Precision Medical Air-Oxygen Blender User Manual
Page 16
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Air-Oxygen Blender
D. Reverse Gas Flow Procedure
(Reference Operational Verification Procedure #’s 2 & 3 in Table, page 16 or 27.)
1.
Disconnect the oxygen hose from the gas source. Remove all outlet
connections from the Blender to ensure that there is no outlet flow.
2.
Place the free end of the oxygen supply hose under water. Gradually increase
the air supply pressure from 30 - 75 psi (2.07 - 5.17 bar), check for leakage
past the oxygen inlet check valve.
3.
Replace the Duckbill Check Valve in the oxygen inlet if bubbles indicate
leakage.
4.
Repeat steps 1-3 to check for leakage past the air inlet check valve.
5.
Reconnect the air inlet hose and adjust both supply pressures back to
standard inlet pressure.
E. Setup of PROPORTIONING VALVE ASSEMBLY CALIBRATION
1. Set air and oxygen inlet pressures to 50 psi.
2. Set flow to 9 lpm.
3. Turn Adjustment Shaft counterclockwise until the Oxygen Analyzer/Monitor displays
a concentration equal to that of the source air (±0.3), reference Part A in Setup.
4. Attach knob guide assembly onto adjustment shaft of proportioning valve assembly
so that the knob stop rests on top of the screw. Ensure knob stop aligns with the
slot in the resistance ring.
5. While applying downward pressure to the 2 screws on the knob guide assembly,
attach nut to adjustment shaft using nut driver.
6. Turn knob guide fully clockwise, Oxygen Analyzer/Monitor display should be
equal to concentration of the source oxygen (±0.3).
7. Turn knob guide back to 21% position to ensure no drift from original reading
(±0.3).
8. Re-attach knob guide, torque nut to adjustment shaft and tighten to 10 in-lbs using
a torque driver.
9. Snap in knob back into knob guide, pay close attention to the key location of the
knob.
10. Set knob to 60 graduation.
11. Replace the top cover.
NOTE: DO NOT install the four (4) mounting screws until the end of the Final Test.
F. Final Test
Complete Operation Verification Procedure as per the test table, page 16 or 27.
Record test results in the test table.
When Final Test is complete replace top cover and install the four (4) mounting screws
into cover.
NOTE: Operation Verification Procedure should be performed at least once a year.