Final Check Valve - Sunrise Medical DeVilbiss 505DZ Service Manual

C O M P O N E N T T E S T I N G , R E P A I R & R E P L A C E M E N T

Final Check Valve

Another check valve is located between the final bacteria filter and the oxygen outlet fitting.This check valve allows only oxygen to
flow out of the unit.When the unit is turned off and oxygen flow stops, the check valve closes to prevent water from being drawn
into the unit.
A defective final check valve may allow water to be drawn in from the humidifier bottle when the unit is turned off.This may occlude
the final bacteria filter and/or the flow meter causing a restriction of flow and making it difficult to adjust the flow rate.
To replace the final check valve (Figure 25, 26, & 27):
1. Ensure the unit is unplugged from the wall outlet.
2. Remove the front and back cabinets and loosen the bib.
3. Remove the hose from the outlet side of the final bacteria filter.
4. Remove the two screws from the back of the oxygen outlet fitting assembly and remove the assembly.
Figure 25
5. Remove the hose from each end of final check valve.
6. Attach the hoses to a new check valve. Ensure that the flat side of the check valve is directed away from the oxygen outlet port.
7. Replace the outlet fitting assembly and connect the hose to the filter.
Screw
(outlet port)
Oxygen outlet
fitting
assembly
Screw
(outlet port)
Oxygen
outlet port
1/8" I.D. hose
Final check
Oxygen
valve
outlet port
Figure 27
31
Final check
valve
outlet port
Final
Plastic
bacteria
elbow fitting
filter
Figure 26
Bib
Oxygen