Flex has two 3D counterlungs contained in the fenestrated case above the can and sensor head with electronics. Each counterlung has 3 liters to ensure sufficient tidal volume. Getting at the C/Ls to clean them is simply a matter of opening side cover door in the fenestrated case. A nice locking system makes this a quick thing to do, with no chance of it happening accidentally. Once the cover is removed, a clear view of the C/Ls, ADV, OPV, O2 orifice,  and electronics bulkhead is gained.

Counterlung cover door

The system was designed so the counterlungs do not have to be completely reassembled for day to day cleaning and drying. Just remove the CL cover and unclip entire top part from the scrubber can. Remove sensor cartridge. Remove hoses. Unclip lower C/L bayonets. Flush/disinfect C/Ls. Hang the entire assembly by the top handles to drip dry.

bayonet connectors

The counterlungs are attached with bayonet connections to the top plate and the scrubber can at the bottom.  The bayonets use same locking mechanism as the BOV or DSVs.

Each coulterlung/bayonet connection has built-in “snorkel” to prevent water traveling into the scrubber can or into the breathing hoses.

“snorkels”

The snorkels prevent the counterlungs covering the breathing ports. They also serve as an anti-collapse device in each counterlung.  This guarantees continuous gas path through each counterlung under all conditions. Bottom snorkels are attached to the scrubber can head, while top snorkels are built-in into the top counterlung bayonets. The OPV in the exhale C/L serves  as a primary water dump by forcibly exhaling and pulling the string whilst in the appropriate position. This OPV is located in the lowest point of the unit when in sidemount position.  Any water entering the loop should collect here before passing into the scrubber.

3D counterlungs with OPV on the left