
Instruction Manual
D100306X012
657 Actuator (30-70 and 87)
December 2010
2
Do not install, operate, or maintain a 657 actuator without being fully trained and qualified in valve, actuator, and
accessory installation, operation, and maintenance. To avoid personal injury or property damage, it is important to
carefully read, understand, and follow all the contents of this manual, including all safety cautions and warnings. If you
have any questions about these instructions, contact your Emerson Process Management sales office before
proceeding.
Table 1. Specifications
SPECIFICATION(1) ACTUATOR SIZE
30 34 40 45 46 50 60 70(1) 87(1)
Nominal Effective Area cm2297 445 445 677 1006 677 1006 1419 1419
Inch246 69 69 105 156 105 156 220 220
Yoke Boss Diameters mm 54 54 71 71 71 90 90 90 127
Inches 2‐1/8 2‐1/8 2‐13/16 2‐13/16 2‐13/16 3‐9/16 3‐9/16 3‐9/16 5
Acceptable Valve
Stem Diameters
mm 9.5 9.5 12.7 12.7 12.7 19.1 19.1 19.1 25.4
Inches 3/8 3/8 1/2 1/2 1/2 3/4 3/4 3/4 1
Maximum Allowable
Output Thrust(4)
N 10230 10230 12010 25131 33582 25131 30246 39142 39142
Lb 2300 2300 2700 5650 7550 5650 6800 8800 8800
Maximum Travel(2) mm 19 29 38 51 51 51 51 76(3) 76(3)
Inches 0.75 1.125 1.5 2 2 2 2 3(3) 3(3)
Maximum Casing
Pressure for
Actuator Sizing(4)
Bar 8.6 4.5 4.5 3.4 2.8 3.4 2.8 3.8 3.8
Psig 125 65 65 50 40 50 40 55 55
Maximum Diaphragm
Casing Pressure(4)(5)
Bar 9.6 5.2 5.2 4.1 3.4 4.1 3.4 4.5 4.5
Psig 140 75 75 60 50 60 50 65 65
Material Temperature
Capabilities
_CNitrile Elastomers: -40 to 82_C, Silicone Elastomers: -54 to 149_C, Fluorocarbons: -18 to 149_C
_FNitrile Elastomers: -40 to 180_F, Silicone Elastomers: -65 to 300_F, Fluorocarbons: 0 to 300_F
Pressure Connections
(internal)
1/4 NPT X X X X X X X ‐ ‐ ‐ ‐ ‐ ‐
1/2 NPT ‐ ‐ ‐ ‐ ‐ ‐ ‐ ‐ ‐ ‐ ‐ ‐ ‐ ‐ ‐ ‐ ‐ ‐ ‐ ‐ ‐ X X
Approximate Weights kg 16 22 23 37 49 42 53 107 116
Lb 36 48 51 82 107 92 116 235 255
1. These values also apply to the 657‐4 actuator construction.
2. Actuator travel may be less than the value listed after connecting the actuator to the valve.
3. Maximum travel for 657‐4 is 102 mm (4 inches).
4. Normal operating diaphragm pressure must not exceed maximum diaphragm casing pressure and must not produce a force on the actuator stem greater than the maximum allowable out
put thrust or the maximum allowable valve stem load. Contact your Emerson Process Management sales office with questions concerning maximum allowable valve stem load.
5. This maximum casing pressure is not to be used for normal operating pressure. Its purpose is to allow for typical regulator supply settings and/or relief valve tolerances.
Description
The 657 actuator (figure 1) and the 657‐4 actuator are direct‐acting, spring‐opposed diaphragm actuators. They
provide automatic operation of control valve body assemblies. The 657 actuator offers 76 mm (3 inches) maximum
actuator travel. The 657‐4 actuator provides 102 mm (4 inches) maximum actuator travel. Both actuators position the
valve plug in response to varying pneumatic loading pressure on the actuator diaphragm. Figure 2 shows the
operation of these actuators.
A 657 or 657‐4 actuator can be equipped with either a top‐mounted or a side‐mounted handwheel assembly. A
top‐mounted handwheel assembly is used as an adjustable up travel stop to limit actuator travel in the up direction
(see figure 2). A side‐mounted handwheel assembly is usually used as an auxiliary manual actuator. Adjustable
casing‐mounted up or down travel stops are also available for this actuator.