COLD WEATHER OPERATION
SUGGESTED PROCEDURES FOR COLD WEATHER
OPERATION
Moisture can cause problems in air masks if it freezes.
However, moisture can cause freezing problems even if
the surrounding air is above freezing. This is due to air
flowing from the cylinder through the regulator drops from
cylinder pressure to close to atmospheric pressure very
quickly. As it does so it expands, causing the air and the
regulator to become colder. Although the surrounding
temperature may be warmer than 32°F, the temperature
inside the regulator may be lower. Any water inside could
turn to ice and restrict air flow.
1. To keep moisture from entering the mask mounted
regulator. Stow the regulator in the stand-by belt
mount.
2. When the air mask is away from heat, water can
freeze on the regulator surface. Ice can build up and
freeze the buttons, bypass valve, and the release tabs.
Before entering or re-entering a hazardous atmos-
phere, make sure the buttons, release tabs, and
bypass valve are ice-free and operating properly.
Periodically, check the bypass to be sure it is ice-free.
3. Moisture can enter through the cylinder valve or cou-
pling nut when cylinders are replaced on the air mask.
When replacing cylinders, be careful to prevent mois-
ture or contamination from entering the system.
Remove any ice from these fittings. Wipe the coupling
nut threads and cylinder valve threads dry before dis-
connecting the cylinder. Water can contaminate the
system and freeze.
4. NIOSH certification requires a nosecup at tempera-
tures below 32°F. The nosecup reduces lens fogging
and must be used whenever freezing conditions are
encountered.
5. Thoroughly dry the facepiece and mask mounted reg-
ulator after cleaning and disinfecting. Follow
Confidence Plus
®
Cleaning Solution Instructions.
19
TAL 601 (L) Rev. 5 - 10041214
