User manual
37
6.2.2 BREATHING VALVE
All breathing valves from Interspiro provide air during inhalation. When the diver inhales, air ows from
the breathing hose through the breathing valve into the diver's lungs. Expansion of the supplied air causes
the air at the valve inow to be cooled to approximately -10°C (14°F) at a water temperature of 0°C (32°F).
Any moisture in the inow section of the breathing valve can then be transformed to ice and thereby increase
friction between the valve mechanism's moving parts to such a degree that the return spring does not close
the valve when inhalation is concluded. If this happens, the breathing valve will ow freely. To minimize the
risk of this occurring, the breathing valve is equipped with a check valve in the inow section of the breath-
ing valve. Moisture can force its way into the breathing valve's inow section for the following reasons:
a
) The breathing valve is cleaned in water and not allowed to dry properly.
b) The breathing valve's check valve is leaking. Information about the leakage test can be found in Chapter
12 “Maintenance”.
c
) The breathing valve is initially submerged in water and then exposed to air with a temperature under
zero degrees prior to diving. To prevent this, the breathing valve should not be submerged in water before
use. If the breathing valve has already been submerged in water, it should be adequately vented.
6.2.3 FULL-FACE MASK
The Divator Full-Face Mask protects the diver's face from being exposed to ice-cold water. The Divator Full-
Face Mask separates inhalation air from exhalation air. This means that moisture in the diver's exhalation
air cannot reach the inhalation valve's inow section through the mask's air channels or through the valve
mechanism. This signicantly reduces the risk of freezing.
6.2.4 OCTOPUS
Octopus has separate channels for inhalation and exhalation. The breathing valve's inhalation opening is
protected against water by a check valve that minimizes the risk of the valve freezing.