12
Model EA91A＆EA90A
Orifice Plate
for Standard Size
V Groove 1
V Groove with Black-coating
Pilot Cover
Pilot Cover
Fixing Screw
for Cover
Manifold
Gasket(B)
Gasket(B)
Gasket(A)
Gasket(A)
Cut for Identification
Orifice Plate
Orifice Plate
Pilot Ass'y
Pilot Ass'y
V
Groove
2
V
Groove
3
V Grooves
V Grooves
Orifice Plate for
Small Size Actuator
No
1
2
Positioner
Types
No. of Groove
for Identification
Actuator Size
∅270〜∅330
∅400〜∅650
∅240
∅200
4.6 Conformity of Capacity and Characteristics
⑴ The orifice plate has two types in accordance with the actuator size. One standard plate can be
compatible with three kinds of size of actuator.
⑵ When using each size of orifice plate, align V groove position of orifice plate with cut position of gasket.
⑶ When replacing or changing the position of orifice plate, remove pilot cover, and loosen three screws
fixing pilot assembly.
⑷ General classification for usage of orifice plate, see table below.
⑸ To install booster relay for actuator size ∅270 and larger, use V groove 1 of orifice plate No.1.
⑹ Model 3800 actuator ∅280 and larger with rated travel 15, 20, 25mm and spring range
20-100kPaG(0.2-1.0kgf/cm
2
), use V groove 3 of orifice plate No. 1.
For the purpose of obtaining stable actuation of positioner with small-capacity actuator to large-capacity
actuator, the Models EA91A and EA90A Electro-pneumatic Positioner are equipped with appropriate orifice
plate in accordance with actuator size.
4.6.1 Selection of Orifice Plate for Actuator Capacity
V Groove 1
V Groove 2
V Groove 3
V Groove with
Black-coating
Linear,
Buit-in Cam
Linear,
Buit-in Cam
Linear,
Buit-in Cam
Linear
