MSA PremAire System Manual page 11

Note: Rub a small amount of Never-Seez (P/N 29527) on
the valve threads.
b. Line up the exhalation valve threads with the face-
piece mounting hole. Place one hand inside the
facepiece and stretch the hole slightly.
c. Push the valve threads into the facepiece. Use a
"threading" motion to insert the valve until the valve
body rests against the facepiece rubber.
Note: The "MSA" logo on the exhalation valve cover does
not have to be aligned to any special position.
d. Pull the facepiece chin cup back so that you can
see the valve, then thread the retaining nut on.
ULTRAVUE FACEPIECE REPAIR
e. Tighten the retaining nut, using the spanner wrench
(P/N 461828). Reposition the facepiece headstrap.
6. Inspect the exhalation valve.
7. Visually inspect the spring to see that it is located
properly in its socket.
Do not store the facepiece with the headstraps
stretched over the lens. Doing so may distort the seal-
ing surface and affect the facepiece seal.
8. Don the facepiece and check the face-to-facepiece
seal. Follow the steps in the Facepiece Fit Check.
11 TAL 502 (L) Rev. 0 - 10064385