JFD B44771, Operation And Maintenance Manual, Page: 29 / 136

OM131 17
P1939-OM-131 R11 Chapter 2
2.2.1 Main backpack housing
The main Backpack (Fig 2.2, Item 1) contains the gas cylinders and manifold (Fig 2.2, Item 9), the
charging point and the associated regulators (Fig 2.2, Items 4 & 6) in its lower part. The upper part
of the Backpack contains the CO
2
scrubber housing (Fig 2.2, Item 8) the canister lift mechanism
(Fig 2.2, Item 10), the thermal regenerator (Fig 2.2, Item 12) and the penetrators (Fig 2.2, Item 11).
2.2.2 Scrubber door assembly
The lid screw assembly (Fig 2.2, Item 3) seals the internal CO
2
scrubber housing closed. Access to
the CO2 scrubber canister is obtained by first removing the outer side door (Fig 2.2, Item 13). The
lid screw assembly (Fig 2.2, Item 3) can then be opened by releasing the catch. Within the housing
the refillable CO
2
scrubber canister (Fig 2.2, Item 8) is held in place by the scrubber lift mechanism
(Fig 2.2, Item 10).
2.2.3 CO
2
scrubber canister
During normal diving, hot water is passed through an outer compartment that surrounds the CO
2
scrubber housing (Fig 2.2, Item 8). This water maintains the temperature of the CO
2
scrubber
canister (Fig 2.2, Item 8) and ensures that should the SLS System be required, the CO
2
absorbent
is warm enough to enable the required chemical reaction to take place and absorb the CO
2
.
N
OTE
Failure to connect this water supply could result in a hazard to the user if the SLS System is
required.
2.2.4 CO
2
scrubber canister lift mechanism
The CO
2
scrubber canister lift mechanism (Fig 2.2, Item 10) is secured to the penetrators (Fig 2.2,
Item 11). This lifts the CO
2
scrubber canister (Fig 2.2, Item 8) and presses it against a gasket,
creating the loading necessary to effect a seal. Beneath this mechanism is a highly absorbent
sponge pad which absorbs any moisture (e.g. condensation, saliva etc.) which may collect within
the SLS System when in use. Removal of the CO
2
scrubber lift mechanism (Fig 2.2, Item 10) to give
access to the sponge pad, is facilitated by pressing down on the centre and sliding it towards the
door. This releases it from the locating feature incorporated in the penetrators.
2.2.5 Thermal regenerator
When the CO
2
scrubber canister (Fig 2.2, Item 8) is removed, the thermal regenerator (Fig 2.2, Item
12) may be seen in the upper part of the scrubber housing (Fig 2.2, Item 1). This is a passive device
which recovers heat from the exhaled gas passing to the counterlungs, and uses this heat to then
pre-heat the gas passing from the counterlungs back to the diver.
2.2.6 Penetrators
There are two penetrators (Fig 2.2, Item 11). One contains the restrictor orifice through which the
gas injection enters the SLS System during use. The other penetrator is blank and is used as a
locating pin for the scrubber lift mechanism.