Mattress and Seat Systems Service Manual
Repair
Page 38
5
Replacing the Non-Return Valve Assemblies
Not all of the mattress replacements and overlays detailed in this service manual have non-return valve
assemblies. Only those mattress replacements and overlays which have static head cells have non-
return valve assemblies fitted in the manifold assembly. None of the seat systems have static cells or
non-return valve assemblies. Refer to Chapter 1, Page 6, Table 2 for details of which mattresses have
static head cells.
On those mattresses which do have non-return valve assemblies, they are installed near the head end
of the mattress. There are two non-return valve assemblies, which are replaced as follows:
5.1
Remove the top cover (Refer to Page 36, Section 3).
5.2
On the last six cells at the head end of the mattress, pull apart the press studs that secure the
end of the cell to the loop base sheet assembly. This will allow access to the non-return valve
assemblies.
5.3
Move the cells away from the manifold assembly.
5.4
Remove the two ends of the non-return valve assembly from the manifold tubes.
5.5
Carefully insert the two ends of the new non-return valve assembly into the manifold tubes.
Note:
Make sure the arrow mark on the non-return valve body points towards the head end of
the mattress (Refer to Figure 23). Mattress malfunction will occur if the non-return valve
assemblies are fitted incorrectly.
5.6
On the last six cells at the head end of the mattress, Connect the press studs together that
secure the end of the cell to the loop base sheet assembly.
5.7
Install the top cover (Refer to Page 37, Section 4).
Figure 23 - Orientation of the Non-Return Valve Assembly
Manifold Tube
Manifold Tube
Air Flow
Arrow Mark
Head End
of Mattress
Non-Return Valve Body
