Visor; Description Of Operating Principle - INTERSPIRO DIVATOR-Vollmaske Benutzerhandbuch

visor

the visor (figure 2) is designed to minimize the volume of air inside the full face
mask to reduce the positive buoyancy. If it is necessary to adjust the mask to a neutral
buoyancy, weights are available which can be attached to each side of the visor. the
visor is close to the wearer's eyes which gives the user a wider field of vision. The
sides of the visor have a matte finish to avoid optical distortions.
Additional mounting system for attaching lights, cameras, welding visors, etc. to the
visor are available from Interspiro.

Description oF operating principle

the mask is provided with an inner mask and separate inhalation and exhalation
channels that connect with channels in the breathing valve. this ensures that
inhalation and exhalation air will not be mixed. During inhalation, air flows from
the breathing valve up through the anti-fogging ports, over the inside of the visor,
and through the non-return valves into the inner mask. during exhalation, the air is
exhaled to the ambient water through the exhalation valve.
mask and breathing valve parts indicated in figure 3:
1 diaphragm assembly
2 lever
3 sealing spring
4 sealing cone
5 connection nipple
6 non-return valve (two)
7 exhalation channel
the following describes the operation of the breathing valve. refer to figure 3.
when the diver inhales, the diaphragm assembly (1) is drawn inward and pushes on
the lever (2). the lever lifts the sealing cone (4) from the valve seat on the connection
nipple (5). Breathing air can now flow through the inhalation channel and into
the inner mask through the non-return valves (6). when the diver stops inhaling,
the diaphragm assembly (1), lever (2) and sealing cone (4) return to their initial
positions, and the inlet is closed by the sealing spring (3). when the diver exhales,
air flows from the inner mask through the exhalation channel (7) and the exhalation
valve (8) and lifts the sealing disc (10). This allows air to flow out to the ambient
water through the slits in the cover (9). the relief valve mechanism serves as a safety
valve for the first stage regulator, since the sealing cone opens automatically if the
secondary pressure increases to between 13-17 bar (189-247 psi). this may happen,
for instance, if the regulator leaks. In this case, the relief valve spring (12) can no
longer withstand the pressure on the central part of the balancing diaphragm (13).
the counter-pressure piston is then pressed inwards and actuated so that the valve
mechanism lifts and pulls the sealing cone away from the valve seat. Air is then
released until the pressure falls to about 10 bar (145 psi). the breathing valve has a
non-return valve (not shown) in the inhalation channel to prevent water entering and
to minimize the risk of freezing.
8 exhalation valve
9 cover
10 sealing disc
11 relief valve piston
12 relief valve spring
13 Balancing diaphragm
11