidly vaporizes to gas during discharge and evaporates
cleanly, leaving no residue behind, which means no costly cleanup.
Earth Friendly
Clean Agents are non ozone depleting and have a short atmospheric lifetime.

LIMITATIONS
1. Chemicals containing their own supply of oxygen, such as
cellulose nitrate, gunpowder.
2. Mixtures containing oxidising materials, such as sodium
chlorate or sodium nitrate.
3. Reactive metals such as lithium, sodium, potassium,
magnesium, titanium, zirconium, uranium and plutonium..
4. Chemicals capable of undergoing auto-thermal
decomposition such as certain organic peroxides and
hydrazine.
5. All above materials would in case of fire create an explosion
Generally, Clean Agent Fire Suppression system shall
not be used to extinguish fires in

How the agent works
Heat Reducing Agents
FM - 200
Interrupts Chemical Reaction
Oxygen Reducing Agents
NOVEC 1230 ECARO
Halon FE-13, 25, 36
Argon Argonite Inergen
CO2

How the system work?
Input
Photo
Smoke
Detector
Ion Smoke
Detector
Control
Panel
Output
Strobe Lamp + Bell Alarm
Manual Release
& Abort switch
Input
Gas FM 200
discharge to Room
FM 200 Activated
Output
Fire Suppressed
Smoke cause from
fire

ADDRESABLE WIRING INSTALLATION
Zone 1 Zone 2
Alarm
220
VAC
Horn&
Strobe
Manual
Release
Abort
Output
Mod
Output
Mod
Output
Mod
Output
Mod
Input
Mod
Input
Mod

ENVIRONMENTAL PROPERTIES
Properties Novec 1230
(FK-5-1-12)
Halon 1301 FM-200
(HFC-227ea)
ECARO-25
(HFC-125)
Ozone
Depletion
Potential
0 10 0 0
Global
Warming
Potential
1 6900 3220 3500
Atmospheric
Lifetime
(years)
0.014 65 29 33
EPA's SNAP
Conformance
Yes N/A Yes Yes
Source: Fireflex System Inc., Technical Presentation to ASPE
Cleveland, OH on March 10, 2010

PHYSICAL PROPERTIES
Properties Novec 1230
(FK-5-1-12)
Halon 1301 FM-200
(HFC-227ea)
ECARO-25
(HFC-125)
Design % 4-6% 5 % 6.25-8.7 % 8-11.3 %
NOAEL % 10 5 9 7.5
Occupants
Safety
Margin %
67-150 % Nil 3-44 % Nil
Source: Fireflex System Inc., Technical Presentation to ASPE
Cleveland, OH on March 10, 2010
(NOAEL) No Observable Adverse Effects Level for acute toxicity, including cardiac sensitization

The design, installation, testing and maintenance of the
Clean Agent Fire Extinguishing System shall be in
accordance with the following codes and standards
1. NFPA 2001: Standard For Clean Agent Fire Extinguishing System
2. UL1266: Standard For Halocarbon Clean Agent Extinguishing System
Units
3. ANSI B1.20.1: Standard For Pipe Threads, General Purpose
4. NFPA 72: National Fire Alarm Code
5. Factory Mutual Approval Guide (FM)
6. Requirements of the local Authorities Having Jurisdiction

Engineered System – a system that
requires individual calculation and
design to determine the flow rates,
nozzle pressures, pipe sizes, area of
volume protected by each nozzle,
quantity of agent, and the number and
types of nozzles and placement in the
enclosed system.
Pre-engineered System – a
system that does not require
calculation, the specifications are
pre-determined. Fixed amount of
agent to protect a predetermined
hazard and volume.
Types of Clean Agent Systems

a. Storage Containers
FM-200 is stored in a solid-draw,
seamless cylinder with
commercial sizes of 8, 16, 32, 52,
106, 147 and 180 liters.
Containers sharing the same
manifold shall be equal in size
and fill density.
A typical Clean Agent system should have the following major
components that includes detection, actuation and control
systems
Container
Capacity
Vol, liters
Nom.
Volume, kg
Outlet
Size, in
Diameter
(in)
Empty
weight, kg
8 4.5 - 8.0 1 10 14.8
16 9.0 - 17.5 1 10 18.4
32 17 - 33.5 1 10 26.1
52 27.0 - 33.5 2 16 49.1
106 53.5 - 106.5 2 16 71.8
147 74.0 - 147.5 2 16 89.9
180 91 .5 - 182.0 2 16 105.8
Storage Components – Storage
components consist of the
cylinder assembly(s), which
contains the FM-200 chemical
agent, and the cylinder
bracket(s), which holds the
cylinder assembly securely in
place.

Flexible Discharge Hose
It is used to connect the cylinder containers
to the manifold assembly.
Distribution Components – Distribution components consist of the
discharge nozzles used to introduce the FM-200 into a protected hazard
along with the associated piping system used to connect the nozzles to the
cylinder assembly.
Valve Assembly
The valve assembly is factory-fitted to the
container and is supplied pre-assembled with a
low pressure switch, pressure gauge and burst
disc.
Operation of the valve occurs when the upper
chamber is vented faster than the 'make up
device' shuttle. Thereby, allowing the shuttle to
be forced up, and free flow of FM-200 from the
valve.

Manifold
A manifold is a fabricated section of
steel pipe work (Sch 40). It enables
multiple containers to be connected to
a common pipe network. This manifold
can be used in conjunction with
directional valves to provide protection
for multiple risk areas and in situations
where main/reserve container
arrangements are required.
Discharge Nozzle
 Agent is distributed within the
protected area by the discharge
nozzle which is sized to ensure the
correct flow of agent for the risk.
 Nozzles are available with seven or
eight ports to allow for 180˚ or 360˚
horizontal discharge patterns.

a. Manual Actuator
The manual actuator is a simple ‘strike knob’
assembly which is fitted to the top of the
valve assembly or solenoid actuator.
Inadvertent operation is prevented by a pin
which has to be removed before activation.
Manual Actuator is usually used together
with electrical actuator to enable human
intervention in operating the system.
b. Electrical Actuator
Electrical actuator is similar to a manual
actuator and is also located at the top of the
valve assembly only operated by electrical
means.
Manual Actuator
Electric Valve Actuator
Trim Components – Trim components
complete the installation of the CASS
system and consist of connection fittings,
pressure gauge, low-pressure supervisory
switch, electric valve actuator, and manual
valve actuator

Pressure Switch
 The device continuously monitors the
container pressure and in the event of the
pressure dropping below the standard
operating pressure, the switch operates to
enable the condition to be signaled to a
control unit.
 A low pressure warning switch is fitted to
every container and must be utilized to
safeguard the warranty requirements.

Slave Arrangement Components – Slave arrangement components consist of
the pneumatic valve actuator(s), actuation check valve, vent check, actuation
hose, and fittings required for a multiple cylinder (slave) arrangement.

The panel receives information from
environmental sensors and it is designed to
perform the following:
a. detect changes associated with fire
b. monitors their operational integrity
c. provides for automatic gas release of
clean agent
d. transmission of information necessary to
prepare the facility for fire based on a
predetermined sequence.
The panel also supply electrical energy to
operate any associated sensor, actuators,
transmitter, or relay.
Control Panel – This device monitors the condition of the electric actuator,
detectors, warning devices, cylinder pressure, and any manual release and
abort stations. All electric or electronic devices must connect to the control
panel in order to function.

Detectors
Detectors perform several vital functions:
• Warn facility occupants of possible fire.
• Shut down all electrical service to the
equipment so as not to "fuel the fire."
• Activate the suppression medium.
Electrical detectors are preferred than mechanical
detectors because it can be reset once activated.
It uses heat detectors equipped with self-
restoring, normally-open contacts which close
when a predetermined temperature is reached.
Alarm Bells and Sounders
Bells and sounders will indicate an audible alarm
for fire which has been detected in the room and
alarm warning of an imminent fire suppression gas
release.
Early Warning Detection and Alarm Devices – Early warning detection
devices coupled with manual release and abort stations maximize system
efficiency while audible and visual alarm devices alert staff of alarm conditions

Clean agent must have a dedicated detection, actuation, alarm &
control systems installed, tested, and maintained in accordance with
NFPA 72, National Fire Alarm and Signaling Code
Automatic Detection
Adequate and reliable primary and 24-hour minimum standby sources of energy shall
be used to provide for operation of the detection, signaling, control, and actuation
requirements of the system.
Automatic Detection shall be a listed device capable of detecting and indicating heat,
flame, smoke, combustible vapors, or an abnormal condition in the hazard, such as
process trouble, that is likely to produce fire.
Operating Devices
Operating devices shall include agent releasing devices or valves, discharge controls,
and shutdown equipment necessary for successful performance of the system.
All devices shall be located, installed, or suitably protected so that they are not subject
to mechanical, chemical, or other damage that would render them inoperative or
susceptible to accidental operation. It shall be designed to function from -29 C to 54C
A means of manual release of the system shall be provided. The release shall cause
simultaneous operation of automatically operated valves controlling agent release and
distribution.

Operating Alarms and Indicators
Time Delays
Alarms or indicators or both shall be used to indicate the operation of the system,
hazards to personnel, or failure of any supervised device.
Audible and visual pre-discharge alarms shall be provided within the protected area
to give positive warning of impending discharge.
Alarm indicating failure of supervised devices or equipment shall give prompt and
positive indication of any failure and shall be distinctive from alarms indicating
operation or hazardous conditions.
Abort switches are not recommended.
A pre-discharge alarm and time delay, sufficient to allow personnel evacuation prior to
discharge, shall be provided. Where the provision of a time delay would seriously
increase the threat to life and property, a time delay shall be permitted to be
eliminated.
Time delays shall not be used as a means of confirming operation of a detection
device before automatic actuation occurs.

Fires in IT, Server Rooms and Data Centers occupied by
personnel are suppressed in two different ways
Inert Gas System – works by reducing Oxygen level of the protected area
to below 15% in the event of fire. It uses Argon/Nitrogen and sometimes a
small element of CO2. It has the following characteristics:
a. Inert gas fire suppression systems will discharge its payload within 1-2 min.
b. Will generally have more cylinders than chemical gases
c. Works with high pressures, 200 Bar or 300 Bar
d. Will require pressure relief valve for venting
e. Common names of gases are Pro-Inert, IG155, IG541, Argonite and Inergen
Chemical/Synthetic Gas System – works by removing the heat elements
of the fire triangle (oxygen, heat and fuel) of the protected area. Its
characteristics are:
a. Synthetic fire suppression systems will deliver its payload within 10 seconds
b. The system use less gas and significantly cools down the protected area.
c. Low pressures are used, 25 bar and 42 bar
d. Will require pressure relief venting for both negative and positive pressures during
discharge
e. Common names for synthetic agents are FM200, Halon, Novec1230, Ecaro,
HFC227ea and HFC125

Consideration of pros and cons in Clean Agent
selection: IG-541 (Inergen) and HFC-227ea (FM-200)
Cost
First Cost: FM-200 is less expensive than Inergen by as much as 20%
Maintenance Cost: FM-200 is costly than Inergen by as much as 30%
Storage
FM 200 requires much less room for storage than Inergen. In addition, much
smaller quantities of FM 200 are required to do the same job as Inergen.
However, Inergen can cover a much larger area and can protect multiple
hazards.
Environmental Issues
Both FM 200 and Inergen are clean agents, but FM 200 is made of all man-
made substances while Inergen is a non-chemical agent and contains naturally
occurring substances. Inergen requires more energy for its manufacture,
storage and transportation.
Reaction of Agents in the event of fire
FM-200 discharges very quickly to suppress the onset of fire for duration of
about 10 seconds while it takes 45 seconds for Inergen to reach 95% of the
design concentration.

Comparative storage space requirements
Halon 1301
CO 2
Inert Gas

In a two-phase state of Clean Agent, the effect of mechanical separation of liquid and
vapor phases due to centripetal forces when it is passes the piping network is not
predicted by thermodynamics but was inferred from test data and confirmed by using
ultra-high speed photography (HFLOW method, DiNenno et al., 1995).
NFPA 2001 recognized that calculation of two-phase separation
effects at tees, pressure drop and quantity of agent discharged in
an unbalanced system is a complex iteration hence manual
calculation is not practical and computer program must be used
Empirical corrections based on the degree of flow split, orientation of the tee junction,
component fraction, and phase distribution are developed for the specific liquefied
compressed gas to accurately predict the quantity of agent discharge from each nozzle
in the system.
In design calculation, it is assumed that the flow through the pipe network is
homogeneous. Liquid and vapor flow through the piping is at the same velocity evenly
dispersed.
The manual calculation must be rechecked with the manufacturer’s computer
program to determine the detailed discharge from each nozzle. Adjustment
must be made in the sizing and capacity of the Clean Agent accordingly.

In absence of computer program, the manual design
procedures published by Kidde Fenwal (February 2004),
Design & Installation Manual for FM-200, will be used.
a. Determine the Design Concentration
b. Determine the Minimum and Maximum Temperature
c. Determine the Volume of the Hazard
d. Determine the Minimum Design Concentration
e. Check the Maximum Reached Concentration
f. Select Container Size
g. Select Nozzle and Determine Location
h. Determine Pipe Sizes
i. Determine the Venting Area

Fuel Extinguis
hment, %
Minimum
Design,
%
Heptane 6.9 9
Surface Class A*
Hazards
5.8 7.5
FM-200 (HFC-227ea) Extinguishing
and Design Concentrations
Design concentration is the minimum amount of clean agent
in an agent/air mixture to suppress different types or class of
fire hazards
a. Class A Fire – Fire in ordinary combustible materials, such as wood, cloth, paper,
rubber and many plastics.
b. Class B Fire – Fire in flammable liquids, oils, greases, tars, oil-base paints,
lacquers, and flammable gases.
c. Class C Fire – Fire that involves energized electrical and electronic equipment
where the electrical resistivity of the extinguishing media is of importance.
The major components of the
area to be protected consist of
electronic devices which fall
under Class C hazard.
Different Classes of Fire Hazards
* Note: NFPA 2001
recommend that the design
concentration for Class C
hazard shall be equivalent
to that of Class A. Thus,
design concentration
applicable is 7.5%.
DETERMINE THE DESIGN CONCENTRATION

Get from the nameplate of installed equipment the minimum and
maximum temperature required. Let us assume the min and max
temp is 22˚C and 24˚C respectively
 The minimum temperature
will be the basis of
determining the minimum
amount of agent required to
achieve total flooding.
 The maximum temperature is
used to confirm if the
resulting design concentration
will not exceed the No
Observed Adverse Effect
Level (NOAEL).
 For FM-200 (HFC-227ea,
NOAEL is 9% and human
exposure is allowed within 5
minutes upon agent
discharge.
Total Flooding is the manner of discharging an agent for the purpose of achieving
a specified minimum agent concentration throughout a hazard volume.
DETERMINE THE MINIMUM AND MAXIMUM TEMPERATURE

The selection of Clean Agent for the protection of IT and server
rooms and data center are limited to 13 agents recognized by
NFPA 2001
Previously, the most popular are
Halons and Carbon Dioxide.
1. Halogenized agents were phased
out in 1994 because all halons
are ozone depleters.
2. Carbon dioxide on the other
hand, displaces oxygen; its
discharge would cause
asphyxiation or suffocation to any
occupants.
NFPA 2001 has identified the 13
Halon replacement agents as
shown in the table.
Two Clean Agents that are in
wide use today are IG-541
(better known as Inergen) and
HFC-227ea (commonly known
as FM-200).

Choice of Clean Agent for an I.T. Building with the following
assumed dimensions
 The hazard space to be protected is
composed of two adjacent enclosures.
 The Data Center and UPS
(Uninterrupted Power Supply) Rooms
are relatively small space hence it
requires a simpler and smaller
installation.
 A big factor considered is the fact that
FM-200 discharges very quickly to
suppress the onset of fire for duration
of about 10 seconds while it takes 45
seconds for Inergen to reach 95% of
the design concentration.
Since the data center and UPS room
are small enclosures but very vital to
operation of Sutherland, the use of
FM-200 is the most appropriate clean
agent to use.

Description Units Measurement
Molecular Weight N/A 170.03
Boiling Point at 19.7 psia ˚C -16.4
Freeezing Point ˚C -13.1
Critical Temperature ˚C 101.7
Critical Pressure kPa 2912
Critical Volume cc/mole 274
Critical Density Kg/cu.mtr 621
Specific Heat, Liquid at 77˚F kJ/kg-˚C 1.184
Specific Heat, Vapor at Constant
Pressure (1 atm) and 77˚F
kJ/kg-˚C 0.808
Heat of Vaporization at Boiling
Point
kJ/kg-˚C 132.6
Thermal Conductivity of Liquid at
77˚F
W/m˚C 0.069
Viscosity, Liquid at 77˚F centipose 0.814
Relative Dielectric Strength at 1
atm at 734 mm Hg, 77˚F
N/A 2.00
Solubility by Weight, of Water in
Agent at 70˚F
Ppm
0.06% by
weight
FM-200 Physical Properties
 FM-200 (HFC-227ea) is a
clean, gaseous agent
containing no particles or
oily residues. It leaves no
residue or oily deposits on
delicate electronic
equipment, and can be
removed from the
protected space by
ventilation.
 FM-200 is a chemical
blend (heptafluoro-
propane), stored as a
liquefied compressed gas
within the agent cylinder
and discharged into the
protected areas as a
colorless gas.
80% of FM-200 fire fighting effectiveness is achieved through heat absorption
and 20% through direct chemical means (action of the fluorine radical on the
chain reaction of a flame).

 Volume of Data Center, Va
Va = Area x Height
Va = 8.625 m X 7.414 m X 4.5 m
Va = 287.76 m3
Calculating for the volume of the hazard area
 Volume of UPS Room, Vb
Vb = Area x Height
Vb = 11.867 m X 4.1 m X 4.5 m
Vb = 218.99 m3
 Total Volume, Vt
Vt = Va + Vb
Vt = 287.76 m3 + 218.99 m3
Vt = 506.76 m3
DETERMINE THE VOLUME OF THE HAZARD

Where:
W = weight of clean agent [lb, (kg)]
V = net volume of hazard, calculated as the gross
volume minus the volume of fixed structures
impervious to clean agent vapor
s = specific volume of the superheated agent vapor at
1 atmosphere and the temperature, t [ft3 / lb (m3 / kg)]
= 0.1269 + 0.0005 t, where t is in ˚C
C = agent design concentration [volume percent]
= 7.5% (from the Table of FM-200 Design Concentration)
t = minimum anticipated or required temperature of the
protected volume [˚F(˚C)]
The Total Flooding Quantity is the amount of clean agent required
to achieve the minimum design concentration
FM-200 (HFC-227ea) Extinguishing
and Design Concentrations
DETERMINE THE MINIMUM DESIGN CONCENTRATION
NFPA 2001 provided the formula that includes allowance for the normal leakage
from a “tight” enclosure due to agent expansion.

Substituting the values below, we will have:
i. Design Concentration, C = 7.5%
ii. Temperature t, tmin = 21˚C; tmax = 24˚C
iii. Volume of Hazard Space V, Va = 287.76 m3;
Vb = 218.99 m3;
Vt = 506.76 m3
iv. Specific Volume, s
s = 0.1269 + 0.0005 tmin
s = 0.1269 + 0.0005 (21˚C)
s = 0.1379 m3 / kg
Substituting known values to get the Total Flooding Quantity
which represents the Minimum Design Concentration of Clean
Agent
 Quantity of agent required for the data center, Wa
Wa = [287.76 m3 / 0.1379 m3 / kg] x [(7.5/100-7.5)
Wa = 169.194 kg

 Quantity of agent required for UPS Room, Wb
Wb = = 218.99 m3/ 0.1379 m3/kg (7.5/100-7.5)
Wb = 128.75 kg
 Total Quantity of FM-200 required, Wt
Wt = Wa + Wb
Wt = 169.194 kg + 128.75 kg
Wt = 297.94 kg or 657 lbs
The above total quantity or 297.94 Kg represents the Minimum Design
Quantity (MDQ) or the minimum amount of Clean Agent required to
achieve the design concentration.

NFPA 2001 requires that the Minimum Design Quantity (MDQ)
have to be adjusted to account for any special conditions as
design factors that would affect the extinguishing efficiency
Tee Design Factor. Starting from the
point where the pipe system enters the
hazard, the number of tees in the flow
path returning to the agent supply shall
be included in the design factor tee count
for the hazard. Table 3-5.3.1 gives the
equivalent quantity.
Considering the above designed piping layout for this project, it is clear that tees
inside the hazard area is less than 4, so therefore the design factor is 0.
NFPA 2001 Table 3-5.3.1

Design Factor for
Atmospheric Correction
NFPA 2001 requires that the
design quantity of the clean agent
shall be adjusted to compensate
for the ambient pressure that vary
more than 11% (equivalent to
approximately 3000 ft of elevation
change) from standard sea level
pressures, 29.92 in. Hg at 7˚F (760
mm Hg at 0 degrees ˚C)
NFPA 2001, Table 3-5.3.3 shows
that the atmospheric correction
factor at seal level is a unity
factor.
Considering that the tee design and the atmospheric correction factors is 1 then
the Minimum Design Quantity is also the Adjusted Design Quantity equivalent
to 297.94 kg or 657 lbs

The maximum reached concentration must be determined
to ensure safety of personnel working inside the rooms
NFPA 2001 provided the formula to check the concentration, C, expected to reach the hazard.
Where:
Q = Wa = 169.194 kg (for Data Center)
= Wb = 128.75 kg (for UPS Room)
s = specific vapor volume (m3/kg)
= 0.1269 + 0.0005131T (at sea level)
= 0.1269 + 0.0005131(24˚C) = 0.139 m3/kg
For the Data Center:
C = [(169.194kg) x 0.139 m3/kg x 100] / [287.76 m3 + (169.194 kg x 0.139 m3/kg)]
= 7.56 %
For UPS Room
C = [(128.75 kg) x 0.139 m3/kg x 100] / [218.99 m3 + (128.75 kg x 0.139 m3/kg)]
= 7.55 %
Concentration at 24˚C is below NOAEL at 9%, therefore the room is safe for
occupants.
CHECK THE MAXIMUM REACHED CONCENTRATION
T = maximum hazard temperature (24˚C)
V = Va = 287.76 m3 (for Data Center)
= Vb = 218.99 m3 (for UPS Room)

Container
Capacity
Nominal
Volume, kg
Outlet
Size, in
Diame-
ter (in)
8 4.5 - 8.0 1 10
16 9.0 - 17.5 1 10
32 17 - 33.5 1 10
52 27.0 - 33.5 2 16
106 53.5 - 106.5 2 16
147 74.0 - 147.5 2 16
180 91 .5 - 182.0 2 16
Fenwal and Kidde FM-200 Container Details
NFPA 2001, Sec. 2-1.4 requires that clean agent shall be stored in a
containers designed, fabricated, inspected and certified in
accordance to ASME Boiler and Pressure Vessel Code
 NFPA 2001 requires that for clean agents in a multiple container system supplying the
same manifold outlet for distribution of the same agent shall be interchangeable and of
one select size and charge.
 We determined that the
corresponding quantity of
clean agents required for
the data center and UPS
room are 169.194 kg and
128.75 kg respectively.
 The two rooms should be
supplied by two separate
containers, one unit 180-
liter and one unit 147-liter
containers.
In order for the containers to be interchangeable and ensure availability of
spare cylinder during refill or maintenance, the two rooms should be equipped
with similar 180-liter containers.
SELECT CONTAINER SIZE

Proposed design of clean agent piping and containers for two hazard areas.
This design will utilize two (2) separate 180-liter containers with reserve tanks
to hold the required amount of clean agents for the two hazard areas.

Each enclosure shall have a 180-liter containers respectively. NFPA 2001
recommends that a reserve supply shall be provided so a total of four (4) units
containers is required. The containers are to be installed in two separate
manifolds.

Nozzle Selection and Location
This design will utilize a 360˚ nozzle
configuration, which is advantageous as it
provide a full 360˚ discharge pattern
designed for placement in the center of
the hazard.
NFPA 2001 requires that:
a. Nozzles must be mounted perpen-
dicular to the ceiling and oriented with
the orifices radiating symmetrically
outward from pipe network.
b. Nozzles must be installed within 12
inches below the ceiling. The
maximum height for a single row of
nozzles is 16 ft. (4.87 m).
c. Nozzles must be located with at least
four to six feet of clearance from walls
and/or significant obstructions.
Discharge Nozzle Installation Detail
SELECT NOZZLE AND DETERMINE LOCATION
Nozzle Configuration
Nozzle Coverage and Location

Nozzle Coverage Area
Fenwal Maximum Nozzle
Coverage Area
Per FENWAL manufacturer
specifications, the maximum nozzle
coverage area for a 360˚ nozzle is
defined as any rectangle that can
be inscribed in a circle of radius
29.7 ft (9.06 m).
= 2691.51 ft.2
= 250 m2
The preferred configuration is a 360˚ discharge pattern nozzle to be installed at the
center of the hazard.
A = π x r2
= 3.1416 x 29.7 2
The number of nozzles for the enclosure can be obtained by dividing the hazard area
by the maximum nozzle coverage area.
The floor area of data center is 63.94 m2 while the UPS room is 48.65 m2.
Since the maximum coverage area of a 360˚ nozzle is 250 m2, one nozzle for
each compartmented hazard area can sufficiently cover the requirement.
Number of Nozzles

Considering that the hazard areas have an array of cabinets that will obstruct the
uniform dispersion of agent during discharge thus it is recommended to use two (2)
nozzles each room to ensure total flooding of the enclosures within the 10 seconds
discharge time.
Data center area
= 63.94 m2
UPS room area
= 48.65 m2

NFPA 2001 requires that the maximum discharge time for Halocarbon agents is 10
seconds.
In determining pipe size for the distribution piping, flow rate of the
nozzle distribution pipe should be calculated first using the amount
of agent required over the discharge time
a. Mass Flow Rate of Data Center Distribution Pipe, ṁa
ṁa = amount of agent required for data center / discharge time
ṁa = 169.194 kg / 10 seconds
ṁa = 16.91 kg / seconds
b. Mass Flow Rate of UPS Room Distribution Pipe, ṁb
ṁb = 128.75 kg / 10 seconds
ṁb = 12.87 kg / seconds
In the absence of computer program to calculate the two-phase agent flow distribution, the
nozzle flow rate can be determined by assuming that the agent is evenly distributed after
passing the tee split.
Nozzle Flow Rate
Considering that the data center is designed to have 2 nozzles to account for obstructions
of installed data cabinets:
Flow rate Nozzle 001 = Flow rate of Nozzle 002
= ṁa / 2
= 16.91 kg / seconds / 2
= 8.46 kg/sec
DETERMINE PIPE SIZES

Considering that the size of the UPS Room is too small at 48.65 m2, one dicharge
nozzle is enough since it is a separate enclosure.
However, due to presence of equipment cabinets and in order to maintain identical
nozzles for maintenance, uniform stocking and interchangeability of spares, the flow
rate of UPS room should be at least near the flow rate of nozzles for the Data Center.
In order to achieve this, it is recommended to utilize 2 nozzles for UPS. Hence, the flow
rate for each UPS Room nozzles will be:
Flow rate Nozzle 003 = Flow rate of Nozzle 004
= 12.87 / 2 (kg/sec)
= 6.44 kg/sec
Pipe Size Selection
For the Nozzles at Data Center:
The flow rate for each of the two nozzle is 8.46
kg/sec. From the table, the next higher value in
the Max. Flow rate is rate 9.072 kg/sec using
40-mm (1 ½ -in) diameter pipe.
For the Nozzles at UPS Room:
The flow rate for each of the two nozzle is 6.44
kg/sec. From the table, the next higher value in
the Max. Flow rate is rate 9.072 kg/sec using 40-
mm (1 ½ -in) diameter pipe. FM-200 Flow in Schedule 40 Pipe

In actual practice, the distribution piping is commonly designed in such as way that the
pipes are reduced to smaller sizes to prevent the separation of liquid and vapor. If the
pipeline diameter is too large, the two phases may separate, leading to alternate
discharges of liquid and vapor (slugging) or layering of two-phases.
Header and Branch Piping
As recommended by Fenwal Design and Installation Manual, whenever a computer
program is not available to compute the accurate size of the pipeline networks, the best
practice is to reduce the pipe size by increments of half an inch after every reducer.
From Fenwal Estimating Table, the flow rate required for the data center is 2 ½-
inch diameter and UPS room requires 2-inch dia. only. However, considering that
the two hazard areas will be using similar size containers for interchangeability,
this design will utilize a 2-1/2 inches header pipe as starting discharge pipe.

Pressure Venting is required to protect the structural
integrity of the enclosure from raise of internal pressure
during the discharge of any gaseous extinguishing agent
NFPA 2001, Section 5.3.6 states that the protected enclosure shall have the
structural strength and integrity necessary to contain the agent discharge. If the
developed pressure presents a threat to the structural strength of the enclosure,
venting shall be provided to prevent excess pressures.
Where:
A = required venting area
v = specific volume of agent (m3/kg)
ΔP = Maximum allowable pressure increase of
the enclosure (Pa)
ṁ = flow rate (kg/sec)
V = specific volume of homogeneous agent/air
mixture (m3/kg)
c = resistance coefficient for the opening
To calculate the free venting area, NFPA 2001 provided the following formula:
DETERMINE THE VENTING AREA

From the table, we can
obtain the vapor density of
FM-200 at 21˚C and 1 atm
by of interpolation.
And since v = 1/ρ, therefore
the specific volume of FM-
200 agent is:
v = 0.138 m3/kg
21 − 20
25 − 20
=
𝜌 − 7.2815
7.1461 − 7.2815
𝜌 = 7.2544
Specific Volume of FM-200

Flow Rate, ṁ
ṁa = 16.91 kg / seconds, FM-200 flow rate for Data Center
ṁb = 12.875 kg / seconds, FM-200 flow rate for UPS room
Referring to Fenwal and Tyco manufacturer’s recommendations, the value of
the other parameters are as follows:
ΔP = for the maximum allowable pressure increase of the enclosure, a
value between 100 and 300 Pascals should be used if there is no
other value specified by the manufacturer of equipment installed in
the enclosure.
= 300 Pa
V = specific volume of homogeneous agent/air mixture (m3/kg)
= 0.6 is a good average value for below 7.9% FM-200 concentration.
c = resistance coefficient for the opening
= ranges from 0.5 to 1
= to simplify the formula, use 1

a. For the Data Center
Venting area , Aa
Aa = 16.91 x 0.138 / [√300 (0.6)] (1)
= 0.1739 m2
Substituting the values obtained, the required pressure venting
area for each enclosure are:
b. For the UPS Room
Venting area , Ab
Ab = 12.875 x 0.138 / [√300 (0.6)] (1)
= 0.132 m2
𝐴 =
ṁ 𝑣
∆𝑃 𝑉
. 𝑐 Aa = 0.1739 m2
= 269 in2
= π r2
r = 9.3 inches
Ab = 0.132 m2
= 204 in2
= π r2
r = 8 inches

a. General Information
Agent to be used: FM-200
Type of Hazard: Class C (Energized Electrical & Electronics
Equipment)
Enclosure Description: Data Center and UPS Room
Enclosure Volumes: Data Center = 287.76 m3;
UPS Room = 218.99 m3
Minimum Temperature: 21˚C
Maximum Temperature: 24˚C
Quantity of Agent Required: 170 kg for each container
Design Concentration: 7.5%
Atmospheric Correction Factor: 1.0
Tee Design Factor: 0.0
Discharge Time: 10 seconds
Elevation: Sea level
Pressure Venting Area: Data Center = 0.1739 m2
UPS Room = 0.132 m
DESIGN SUMMARY
= 9.3 inch dia.
= 8 inch dia.

b. Containers
Operating Temperature: 21˚C (min)
Construction and Material: Designed, fabricated, inspected, certified
and stamped in accordance with Section 8
of the ASME Boiler and Pressure Vessel
Code
Size of Containers: 180 Liters
Actual Fill Capacity: 95%
Number of Containers: 2 Master Cylinders
2 Slave (Reserved) Cylinders
System Operating Pressure: Manufacturer standard of 360 PSIG at
70 ˚F (25 bar gauge at 21 ˚C)
Accessories: a. Master Cylinder must be equipped with
Master Control Head
b. Slave Cylinder must be equipped with
Pressure Operated Control Head

c. Nozzles
Location: Pendent type installation at the center of
the hazard, 1 foot from the ceiling
Discharge Pattern: 360˚
Number of Ports: 8.0
Material: Brass
Number of Nozzles Data Center – 2
UPS Room – 2
Size of Nozzles: 1 -1/2 inches NPT
Feed Pipe Size: 1-1/2 inches NPT
Estimated Flow Rate: Data Center - 8.46 kg/sec
UPS Room - 6.44 kg/sec
Maximum Total Orifice Area
per Nozzle: 1.46 in2

d. Pipes and Fittings
Pipe Material: API 5L Grade B (BI Pipe), Schedule 40
Sizes: 2-1/2 in., 2 in. and 1-1/2 in.
Total Length: 2-1/2 in: 11 meters
2 in: 10 meters
1-1/2 in: 7 meters
Number of Elbows: 7
Number of Tees: 2
Type of Reducer: Concentric Type
Size of Reducer: 2-1/2 X 2 in. and 2 X 1-1/2 in.
Number of Reducer: 5
Type of Joint Connection: Welded
Manifold Size: 2-1/2 in.
Number of Manifolds: 2
e. Pressure Venting Area
Data Center: 0.1739 m2
UPS Room: 0.132 m2

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