Electro-Pneumatic Positioners
Adjustment - Orifice
①
If the size of actuator is too small relative to the flow rate, positioner can have hunting.
In order to avoid hunting, orifice can be used.
There are three types of
the orifice.
Actuator Size
Orifice Size
Suffix Symbol
90 cm
3
less
∅
1
1
90 ~ 180 cm
3
∅
2
2
180 cm
3
more
none
3
- 16 -
②
Remove the o-ring from OUT1 and OUT2 port and insert appropriate orifice. After
inserting orifice, place back the o-ring.
Make sure there is no substance entering into
port.
<Figure 22>
③
If hunting persists after inserting the orifice, please contact YTC or its appropriate agent.
<Figure 22>
Maintenance - Pilot Valve
Maintenance should be performed on Pilot Valve Relay at least once a year. When dissembling
the pilot valve relay, please do make sure not to loose o-ring or stabilizer spring. Please refer to
<Figure 23> for the instruction.
(1) Remove stopper bolts.
(2) Unlock the Auto/Manual Switch.
(3) Remove if there is any blocking within the port and orifice.
<Figure 23>
