3M FR-M40 18

6.To verify that the valve seat body has been properly re-installed, grasp the two little tabs sticking straight up from the valve seat body and try to turn the entire valve seat body in the port. If it turns freely, the valve seat body has been correctly re-installed.

3M™ FR-M40-103 Nose Cup Valve Disk (Figures 27 and 28)

fig. 27

fig. 28

1.Invert head harness over front of mask assembly.

2.Curl back lip of nose cup toward lens to expose nose cup valve seat and valve disk.

3.Pull nose cup valve disk out of each nose cup valve seat from inside of nose cup.

4.To install new nose cup valve disk, press nose cup valve disk onto nose cup valve seat from inside until nose cup valve disk is flat against nose cup valve seat and the stem slips completely through the hole in the nose cup valve seat. A slight pull on the valve stem may help set it correctly.

5.Gently rotate the nose cup valve disk to make sure that it is completely seated.

6.Repeat steps 2-5 to install the remaining nose cup valve disk.

7.Return head harness to its original position.

3M™ FR-M40-104 Exhalation Valve Cover (Figure 29)

fig. 29

1.Pull quick disconnect coupling from the retainer on the exhalation valve cover.

2.Pull up on the drink tube retainer tab on the bottom of the exhalation valve cover. This will disengage the cover from the exhalation valve body.

3.Remove the exhalation valve cover from the flanges on the top of the exhalation valve body taking care not to rip the cover in the process.

4.To install new exhalation valve cover, press holes in the top of the new cover over the flanges in the top of the exhalation valve body.

5.Using drink tube retainer on the bottom of the exhalation valve cover, pull exhalation valve cover over the exhalation valve body. Inspect to make sure that the exhalation valve cover is in place completely around the exhalation valve body.

6.Install the drink tube quick disconnect coupling securely in the retainer and fasten the external drink tube to the drink tube retainer at the bottom of the exhalation valve cover.