Seac Sub SYNCHRO Serie Manuel D'instructions page 25

The membrane is made in transparent, elastic
silicon while the central disk is made from ac-
etate resin to eliminate any friction in order
to further facilitate inhalation.
The casing is produced from synthetic resin,
particularly resistant to impact, abrasion, ul-
traviolet rays, and external chemical agents.
The O-rings are in nitrile rubber subdivided
into different degrees of hardness (shore) ac-
cording to their applications. The internal
components are made from chrome-plated
brass and stainless steel.
The operation is of the "Downstream" type.
This system allows for low air consumption by
reducing air waste, as it perfectly meets the
breathing demand.
This means that the air flow delivery is per-
fectly controlled by the diver's breathing ac-
tion: a normal breathing action produces a
light air flow, while heavy breathing due to
fatigue or deep diving produces a free air
flow, also increased by the Venturi effect.
In addition, this system also provides safety
margins in case of first stage overpressure:
should the intermediate pressure supplied by
the first stage suddenly increase, the second
stage would continue to work, thus releasing
excess pressure and enabling the diver to
breathe.
The control of the DIVE and PRE-DIVE mecha-
nism adjust the Venturi effect. The lever, reg-
ulating the breathing effort reduction sys-
tem, control this system. By actuating this
mechanism placed to the left of the second
stage you can adjust the Venturi effect and
consequently increase air delivery.
By turning the lever towards the outside you
reach the "DIVE" position, and by turning the
lever towards the diver you reach the "PRE-
DIVE" position (Fig. 11).
The "PRE-DIVE" position is recommended to
prevent accidental delivery when the regula-
tor is under pressure but not in use, while the
"DIVE" position is recommended during the
dive.
Warning! Move the lever to "PRE-DIVE" only
when the regulator is not used, and rotate it
to "DIVE" before starting diving.
26
Fig. 11
SYNCHRO OCTO.
The technical specifications and the materials
used for the SYNCHRO OCTO are the same as
for the second stage version assembled on
the previous described D-SYNCHRO, D-SYN-
CHRO ICE, M-SYNCHRO and P-SYNCHRO reg-
ulators.
The only differences are in the color of the
shield, which is yellow, especially designed for
easy identification in case of quick use, and in
the hose, which is also yellow. The latter is es-
pecially made with a length of 1000 mm (3/8"
thread) for easier use in emergency condi-
tions.
We recommend correct positioning of the
SYNCHRO OCTO to PRE-DIVE and with the air
flow regulation knob fully screwed up if it is
used as an auxiliary or emergency regulator.
A certified technician shall only carry out as-
sembly of the SYCHRO OCTO first stage in or-
der to ensure the functionality and safety re-
quirements needed.
Use a common 4 mm Allen key to remove the
low pressure port closing cap (3/8" thread)
then make sure that the O-ring is present, in-
serted and positioned in the hose over the
relevant thread. Screw up the hose with your
fingers until the end stop is met, and then
tighten the nut with a 14 mm spanner with-
out using excessive force.
Check for proper operation by putting the as-
sembled regulator under pressure from a
cylinder before the dive.
Warning!
For safety reasons you are recommended to
use the SYNCHRO OCTO only on the D-SYN-
CHRO, D-SYNCHRO ICE, M-SYNCHRO and P-
SYNCHRO first stages having an intermediate
pressure of 9.8/10,2 bar.