Advertisement
Type 656
Maximum Recommended Casing Operating
(1)
Pressure
35 psig (2.4 bar)
Maximum Allowable Casing Pressure
Actuator
Size
30
40
60
Maximum Travel
MAXIMUM RATED
STEM TRAVEL,
INCHES (mm)
ACTUATOR
ACTUATOR
SIZE
Standard
Travel
Stop
30
2-1/8 (54)
40
3-1/2 (64)
60
4-1/8 (105)
1. Control and stability may be impaired if this pressure is exceeded.
2. Exceeding this pressure can cause damage to the diaphragm, diaphragm casing, or other parts.
A 1/4" NPT loading pressure connection is located in
the top of the upper diaphragm case. Using either pipe
or tubing, connect either the loading pressure connec-
tion or valve positioner input connection (if a valve po-
sitioner is furnished, the loading pressure connection
to the actuator will be made at the factory) to the out-
put pressure connection on the controller. Keep the
length of the pipe or tubing as short as possible to
avoid transmission lag in the control signal.
When the actuator is completely installed and con-
nected to the controller, it should be checked for cor-
rect travel, freedom from friction and correct PDTC or
PDTO action.
The actuator spring and diaphragm have been se-
lected to meet the requirements of the application. It
should be noted that the actuator spring has a
constant rate of compression and that adjustment of
the spring compression merely shifts the initial spring
setpoint up or down to make the actuator travel within
the initial spring setpoint and the maximum diaphragm
pressure indicated on the nameplate.
In some instances, however, such as high friction but-
terfly and ball valves, the actuator will fully stroke with
2
Table 1. Specifications
(2)
Maximum Casing
Rating, Psig (Bar)
125 (8.6)
65 (4.9)
40 (2.8)
MAXIMUM STEM
RETRACTION
ADJUSTMENT
ADJUSTMENT
Optional
WITH OPTIONAL
Travel
HANDWHEEL,
Stop
INCHES (mm)
Not available
3/4 (19)
3 (76)
1-1/2 (38)
3-13/16 (97)
2 (51)
Maximum Operating Temperature
150 F (66 C) with Nitrile diaphragm material
Casing Connection
1/4-inch NPT female
Actuator Weight
Actuator Size
30
40
60
Options
Top-mounted handwheel/adjustable travel stop
less diaphragm pressure than indicated on the name-
plate. To increase the pressure required to initiate ac-
tuator stem movement, turn the lower bearing seat
(key 14) up toward the spring case. To decrease the
pressure at which movement begins, turn the lower
bearing seat down, away from the spring case.
WARNING
Avoid personal injury or property dam-
age from sudden release of process
pressure or uncontrolled movement of
parts. Before performing any mainte-
nance operations:
Disconnect any operating lines pro-
viding air pressure, electric power, or a
control signal to the actuator. Be sure
the actuator cannot suddenly open or
close the valve.
Use bypass valves or completely
shut off the process to isolate the valve
from process pressure. Relieve process
pressure from both sides of the valve.
Drain the process media from both
sides of the valve.
Approximate
Shipping Weight,
Pounds (kg)
50 (23)
70 (32)
160 (73)
Advertisement
