Amerex 450 User guide

PN 05605 04/2020
PART
NUMBER TITLE DATE CREATED CREATED BY REV. CK’D
05605 MANUAL OWNER’S SERVICE 45– 46- 47-2/7/96 RA K
THIS DRAWING IS THE EXCLUSIVE AND CONFIDENTIAL PROPERTY OF AMEREX
CORPORATION. IT SHALL NOT BE DUPLICATED, USED OR DISCLOSED TO OTHERS
REV DRAWING CHANGE BY ECN# DATE
JMANUAL UPDATE TO PUBLISHER JH B000552 03-18-15
KREFRESHED LAYOUT DESIGN; REVISED TITLE CT B002026 4/29/20
COVER SHEET
DO NOT PRINT THIS PAGE FOR ACTUAL MANUAL. INTERNAL USE ONLY.
#NOTES
1THIS COVERSHEET FOR INFORMATIONAL PURPOSES ONLY - DO NOT PRINT THIS PAGE IN MANUAL.
2DESCRIPTION: MANUAL OWNER’S SERVICE FOR 45-46-47- WHEELED EXTINGUISHERS
3ACTUAL PRINTED MATERIAL TO CONSIST OF ATTACHED
4OVERALL SIZE OF PRINTED DOCUMENT PAGES: 8-1/2” X 11” ON 20 LB PAPER
5PRINTED MATERIAL TO MATCH ATTACHED IN SADDLE STITCHED BOOKLET FORM
6PRINT MATERIAL IS TO BE HOLE PUNCHED 3 EACH 1/4” HOLES DOWN LEFT SIDE FOR STD 3-RING BINDER
7CURENT REVISION DATE: 4/20

PN 05605 04/2020
OWNER’S SERVICE MANUAL
INSTALLATION, OPERATING & SERVICING INSTRUCTIONS
MANUAL PN 05605
125/150 LB. NITROGEN CYLINDER DRY CHEMICAL EXTINGUISHERS
MODELS 450,451,452,467,468,469,470,471,472
All fire extinguishers shall be installed, inspected, and maintained in accordance with the National Fire
Protection Association standard titled "Portable Fire Extinguishers", NFPA 10, or the National Fire Code of
Canada and the requirements of local authorities having jurisdiction.
When maintenance is indicated it shall be performed by trained persons having proper equipment. Fire
extinguishers are pressure vessels and must be treated with respect and handled with care. They are
mechanical devices and require periodic maintenance to be sure that they are ready to operate properly
and safely. Amerex strongly recommends that the maintenance of portable fire extinguishers be done by a
trained professional – your local authorized Amerex Distributor.
Amerex Corporation makes original factory parts available to insure proper maintenance – USE OF
SUBSTITUTE PARTS RELEASES AMEREX OF ITS WARRANTY OBLIGATIONS. Amerex parts have
machined surfaces and threads that are manufactured to exacting tolerances. O-rings, hoses, nozzles, and
all metal parts meet precise specifications and are subjected to multiple in-house inspections and tests for
acceptability. There are substitute parts available that may be incorrectly labeled as UL component parts,
some are advertised as Amerex type. None of these meet UL requirements, and all of them void the
Amerex extinguisher warranty and UL listing. DO NOT SUBSTITUTE.
RECHARGE FIRE EXTINGUISHERS IMMEDIATELY AFTER ANY USE
AMEREX CORPORATION DOES NOT SERVICE, MAINTAIN, OR RECHARGE FIRE EXTINGUISHERS.
THIS MANUAL IS PUBLISHED AS A GUIDE TO ASSIST QUALIFIED SERVICE PERSONNEL IN THE
INSPECTION, MAINTENANCE, AND RECHARGE OF AMEREX FIRE EXTINGUISHERS ONLY. NO
INSTRUCTION MANUAL CAN ANTICIPATE ALL POSSIBLE MALFUNCTIONS THAT MAY BE
ENCOUNTERED IN THE SERVICE OF FIRE EXTINGUISHERS. DUE TO THE POSSIBILITY THAT PRIOR
SERVICE PERFORMED ON THIS EQUIPMENT MAY HAVE BEEN IMPROPERLY DONE, IT IS
EXTREMELY IMPORTANT THAT ALL WARNINGS, CAUTIONS, AND NOTES IN THIS MANUAL BE
CAREFULLY OBSERVED. FAILURE TO HEED THESE INSTRUCTIONS COULD RESULT IN SERIOUS
INJURY. AMEREX ASSUMES NO LIABILITY FOR SERVICE, MAINTENANCE, OR RECHARGE OF FIRE
EXTINGUISHERS BY PUBLISHING THIS MANUAL.
AMEREX CORPORATION – P.O. BOX 81 – TRUSSVILLE, ALABAMA 35173-0081
Phone: [phone] Fax: [phone]
e-mail: [e-mail] Web Page: http://www.amerex-fire.com
REFERENCES IN THIS MAUNUAL:
NFPA 10 Portable Fire Extinguishers
JJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJ
CGA C-1 Methods for Pressure Testing Compressed Gas
Cylinders
CGA C-6 Standard for Visual Inspection of Steel
Compressed Gas Cylinders.
National Fire Code of Canada
AVAILABLE FROM:
National Fire Protection Association, 1 Batterymarch Park,
Quincy, MA 02169-7471
Compressed Gas Association, 14501 George Carter Way,
Chantilly, VA 20151-2923
Compressed Gas Association, 14501 George Carter Way,
Chantilly, VA 20151-2923
National Research Council Canada, 1200 Montreal Road,
Building M-58 Ottawa, ON K1A 0R6 Canada

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INTRODUCTION
THIS MANUAL IS ATTACHED TO EVERY NEW EXTINGUISHER SHIPPED FROM THE FACTORY. IT
CONTAINS VALUABLE INFORMATION WHICH SHALL BE STUDIED BY EVERYONE WHO WILL USE
OR SERVICE THE EXTINGUISHER. THE MANUAL SHALL BE STORED IN A CONVENIENT LOCATION
FOR EASY REFERENCE.
PREPARING YOUR NEW WHEELED EXTINGUISHER FOR USE
1. Remove all shipping straps, and wrappings from unit. Remove attached manual, and review for
proper installation and use of your extinguisher. This wheeled extinguisher is filled at the factory.
2. Examine the extinguisher for shipping damage. If any damage is noted, contact delivering carrier
and request inspection before removing from pallet.
3. Remove extinguisher from pallet.
4. Disconnect discharge hose assembly from agent cylinder. Make sure hose and nozzle is
unobstructed. Verify moisture seal is undamaged and properly seated on the agent cylinder
discharge fitting.
5. Reconnect the discharge hose to the agent cylinder and with the valve in the closed (forward)
position, place it in the holder on the hose rack.
6. Remove the agent cylinder fill cap, and examine the agent for proper type and condition. Replace
the fill cap tightly.
7. Remove the nitrogen cylinder shipping cap. Save the cap as it must be installed whenever the
cylinder is transported. Check the cylinder pressure. The gauge shall read approximately 2015 PSI
(13.9 MPa) at 70*F (21*C) ambient temperature. The “T” handle valve shall have a pull pin and
tamper seal Installed.
8. Remove and save the safety vent plug installed on outlet of T-handle gas cylinder valve. Connect
the gas supply hose firmly into the nitrogen cylinder valve making sure hose is kink free.
9. Record the date the extinguisher is place into service on the inspection tag, and attach it to the
extinguisher. Remove the “preparing your new wheeled extinguisher for use” instruction tag.
INSTALLATION
WARNING: DO NOT PLACE THIS EXTINGUISHER CLOSE TO A POTENTIAL FIRE.
Do not place this extinguisher close to a potential fire hazard. Amerex recommends location no less than a 50
-foot distance from the hazard while leaving an unobstructed access. Avoid placing it in an extremely hot or
cold place. The operational temperature range for this extinguisher is -65°F to +120°F (-54°C to +49°C).
The extinguisher shall be adequately protected if temperatures outside of this range are anticipated. Keep the
extinguisher clean and free from dirt, ice, chemicals, and any contaminants that may interfere with its proper
operation. DO NOT FUNCTIONALLY TEST THIS FIRE EXTINGUISHER. (Testing or any use may cause the
extinguisher to gradually lose pressure over a period of time and make the extinguisher ineffective.)

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OPERATION
NOTE: Persons expected to use this extinguisher shall be trained in initiating its operation and in
the proper fire-fighting technique. Familiarize all personnel with this information before an
emergency occurs.
1. Move the extinguisher to within approximately 50 feet of the fire site and keep extinguisher upright.
Remove pull pin and pull “T” handle to open nitrogen cylinder valve. This will pressurize the extinguisher.
2. Remove nozzle from the mount and with the nozzle lever in the closed position, pull hose from rack.
3. Start back 30 feet (10 m) from the fire, and aim at base of fire nearest you.
4. Open hose and nozzle firmly and be prepared for discharge recoil. Open nozzle by pulling the handle fully
toward you. Slowly sweep side to side across the base of the fire and past both edges. Progressively
follow up until the fire is extinguished.
DISCHARGE TIME (APPROXIMATE) - 48 TO 60 SECONDS
EFFECTIVE RANGE OF THE AGENT THROW - 30 to 40 feet (9 TO 12 m)
HOSE LENGTH – 50 feet (15.24 m)
SHUTDOWN
1. After making sure that the fire has been completely extinguished, close the nozzle valve, and close
nitrogen cylinder valve (push “T” handle to closed position). Wheeled Extinguisher – Tip over until it
rests on both wheels and handle (in this position much of the remaining chemical will stay in the cylinder).
2. Open the nozzle valve slowly to clear the hose of any remaining pressure and chemical (be prepared for
recoil and discharge of agent).
WARNING: MAKE SURE THAT ALL PRESSURE HAS ESCAPED BEFORE ANY FURTHER
DISASSEMBLY.
3. Stand unit upright after complete depressurization.
NOTE: Nitrogen pressure in the agent cylinder cannot escape through a disconnected nitrogen
hose assembly due to a check valve in the system. Always be careful when removing the
fill cap.
4. Coil the extinguisher hose onto the storage rack and position the nozzle onto the mount in preparation for
transport to the recharge location.
CAUTION: DO NOT TRANSPORT A NITROGEN CYLINDER WITHOUT INSTALLING THE
PROTECTIVE SHIPPING CAP.

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INSPECTING THE EXTINGUISHER
NFPA 10 - This extinguisher must be inspected at regular intervals (monthly or more often if circumstances
dictate) to insure that it is ready for use. Inspection is a "quick check" that a fire extinguisher is available and
is in operating condition. It is intended to give reasonable assurance that the fire extinguisher is fully charged.
This is done by verifying that it is in its designated place, that it has not been actuated or tampered with and
that there is no obvious physical damage or condition to prevent its operation.
PERIODIC INSPECTION PROCEDURES
(Monthly or more often if circumstances dictate)
A “quick check” shall be made of the extinguisher for the following:
1. Located in designated place.
2. No obstructions to access or visibility.
3. Operating instructions on pictogram and facing outward.
4. Tamper seal not broken or missing.
5. Determine fullness by weighing (full weight is noted on the nameplate).
6. Examine for obvious physical damage, corrosion, leakage, or clogged nozzle.
7. Pressure gauge (nitrogen cylinder) reading in operable area.
8. Condition of tires and wheels, carriage, hose, and nozzle.
MAINTENANCE
At least once a year, or more frequently if circumstances require, maintenance shall be performed.
Maintenance is a "thorough check" of the extinguisher. It is intended to give maximum assurance that a fire
extinguisher will operate effectively and safely. It includes a thorough examination for physical damage or
condition to prevent its operation and any necessary repair or replacement. It will normally reveal if
hydrostatic testing is required.
NOTE: NFPA 10 spells out wheeled extinguisher maintenance procedures. NFPA requires that
regulators on wheeled extinguishers be checked annually to meet manufacturer’s “dead-set” and
“minimum-flow” recommendations. This information is provided in a special section on page 6 (R-
a thru R-d) for Amerex Regulated Wheeled Models 467, 468, 469, 470, 471 & 472.
NOTE: The Getz Equipment Universal Wheeled Unit Test Kit is available so that NFPA 10 required
maintenance functions can be performed.
ANNUAL MAINTENANCE – SERVICE PROCEDURE
WARNING: BEFORE SERVICING, BE SURE THE EXTINGUISHER AGENT CYLINDER IS NOT
PRESSURIZED. THIS PROCEDURE IS BEST ACCOMPLISHED WITH THE
EXTINGUISHER IN AN UPRIGHT POSITION AND ON A LEVEL SURFACE.
1. Clean extinguisher to remove dirt, grease, or foreign material. Check to make sure that the instruction
pictogram and nameplate is securely fastened and legible. Inspect the cylinders for corrosion, abrasion,
dents, or weld damage. If any damage is found, hydrostatically test in accordance with instructions in
CGA C-1 and C-6 and NFPA 10.
2. Inspect the extinguisher for damaged, missing, or substitute parts. A careful inspection shall be made of
the safety relief (MODELS 450, 451 & 452) to make sure that it has not ruptured, corroded, or been
tampered with. ONLY FACTORY-REPLACEMENT PARTS ARE APPROVED FOR USE ON AMEREX
FIRE EXTINGUISHERS.

PN 05605 04/2020
3. Check the date of manufacture printed on the extinguisher label (nameplate) or on the agent cylinder
dome. The agent cylinder, discharge hose assembly, and nitrogen supply hose must be hydrostatically
tested every 12 years. Test pressure:
a. Agent Cylinder – 500 psi (3447 kPa)
b. Hose Assembly – 300 psi (2068 kPa)
c. Nitrogen Supply hose assembly - 3000 psi (20,684 kPa)
4. Check the hydrostatic test date on the crown of the nitrogen cylinder. The nitrogen cylinder must be
retested in accordance with DOT regulations.
5. Check the gauge on the nitrogen cylinder. If the pressure is below 1700 psi (11.7 MPa) re-pressurize the
cylinder to 2015 psi (13.9 MPa) or replace it. A low gauge pressure may indicate leakage. Check for
leaks. A low gauge reading may also result from low temperature. See the temperature/pressure
relationship chart in the Troubleshooting Guide. Check the tamper seal on the nitrogen valve, and replace
if necessary.
6. Wheeled extinguishers – Inspect the wheels to insure they rotate freely. Lubricate as required.
WARNING: THE FOLLOWING STEPS SHALL ONLY BE PERFORMED BY PROFESSIONALLY
TRAINED AND QUALIFIED SERVICE PERSONNEL THOROUGHLY FAMILIAR WITH
INDUSTRY SERVICE PROCEDURES AND SAFETY PRECAUTIONS AND HAVING THE
NECESSARY EQUIPMENT TO PERFORM THE SERVICE PROPERLY. ALL
EXTINGUISHER AND SERVICE EQUIPMENT COMPONENTS, FITTINGS, AND
ADAPTERS MUST BE IN GOOD CONDIITON AND PROPERLY CONNECTED.
MAINTENANCE OF REGULATED WHEELED EXTINGUISHERS
NOTE: Steps R-a thru R-d apply to models with a Regulator. These procedures shall be performed
only by professionally trained and qualified service personnel thoroughly familiar with industry
service procedures and safety precautions. All extinguisher and service equipment components,
fittings, and adapters must be in good condition and properly connected.
The only regulator used on Amerex dry chemical regulated wheeled extinguishers is Victor PN 1333,
Model 450E.
NOTE: Prior to performing minimum-flow check, make sure that the nitrogen cylinder valve (“T”
handle or handwheel) is FULLY OPEN so that it does not restrict or alter the readings.
R-a. Disconnect the regulator from the agent cylinder. Visually examine the regulator and high-pressure hose
for signs of damage, corrosion, or deterioration. To perform the regulator static pressure, dead-set, and
minimum-pressure flow rate checks. Connect the proper hose service kit adapter to the low-pressure
outlet port of the regulator. Connect the service kit hose assembly and flow chamber to the regulator low
pressure port adapter.
R-b. Make sure all service kit connections are secure and that the kit flow chamber valve is closed. Check
nitrogen cylinder pressure to ensure that it is within the acceptable operating pressure range (1,700 psi,
11.7 MPa minimum). Hold the kit flow chamber in one hand, and slowly open the nitrogen cylinder (with
either the “T” handle operating lever or by turning the handwheel if so equipped). Observe flow chamber
pressure reading to see if it is within the specified static dead-set pressure of 140 psi (965 kPa)
minimum.

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WARNING: IF THE PRESSURE READING EXCEEDS THE GIVEN PARAMETERS, QUICKLY CLOSE THE
NITROGEN CYLINDER “T” HANDLE OR HANDWHEEL VALVE AND VENT THE PRESSURE
BY OPENING THE FLOW CHAMBER BALL VALVE. REGULATORS CANNOT BE FIELD
ADJUSTED – THEY MUST BE REPLACED IF FOUND TO BE OUT OF TOLERANCE.
R-c. Observe the proper regulator static dead-set pressure for a minimum of one minute – then fully open the
flow chamber valve for 1 to 2 seconds, and observe the pressure reading to ensure that the flow
pressure is between 225 and 245 psi (1551 and 1689 kPa). Close the nitrogen cylinder valve after the
test and vent the flow chamber pressure by opening the flow chamber valve.
R-d. Disconnect the service kit quick connect adapter from the low-pressure regulator, and reinstall the
regulator securely to the agent cylinder. (THIS STEP IS FOR REGULATED EXTINGUISHERS ONLY)
7. Disconnect the discharge hose from the agent cylinder. Check the couplings, hose, and hose gaskets for
damage or deterioration – replace as necessary.
8. To perform an operational integrity check on the discharge hose and valve/nozzle combination:
a. Connect the test kit hose adapter to the female end of the discharge hose.
b. Connect the discharge valve/nozzle to the hose and properly secure it.
c. Connect a properly regulated and verified nitrogen pressure source (set to the extinguisher operating
pressure 235-245 psi) to the test kit hose adapter.
d. Slowly pressurize the discharge hose/valve/nozzle assembly to the extinguisher operating pressure
and check for leaks or distortion.
e. Operate the discharge valve lever to ensure proper operation and to clear the hose of any obstructions
(if hose is obstructed – refer to Troubleshooting section of this manual.
f. Close the nitrogen pressure source and slowly relieve remaining pressure by fully opening the
discharge valve lever.
9. Remove the agent cylinder fill cap and examine it closely for any signs of damage, cracks, or thread wear.
Clean the agent cylinder fill cap threads and thread vent port on the cap with a stiff bristle nylon brush.
Remove the fill cap gasket and check for wear, cracks, or tears – replace if necessary. Lightly lubricate
the gasket with V-711 and reinstall.
10. Examine the dry chemical agent for proper type and condition. Replace chemical that is contaminated,
caked, or other than the type indicated on the nameplate (label). Do not trust the height of the chemical in
the cylinder when determining agent fill. Dry chemical settles and the only true indication of agent fill is to
weigh the extinguisher and compare with the weight indicated on the nameplate (label).
11. Place the service kit Vent Spacer on top of the agent cylinder fill opening collar. Check again to see that
the fill cap thread vent is clean and that the agent fill cap gasket is in place. Install the agent fill cap
securely over the vent spacer.
CAUTION: (STEP 12) The agent cylinder cap threads must be clear and the cap securely installed
onto the vent spacer and agent cylinder to allow pressure to slowly vent after performing the
siphon tube clearing and gas tube integrity checks.
12. To perform a siphon tube clearing and gas tube integrity check:
a. Remove the service kit Agent Hose Adapter from the discharge hose assembly, and install it securely onto
the agent cylinder siphon tube outlet.

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b. Using a regulated nitrogen pressure source, set to the extinguisher operating pressure, slowly and briefly
pressurize the agent cylinder (the siphon tube shall be clear within a couple of seconds and the
agent cylinder pressure slowly vent from the fill cap thread vent). Pressure and/or dry chemical
agent leaks from the gas tube inlet port (where the nitrogen hose connects) will indicate a defective gas
tube and will require that the agent cylinder be emptied and the gas tube replaced.
c. Close the nitrogen pressure source and allow all pressure to slowly vent from the thread vent port on the
fill cap.
d. AFTER ALL PRESSURE HAS BEEN RELIEVED, SLOWLY OPEN THE FILL CAP, AND REMOVE THE
TEST KIT VENT SPACER.
e. Re-examine the agent to determine if any obstructions were cleared from the siphon tube and have risen
to the surface.
f. Clean the fill cap and agent cylinder thread surfaces. Securely install the fill cap gasket and fill cap.
13. Disconnect the high-pressure hose from the nitrogen cylinder valve. Securely install the service kit
Nitrogen Cylinder Pressure Check Gauge Assembly to the nitrogen cylinder valve outlet, and verify the
indicated cylinder gauge pressure. Nitrogen pressure shall conform to the temperature correction chart
provided in the Troubleshooting section of this manual. Close the nitrogen cylinder valve and disconnect
the Pressure Check Gauge Assembly.
WARNING: IF THE NITROGEN CYLINDER VALVE HAS A "T" HANDLE QUICK OPENING OR A
HANDWHEEL QUICK OPENING TRIP RELEASE, THE SAFETY VENT PLUG SHIPPED
WITH THE EXTINGUISHER, OR THE TEST KIT SAFETY VENT PLUG MUST BE
INSTALLED TO PROTECT SERVICE PERSONNEL FROM A HIGH VELOCITY
DISCHARGE IN CASE THE LEVER IS ACCIDENTALLY OPENED.
14. Install a new Amerex Moisture Seal per instructions in the package. Securely connect the discharge hose
to the extinguisher. When assembling the hose to the agent cylinder or nozzle to the hose, tighten
the coupling ¼ turn after contacting the hose gasket.
15. Coil the hose on to the extinguisher hose rack using the Reverse Loop Procedure (see instructions in this
manual). Install shut-off nozzle with the lever in the Closed (forward) position into the nozzle mount.
16. Remove the safety vent plug from the nitrogen cylinder. Reconnect the high-pressure hose securely to the
nitrogen cylinder valve. Wipe the extinguisher clean. Record service data on the inspection tag according
to NFPA 10 requirements, and attach to extinguisher. Return extinguisher to its proper location.
RECHARGE
NFPA 10 – Recharging is the replacement of the extinguishing agent and also includes the expellant
gas for this type of extinguisher.
RECHARGING PROCEDURE
WARNING: BEFORE ATTEMPTING TO RECHARGE, BE SURE THIS EXTINGUISHER IS
COMPLETELY DEPRESSURIZED. THERE IS A CHECK VALVE IN THE SYSTEM,
WHICH PREVENTS NITROGEN PRESSURE FROM ESCAPING FROM THE AGENT
CYLINDER WHEN THE NITROGEN HOSE IS DISCONNECTED. THE AGENT CYLINDER
MAY BE PRESSURIZED EVEN THOUGH NO PRESSURE ESCAPES FROM THE
CYLINDER NITROGEN CONNECTION.
NOTE: THIS STEP (R-d.) IS FOR REGULATED EXTINGUISHERS ONLY
R-d. Disconnect the service kit quick connector adapter from the low-pressure port of the regulator, and
reinstall the regulator securely to the agent cylinder.

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NOTE: Proper procedure for recharging any dry chemical extinguisher includes the use of a
closed recovery system (NFPA 10). Getz Equipment offers several systems ideal for this
application that provide for the recovery of the remaining agent by direct discharge into
the system, trapping the “fines” while allowing the nitrogen to escape and provides a more
accurate fill of the extinguisher.
IF A “CLOSED-RECOVERY SYSTEM” IS NOT AVAILABLE PROCEED AS FOLLOWS:
1. To depressurize:
a. Close the nitrogen cylinder valve.
b. Carefully tip extinguisher over until it rests on both wheels and handle. (In this position much of the
agent will remain in the cylinder.)
c. Open nozzle valve slowly to clear hose of any remaining pressure and chemical (be prepared for a
recoil and discharge of agent.)
d. Insure that all pressure has escaped before further disassembly.
e. Stand extinguisher upright after complete depressurization.
2. Complete steps 1-6 of Maintenance Procedures. Carefully remove the fill cap. Detach discharge hose
from the agent cylinder and the nozzle assembly from the hose. Blow out any chemical remaining in the
hose. While performing this procedure, all parts and seals shall be cleaned, inspected, and replaced
where necessary.
3. Remove shutoff nozzle assembly from discharge hose and clean thoroughly. Check to make sure that the
valve is closed when the lever is in the forward position (toward the nozzle tip).
4. Detach hose from nitrogen cylinder, install the shipping cap, unscrew the wing nuts, and remove the
nitrogen cylinder from the extinguisher.
5. Remove the 50’ discharge hose from the storage rack, and disconnect the hose from the agent cylinder
fitting. Blow out any dry chemical agent remaining in the hose. Clean hose – remove and discard the
hose gasket from the female coupling.
6. Remove remainder of ruptured moisture seal from the agent cylinder fitting. Replace with new Moisture
Seal Assembly. Carefully follow the installation instructions on the Moisture Seal Assembly
package.
7. Remove the agent cylinder fill cap and gasket. Clean fill cap threads and vent port, lubricate the cap
gasket, and set parts aside. Check the condition and type of any remaining chemical (replace any dry
chemical that is contaminated or caked). Fill extinguisher with the type and amount of dry chemical shown
on the extinguisher nameplate (label) – verify gross weight. Clean agent cylinder collar threads. Install the
fill cap and tighten securely.
WARNING: DO NOT OVERFILL THE EXTINGUISHER. THIS COULD CAUSE A MALFUNCTION. DO
NOT MIX TYPES OF AGENTS – THIS CAN CAUSE A DANGEROUS PRESSURE BUILD
UP AND REDUCE EXTINGUISHER EFFECTIVENESS.
8. Install the proper nitrogen cylinder (pressurized to 2015 psi, 13.89 MPa), remove the shipping cap, place
on the extinguisher, and attach the nitrogen hose.
9. Reattach the discharge hose to the extinguisher (tighten hand tight plus a ¼ turn). Properly coil the hose
onto the storage rack (see page 11). Reattach the shutoff nozzle firmly to the hose, and store it in the
mount with the shutoff lever in the closed (forward) position.
10. Record the service date on the inspection tag, and place the extinguisher in its proper location.

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TROUBLESHOOTING GUIDE
WARNING: BEFORE ATTEMPTING TO CORRECT ANY LEAKAGE PROBLEM, BE SURE THAT THE
AGENT CYLINDER IS COMPLETELY DEPRESSURIZED. Always use caution when opening
the shutoff nozzle or any other connection as a leaking nitrogen cylinder valve seat may
have pressurized the agent cylinder. Refer to the recharge procedure for proper method
of depressurization.
PROBLEM CORRECTIVE ACTION
1.
Nitrogen cylinder gauge
reads low or high
Temperature may have affected the pressure reading
Temperature (F) 35º 70º 120º
Temperature (C) 2º 21º 49º
Recommended Pressure
psi 1880 2015 2200
MPa 13.0 13.9 15.2
Minimum Pressure
psi 1590 1700 1900
MPa 11.0 11.7 13.1
NO CORRECTIVE ACTION IS REQUIRED IF THE PRESSURE
IS WITHIN PARAMETERS STATED ABOVE.
2.
Nitrogen pressure is too low.
Valve is closed. Tamper seal
is intact. There is pressure in
the agent and nitrogen
cylinders.
Valve seat has leaked and has pressurized the agent cylinder.
Follow Recharge Procedure for restoring the extinguisher to
service.
3.
Nitrogen pressure is too low.
Valve is closed. Tamper seal
is intact. No pressure
observed in the agent
cylinder.
Leakage in the nitrogen valve at other than the valve seal.
Replace with a properly charged nitrogen cylinder.
4.
Shutoff nozzle does not move
freely.
Disassemble, clean, and lubricate.
5.
Unable to remove the agent
cylinder cap.
Agent cylinder may be pressurized. Make no further attempt to
remove the cap until this is checked. See the Recharge
Procedure for proper depressurization method.
6. Nitrogen hose cut, cracked or
abraded.
Replace hose assembly.
7.
Chemical agent and pressure
leaking from the safety disc
assembly. (Models 450, 451,
452)
Inspect safety outlet for tightness or damage. Tighten if
necessary. NOTE: Only tighten the large hex nut of the
assembly. The small round nut containing the holes is factory set
to a specific torque value. Do not attempt to adjust. If damaged
or ruptured, replace complete Amerex Safety Disc Assembly.

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Guide to Proper Installation of Hose on
Wheeled Fire Extinguishers
1
Connect hose coupling to outlet on the
extinguisher. Lay hose straight on ground
to its full 50-foot. (15.24 m) length. Start
first regular loop counter-clockwise by
placing between side brackets and over
the top bracket.
2
The second loop is a REVERSE loop. Notice
that the hose passes behind the loop on this
reverse loop. If instructions are followed, the
hose will uncoil without kinks.
3
The next loop is a regular "hose in front"
loop. Succeeding loops are alternated:
reverse, front, reverse, etc. for six full loops.
4
Adjust the loops so that the nozzle fits into
the nozzle mount. Loops shall be
approximately the same size