b. Make sure the unit is supplied with quantities
faces with a suitable rustproof material after first
of fresh air. Do not operate it in an enclosed area
removing any accumulation of rust.
that does not have ample ventilation.
24. Operation at High Altitudes
c. Fill the fuel tank at the end of each day's op-
eration to prevent condensation of moisture in the
fuel tank.
efficiently at elevations up to 5,000 feet. There will
be a reduction in efficiency because of the rarified air
d. Adjust the carburetor to compensate for the
reduced amount of oxygen available to the carbu-
at this level. This is a normal condition that cannot
retor (TM 52805-208-14).
be prevented.
Section V. OPERATION OF MATERIEL USED IN CONJUNCTION WITH THE EQUIPMENT
d. Maintenance. Weigh fire extinguisher every 3
25. Fire Extinguisher (Monobromotri-
months and replace cylinder if gross weight has
fluoromethane Type)
decreased 4 ounces or more. Lubricate cylinder
a. Description. The monobromotrifluoromethane
neck threads with one drop of OE 30 oil before
type fire extinguisher is generally suitable for all
reassembly.
types of fire, except fires involved with LOX (liquid
oxygen ) generating equipment, The fire extinguisher
is furnished with a disposable type cylinder.
a. Description. The carbon dioxide type fire ex-
b. Operation. To operate the first extinguisher,
tinguisher is suitable for electrical and flammable
perform the following:
liquid fires. The carbon dioxide types are the 4-
(1) Remove first extinguisher from its location.
pound, 7 pound, and 10-pound sizes. The 4-pound
extinguisher is portable, the other two are the fixed
(2) Break seal by pulling safety pin from
type.
handle.
(3) Point horn at base of flame.
b. Operation. Remove the fire extinguisher from
(4) Press trigger for discharge and direct
its location; break the seal, operate the control
stream at base of flame.
valve, and direct the stream at base of the flame.
(5) Replace cylinder immediately after using.
c. Maintenance. For maintenance of the first ex-
tinguisher, refer to TM 5-687.
c. Replacement of Cylinder. To replace cylinder,
perform the following:
27. Fire Extinguisher (Carbon Tetrachloride
(1) Press lever to release pressure from used
Type)
cylinder.
(2) Loosen swivel valve coupling nut and re-
a. Description. The carbon tetrachloride type fire
move valve assembly from used cylinder.
extinguisher is suitable for electrical fires because it
will not damage electrical equipment or conduct
(3) R e m o v e instruction band from used
cylinder.
electricity. It is a l-quart, vaporizing-liquid, pump-
(4) Place new cylinder through instruction
operated extinguisher.
band.
b. Operation. Remove fire extinguisher from its
(5) Replace safety pin in valve and seal pin
location; turn the handle and work the handle like
with sealing wire.
a pump. Direct the stream at base of flame.
(6) Attach valve assembly and tighten swivel
Warning: Be extremely careful when using
coupling nut on the new cylinder and place
a carbon tetrachloride fire extinguisher in a n
fire extinguisher in mounting bracket.
enclosed area. Provide adequate ventilation
(7) Adjust instruction band on cylinder to
before entering an enclosed area where carbon
show maintenance a n d operating in-
structions.
tetrachloride has been used.
