Special Maintenance Work - Dräger Panorama Nova ESA Gebrauchsanweisung

(2) Checking leak-tightness by sealing the exhalation valve
1. Remove the exhalation valve disc.
2. Insert the exhalation valve plug and fasten it with the spring carrier.
3. Generate a negative pressure of 10 mbar.
4. Remove the exhalation valve plug if the pressure difference is less
than 1 mbar after 1 minute, insert a new valve disc and repeat the
leak test. Otherwise, continue with (3).
(3) Leak test under water
1. Completely immerse the test head with the applied full face mask
in water.
2. Create an overpressure of approx. 10 mbar and slowly turn the
immersed test head. 
Emerging air bubbles indicate the leak.
3. Remove the test head with the applied full face mask from the
water. Repair the full face mask and replace leaking parts.
4. Remove the exhalation valve plug and insert the exhalation valve.
5. Repeat the leak test (1).
Checking the opening pressure of the exhalation valve
When using the Quaestor test unit, the initial pressure should be at
least 4.2 mbar at a constant flow rate of 10 litres per minute through
the full face mask. Otherwise, replace the spring and repeat the test.
When using a test unit that does not allow for this constant flow rate
(e.g. Testor), the initial pressure must be at least 4.5 mbar.
After testing
1. Disconnect the adapter.
2. Remove the full face mask from the test head and dry it if
necessary.
3. Fit the exhalation valve cover. Ensure that it locks into place.
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4.4

Special maintenance work

4.4.1 Replacing the visor
1. Hold the hexagon nuts in position and unscrew the screws.
2. Pry the visor frame apart at the joints using a screwdriver, then pull
it off to the top and bottom.
3. If necessary, remove the support plate (see Chapter 4.4.2 on
Page 21).
4. Detach 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 mask body.
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 soapy water.
8. First press on the upper, then the lower visor frame.
9. Insert the support plate if necessary.
10. Screw the screws into the hexagon nuts and tighten until the gap
between the clamping cams is 3 to 0.5 mm.
(approved by Dekra Exam) Panorama Nova ESA