Breathing Loop
FX Counterlungs
The FX-CCR unit is equipped with 3D shaped Counterlungs designed as gas-tight bags of a cuboid
shape, made of soft Cordura with inner PU coating.
The Counterlungs are located above the Canister and have unique and secure Click-Lock Bayonet
Couplers for easy connection and disconnection to the breathing loop.
The Click-Lock Bayonet Couplers have different keying on each bayonet connector, which makes it
impossible to connect the counterlungs incorrectly.
The exhalation counterlung is equipped with an internal snorkel
to prevent water from flowing directly into the
canister and with an adjustable Over pressure /
dump valve allowing also to drain eventual
water. The overpressure/dump valve can be
manually operated by pulling the cord.
The Counterlungs are secured in the FX Case using snap rings, enabling them to be quickly and easily
removed and reattached.
The Counterlungs can be easily removed for cleaning, disinfection, drying or storing.
ADV & L-pieces
The L-pieces ensure connection of the breathing hoses with the counterlungs.
They are attached to the counterlungs with click-lock bayonet couplers on the top of the FX case.
The exhalation L-piece is connected to the breathing hose and is attached to the exhale counterlung
with Click-lock bayonet coupler. It has an inlet for manual addition of oxygen to the loop from the Oxy
MAV.
The inhalation ADV L-piece has an integrated Automatic Diluent Valve (ADV) and an inlet for manual
addition of diluent to the loop from the diluent MAV.
The ADV L-piece is connected to the breathing hose and is attached to the inhale counterlung with Click-
lock bayonet coupler.
The ADV is designed in a similar way like a 2nd stage regulator. It is activated by a negative pressure in
the breathing loop and automatically adds diluent to the breathing loop when needed.
The ADV is fed by an LP hose 20cm from the Diluent MAV. This hose is connected to the shut-
off valve that can be used to shut off the diluent gas if necessary. The shut-off valve is
operated by moving the black control ring up or down. It is useful when the diver wants
to have full control over the addition of diluent or in case of malfunction of the ADV.
Breathing hoses
are attached to L-pieces and the free ends are connected to the BOV
Shrimp via the unique and secure Click-Lock Bayonet
Connectors.
It is impossible to connect the breathing hoses
incorrectly due to different keying on each
bayonet coupler on the hoses.
MAVs – manual adding valves
Manual adding valves are used for manual dosing of oxygen and diluent into
the breathing loop and also as an integrated manifold for connecting other
elements.
The Oxygen MAV
is located on the right side of the unit and is intended for manual addition of
oxygen to the breathing loop. It has a manual trigger controlled outlet and a
pass-through outlet.
The manual trigger outlet is used for manual addition of oxygen to the
breathing loop and is connected to the exhalation L-piece via a 25cm blue LP
hose.
The pass-through outlet is connected to the oxygen inlet port on the FX head
via a 62cm blue LP hose to supply the solenoid.
The Oxy MAV is connected to the 1st stage regulator on the oxygen cylinder
via a 10cm LP hose.
The Diluent MAV
is located on the left side of the unit and is intended for manual
addition of diluent to the breathing loop. It has one manual trigger
controlled outlet and two pass-through outlet.
One pass-through outlet is connected via the Shut-off valve and a
20cm LP hose to the ADV port located in the middle of the ADV L-
piece.
The second pass-through outlet is connected via a 56cm LP hose
leading to the 2nd stage of the BOV Shrimp (the Bail-Out Valve).
The outlet controlled by the manual push-button is connected via
an LP hose to the Diluent injection port on the ADV L-piece.
The Diluent MAV inlet is equipped with the QC6 quick connect
coupler connected to the off-board diluent cylinder.
BOV Shrimp (the Bail-Out Valve)
The BOV Shrimp a Bail-out Valve with a 2nd stage
regulator incorporated into the mouthpiece with the
ability of supplying the diver with open circuit
breathing gas when needed. This allow the diver to
have a source of breathing gas at all times.
The BOV Shrimp is a standard part of the FX CCR loop.
The CC/OC valve allows to easily and quickly switch
between the close circuit (the CC mode) and the open
circuit (OC mode) by one hand. It is operated by
rotating the knob on the front of the BOV.
When the BOV is switched to the CC mode –
the breathing loop is open via the mouthpiece
and allows the diver to breathe on the
rebreather closed circuit.
One-way directional valves (mushroom
valves) provide and ensure the correct
breathing gas circulation in the breathing
loop in the correct direction from left to right,
from the inhalation counterlung to the
exhalation counterlung.
When the BOV is switched to the OC mode –
the breathing loop is closed and allows the
diver to breathe on open circuit via the 2nd
stage regulator. In this position no water can
enter the breathing loop even when the BOV
is out of the diver’s mouth and submerged.
The 2nd stage regulator is operable in the OC
mode and allows the diver to breathe an open
circuit bail-out gas. The 2nd stage regulator
has an adjusting knob allowing to adjust
optimal breathing resistance.
The BOV 2nd stage regulator is connected via the LP hose to the diluent MAV. Alternatively it can be
connected to a 1st stage regulator on a off-board bailout stage cylinder.
DSV Shrimp (the Diver Surface Valve)
The DSV Shrimp can be used as an alternative to BOV.
The DSV Shrimp allows to open and close the mouthpiece and breathing loop. It is operated by rotating
the knob on the front of the SM DSV by one hand.
When the SM DSV is switched to the
OPEN mode – the breathing loop is
open via the mouthpiece and allows the
diver to breathe on the rebreather
closed circuit. In this position water can
enter the breathing loop when the DSV
is out of the diver’s mouth.
When the SM DSV is switched to the
CLOSE mode – the breathing loop is
closed and in this position no water can
enter the breathing loop even when the
DSV is out of the diver’s mouth and
submerged.
One-way directional valves (mushroom
valves) provide and ensure the correct
breathing gas circulation in the
breathing loop in the correct direction
from left to right, from the inhalation
counterlung to the exhalation
counterlung.
Breathing hoses are connected to the SM DSV via the unique and secure Click-Lock Bayonet Couplers.
It is impossible to connect the breathing hoses incorrectly due to different keying on each bayonet
connector on the loop.
Learn more about FX CCR: