User manual
36
6 DIVING
6.1 CHECKS DURING AN ONGOING DIVE
• Read the pressure gauge regularly.
• Make sure that other equipment does not block usage or access to necessary controls and components.
• Check for leaks.
Important: The dive must be terminated when the diver activates the reserve valve. The dive should be
planned with the aim of not using reserve air.
6.2 DIVING IN COLD WATER
Diving in cold water is full of risk and requires special planning and special preparations.
Below is information about the effects cold water can have on the components in the Divator system.
6.2.1 THE REGULATOR UNIT
Internal freezing
First-stage regulators reduce cylinder pressure to approximately 8 bar (116 psi). The air expands with an
accompanying pressure drop and a signicant drop in temperature. If the air is humid, ice crystals can form
thereby risking blockage to the air supply. “Internal freezing” of this kind can also cause a total stoppage
of air. Therefore, always use dry and clean air. Information about quality requirements for the air can be
found in Chapter 8 “Filling”.
Internal freeing can result if the water and/or temperature is low and the regulator's anti-freezing unit is
damaged, when this occurs in combination with the cooling brought about by the pressure drop in the
regulator. If this happens, water will force its way into the regulator and solid ice will form in the spring
housing, resulting in the regulator's mechanism getting stuck in open position. Secondary pressure will rise
to above normal level and open the breathing valve's safety valve. The excess air will then ow through
the face mask (the mouthpiece) and out into the surrounding water. To prevent this, the anti-freezing unit
should be checked before diving.
External freezing
Under extreme conditions, i.e. diving in ice-cold water, it can be difcult, or in the worst case impossible
to operate the reserve valve handle due to ice formation on the outside of the reserve valve handle. If this
occurs, the octopus breathing valve can be used as an emergency air system.
External freezing as described above is very unusual and only occurs in very cold water.