(2) Rotate the canisters to ensure the absorption capacity of the soda lime
is more fully used.
(a) Fill the top canister with fresh soda lime.
(b) Replace the lower canister with the top canister.
Replace the top canister with the lower canister.
b. Check Valve Maintenance. Periodically, ensure that the check valve is
clean. Refer to figure 1-3 to see an exploded view of the control head.
Avoid damaging the seat. Do not pull on the valve disc.
Check for valve cleanliness.
Disassemble the valve if it is not clean.
(a) Unscrew the threaded ring.
(b) Lift off the window and gasket.
Pull the valve cage and the valve disc off the seat.
Figure 1-3. Control head-check valve.