User manual
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3.5.1 WORKING PRINCIPLE
• The pressure regulator is a pressure-balanced, piston-equipped counter-ow regulator. The result of
balancing is rmly reduced pressure (intermediate pressure) that is not affected by pressure uctuations in
the air supply (high-pressure).
The regulator opens at corresponding gas pressure. The principle is called downstream regulation. Thanks
to this, the regulator can regulate pressure from the maximum ow rate to a minimum supply pressure of
approximately 15 bar (218 psi).
The regulator reduces the highest pressure to 8.5 bar (123 psi) dynamic pressure. The constant pressure
regulation results in a sharp temperature drop. If the air is humid, ice crystals can form thereby risking
blockage to the air supply. This is called “internal freezing” and can cause total air stoppage. For this reason,
dry and clean air must always be used. Information about quality requirements for the air can be found in
chapter 8 "Filling".
3.5.2 HIGH-PRESSURE HOSE
• The high-pressure hose consists of a plastic inner hose (sealing layer) clad in metal and aramid (pressure
load absorption) with an outer black plastic jacket of polyurethane (wear protection). Airow to the high-
pressure hose is limited by an orice. This minimizes a rapid pressure drop in the event of a hose rupture,
and protects the pressure gauge from pressure impacts.
3.5.3 RESERVE VALVE HANDLE (CDR)
• The reserve valve handle is used to switch between different air supply units. Air is added either from
the DP1 Supply Hose System, from the diver's cylinder pack or from the cylinder pack's backup volume.
The reserve valve handle is sometimes called the “CDR handle”, whereby CDR represents the handle's
3 positions: Closed - Diving - Reserve.
When diving with surface air, e.g. DP1, the reserve valve handle should be in closed (C) position in order
to ensure that only air from the surface is used. If for some reason the surface air supply is interrupted,
the diver will receive a warning since air is not being supplied from the cylinder pack. If the surface air
supply is interrupted, the diver can simply pull the reserve valve handle to activate the air supply from the
cylinder pack.
For independent diving when only air supply from the cylinder pack is used, the reserve pressure handle
must be opened by pulling it out to diving position (D) so that the air supply from the cylinder pack is
activated.
When the cylinder pressure falls to about 65 bar (943 psi), the air supply warning is activated (which is
indicated by increased breathing resistance). In this case, the diver should pull out the reserve valve handle
to the reserve position (R) in order to subsequently utilize the cylinder pack's reserve air volume.
Pull for air in all diving positions!
C D R
(Closed Diving Reserve)