Checking The Opening Pressure Of The Exhalation Valve (P-Type Connector Only); Maintenance Work - Dräger FPS 7000 Notice D'utilisation

3. Slowly turn the test head under the water surface. Emerging
bubbles indicate leaks.
4. Take the test head with the facepiece out of the water, repair the
facepiece, or replace leaking components.
5. Remove the exhalation valve test plug and install the exhalation
valve.
6. Repeat leak test (1).
4.4 Checking the opening pressure of the exhala-
tion valve (P-type connector only)
The opening pressure must be at least 4.2 mbar (approx. 4.2 cm H
at a constant flow of 10 l/min. If this opening pressure is not reached,
turn the valve disc to remove dust particles, or the like, between the
crater and the valve disc. Repeat the test. If the opening pressure is
still not reached, replace the spring and repeat the test.
4.5

Maintenance work

1. Check all parts for deformation and damage and replace them if
necessary.
NOTICE
i i
During maintenance work, the exhalation valve cover might
be detached from the cap. It can simply be hooked into the
cap again.
2. Perform a leak test after any maintenance work and/or
replacement of components.
4.5.1 Replacing the visor (Figures F1 and F2 on page 226)
1. Unhook the cap on both sides from the visor frame (Figure F1-1).
2. Use your thumbs to press against the bottom part of the cap and
remove it from the fastening lugs (Figure F1-2).
3. Pull the cap from the facepiece.
Dräger FPS 7000
O)
2
(text approved by NIOSH, not approved by any other notified body)
4. Remove the screws from the visor frame (Figure F2).
5. Spread the frame apart, tilt it towards the front and pull apart
sideways.
6. Detach the visor from the rubber frame.
NOTICE
i i
Moistening either the facepiece body or the visor frame
facilitates the assembly.
Observe the center marking on the visor.
7. Center the new visor when inserting and make sure that it is
properly seated in the facepiece body.
8. Apply pressure to the visor frame until it snaps into place at the
center of the visor, then tighten with new self-locking screws until
the gap between top and bottom part of the frame is shut.
9. Put the cap on the connector, lock it into place on the fastening
lugs (Figure F1-2) and hook it into the visor frame (Figure F1-1).
4.5.2 Replacing the nose cup (Figure G on page 226)
1. Take hold of the nose cup at the tip of the nose, then pull it off the
pin and out of the speech diaphragm groove.
2. Put the new nose cup onto the pin to center it.
3. Press the ring of the nose cup into the speech diaphragm groove
- at first at the bottom and then all around the speech diaphragm.
4.5.3 Replacing the speech diaphragm (Figure H on page 226)
1. Take hold of the nose cup at the tip of the nose, then pull it off the
pin and out of the speech diaphragm groove.
2. Remove the speech diaphragm using wrench R 26 817.
3. Perform visual inspection of speech diaphragm and O-ring and
replace by new ones if necessary.
4. Insert O-ring, then screw in speech diaphragm
(recommended torque: 2.95 ±0.37 ft lb/400 ±50 Ncm).
5. Put the nose cup onto the pin to center it.
Maintenance
221