Maxi-Maintenance Procedures (Valve Body); M11 Procedure - Valve Body Disassembly - Siemens Maxum II PD PA AP Service Manual

Valves
4.6 Model 11 Valve
4.6.9

Maxi-Maintenance Procedures (Valve Body)

4.6.9.1

M11 Procedure - Valve Body Disassembly

1. Remove the six plungers (7) by inverting valve body (8) and then shaking it. Plungers should
fall into the palm of the hand.
If a plunger(s) is stuck and does not fall out, delay removing it until after the spring loaded
and air loaded pistons (14 and 11) are removed. The plungers can then be forced out from
bottom of valve body.
2. Examine plungers for damage. Any plunger showing defects, such as nicks, must be
discarded and replaced with a new part.
3. Remove air signal manifold (23) by removing the two screws (24&25) that secure it to the
valve body (8). After manifold is detached, inspect the three o-rings (22) and replace if
necessary. If the o-rings are undamaged, then set them aside (on a clean surface) for
installation later.
4. Use the special set of pliers supplied with the repair kit to remove the retaining ring clip
(19). Inset the tips of the pliers into the holes in the clip and firmly squeeze. Extract the
clip from the base of the valve, holding the pliers firmly to prevent clip from flying off.
5. Remove retaining base (18), compression plate (17), compression spring (16) and
compensation plate (15) from bottom of valve body (8). Refer to Figure 7-4.
6. Use the special retaining clip pliers supplied with the repair kit to remove the spring‑loaded
piston (14) from valve body (8). Insert the tips of the pliers into the holes in the underside
of the piston and pull slowly.
7. Remove air-loaded piston (11) from valve body (8)
8. Using care to catch plungers (7), remove any stuck plunger using one of the tips from the
retaining ring pliers.
9. Examine plungers (7) for damage. Any plunger showing defects, such as nicks, must be
discarded and replaced with a new part.
10.Inspect interior of valve body (8), spring loaded piston (14) and air loaded piston (11) and
silicon rubber "O" rings (13, 12 and 9) for contamination, odor or mechanical wear.
Any part showing evidence of excessive wear or defects must be replaced with a new
component. Do not re-install any defective component.
96
NOTICE
When shaking plungers from valve body, do not allow them to fall on any abrasive surface.
It is recommended that a lint free cloth, free of contaminants, be placed under the hand
to protect plungers from damage.
Maxum II Valves and Oven Components
Service Manual, 10/2018, A5E42019844001