Maintenance Work; Visual Inspections - Dräger CDR 4500 Gebrauchsanweisung

Maintenance
4.3

Maintenance work

Following any maintenance work and/or replacement of components,
repeat the leak test.
4.3.1

Visual inspections

The speech diaphragm must not be damaged. Replace the

speech diaphragm, if necessary (see Chap. 4.3.5 on Page 17).
To check the exhalation valve, remove the exhalation valve cover

from the connector and thoroughly inspect the valve disc. The
valve disc and valve seat must be clean and undamaged. Clean or
replace them as necessary (see Chap. 4.3.6 on Page 17).
Check all parts for damage and replace them if necessary.

4.3.2 Replacing the visor
1. Loosen both screws.
2. Pry the visor frame apart at the joints using a screwdriver, then pull
it off to the top and bottom.
3. Remove the support plate, if necessary (see Chap. 4.3.3 on
Page 16).
4. Remove the old visor from the rubber frame.
5. Insert the new visor first in the upper and then in the lower part of
the rubber frame.
The centre markings on the visor should line up with the seam on
the facepiece.
6. Pull the rubber frame over the left and right edges of the visor.
7. Moisten the outside of the rubber frame and the inside of the visor
frame with soap solution.
8. First press on the upper, then the lower visor frame.
9. Insert the support plate if necessary.
10. Tighten both screws.
16
4.3.3 Replacing the connector
1. Pull the inner mask out of the groove of the threaded ring.
2. Force open the clamping ring with a screwdriver.
3. Remove the clamping ring and slip ring and the support plate.
4. Pull the connector out of the mask body.
5. Fit the new connector with a speech diaphragm as well as in- and
exhalation valves and insert the connector so that the markings on
the centres of the connector and the mask body are aligned.
6. Fit the slip ring and new clamping ring.
7. Attach the hook to ensure the tightest possible fit of the clamping
ring.
8. Push the support plate between the clamping ring and the slip ring;
fit it into the lower visor frame and align it.
9. Compress the nose of the clamping ring with pliers until the
equipment connector is securely located in the mask body.
10. Attach the inner mask. Make sure that the edge lies in the groove
all around. The centre markings on the connector and on the inner
mask must coincide.
4.3.4 Replacing the valve discs on the control valves of the
inner mask
1. Pull out the old valve disc towards the inside.
2. Insert the stud of the new valve disc into the hole from inside and
pull it towards the visor until the undercut of the stud is visible. The
valve disc must make even contact with the inside surface.
(approved by Dekra Exam) Dräger CDR 4500