BIO-MED DEVICES CROSSVENT-3+ Operation & Service Manual page 60

IX. MAINTENANCE AND SERVICE- cont.
i. Remove the shaft extender from the valve shaft by loosening the two setscrews.
j. Turn the valve shaft until the specification stated above (4e) is met. Position the shaft extender on
the MAX Valve shaft with its stop pin against the left side of the stop. Tighten the setscrews in this
position.
k. Remove hemostats.
5. FLOW VALVE/POTENTIOMETER ZERO - ≤500 ML/M
WARNING: Any time the flow valve(s) are disturbed, the flow calibration in the CAL
menu must be performed as explained in Steps 13 & 14.
CAUTION: The Flow Valve (11) is geared to the Potentiometer (20) and it is the
rotational limits of the potentiometer that stops the valve from turning. Do not force.
TO TEST:
a. Connect the Patient Connector on the side of the CROSSVENT to a low flow test instrument using
a single length of tubing.
b. Occlude the opening of the DARV or turn up MAX Pressure fully if it's calibrated.
c. In the CAL menu, activate valves, and turn on valve A.
d. Turn the Flow Knob fully CCW to the stop. Flow should be ≤500 ML/M as observed on the test
instrument.
e. Entrainment Flow Valve (optional feature) - set up same as above (5a-c). Set the Entrainment
Switch to ON. From the back of the unit, occlude the entrainment inlet in the venturi.
f. Turn the Flow Knob fully CCW to the stop. Flow should be ≤500 ml/M as observed on the test
instrument.
IF IT FAILS THE ABOVE TEST, CALIBRATE AS FOLLOWS:
g. Remove the PC Board. (See the caution at beginning of the calibration procedures.)
h. Remove the gear from the Potentiometer by loosening the setscrews located in the teeth of the gear.
There will be two setscrews per hole, one on top of the other. Remove the top one and then loosen
the one underneath.
i. Carefully disconnect the clear tube from the PEEP Valve (18). Be sure the supply pressure is off at
this point. Carefully remove the green tube where it is connected to the Pilot Valve at the bottom of
the Regulator and connect the clear tube from the PEEP valve here. This will turn on the patient
flow whenever the supply pressure is turned on, thus bypassing the software and solenoid.
If your unit
j. Zero the Entrainment Flow Valve (optional feature) – On the entrainment venturi assembly,
carefully remove the clear tube from the barb that is closest to the front of the Crossvent in the top
row. Connect this tube to a low flow test instrument.
k. Turn on entrainment, turn on the supply gas, and turn the Entrainment Flow Valve shaft CW until
≤500 ml/M is obtained. Leave the valve in this position.
NOTE: The front of the valve gear should be flush with the end of the shaft and when the valve is properly
zeroed, the setscrews should be on the bottom (5 & 7 o'clock position). If they are not, loosen them and
reposition the gear so they are. The unit will have two screws per hole, one on top of the other. Remove the
top setscrew and then loosen the bottom one in both holes. To tighten, tighten the shorter one inside the hole
first, then install and tighten the second setscrew (approximately 1 inch-pound [.01 kg]). Do not over
tighten the second one or the gear may distort causing it to bind when engaging the potentiometer gear.
l. Reconnect the clear tube to the entrainment barb.
m. Zero the Flow Valve - Connect the Patient Connector on the side of the CROSSVENT to a low
flow test instrument using a single length of tubing.
n. Turn on the supply pressure, occlude the opening of the DARV, or turn up MAX Pressure fully if
it's calibrated, and turn the Flow Valve shaft CW until the flow measured is ≤500 ml/M. DO NOT
FORCE. (Slight resistance in the valve at this point is normal. However, do not force the valve. If
abnormal resistance is felt prior to the valve closing to within this specification, it should be
replaced.)
NOTE: See note in 5k regarding the position of the flow gear relative to the flow shaft .
o. Reinstall the Potentiometer Gear- While leaving the Flow Valve in the zero position, turn the
Potentiometer shaft fully CCW until it stops. Place the Potentiometer gear onto the shaft so its
setscrews are facing 180 opposite the screws on the flow shaft(s), i.e., at the top if the Flow Valve
setscrews are at the bottom. (This helps prevent binding as the gears are turned.) Referring to Fig.
11, tighten the inner setscrews and replace and tighten the outer setscrews.
p. Test again and ensure that the Potentiometer hits its stop at the same time the Flow Valve reaches
zero. DO NOT FORCE. Reconnect all tubing to their original state.
q. The flow calibration will have to be verified prior to putting the Crossvent back in service. See the
flow calibration procedure later in this section.
has entrainment, continue with step j, otherwise go to step m.
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