INTERSPIRO DIVATOR MKII, Manual

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Cold water conditions / Low air
temperatures
Freezing may result in more or less serious malfunctions. These malfunctions
can be reduced or prevented by the measures described in this document.
Expansion of air causes the inhalation part of the breathing valve to be cooled
to about 15 °C / 59 °F below the ambient temperature. Any moisture in the inlet
section of the breathing valve might freeze to ice with the risk of causing free
flow or that the valve becomes completely blocked.
Moisture can find its way into the breathing valve in the following ways:
1. The breathing valve has been washed in water but not properly dried.
2. The non-return valve of the breathing valve is not watertight.
3. The breathing valve is immersed in water.
4. By moisture from medium pressure hoses.
5. By moist air from the cylinder.
6. By moisture from DP1 surface supply unit.
It is important that the breathing valve and medium pressure hoses are
absolutely dry when starting a dive in cold conditions. The breathing valve
is the most common part of the breathing equipment to freeze during a dive.
The breathing valve may be disassembled to allow all parts to completely dry
or they can be manually dried, before starting a dive in cold conditions. If
the operating procedure at the dive does not allow the breathing valve to be
disassembled, make sure to use a valve that is dry.
To avoid moist from cylinders it is important that the gas used for filling the
cylinders meets the requirements in EN12021 of according maximum water
content.
If surface supply is used, use a completely dry P+ regulator and dry DP1
surface supply hose. The anti freezing cap shall be checked before the dive
and be completely dry. Dry the P+ regulator and hose by using the vent
handle before the dive to remove any moisture from the system. The surface
supply system should be pressurized when using the vent handle to expel any
moisture without allowing new mositure to enter.
Diving in extreme conditions
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