Ametek PMT 40, Manual

Page: 18 / 49

User Manual
13
OUTPUT GAUGE
TO NOZZLE
ORIFICE CLEANER BUTTON
MTG. SCREW (6)
TO FEEDBACK
TO REMOTE OUTPUT GAUGE
(SUPPLY GAUGE OPTION)
SUPPLY
INLET PORT
CAP NUT
VALVE STEM
BIAS SPRING
OUTPUT
PUSH BUTTON
ORIFICE
OUTPUT DIAPHRAGM
EXHAUST PORT
NOZZLE DIAPHRAGM
TO NOZZLE
CONNECTION
OU
TPUT
METAL TO METAL SEAL
PROPORTIONAL CONTROLLER
To replace feedback – unhook feedback link
at proportional band dial. Remove feedback
line from relay. Remove synchronizing nut.
Replace in reverse order. See ALIGNMENT for
synchronizing nut adjustment.
Alignment – with all components assembled and
supply air on, proceed as follows:
1. Set proportional band at 10% (2% for 1-15%
instrument)
2. Move red pointer with setting knob until
output is at mid-span.
3. Turn proportional band to maximum setting.
Output pressure should not change more
than 10% of output span.
4. Adjust synchronizing nut to obtain mid-span
output.
5. Repeat steps 1 thru 4 until output does not
vary more than 10% of output span when the
proportional band changes.
6. If red pointer does not coincide with black
pointer at mid-span output, hold red pointer
hub with 0.25” wrench and turn red pointer
until it coincides. Caution: Apply torque near
hub to avoid bending pointer.
PROPOR RESET CONTROLLER
(Fig. 14)
To replace feedback –
unhook link at
proportional band dial. Remove feedback line
from relay. Remove two reset block mounting
screws. Replace in reverse order. See
ALIGNMENT for pointer adjustment.
T
o replace Valve and Filter –
loosen two valve
screws (3 turns without removing). Pull up and
rotate clockwise until tabs on valve are clear of the
screw heads. Remove and replace in the reverse
order.
To clean Valve and Filter – remove valve pin by
disengaging tension spring from slotted end of
pin. Clean seat and pin with suitable solvent. To
remove filter, first remove bottom “O” ring. (Do
not cut “O” ring on tension spring). Remove filter
and clean with solvent.
Alignment –
with all components assembled and
supply air on, proceed as follows:
1. Set proportional band at 10%.
2. Open reset valve by turning fully clockwise on
stop.
3. Set red pointer for full output.
4. Reduce supply pressure until mid-span
output is obtained.
5. Shut reset valve by turning full
counterclockwise (reset chamber now has
mid-span output pressure trapped inside
and controller will act like a proportional
controller).
6. Restore supply pressure to correct pressure.
7. Move red pointer with setting knob until
output pressure is at mid-span.
8. Turn proportional band to maximum setting.
Output pressure should not change more
than 10% of output span.
9. To obtain mid-span output pressure, loosen
locking nuts and move adjusting link to the
left or right. Tighten locking nuts.
10. Return band to 10%.
11. Repeat steps 7 thru 10 until output does not
vary more than 10% of output span when the
proportional band changes.
12. If red pointer does not coincide with black
pointer at mid-span output, hold red pointer
hub with 0.25” wrench and turn red pointer
until it coincides (apply torque near hub to
avoid bending pointer.)
Figure 13