Gas Input Filter; Preventive Maintenance Kits - BIO-MED DEVICES CROSSVENT-3+ Operation & Service Manual

IX. MAINTENANCE AND SERVICE- cont.
1. Remove the rear panel and battery.
2. Turn the knob on the outside of the case to the ON position.
3. Unplug the Entrainment Switch cable (JENTRAIN) from the front of the PCB, remove the two
screws retaining the micro-switch and remove it.
4. Mount the new switch so that the plunger is directly under the cam on the shaft of the ON/OFF
switch.
5. Connect an ohmmeter to the micro-switch cable and observe continuity as the On/OFF knob is
positioned from ON to OFF and OFF to ON. The micro-switch should be open when in the OFF
position and closed when ON. If it does not meet these criteria, loosen the setscrew in the cam
above the micro-switch and reposition the cam so it does.
6. Reinstall the battery and rear panel.

11. GAS INPUT FILTER

11. GAS INPUT FILTER
11. GAS INPUT FILTER 11. GAS INPUT FILTER
1. Remove the Rear Panel. Be careful of the battery, which is now free. It may be secured by taping it
in place or it may be removed.
2. Remove the two exterior screws at the bleed exhaust screen next to the gas supply fitting. This will
free the 9-port bleed manifold inside the case. Move this manifold to the side so a wrench can
engage the hex fitting on the regulator behind it. Watch for the o-ring inside this manifold. Do not
misplace this if it should fall out.
3. Hold the large hex fitting on the regulator from turning with one wrench and use a second wrench
to unscrew the outside supply fitting.
4. Remove the conical filter that is inside these fittings and replace it with a new one.
5. Reassemble in the reverse order.
(approximately 25 foot-pounds [3.5 kg]).
6. If this Crossvent has the Entrainment feature, there will be a second filter which is located in the
venturi assembly. Remove the black ring around the venturi inlet and replace the filter within.
Replace the ring.

12. PREVENTIVE MAINTENANCE KITS

12. PREVENTIVE MAINTENANCE KITS
12. PREVENTIVE MAINTENANCE KITS 12. PREVENTIVE MAINTENANCE KITS
1. The simplest way to replace the pneumatic logic lines is to do them one line, one point at a time.
2. Once all the logic lines in the kit have been replaced, they will need to be calibrated. Refer to the
Pneumatic Calibration Procedures for these instructions.
3. The process for removal and replacement is the same for each line as described here.
a. Observe the new logic line and locate the existing matching line in the Crossvent. Study how it
is installed and where each end is connected.
b. It does not matter which end you start with so pick an end on the new line and match it up with
the line to be replaced.
c. Using a sharp X-acto style knife, remove the tube from the barb by slicing it along the length of
the barbed fitting starting at the base and stopping at the barb (see illustration). It is important
not to damage the actual barb in any way or a gas leak may occur after reassembly.
d. Using needle nose pliers, grab the cut tubing and peel it back
and remove it from the fitting.
e. Push the matching end of the new line onto the barbed
fitting with the needle nose pliers being careful not to
damage the tubing in the process.
reach the base of the barb.
f. Repeat this process for each end of the new line, one at a
time, until the old line is completely removed and the new
one is completely installed.
g. When done, ensure that no part of the pneumatic logics can make contact with the PCB. Use
cable ties if necessary, but use them loosely.
h. Before the Crossvent can be returned to service, these parts
must be calibrated as outlined in the Pneumatic Calibration
section.
Be sure to tighten these fittings enough to seal the filter
Push it on far enough to
FIG. 16- CUTTING TUBE
65 65
65 65