Emerson Fisher 785C User manual

www.Fisher.com
Fisher™785C Piston Actuators
Contents
Introduction 1.................................
Scope of Manual 1.............................
Description 1.................................
Specifications 3...............................
Educational Services 3.........................
Principle of Operation 3.........................
Installation 16.................................
Three‐Way Valve Applications Note 17............
Actuator Mounting 18...........................
Manual Override 17............................
Handwheel Operation 17.......................
Maintenance 19................................
Actuator Removal 20..........................
Seal and O-ring Replacement 20.................
Parts Ordering 23...............................
Parts Kits 23...................................
Parts List 26...................................
Figure 1. Fisher 785C Springless Piston Actuator
Introduction
Scope of Manual
This instruction manual includes installation, maintenance, and parts information for the Fisher 785C piston actuator.
Refer to separate instruction manuals for information regarding other equipment and accessories used with these
actuators.
Do not install, operate, or maintain 785C actuators 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 sales office before proceeding.
Description
The 785C products line encompasses medium to large spring-return single-acting and double-acting piston actuators
that provide accurate, high thrust output for short to long travel applications. These actuators are designed for use
with a variety of medium to large Fisher sliding-stem control valves including.
The single-acting actuators feature an internal bias spring that forces the actuator piston rod to extend or retract upon
a loss of supply pressure, thereby ensuring a fail-closed or fail-open mode of operation. This effectively eliminates the
need for a trip valve and volume tank in most constructions.
Instruction Manual
D104483X012
785C Actuator
May 2019

Instruction Manual
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785C Actuator
May 2019
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Table 1. Specifications
Operating Pressure(1)
Minimum: 2.7 bar (40 psig)
Maximum Allowable: 12 bar (174 psig)
Consult your Emerson sales office for supply
pressures up to 2.7 bar (40 psig)
Travel(2)
25 mm (1 inch) through 610 mm (24 inch)
See table 2 and 4
Thrust Capabilities
See table 3, 5, and 6
Stroking Speeds
Varies with actuator size, spring, travel, and supply
pressure. If stroking speed is critical, consult your
Emerson sales office.
Piston Diameter and Area(2)
Available diameters range from 280 to 685 mm
(11 to 27 inches).
See table 2 and 4
For additional sizes, contact your Emerson sales
office.
Operative Temperature Limits(3)
Standard: -20 to 100_C (-4 to 212_F)
Low Temperature Options:
-40 to 100_C (-40 to 212_F) or
-60 to 100_C (-76 to 212_F)
High Temperature Option:
-20 to 200_C (-4 to 392_F)
Yoke Boss and Valve Stem Diameter
J127 mm (5 inch) yoke boss with 25.4 mm
(1 inch) stem
J127 mm (5H inch) yoke boss with 32 mm
(1-1/4 inch) stem
J178 mm (7 inch) yoke boss with 51 mm
(2 inch) stem
Pressure Connections
Standard: 3/4 NPT
Optional: 1 and 1-1/4 NPT
See table 7
Instrument Mounting
Mounting kits are available for use with FIELDVUE™
DVC6200 Series digital valve controllers
Construction Materials(4)
Part Material
Cylinder Carbon Steel
Nameplate and Travel Scale Stainless Steel
Piston Carbon Steel
Piston Rod Stainless Steel
Stem Connector Carbon Steel or Stainless Steel
Tie Rod Carbon Steel or Stainless Steel
Upper/Lower Heads Carbon Steel
Yoke Carbon Steel
Weights
See table 13, 14, 15, 16, 17, 18, 19, and 20
Lifting Point Load Ratings
See table 21 and figure 4 and 5
Options
JTop mounted handwheel
JSide mounted handpump,
JPneumatic fail mode via Fisher 377 trip valve
JVolume Boosters
Dimensions
See figure 3 and 3 and table 8, 9, 10, 11, and 12
Optional Certifications(5)
JPressure Equipment Directive (PED) 2014/68/EU
and Machinery Directive 2006/42/EC
JATEX Group II Category 2 Gas and Dust
JCustoms Union Technical Regulations (CUTR)
010/2011 and 012/2011
JSafety Instrumented System, SIL 3 Capable
1. The pressure/temperature limits in this bulletin and any other applicable standard or code should not be exceeded.
2. Consult your Emerson sales office for longer travels or larger cylinder diameters. The Fisher 585C family of actuators can be used for smaller travels or cylinder diameters.
3 Standard temperature -20 to 100_C (-4 to 212_F) and -40 to 100_C (-40 to 212_F) are PED 2014/68/EU and 2006/42/EC compliant. The low ambient temperature option, -60 to 100_C (-76 to 212_F)
is not PED compliant. The high temperature option, if used in conjunction with ATEX, is limited to 135_C (275_F).
4. Full stainless steel constructions are available upon request.
5. Refer to the product nameplates to determine which certifications each actuator construction possesses

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785C Actuator
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Specifications
Specifications for the 785C line of piston actuators are shown in table 1. Refer to the nameplate affixed to the actuator
yoke for specifications specific to individual constructions.
Educational Services
For information on available courses for Fisher 785C Series piston actuators, as well as a variety of other products,
contact:
Emerson Automation Solutions
Educational Services - Registration
Phone: [phone] or 1-800-338-8158
E-mail: [email protected]
emerson.com/fishervalvetraining
Principle of Operation
785C piston actuators utilize a pneumatically controlled piston that moves inside of a cylinder to generate thrust. A
seal contained on the circumference of the piston provides a seal between the top and bottom of the cylinder,
preventing supply pressure leakage.
785C single-acting spring-return piston actuators utilize a spring below the piston (outside the pressurized chamber)
that will drive the piston rod upon a loss of supply pressure. This fail action will result in forcing an attached control
valve to either fail-open or fail-closed.
From an equilibrium state, the actuator operates by reacting to a force unbalance that is created by increasing supply
pressure on one side of the piston and decreasing it on the other. This moves the piston up or down, and results in a
repositioning of the attached control valve. Travel can be adjusted using travel limits within a valve positioner, which
limit the travel range of the actuator. The optional manual override does not have the ability to act as a hard travel
stop.
An optional manual override (top mounted handwheel or side mounted handpump) is capable of extending or
retracting the actuator manually and can be engaged at any position from full open to full close. The top-mounted
handwheel utilizes an engagement lever that couples the handwheel and piston rod. The handpump has a hydraulic
cylinder attached to the piston rod. This enables the handpump to operate the actuator manually, unless the
handpump is set to bypass position.

Instruction Manual
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Table 2. 785C Double Acting Springless Standard Constructions(1)
ACTUATOR
SIZE
PISTON AREA VALVE STEM
CONNECTOR SIZE
YOKE BOSS
DIAMETER AVAILABLE TRAVEL
Without Manual
Override
With Manual
Override(2)
cm2Inch2cm2Inch2mm Inch mm Inch mm Inch
280 616 95 616 95 25 1 127 5
25 - 609 1 - 24
32 1 1/4 127 5H
335 881 137 881 137 25 1 127 5
32 1 1/4 127 5H
385 1164 180 1164 180 25 1 127 5
32 1 1/4 127 5H
435 1486 230 1474 228
25 1 127 5
32 1 1/4 127 5H
51 2 178 7
485 1847 286 1828 283
25 1 127 5
32 1 1/4 127 5H
51 2 178 7
535 2248 348 2228 345
25 1 127 5
32 1 1/4 127 5H
51 2 178 7
585 2688 417 2660 412 32 1 1/4 127 5H
51 2 178 7
635 3167 491 3139 487 32 1 1/4 127 5H
51 2 178 7
685 3685 571 3657 567 32 1 1/4 127 5H
51 2 178 7
1. Consult your Emerson sales office for additional sizes.
2. Actuator size 280-385 are available with a top mounted handwheel. Size 435-685 are available with a manual handpump.
Table 3. 785C Double-Acting Springless Available Thrust
ACTUATOR
SIZE
MAXIMUM ALLOWABLE
CYLINDER PRESSURE
MAXIMUM ALLOWABLE THRUST
Without Manual Override With Manual Override(1)
barg psig N lb N lb
280
12 174
73890 16611 73890 16611
335 105769 23778 105769 23778
385 139699 31406 139699 31406
435 178340 40092 176832 39753
485 221694 49839 219338 49309
535 269761 60645 267404 60115
585 322540 72510 319146 71747
635 380030 85434 376638 84672
685 442234 99418 438841 98655
1. Actuator size 280-385 are available with a top mounted handwheel. Size 435-685 are available with a manual handpump.

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785C Actuator
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Table 4. 785C Single-Acting Spring Return Standard Constructions(1)
ACTUATOR
SIZE
PISTON AREA VALVE STEM
CONNECTOR
SIZE
YOKE BOSS
DIAMETER AVAILABLE TRAVEL
Without Manual Override With Manual Override(2)
Spring Extends Spring Retracts Spring Extends Spring Retracts
cm2Inch2cm2Inch2cm2Inch2cm2Inch2mm Inch mm Inch mm Inch
335 881 137 869 135 881 137 869 135 25 1 127 5
25.4 - 203 1 - 8
32 1 1/4 127 5H
385 1164 180 1152 179 1164 180 1152 179 25 1 127 5
32 1 1/4 127 5H
435 1486 230 1474 228 1474 228 1474 228
25 1 127 5
32 1 1/4 127 5H
51 2 178 7
485 1847 286 1835 284 1828 283 1835 284
25 1 127 5
32 1 1/4 127 5H
51 2 178 7
535 2248 348 2235 347 2228 345 2235 347
25 1 127 5
32 1 1/4 127 5H
51 2 178 7
585 2688 417 2660 412 2660 412 2660 412 32 1 1/4 127 5H
51 2 178 7
635 3167 491 3139 487 3139 487 3139 487 32 1 1/4 127 5H
51 2 178 7
685 3685 571 3657 567 3657 567 3657 567 32 1 1/4 127 5H
51 2 178 7
1. Consult your Emerson sales office for additional sizes.
2. Actuator size 335-385 are available with a top mounted handwheel. Size 435-685 are available with a manual handpump.
Table 5. Handwheel Specification
ACTUATOR
SIZE
OUTPUT THRUST HANDWHEEL DIAMETER TURNS PER mm
OF TRAVEL
TURNS PER INCH
OF TRAVEL
MAXIMUM RIM
FORCE REQUIRED
N lbs mm Inch N lbs
280 32635 7337 850 33 0.2 4.2 437 98
335 46715 10502 1200 47 0.2 4.2 435 98
385 61700 13871 1400 55 0.2 4.2 489 110
Table 6. Handpump Specification
ACTUATOR SIZE HYDRAULIC CYLINDER OUTPUT THRUST
mm Inch N lbf
435 135 5.3 78726 17698
485 175 6.9 132291 29740
535 175 6.9 132291 29740
585 200 7.9 172788 38844
635 200 7.9 172788 38844
685 235 9.3 238555 53629
Table 7. Pressure Connections
Actuator Size
Standard
Pressure Connection Size, NPT
(Top)/(Bottom)
Optional
Pressure Connection Size, NPT
(Top)/(Bottom)
Quantity
(Top/Bottom)
280 (3/4)(1) / (3/4) (3/4)(1) / (3/4)
3/3
335 (3/4) / (3/4) (1) / (3/4)
385 (3/4) / (3/4) (1 1/4) / (3/4)
435 (3/4) / (3/4) (1 1/4) / (3/4)
485 to 685 (3/4) / (3/4) (1 1/4) / (1 1/4)
1. With use of top mounted handwheel, pressure connection size is 1/2 NPT.

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785C Actuator
May 2019
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Figure 2. Fisher 785C Double-Acting Springless Piston Actuator (see table 8 and 9)
FRONT VIEW
W
SECTION B-B
Z
A2
A1
A3
G
AR
BB
Table 8. 785C Double-Acting Springless Dimensions A1, A3, AR, and G
ACTUATOR
SIZE
YOKE BOSS MAXIMUM TRAVEL A1 A3 AR(1) G(2)
Inch (mm) mm Inch mm Inch mm Inch mm Inch mm Inch
280
5101.6 4.0 738 29.1 245 9.6 346 14 369 14.5
203.2 8.0 923 36.3 346 13.6 432 17 461.5 18.2
5H 101.6 4.0 738 29.1 245 9.6 346 13.6 462 18.2
203.2 8.0 923 36.3 346 13.6 432 17 372 14.6
335
5101.6 4.0 744 29.3 248 9.8 346 14 372 14.6
203.2 8.0 929 36.6 349 13.7 432 17 464.5 18.3
5H 101.6 4.0 744 29.3 248 9.8 346 13.6 465 18.3
203.2 8.0 929 36.6 349 13.7 432 17 372 14.6
385
5101.6 4.0 744 29.3 248 9.8 346 14 372 14.6
203.2 8.0 929 36.6 349 13.7 432 17 464.5 18.3
5H 101.6 4.0 744 29.3 248 9.8 346 13.6 465 18.3
203.2 8.0 929 36.6 349 13.7 432 17 372 14.6
7101.6 4.0 744 30.5 248 9.8 432 17 387 15.2
203.2 8.0 1005 39.6 349 13.7 508 20 503 19.8
‐continued‐

Instruction Manual
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785C Actuator
May 2019
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Table 8. 785C Double-Acting Springless Dimensions A1, A3, AR, and G (cont.)
ACTUATOR
SIZE
YOKE BOSS MAXIMUM TRAVEL A1 A3 AR(1) G(2)
Inch (mm) mm Inch mm Inch mm Inch mm Inch mm Inch
435
5101.6 4.0 744 29.3 248 9.8 346 14 372 14.6
203.2 8.0 929 36.6 349 13.7 432 17 464.5 18.3
5H 101.6 4.0 744 29.3 248 9.8 346 13.6 465 18.3
203.2 8.0 929 36.6 349 13.7 432 17 384 15.1
7101.6 4.0 744 30.5 248 9.8 432 17 387 15.2
203.2 8.0 1005 39.6 349 13.7 508 20 503 19.8
485
5101.6 4.0 767 30.2 251 9.9 346 14 383.5 15.1
203.2 8.0 952 37.5 352 13.9 432 17 476 18.7
5H 101.6 4.0 767 30.2 251 9.9 346 13.6 476 18.7
203.2 8.0 952 37.5 352 13.9 432 17 385 15.1
7101.6 4.0 797 31.4 251 9.9 432 17 399 15.7
203.2 8.0 1028 40.5 352 13.9 508 20 514 20.2
535
5101.6 4.0 769 30.3 253 10 346 14 384.5 15.1
203.2 8.0 954 37.6 354 13.9 432 17 477 18.8
5H 101.6 4.0 769 30.3 253 10 346 13.6 477 18.8
203.2 8.0 954 37.6 354 13.9 432 17 399 15.7
7101.6 4.0 799 31.5 253 10 432 17 400 15.7
203.2 8.0 1030 40.6 354 13.9 508 20 515 20.3
585
5H 101.6 4.0 798 31.4 271 10.7 346 13.6 399 15.7
203.2 8.0 994 39.1 372 14.6 432 17 497 19.6
7101.6 4.0 839 33 271 10.7 432 17 420 16.5
203.2 8.0 1070 42.1 372 14.6 508 20 535 21.1
635
5H 101.6 4.0 798 31.4 271 10.7 346 13.6 399 15.7
203.2 8.5 994 39.1 372 14.6 432 17 497 19.6
7101.6 4.0 839 33 271 10.7 432 17 420 16.5
203.2 8.0 1070 42.1 372 14.6 508 20 535 21.1
685
5H 101.6 4.0 798 31.4 271 10.7 346 13.6 399 15.7
203.2 8.0 994 39.1 372 14.6 432 17 497 19.6
7101.6 4.0 839 33 271 10.7 432 17 420 16.5
203.2 8.0 1070 42.1 372 14.6 508 20 535 21.1
1. Actuator Removal Clearance
2. Center of Gravity
Table 9. 785C Double-Acting Springless Dimension Z and W
ACTUATOR
SIZE
WITHOUT MANUAL OVERRIDE WITH MANUAL OVERRIDE
Z W Z W
5, 5H, or 7 Inch Yoke Boss 5, 5H, or 7 Inch Yoke Boss
mm Inch mm Inch mm Inch mm Inch
280 254 10 292 11.5 254 10 292 11.5
335 254 10 292 11.5 254 10 292 11.5
385 330 13 330 13 330 13 330 13
435 330 13 330 13 330 13 330 13
485 330 13 330 13 330 13 330 13
535 330 13 330 13 330 13 330 13
585 487 19.2 436 17.2 487 19.2 436 17.2
635 487 19.2 436 17.2 487 19.2 436 17.2
685 487 19.2 436 17.2 487 19.2 436 17.2

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785C Actuator
May 2019
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Figure 3. Fisher 785C Single-Acting Spring Return Piston Actuator (see table 10, 11, and 12)
FRONT VIEW
W
SECTION B-B
Z
A2
A
A3
G
AR
BB
A1

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785C Actuator
May 2019
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Table 10. 785C Single-Acting Spring Return (Spring Retracts) Dimensions A, A2, A3, AR, and G
ACTUATOR
SIZE
YOKE
BOSS Maximum Travel
Spring
A A2 A3 AR(1) G(2)
Inch
(mm) mm Inch mm Inch mm Inch mm Inch mm Inch mm Inch
335 5 or 5H 101.6 4.0 F1 1164 45.8 420 16.5 248 9.8 346 13.6 582 22.9
203.2 8.0 F1 1537 60.5 608 23.9 349 13.7 432 17 768.5 30.3
385
5 or 5H 101.6 4.0 F1 1219 48 475 18.7 248 9.8 346 13.6 609.5 24
F2 1195 47 451 17.8 248 9.8 346 13.6 597.5 23.5
203.2 8.0 F1 1516 59.7 587 23.1 349 13.7 432 17 758 29.8
7101.6 4.0 F1 1249 49.2 475 18.7 248 9.8 432 17 625 24.6
F2 1225 48.2 451 17.8 248 9.8 432 17 613 24.1
203.2 8.0 F1 1592 62.7 587 23.1 349 13.7 508 20 796 31.3
435
5 or 5H 101.6 4.0 F1 1264 49.8 520 20.5 248 9.8 346 13.6 632 24.9
F2 1207 47.5 463 18.2 248 9.8 346 13.6 603.5 23.8
203.2 8.0 F1 1704 67.1 775 30.5 349 13.7 432 17 852 25.5
7101.6 4.0 F1 1294 50.9 520 20.5 248 9.8 432 17 647 24.4
F2 1237 48.7 463 18.2 248 9.8 432 17 619 35.0
203.2 8.0 F1 1780 70.1 775 30.5 349 13.7 508 20 890 39.5
485
5 or 5H 101.6 4.0 F1 1331 52.4 564 22.2 251 9.9 346 13.6 665.5 26.2
F2 1284 50.6 517 20.4 251 9.9 346 13.6 642 25.3
203.2 8.0 F1 1724 67.9 772 30.4 352 13.9 432 17 862 33.9
7101.6 4.0 F1 1361 53.6 564 22.2 251 9.9 432 17 681 26.8
F2 1314 51.7 517 20.4 251 9.9 432 17 657 25.9
203.2 8.0 F1 1800 70.9 772 30.4 352 13.9 508 20 900 35.4
535
5 or 5H 101.6 4.0 F1 1258 49.5 489 19.3 253 10 346 13.6 629 24.8
F2 1313 51.7 544 21.4 253 10 346 13.6 656.5 25.8
203.2 8.0 F1 1753 69 799 31.5 354 13.9 432 17 876.5 34.5
7101.6 4.0 F1 1288 50.7 489 19.3 253 10 432 17 644 25.4
F2 1343 52.9 544 21.4 253 10 432 17 672 26.4
203.2 8.0 F1 1829 72 799 31.5 354 13.9 508 20 915 36.0
585
5H 101.6 4.0 F1 1296 51 498 19.6 271 10.7 346 13.6 648 25.5
F2 1297 51.1 499 19.6 271 10.7 346 13.6 648.5 25.5
203.2 8.0 F1 1810 71.3 816 32.1 372 14.6 432 17 905 35.6
7101.6 4.0 F1 1337 52.6 498 19.6 271 10.7 432 17 669 26.3
F2 1338 52.7 499 19.6 271 10.7 432 17 669 26.3
203.2 8.0 F1 1886 74.3 816 32.1 372 14.6 508 20 943 37.1
635
5H 101.6 4.0 F1 1297 51.1 499 19.6 271 10.7 346 13.6 648.5 25.5
F2 1297 51.1 499 19.6 271 10.7 346 13.6 648.5 25.5
203.2 8.0 F1 1810 71.3 816 32.1 372 14.6 432 17 905 35.6
7101.6 4.0 F1 1338 52.7 499 19.6 271 10.7 432 17 669 26.3
F2 1338 52.7 499 19.6 271 10.7 432 17 669 26.3
203.2 8.0 F1 1886 74.3 816 32.1 372 14.6 508 20 943 37.1
685
5H 101.6 4.0 F1 1467 57.8 669 26.3 271 10.7 346 13.6 733.5 28.9
F2 1297 51.1 499 19.6 271 10.7 346 13.6 648.5 25.5
203.2 8.0 F1 1810 71.3 816 32.1 372 14.6 432 17 905 35.6
7101.6 4.0 F1 1508 59.4 669 26.3 271 10.7 432 17 754 29.7
F2 1338 52.7 499 19.6 271 10.7 432 17 669 26.3
203.2 8.0 F1 1886 74.3 816 32.1 372 14.6 508 20 943 37.1
1. Actuator Removal Clearance
2. Center of Gravity

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785C Actuator
May 2019
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Table 11. 785C Single-Acting Spring Return (Spring Extends) Dimensions A, A2, A3, AR, and G
ACTUATOR
SIZE
YOKE
BOSS Maximum Travel
Spring
A A2 A3 AR(1) G(2)
Inch
(mm) mm Inch mm Inch mm Inch mm Inch mm Inch mm Inch
335 5 or 5H 101.6 4.0 F1 1220 48 476 18.7 248 9.8 346 13.6 610 24
F2 1255 49.4 511 20.1 248 9.8 346 13.6 627.5 24.7
203.2 8.0 F1 1600 63 671 26.4 349 13.7 432 17 800 31.5
385
5 or 5H
101.6 4.0 F1 1353 53.3 609 24 248 9.8 346 13.6 676.5 26.6
F2 1352 53.2 608 23.9 248 9.8 346 13.6 676 26.6
203.2 8.0
F1 1497 58.9 568 22.4 349 13.7 432 17 748.5 29.5
F2 1490 58.7 561 22.1 349 13.7 432 17 745 29.3
F3 1611 63.4 682 26.9 349 13.7 432 17 805.5 31.7
7
101.6 4.0 F1 1383 54.4 609 24 248 9.8 432 17 692 27.2
F2 1382 54.4 608 23.9 248 9.8 432 17 692 27.2
203.2 8.0
F1 1573 61.9 568 22.4 349 13.7 508 20 787 31.0
F2 1566 61.7 561 22.1 349 13.7 508 20 783 30.8
F3 1687 66.4 682 26.9 349 13.7 508 20 844 33.2
435
5 or 5H
101.6 4.0 F1 1274 50.2 530 20.9 248 9.8 346 13.6 637 25.1
F2 1231 48.5 487 19.2 248 9.8 346 13.6 615.5 24.2
203.2 8.0
F1 1622 63.9 693 27.3 349 13.7 432 17 811 31.9
F2 1671 65.8 742 29.2 349 13.7 432 17 835.5 32.9
F3 1676 66 747 29 349 13.7 432 17 838 33
7
101.6 4.0 F1 1304 51.3 530 20.9 248 9.8 432 17 652 25.7
F2 1261 49.6 487 19.2 248 9.8 432 17 630.5 24.8
203.2 8.0
F1 1698 66.9 693 27.3 349 13.7 508 20 849 33.4
F2 1747 68.8 742 29.2 349 13.7 508 20 873.5 34.4
F3 1752 69 747 29.4 349 13.7 508 20 876 34.5
485
5 or 5H
101.6 4.0 F1 1288 50.7 521 20.5 251 9.9 346 13.6 644 25.4
F2 1264 59.8 497 19.6 251 9.9 346 13.6 632 24.9
203.2 8.0
F1 1643 64.7 691 27.2 352 13.9 432 17 821.5 32.3
F2 1690 66.5 738 29.1 352 13.9 432 17 845 33.3
F3 1696 66.8 744 29.3 352 13.9 432 17 848 33.4
7
101.6 4.0 F1 1318 51.9 521 20.5 251 9.9 432 17 659 25.9
F2 1294 50.9 497 19.6 251 9.9 432 17 647 25.5
203.2 8.0
F1 1719 67.7 691 27.2 352 13.9 508 20 859.5 33.8
F2 1766 69.5 738 29.1 352 13.9 508 20 883 34.8
F3 1772 69.8 744 29.3 352 13.9 508 20 886 34.9
535
5 or 5H
101.6 4.0 F1 1266 49.8 497 19.6 253 10 346 13.6 633 24.9
F2 1375 54.1 606 23.9 253 10 346 13.6 687.5 27.1
203.2 8.0
F1 1751 68.9 797 31.4 354 13.9 432 17 875.5 34.5
F2 1641 64.6 687 27 354 13.9 432 17 820.5 32.3
F3 1649 64.9 695 27.4 354 13.9 432 17 824.5 32.5
7
101.6 4.0 F1 1296 51 497 19.6 253 10 432 17 648 25.5
F2 1405 55.3 606 23.9 253 10 432 17 702.5 27.7
203.2 8.0
F1 1827 71.9 797 31.4 354 13.9 508 20 913.5 36.0
F2 1717 67.6 687 27 354 13.9 508 20 858.5 33.8
F3 1725 67.9 695 27.4 354 13.9 508 20 1862.5 34.0
-continued-

Instruction Manual
D104483X012
785C Actuator
May 2019
11
Table 11. 785C Single-Acting Spring Return (Spring Extends) Dimensions A, A2, A3, AR, and G (cont.)
ACTUATOR
SIZE
YOKE
BOSS Maximum Travel
Spring
A A2 A3 AR(1) G(2)
Inch
(mm) mm Inch mm Inch mm Inch mm Inch mm Inch mm Inch
585
5H
101.6 4.0 F1 1419 55.9 621 24.4 271 10.7 346 13.6 709.5 27.9
F2 1273 50.1 475 18.7 271 10.7 346 13.6 636.5 25.1
203.2 8.0
F1 1695 66.7 701 27.6 372 14.6 432 17 847.5 33.4
F2 1759 69.3 765 30.1 372 14.6 432 17 879.5 34.6
F3 1759 69.3 765 30.1 372 14.6 432 17 879.5 34.6
7
101.6 4.0 F1 1460 57.5 621 24.4 271 10.7 432 17 730 28.7
F2 1314 51.7 475 18.7 271 10.7 432 17 657 25.9
203.2 8.0
F1 1771 69.7 701 27.6 372 14.6 508 20 885.5 34.9
F2 1835 72.2 765 30.1 372 14.6 508 20 917.5 36.1
F3 1835 72.2 765 30.1 372 14.6 508 20 917.5 36.1
635
5H
101.6 4.0 F1 1330 52.4 532 20.9 271 10.7 346 13.6 665 26.2
F2 1438 56.6 640 25.2 271 10.7 346 13.6 719 28.3
203.2 8.0
F1 1839 72.4 845 33.3 372 14.6 432 17 919.5 36.2
F2 1737 68.4 743 29.3 372 14.6 432 17 868.5 34.2
F3 1737 68.4 743 29.3 372 14.6 432 17 868.5 34.2
7
101.6 4.0 F1 1371 54 532 20.9 271 10.7 432 17 685.5 27.0
F2 1479 58.2 640 25.2 271 10.7 432 17 739.5 29.1
203.2 8.0
F1 1915 75.4 845 33.3 372 14.6 508 20 957.5 37.7
F2 1813 71.4 743 29.3 372 14.6 508 20 906.5 35.7
F3 1813 71.4 743 29.3 372 14.6 508 20 906.5 35.7
685
5H
101.6 4.0
F1 1376 54.2 578 22.8 271 10.7 346 13.6 688 27.1
F2 1372 54 574 22.6 271 10.7 346 13.6 686 27
F3 1612 63.5 814 32 271 10.7 346 13.6 806 31.7
203.2 8.0
F1 1702 67 708 27.9 372 14.6 432 17 851 33.5
F2 1711 67.4 717 28.2 372 14.6 432 17 855.5 33.7
F3 1773 69.8 779 30.7 372 14.6 432 17 886.5 34.9
7
101.6 4.0
F1 1417 55.8 578 22.8 271 10.7 432 17 708.5 27.9
F2 1413 55.6 574 22.6 271 10.7 432 17 706.5 27.8
F3 1653 65.1 814 32 271 10.7 432 17 826.5 32.5
203.2 8.0
F1 1778 70 708 27.9 372 14.6 508 20 889 35.0
F2 1787 70.4 717 28.2 372 14.6 508 20 893.5 35.2
F3 1849 72.8 779 30.7 372 14.6 508 20 924.5 36.4
1. Actuator Removal Clearance
2. Center of Gravity
Table 12. 785C Single-Acting Spring Return (Spring Retracts or Spring Extends) Dimensions Z and W
ACTUATOR SIZE
WITHOUT MANUAL OVERRIDE WITH MANUAL OVERRIDE
Z W Z W
5, 5H, or 7 Inch Yoke Boss 5, 5H, or 7 Inch Yoke Boss
mm Inch mm Inch mm Inch mm Inch
335 254 10 292 11.5 254 10 292 11.5
385 330 13 330 13 330 13 330 13
435 330 13 330 13 330 13 330 13
485 330 13 330 13 330 13 330 13
535 330 13 330 13 330 13 330 13
585 487 19.2 436 17.2 487 19.2 436 17.2
635 487 19.2 436 17.2 487 19.2 436 17.2
685 487 19.2 436 17.2 487 19.2 436 17.2

Instruction Manual
D104483X012
785C Actuator
May 2019
12
Table 13. 785C Double-Acting Springless Approximate Weights for Constructions without Manual Override
Actuator Size 280, 335, 385, and 435
MAXIMUM
VALVE
TRAVEL
APPROXIMATE WEIGHT FOR ACTUATOR SIZE, kg (lbs)
280 335 385 435
mm
(inches)
5 Yoke
Boss
5H Yoke
Boss
5 Yoke
Boss
5H Yoke
Boss
5 Yoke
Boss
5H Yoke
Boss
7 Yoke
Boss
5 Yoke
Boss
5H Yoke
Boss
7 Yoke
Boss
101.6 (4) 143 (316) 136 (301) 174 (384) 167 (370) 223 (493) 228 (503) 224 (496) 266 (588) 271 (598) 267 (589)
203.6 (8) 142 (314) 142 (314) 173 (382) 173 (382) 228 (503) 240 (530) 232 (512) 271 (598) 283 (625) 275 (606)
Table 14. 785C Double-Acting Springless Approximate Weights for Constructions without Manual Override
Actuator Size 485, 535, 585, 635, and 685
MAXIMUM
VALVE
TRAVEL
APPROXIMATE WEIGHT FOR ACTUATOR SIZE, kg (lbs)
485 535 585 635 685
mm
(inches)
5 Yoke
Boss
5H Yoke
Boss
7 Yoke
Boss
5 Yoke
Boss
5H Yoke
Boss
7 Yoke
Boss
5H Yoke
Boss
7 Yoke
Boss
5H Yoke
Boss
7 Yoke
Boss
5H Yoke
Boss
7 Yoke
Boss
101.6 (4) 308
(681)
312
(690)
309
(681)
356
(788)
361
(797)
358
(788)
488
(1079)
486
(1072)
560
(1237)
558
(1230)
627
(1386)
625
(1377)
203.6 (8) 312
(690)
325
(717)
317
(698)
361
(797)
373
(824)
365
(805)
490
(1082)
497
(1096)
561
(1240)
569
(1254)
660
(1459)
668
(1472)
Table 15. 785C Double Acting Springless Approximate Weights for Constructions with Manual Override
Actuator Size 280, 335, 385, and 435
MAXIMUM
VALVE
TRAVEL
APPROXIMATE WEIGHT FOR ACTUATOR SIZE, kg (lbs)
280 335 385 435
mm
(inches)
5 Yoke
Boss
5H Yoke
Boss
5 Yoke
Boss
5H Yoke
Boss
5 Yoke
Boss
5H Yoke
Boss
7 Yoke
Boss
5 Yoke
Boss
5H Yoke
Boss
7 Yoke
Boss
101.6 (4) 226 (498) 219 (484) 268 (592) 261 (578) 345 (762) 349 (772) 346 (764) 416 (919) 420 (929) 417 (921)
203.6 (8) 224 (496) 224 (496) 267 (590) 267 (590) 349 (772) 361 (798) 354 (781) 420 (929) 432 (955) 425 (938)
Table 16. 785C Double Acting Springless Approximate Weights for Constructions with Manual Override
Actuator Size 485, 535, 585, 635, and 685
MAXIMUM
VALVE
TRAVEL
APPROXIMATE WEIGHT FOR ACTUATOR SIZE, kg (lbs)
485 535 585 635 685
mm
(inches)
5 Yoke
Boss
5H Yoke
Boss
7 Yoke
Boss
5 Yoke
Boss
5H Yoke
Boss
7 Yoke
Boss
5H Yoke
Boss
7 Yoke
Boss
5H Yoke
Boss
7 Yoke
Boss
5H Yoke
Boss
7 Yoke
Boss
101.6 (4) 497
(1099)
502
(1109)
498
(1101)
584
(1291)
589
(1301)
585
(1294)
779
(1721)
777
(1716)
908
(2006)
905
(2001)
1028
(2272)
1026
(2268)
203.6 (8) 502
(1109)
514
(1135)
506
(1118)
589
(1301)
601
(1328)
593
(1311)
780
(1724)
788
(1741)
909
(2008)
916
(2025)
1120
(2474)
1127
(2491)

Instruction Manual
D104483X012
785C Actuator
May 2019
13
Table 17. 785C Single-Acting Spring Return Approximate Weights for Constructions without Manual Override
Actuator Size 335, 385, 435, and 485
MAXIMUM
VALVE
TRAVEL
APPROXIMATE WEIGHT FOR ACTUATOR SIZE, kg (lbs)
335 385 435 485
mm
(inches)
5 Yoke
Boss
5H Yoke
Boss
5 Yoke
Boss
5H Yoke
Boss
7 Yoke
Boss
5 Yoke
Boss
5H Yoke
Boss
7 Yoke
Boss
5 Yoke
Boss
5H Yoke
Boss
7 Yoke
Boss
101.6 (4) 350
(775)
250
(551)
505
(1117)
388
(856)
385
(851)
655
(1446)
509
(1123)
506
(1118)
754
(1665)
569
(1254)
565
(1250)
203.6 (8) 415
(918)
321
(708)
574
(1268)
464
(1023)
457
(1009)
579
(1279)
441
(973)
433
(958)
737
(1628)
560
(1234)
552
(1220)
Table 18. 785C Single-Acting Spring Return Approximate Weights for Constructions without Manual Override
Actuator Size 535, 585, 635, and 685
MAXIMUM
VALVE
TRAVEL
APPROXIMATE WEIGHT FOR ACTUATOR SIZE, kg (lbs)
535 585 635 685
mm
(inches)
5 Yoke
Boss
5H Yoke
Boss
7 Yoke
Boss
5H Yoke
Boss
7 Yoke
Boss
5H Yoke
Boss
7 Yoke
Boss
5H Yoke
Boss
7 Yoke
Boss
101.6 (4) 841 (1858) 617 (1361) 614 (1357) 745 (1642) 743 (1642) 793 (1749) 791 (1748) 887 (1956) 885 (1956)
203.6 (8) 876 (1936) 660 (1455) 652 (1442) 698 (1539) 706 (1560) 817 (1801) 825 (1822) 912 (2011) 920 (2033)
Table 19. 785C Single-Acting Spring Return Approximate Weights for Constructions with Manual Override
Actuator Size 335, 385, 435, and 485
MAXIMUM
VALVE
TRAVEL
APPROXIMATE WEIGHT FOR ACTUATOR SIZE, kg (lbs)
335 385 435 485
mm
(inches)
5 Yoke
Boss
5H Yoke
Boss
5 Yoke
Boss
5H Yoke
Boss
7 Yoke
Boss
5 Yoke
Boss
5H Yoke
Boss
7 Yoke
Boss
5 Yoke
Boss
5H Yoke
Boss
7 Yoke
Boss
101.6 (4) 350
(775)
344
(760)
505
(1117)
510
(1127)
506
(1119)
655
(1446)
507
(1121)
656
(1449)
754
(1665)
758
(1675)
755
(1660)
203.6 (8) 415
(918)
415
(918)
574
(1268)
586
(1294)
578
(1277)
579
(1279)
591
(1305)
583
(1288)
737
(1628)
749
(1655)
741
(1638)
Table 20. 785C Single-Acting Spring Return Approximate Weights for Constructions with Manual Override
Actuator Size 535, 585, 635, and 685
MAXIMUM
VALVE
TRAVEL
APPROXIMATE WEIGHT FOR ACTUATOR SIZE, kg (lbs)
535 585 635 685
mm
(inches)
5 Yoke
Boss
5H Yoke
Boss
7 Yoke
Boss
5H Yoke
Boss
7 Yoke
Boss
5H Yoke
Boss
7 Yoke
Boss
5H Yoke
Boss
7 Yoke
Boss
101.6 (4) 841 (1858) 845 (1867) 842 (1860) 1035 (2288) 1033 (2283) 1141 (2521) 1138 (2516) 1288 (2847) 1286 (2842)
203.6 (8) 876 (1936) 888 (1962) 880 (1945 989 (2185) 996 (2202) 1165 (2574) 1172 (2591) 1372 (3032) 1379 (3049)

Instruction Manual
D104483X012
785C Actuator
May 2019
14
Table 21. Lifting Point Load Ratings
ACTUATOR SIZE LIFTING ORIENTATION NUMBER OF LIFTING
POINTS USED
MAXIMUM WELDED EYELET LOAD
AT LIFTING ANGLE a3205
(SEE FIGURE 5)
Kg lbs
280
Actuator Centerline Horizontal(1)
2 1747 3851
335 2 1747 3851
385 2 1747 3851
435 2 1747 3851
485 2 6330 13955
535 2 6330 13955
585 2 6330 13955
635 2 6330 13955
685 2 6330 13955
ACTUATOR SIZE LIFTING ORIENTATION NUMBER OF LIFTING
POINTS USED
MAXIMUM LOAD AT EYEBOLT
LIFTING ANGLE a3455
(SEE FIGURE 6)
Kg lbs
280
Actuator Centerline Vertical(2)
4 864 1905
335 4 864 1905
385 4 864 1905
435 4 864 1905
485 4 3096 6826
535 4 3096 6826
585 4 3096 6826
635 4 3096 6826
685 4 3096 6826
1. Welded eyelets for horizontal lifting are only available for the 785C Spring Return.
2. Vertical lifting loads are applicable to both the 785C Springless and Spring Return.

Instruction Manual
D104483X012
785C Actuator
May 2019
15
Figure 4. Lifting Angle for Welded Eyelets
V
T
N

Instruction Manual
D104483X012
785C Actuator
May 2019
16
Figure 5. Spring Return Actuator Centerline
Horizontal Lift
TT
NN
Figure 6. Spring Return Actuator Centerline
Vertical Lift
TT
N
Installation
Key numbers in this procedure are shown in figures 8, 9, and 10, unless otherwise indicated.
WARNING
To avoid personal injury or property damage caused by cylinder fracture as a result of piston impact, install the stem
connector securely before supplying pressure to the positioner. Use only a regulator-controlled air supply to move the
actuator piston so that you can install the stem connector. Do not use the positioner to move the actuator piston before
installing the stem connector.
Always wear protective gloves, clothing, and eyewear when performing any installation operations to avoid personal
injury.
If installing into an existing application, also refer to the warning at the beginning of the Maintenance section in this
manual.
Check with your process or safety engineer for any additional measures that must be taken to protect against process
media.
To avoid personal injury or property damage caused by bursting of pressure‐retaining parts, be certain the cylinder
pressure or other pressure ratings do not exceed the limits listed in table 1. Use pressure‐limiting or pressure‐relieving
devices to prevent cylinder pressure or other pressures from exceeding these limits.
To avoid personal injury or equipment damage, use proper lifting and rigging practices while lifting the actuator or
valve/actuator assembly. For all mounting procedures use an adequately sized chain, sling, hoist, or crane to handle the
actuator and any attached accessories and/or valve. Use caution during lifting and handling to prevent slippage, swinging,
faulty equipment connections, or sudden shock loads.

Instruction Manual
D104483X012
785C Actuator
May 2019
17
CAUTION
Special care must be taken when installing an actuator in a horizontal service orientation. To avoid cantilever loads on the
valve stem and yoke, it is the customer’s responsibility to ensure proper support for a horizontal actuator.
When an actuator and control valve are shipped together as a control valve assembly, the actuator is normally
mounted on the valve. Follow the valve instructions when installing the valve in the pipeline. If the actuator is shipped
separately or if it is necessary to mount the actuator on the valve, perform the actuator mounting procedures in this
instruction manual. Refer to the individual product instruction manuals for the installation or mounting of a FIELDVUE
DVC6200 digital valve controller.
If the actuator is being installed without a positioner, the cylinder loading pressures should be supplied through a
4-way solenoid valve or a switching valve.
Pressure connections are located on top of the pneumatic cylinder end flange (key 2210) and on the side of the
pneumatic cylinder head flange (key 2201).
D The supply pressure medium should be clean, dry filtered air. If the supply source is capable of exceeding the
maximum actuator operating pressure or positioner supply pressure, appropriate steps must be taken during
installation to protect the positioner and all connected equipment against over pressurization.
D The control valve should be located where it will be accessible for servicing. Space should be left above and below
the control valve to permit removal of the actuator and valve plug.
Three‐Way Valve Applications Note
In three-way valve applications where the actuator fully strokes at a frequency of once per minute or faster, and the
stroking speed is rapid (less than 0.5 seconds per stroke), there is a possibility that the stem can fracture at the plug if
the actuator cylinder pressure is greater than 5.5 bar (80 psig). This can cause loss of control of process fluid and
further damage to the actuator. Considerations should be given to the use of high-strength, fatigue-resistant stem
materials in these applications.
WARNING
To avoid loss of control of process fluid and subsequent personal injury or property damage caused by bursting of
pressure‐retaining parts, be sure the cylinder pressure does not exceed 80 psig in high cycle‐rate, fast stroking speed,
three‐way valve applications.
Manual Override
The actuator can be equipped with a manual override. The manual override can be executed with a Manual Handwheel
or a Manual Hydraulic Pump which can operate the actuator.
Handwheel Operation
If manual operation is required for actuator sizes 280, 335, and 385 a manual handwheel should be equipped.
CAUTION
To avoid damage to actuator parts and difficult operation of actuator handwheels, open the bypass valve before using a
handwheel.

Instruction Manual
D104483X012
785C Actuator
May 2019
18
Do not disengage the handwheel if the spring thrust is not balanced by pneumatic load.
If it is necessary to keep the valve in its position and if the pneumatic supply is not restored yet, do not disengage the
handwheel.
If it not is necessary to keep the valve in its position and if the pneumatic supply is not restored yet, in order to disengage
take the handwheel to the end of the stroke (spring fully released).
The following steps reference figure 7. Refer to table 5 for handwheel specifications.
1. Engage the manual override by rotating its handle, reference figure 7. Note that there is only one position (at 360°
rotation of the handwheel) where the handle will correctly engage the manual operation. To reach that position
during the rotation of the handle, slowly rotate the handwheel until the correct position, as indicated on the
warning plate shown in figure 7.
2. Turn the handwheel of the manual override clockwise to close, or counter clockwise to open, as indicated on the
instruction label.
3. Check the correct operation of the actuator by monitoring the movement of the travel indicator.
4. Once manual operation is completed, ensure the spring thrust is balanced by applying a pneumatic load and
disengage the manual override, by rotating the handle as shown on the instruction plate. This allows the actuator to
be operated by the pneumatic supply.
Figure 7. Manual Handwheel
HANDLE
HANDWHEEL
INSTRUCTION
WARNING
Actuator Mounting
The following procedure describes how to mount a 785C actuator on a push down to close valve so that the piston rod
to valve plug stem connection allows full travel and proper shutoff. Key numbers referenced in the following steps are
shown in figures 8 and 9. If you purchase a 785C actuator for field installation on a control valve, mount the actuator
on the valve and secure it to the bonnet with the bonnet-to-actuator bolts. The stem connection should then be made
up to clamp the actuator stem and valve plug stem together to provide proper valve travel.

Instruction Manual
D104483X012
785C Actuator
May 2019
19
WARNING
When moving the piston rod with loading pressure applied, exercise caution to keep hands and tools out of the piston rod
travel path. If the loading pressure is accidentally disconnected, personal injury and property damage is possible is
something is caught between the piston rod and other control valve parts.
CAUTION
The 785C spring extend actuator spring load will force the piston rod to extend out of the cylinder, and it can come into
contact with the valve stem during actuator mounting.
If the valve stem is allowed to remain in the up position (towards the actuator) during mounting, it can interfere with the
actuator mounting, possibly damage valve stem threads or bend the valve stem. Be sure the valve stem is pushed down
(into the valve body), away from the actuator while mounting.
To avoid damaging the valve plug seating surfaces, do not rotate the valve plug while it is seated. Also avoid damage to the
valve plug stem by careful use of tools during travel adjustment.
1. Using the given lifting eye bolts (key 2215), hoist the actuator vertically oriented. Slowly lower it over the valve
taking care not to contact the stem in manner that could cause damage.
2. Once the actuator is seated on the bonnet yoke, install the studs through the yoke mounting plate. Install the nuts
and tighten to the appropriate torque as specified in the applicable valve instruction manual.
3. Starting with the piston (key 2206) at the top of the pneumatic cylinder, manually, or with air pressure, extend the
piston rod (key 2350) to the specified valve travel. Before pressurizing the cylinder, ensure the plastic plugs are
removed from the pneumatic cylinder and replaced with appropriate metal plugs or other pressure-retaining
devices.
4. With the valve plug on the seat, attach the valve stem connector (key 4301) by inserting the socket head cap screws
(key 4302), clamping the piston rod (key 2350) to the valve stem. Make sure to attach the travel indicator (key
5000) and anti-rotator plate (key 4850) if supplied. Confirm proper operation and check travel, travel indicator
adjustment, etc. before placing the actuator into operation.
Maintenance
Actuator parts are subject to normal wear and must be inspected and replaced when necessary. The frequency of
inspection and replacement depends on the severity of service conditions.
WARNING
Avoid personal injury and property damage from sudden release of process pressure or bursting of parts. Before
performing any maintenance operations:
D Do not remove the actuator from the valve while the valve is still pressurized.
D Always wear protective gloves, clothing, and eyewear when performing any maintenance operations.
D Disconnect any operating lines providing air pressure, electric power, or a control signal to the actuator. Be sure the
actuator cannot suddenly open or close the valve.
D Use bypass valves or completely shut off the process to isolate the valve from process pressure. Relieve process pressure
on both sides of the valve. Drain the process media from both sides of the valve.
D Vent the power actuator loading pressure and relieve any spring pre-compression.
D Use lock‐out procedures to be sure the above measures stay in effect while you work on the equipment.

Instruction Manual
D104483X012
785C Actuator
May 2019
20
D The valve packing box may contain process fluids that are pressurized, even when the valve has been removed from the
pipeline. Process fluids may spray out when removing the packing hardware or packing rings, or when loosening the
packing box pipe plug.
D Check with your process or safety engineer for any additional measures that must be taken to protect against process
media.
Instructions are given below for complete disassembly of the actuator, seal replacement, and O-ring replacement. When
inspection or repair is necessary, disassemble the actuator only as far as is required to accomplish the job. Key numbers
referenced in the following steps are shown in figures 8, 9, and 10.
Actuator Removal
The following procedure is for the removal of the actuator from the valve.
WARNING
To avoid personal injury or equipment damage, use proper lifting and rigging practices while lifting the actuator assembly.
To avoid personal injury due to the sudden uncontrolled movement of parts, do not loosen the stem connector hex nuts
when the stem connector has spring force applied to it.
1. Ensure the valve and actuator are de-energized (mechanical, pneumatic, and electric) and appropriately isolated.
Disconnect the actuator tubing from the pressure connections on the pneumatic cylinder head flange and end
flange (key 2201 and 2210) and positioner. Provisions may need to be made if the actuator is spring extended.
For 785C Spring Extend actuator: It may be necessary to apply a temporary loading pressure to the bottom cylinder
pressure connection to move the piston rod away from the valve stem during removal. If it is not possible to provide
a temporary loading pressure, exercise caution when removing the actuator to prevent damage to the valve stem
or piston rod.
2. Disconnect the stem connection by removing socket head cap screws (key 4302) from the valve stem connector
(key 4301).
3. Remove the bonnet-to-actuator bolting securing the actuator to the valve bonnet. Make sure the actuator is
supported and secured by other means prior to loosening nuts.
4. Using the lifting points provided (key 2215), hoist the actuator vertically taking care not to contact the stem in a
manner that would cause damage.
Seal and O-Ring Replacement
The following procedure is for the replacement of the internal piston seals, bearing seals, and O-rings:
1. Complete Actuator Removal procedures per the applicable section of this instruction manual.
2. Loosen the tie-rod hex nuts (key 2212) in a crisscross pattern to remove the pneumatic cylinder tie rod bolts (key
2213).
3. Remove the top cylinder end flange (key 2210) and cylinder tube (key 2209). Set aside.
4. Unscrew the piston (key 2206) using the two threaded holes (for actuator sizes 280-435 thread size is M10; for sizes
485-685 thread size is M16). Remove and set aside.
5. Remove the socket head cap screws from the spring cartridge end flange (key 2411) and the screws from the
pneumatic cylinder head flange (key 2201). Remove the pneumatic cylinder head flange (key 2201) taking care not
to contact the piston rod (key 2350) in a manner that could result in damage. Set aside.