Anesthesia APL Valve Test and Repair
The APL (scavenging / adjustable pressure limiting) valve controls the pressure in the system.
If the pressure in the system exceeds the pressure exerted by the weight of the poppet or the pressure exerted by the compression spring, the valve opens and gas escapes. This normally occurs when the patient is exhaling.
The pressure in the anesthesia machine and the patient’s lungs can be controlled by turning the adjustment knob on top of the valve.
Fully open, the APL valve maintains a pressure in the anesthesia machine and the patient’s lungs, of 1-3cm H2O.
APL Valve Functional Test
1.Open APL valve all the way by turning knob counter clockwise.
2.Place thumb over patient connection of breathing circuit Y-piece.
3.Turn on oxygen supply (50-55 PSI - 3.4-3.8 Bar), turn flowmeter to 4 LPM.
4.Observe pressure gauge. Verify reading is less than 4cm H2O.
5.Slowly begin closing APL valve. Pressure gauge should move smoothly as pressure increases. DO NOT EXCEED 40cm H2O!
6.Open APL valve all the way by turning knob counter clockwise. Observe pressure gauge and return to less than 4cm H2O.
