MSA PremAire System Manual page 9

d. The band clamp
must be positioned
so that the screw is
at the 5 or 7 o'clock
position. The screw-
head must be to the
left so that it will not
rub the facepiece
rubber.
e. Tighten the band clamp until the inlet is secured. Be
sure that the band clamp will not pull the facepiece
rubber away from the assembly. Do not over-tight-
en. If the facepiece rubber "bulges" out through the
slots in the clamp, the clamp is too tight and must
be loosened and re-tightened.
3. Don the facepiece and check the face-to-facepiece
seal. Follow the steps in the Facepiece Fit Check.
SPEAKING DIAPHRAGM
1. Unscrew the retainer
ring, using the face-
piece spanner wrench
(P/N 461828).
2. Turn the facepiece upside down and shake out the
metal speaking diaphragm.
3. Check the speaking diaphragm for damage. Replace it
if it is worn or damaged.
4. Check the speaking diaphragm gasket or O-ring.
Replace the gasket or O-ring if either is worn or dam-
aged.
The flat gasket (used on old-style facepieces) and the
O-ring (used on the new design) are not interchange-
able. Replace the gasket with the P/N 83630 gasket
only. Replace the O-ring with the P/N 629935 O-ring
only. Failure to follow this warning may cause inhala-
tion of contaminant and result in serious respiratory
injury or death.
5. To reassemble the speaking diaphragm, place the
gasket or o-ring in the groove of the speaking
diaphragm housing.
ULTRAVUE FACEPIECE REPAIR
6. Place the speaking
diaphragm in the hous-
ing so that the rolled lip
rests on the gasket or
o-ring.
Be sure that the crimped side of the speaking diaphragm
is facing up (away from the gasket or o-ring).
7. Replace the retainer ring and tighten, using the span-
ner wrench.
8. Don the facepiece and check the face-to-facepiece
seal. Follow the steps in the Facepiece Fit Check.
INHALATION DISC VALVE
1. Use the spanner
wrench (P/N 496317).
Press the adapter slip
nut in. Turn the wrench
counter-clockwise (left)
to unthread the
adapter.
2. Lift the neckstrap retaining ring off the housing. Note
how the "fingers'' line up in the housing.
3. Lift the spider gasket
out of the coupling nut
housing by its tab.
4. Remove the valve disc from the coupling nut housing.
If you cannot grasp the disc with your fingers, use a
blunt object, such as a ballpoint pen to lift one edge,
then remove the disc. Be careful not to tear the soft
disc.
5. Inspect the disc for tears or punctures. The disc
should be very soft and pliable. Install a new disc if it
is damaged or hardened.
9 TAL 502 (L) Rev. 0 - 10064385