F. CCR Loop w/ built-in water trap

MX Rebreather - CCR Loop w/ built-in water trap

Visually there are “four” breathing hoses to this Closed Circuit Breathing loop. However, in reality there is a right and left side (inhalation and exhalation respectively). They are then broken into two sections. The first section goes from the CO2 Canister and head to the back-mounted counter lungs, while the second section goes from the back-mounted counter lungs to the diver’s interface or mouthpiece. The junction of the two sections is at the back-mounted counter lungs and is a T-piece that is mounted at the highest point of the back-mounted counter lungs (assuming prone position). The T-piece has a divider between the two sections – this, along with the fact that it is at the highest point, effectively creates “a water trap” on both the right and left side.  As the “typical” break  or place for a water intrusion is at the diver’s interface (mouthpiece), the water is exhaled through the loop hose back to the t-piece and then dumped into the back-mounted counter lung. It can be then dumped through the over pressure relief valve (OPV) mounted on the lowest point of the back-mounted counter lung. If the water was to enter into the canister and then pass through the sofnolime, creating a “caustic cocktail”, it would then travel from the canister back towards the diver, but again it would be intercepted by the T-piece water trap in the inhalation side back-mounted counter lung – an additional defense mechanism to this “caustic cocktail”

The T-pieces are also the point at which we inject either the O2 or Diluent. The loop direction is from right to left – inhale right, exhale left. This was chosen to remain within standard OC convention in the that breathing gas regulators come over the right shoulder. This concept also allows injection of the diluent on the right side, as it comes from the right post, and the O2 injection on the left side, as we wear the off-board O2 cylinders on the left side as in standard UTD/DIR. The other advantage to adding O2 on the left is that it is the furtherest point from the diver’s inhalation side.

The water trap dump, or counterlung OPV, is also opposite the diluent injection valve to ensure the diver is able to use his left hand to dump water from the left back-mounted counter lung – the water trap – while simultaneously using his right hand to flush the loop with gas (dil) to drive water from the water trap.