Emerson Fisher 3570 Instruction Manual
Instruction Manual
D200137X012
Fisherr 3570 Pneumatic Valve Positioners
3570 Positioners
September 2011
Contents
Introduction 1.................................
Scope of Manual 1.............................
Description 2.................................
Valve Positioner Type Numbers 2.............
Specifications 4...............................
Educational Services 4.........................
Installation, Mounting, and Connections 5..........
Installation 5.................................
Diagnostic Test Connections (Optional) 6.....
Connections 7................................
Piping Sizes 7.............................
Vent 8...................................
Supply Pressure Connections 9..............
Cylinder Connections 10....................
Instrument Connection 10..................
Operating Information 11........................
Initial Adjustments 11..........................
Signal Range Codes 11.........................
Frequency Response 12........................
Adjustment Procedures 14......................
Changing Positioner Action 17..................
Split Range Operation 19.......................
Initial Range Spring Extension Procedure
for 3570P and 3570PC Positioners 19..........
Principle of Operation 21........................
3570, 3570C, 3570P, 3570PC, and
3571 Valve Positioners 21....................
3572 and 3576 Valve Positioners 22..............
3573 and 3577 Valve Positioners 23..............
Relay Operation 24............................
Maintenance 25................................
Troubleshooting 26............................
Converting a 3570 Valve Positioner to a
3570C Valve Positioner 27....................
Range Spring 28..............................
Disassembly 28...........................
Assembly 28..............................
Figure 1. Fisher 3570 Positioner Mounted on
470 Actuator
W5566*/IL
Bias Spring 29................................
Disassembly 29...........................
Assembly 29..............................
Parts Ordering 29...............................
Parts Kits 30...................................
Positioner Repair Kits 30........................
Diagnostic Test Connection Kits 30...............
Parts List 30...................................
Positioner Common Parts 30....................
Introduction
Scope of Manual
This manual provides installation, operation, adjustment, maintenance, and parts ordering information for Fisher
3570 pneumatic valve positioners. The various product types within this series are described later in this manual. Refer
www.Fisher.com
3570 Positioners
September 2011
to figure 1 for a typical mounting of a 3570 positioner. Refer to separate instruction manuals for information
concerning the actuator, valve, and accessories.
Do not install, operate or maintain a 3570 positioner 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.
Instruction Manual
D200137X012
Description
3570 pneumatic valve positioners are used with control valve assemblies to provide an accurate valve stem position
that is proportional to the input signal received from a control device. The input signal range can be 0.2 to 1.0 bar (3 to
15 psig), 0.4 to 2.0 bar (6 to 30 psig), or another pneumatic input signal range, as required.
These positioners are normally used with pneumatic piston actuators. However, product types within the 3570 family
can be used with pneumatic, long‐stroke, cylinder actuators or with pneumatic diaphragm actuators.
Valve Positioner Type Numbers
3570 — Pneumatic valve positioner with two relays for use with Fisher 470 and 480 pneumatic piston actuators. See
figure 4. The positioner includes three pressure gauges to monitor input signal, relay output pressure to the top of the
actuator cylinder, and relay output pressure to the bottom (piston underside) of the actuator cylinder.
The 3570 positioner is mounted on the top of the actuator cylinder. The actuator stem position feedback is provided
through extension of the range spring attached to the actuator piston rod.
3570C — Pneumatic valve positioner with automotive tire valves instead of pressure gauges. Tire valves can be used
for clip‐on test pressure gauges. The relay nozzles are locked in place with locknuts to resist unwanted nozzle
movement due to vibration.
3570P — Pneumatic valve positioner with two relays for use with Fisher 490 pneumatic piston actuators. The
positioner includes three pressure gauges to monitor input signal, relay output pressure to the top of the actuator
cylinder, and relay output pressure to the bottom (piston underside) of the actuator cylinder.
The 3570P positioner is mounted alongside the actuator cylinder. Actuator stem position feedback is provided from
the actuator‐valve stem connector through a cable and spool assembly.
3570PC — Pneumatic valve positioner with automotive tire valves instead of pressure gauges. Tire valves can be used
for clip‐on test pressure gauges. The relay nozzles are locked in place with locknuts to resist unwanted nozzle
movement due to vibration.
3571 (Discontinued)— Pneumatic valve positioner with two relays for use with long‐stroke cylinder actuators. The
positioner includes three pressure gauges to monitor input signal, relay output pressure to the top of the actuator
cylinder, and relay output pressure to the bottom (piston underside) of the actuator cylinder.
The 3571 positioner is bracket‐mounted to the side of the actuator. Actuator stem position feedback is provided
through a wire from the actuator‐valve stem connector.
3572 — Pneumatic valve positioner with one relay. The 3572 positioner is normally used on the 472 pneumatic piston
actuator mounted on valve bodies having push‐down‐to‐open (PDTO) action. The positioner includes two pressure
gauges to monitor input signal pressure and relay output pressure to the top of the actuator cylinder.
The 3572 positioner is mounted on the top of the actuator cylinder. Actuator stem position feedback is provided
through an extension of the actuator piston rod.
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Instruction Manual
D200137X012
Table 1. Specifications
3570 Positioners
September 2011
Available Configurations
See the positioner type number descriptions given
above.
Input Signal
Standard Ranges: 0.2 to 1.0 bar (3 to 15 psig) or 0.4
Supply Pressure
Maximum: 10.4 bar (150 psig)
Minimum: 2.4 bar (35 psig)
Supply Medium
Air or Natural gas
(2)
to 2.0 bar (6 to 30 psig)
Optional Ranges: As desired, within the limits of the
bellows
Split Ranges: Use one‐half of either standard range
when two control valves are operated by one
output signal form a single control device
Steady‐State Air Consumption
0.54 normal m3/h (20 scfh) with 6.9 bar (100 psig)
supply pressure
Operative Ambient Temperature Limits
Output Signal
Type: Pneumatic pressure as required to maintain
the correct valve stem position and seat load
Action: Field‐reversible between direct and reverse
Resolution
(1)
0.2% of instrument pressure span
With Nitrile O‐Rings and Diaphragms: –34 to 71°C
(–30 to 160°F)
With Fluorocarbon O‐Rings and Diaphragms
(Optional): 0 to 104°C (32 to 220°F)
Hazardous Area Classification
Complies with the requirements of ATEX Group II
Category 2 Gas and Dust
Repeatability
(1)
0.3% of total stroke or instrument pressure span
Options
Frequency Response
(1)
J Restrictor (high‐frequency filter for bellows)
See figure 5
Approximate Weight
Pressure Connections
Vent: 3/8 NPT
All others: 1/4 NPT
Pressure Indications
3570C and 3570CP Positioners: Tire valves accept
standard pressure gauge chucks (gauges not
supplied)
All Other Types: Gauges supplied per table 3
2.7 kg (6 pounds) without optional mounting
bracket or actuator/valve assembly
Declaration of SEP
Fisher Controls International LLC declares this
product to be in compliance with Article 3
paragraph 3 of the Pressure Equipment Directive
(PED) 97 / 23 / EC. It was designed and
manufactured in accordance with Sound
Engineering Practice (SEP) and cannot bear the CE
marking related to PED compliance.
Bellows Pressure Rating
Standard Bellows: 3.4 bar (50 psig)
Optional Bellows: 6.2 bar (90 psig)
NOTE: Specialized instrument terms are defined in ANSI/ISA Standard 51.1 - Process Instrument Terminology.
1. For a 3570 or 3570C positioner mounted on a 470 or 480 actuator. Values do not apply to other constructions or actuator‐valve combinations.
2. Natural gas should not contain more than 20 ppm of H
3
3. m
/h at 0°C, 1.01325 bar, absolute (Scfh at 60°F, 14.7 psia).
S.
2
However, the product may bear the CE marking to
indicate compliance with other applicable European
Community Directives.
(3)
(1)
3
3570 Positioners
September 2011
Instruction Manual
D200137X012
Table 2. Action Under Normal Operating Conditions
POSITIONER ACTION
Direct‐acting Increasing input signal pressure to bellows Decreasing input signal pressure to bellows
Reverse‐acting Decreasing input signal pressure to bellows Increasing input signal pressure to bellows
1. Supply pressure is routed through relays to piston.
Down Up
DESIRED PISTON MOTION
(1)
Table 3. Pressure Indications
NUMBER OF GAUGES SUPPLIED
PRESSURE MONITORED
Positioner input signal pressure 1 1
Cylinder (relay output) pressure 2 1 0‐160 psi/0‐1.1 MPa/0‐11 bar
1. For gauges marked in other units and ranges, consult your Emerson Process Management sales office.
Two‐Relay
Positioner
One‐Relay
Positioner
0‐30 psi/0‐0.2 MPa/0‐2 bar or
0‐60 psi/0‐0.4 MPa/0‐4 bar
STANDARD GAUGE RANGE
(1)
3573 — Pneumatic valve positioner that is similar to The 3572 positioner with the relay output pressure piped to the
bottom (piston underside) of the actuator cylinder. The 3573 positioner is normally used on the 473 pneumatic piston
actuator with valve bodies having push‐down‐to‐close (PDTC) action.
3576 (Discontinued)— Pneumatic valve positioner with one relay for use on direct‐acting pneumatic diaphragm
actuators that require high operating pressures. The 3576 positioner includes two pressure gauges to monitor input
signal pressure and relay output pressure to the top of the actuator diaphragm.
The 3576 positioner is bracket‐mounted to the actuator yoke. Actuator stem position feedback is provided through a
wire from the actuator‐valve stem connector.
3577 (Discontinued)— Pneumatic valve positioner that is similar to 3576 positioner with the relay output pressure
piped to the underside of the actuator diaphragm on reverse‐acting pneumatic diaphragm actuators.
Specifications
Specifications for 3570 positioners are listed in table 1.
Educational Services
For information on available courses for 3570 positioners, as well as a variety of other products, contact:
Emerson Process Management
Educational Services, Registration
P.O. Box 190; 301 S. 1st Ave.
Marshalltown, IA 50158-2823
Phone: 800-338-8158 or
Phone: 641-754-3771
FAX: 641-754-3431
e‐mail: education@emerson.com
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Instruction Manual
D200137X012
3570 Positioners
September 2011
Installation, Mounting, and Connections
Installation
WARNING
D Always wear protective clothing, gloves, and eyewear when performing any installation operations to avoid personal
injury.
D Personal injury or property damage may result from fire or explosion if natural gas is used as the supply medium and
preventive measures are not taken. Preventive measures may include, but are not limited to, one or more of the
following: Remote venting of the unit, re‐evaluating the hazardous area classification, ensuring adequate ventilation,
and the removal of any ignition sources. For information on remote venting of this positioner, refer to page 8.
D Check with your process or safety engineer for any additional measures that must be taken to protect against process
media.
D If installing this into an existing application, also refer to the WARNING at the beginning of the Maintenance section of
this instruction manual.
The positioner is usually mounted on the actuator at the factory. However, if the positioner and actuator are ordered
separately, it is necessary to mount the positioner on the actuator. Before mounting the positioner, be certain the
O‐ring (key 33, figure 11) is in place in the cylinder (top connection) in the base of the positioner.
For appropriate actuator/positioner combinations, refer to the positioner type number descriptions given earlier in
this instruction manual.
D For 3570, 3570C, 3572, and 3573 positioners, mount the positioner with two cap screws (key 32, figure 11). If the
range and bias springs are not installed in the positioner, refer to the range spring and bias spring procedures in the
Maintenance section.
Insert the threaded end of the spring retainer (key 19, figure 2) into the center of the range spring (see figure 2). Then,
insert a screwdriver into the center of the range spring and extend the spring until the spring retainer can be screwed
into the top of the actuator piston rod extension. Tighten the spring retainer into the top of the actuator piston rod
extension. If the range spring and/or bias spring is not installed in the positioner, refer to the procedures for either
spring in the Maintenance section.
D For 3570P and 3570PC positioners, attach the positioner extension and positioner to the cylinder mounting plate
with the two cap screws (key 100, figure 14). Make the required pressure connections as described in the following
procedure. Go to the initial range spring extension procedures for 3570P and 3570PC positioners.
D For 3571, 3576, and 3577 positioners, insert two cap screws through the holes in the mounting bracket (key 55,
figure 13) to attach the positioner to the actuator mounting boss. Attach the hex drive stud to the actuator‐valve
stem connection. Attach the end bearing (key 56E, figure 13) to the hex drive stud.
5
3570 Positioners
September 2011
Figure 2. Bias and Range Springs for Zero and Span Adjustments
Instruction Manual
D200137X012
BEAM TRAVEL
STOP (E‐RING)
BIAS SPRING POST
BIAS SPRING
ZERO ADJUSTMENT
LOCKNUTS
EFFECTIVE LENGTH
SPRING
RETAINER
NOTE:
BOTTOM OF BIAS SPRING POST THREAD MUST BE POSITIONED
AS SHOWN FOR PROPER POSITION OF E‐RING TRAVEL STOPS.
AJ7270‐C
1H8907‐C
1J2233‐C
B2402/IL
SPRING LOCK
BELLOWS
BEAM
RANGE SPRING
(KEY 18)
SPRING RETAINER
(KEY 19)
SPRING RETAINER SPACER
(IF REQUIRED) (KEY 235)
PISTON ROD EXTENSION
(OPTIONAL)
EFFECTIVE LENGTH
OVERALL
LENGTH
SPRING RETAINER SPACER
Diagnostic Test Connectors (Optional)
Diagnostic test connectors are available from the factory, when the unit is ordered, or they can be installed on an
existing control valve assembly in the field. These connectors are especially useful for “quick” connections when using
the FlowScannert valve diagnostic system. The FlowScanner is a portable, microprocessor‐based diagnostic and
calibration system specifically designed for use with pneumatically‐operated control valves.
To support diagnostic testing of the control valve assembly, the connectors, piping, and other hardware can be
installed between the 3570 positioner and the actuator. A typical connector installation is shown in figure 3. For
connectors, refer to the FlowScanner Diagnostic Connection kit listing in the parts list.
The hardware used includes 3/4 NPT pipe nipple, pipe tee, and pipe bushings with a 1/8 NPT pipe bushing for the
connector. The connector consists of 1/8 NPT body and body protector (see figure 3).
1. Before assembling the pipe nipple, pipe tee, pipe bushings, actuator piping, and connector body, apply sealant to
all threads.
2. Position the pipe tee, connector body, and body protector for easy access when doing diagnostic testing.
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Instruction Manual
D200137X012
Figure 3. Diagnostic Test Connections
PIPE NIPPLE TO
INSTRUMENT CONNECTION
PIPE NIPPLE
TO SUPPLY
CONNECTION
3570
POSITIONER
3570 Positioners
September 2011
BODY PROTECTOR
BODY
PIPE BUSHING
FROM 377
TRIP VALVE
PIPE NIPPLE
TO BOTTOM
CYLINDER
PIPE TEE
GAUGE
STEM
REQUIRED WHEN
PURCHASED WITH GAUGE
12B8044‐A
A6112/IL
377 TRIP VALVE
(OPTIONAL)
ACTUATOR
Connections
Piping Sizes
All pressure connections on 3570 positioners are 1/4 NPT (internal). Use 3/8‐inch pipe or tubing for supply, cylinder
(bottom connection), and instrument (input signal) connections. For the remote vent pipe, if one is required, use 19
mm (3/4‐inch) (minimum inside diameter) pipe for runs up to 6.09 meters (20 feet). For vent piping runs from 6.09 to
30.5 meters (20 to 100 feet), use 25.4 mm (1‐inch) (minimum inside diameter) pipe. Refer to figure 4 for the locations
and sizes of connections.
7
3570 Positioners
September 2011
Figure 4. Typical Location of Fisher 3570 Positioner Parts and Adjustments
Instruction Manual
D200137X012
RANGE SPRING
(SPAN ADJUSTMENT)
CYLINDER
BOTTOM
PRESSURE
INSTRUMENT
PRESSURE
VENT CONNECTION
3/8 NPT
ZERO ADJUSTMENT
W4025*/IL
NOTES:
1
ON SOME CONSTRUCTIONS, TWO NOZZLES AND ADJUSTMENTS ARE REQUIRED.
FRONT VIEW
CLEAN‐OUT
PLUNGER
CYLINDER
TOP PRESSURE
CYLINDER
(TOP CONNECTION)
(O‐RING, KEY 33)
HORIZONTAL
RELAY
RELAY NOZZLE
(OUTPUT PRESSURE
ADJUSTMENT)
BELLOWS POSTS
1
W4027*/IL
BELLOWS
CYLINDER (BOTTOM
CONNECTION) (1/4 NPT)
BACK VIEW
VERTICAL
RELAY
SUPPLY
CONNECTION
(NOT SHOWN)
(1/4 NPT)
INSTRUMENT
CONNECTION
(INPUT SIGNAL)
(1/4 NPT)
Vent
WARNING
Personal injury or property damage could result from fire or explosion of accumulated gas, or from contact with hazardous
gas, if a flammable or hazardous gas is used as the supply pressure medium.
The positioner/actuator assembly does not form a gas‐tight seal, and flammable or hazardous gas could leak from the
assembly. Therefore, if the assembly is enclosed install a remote vent line from the enclosure. However, a remote vent pipe
alone cannot be relied upon to remove all hazardous gas. Use adequate ventilation, and necessary safety measures. Vent
line piping should comply with local and regional codes and should be as short as possible with adequate inside diameter
and few bends to reduce case pressure buildup.
CAUTION
When installing a remote vent pipe, take care not to overtighten the pipe in the vent connection. Excessive torque will
damage the threads in the connection.
Note
The vent connection is always plugged with a pipe plug for 3570P and 3570PC positioners when mounted on 490 actuators.
8
Instruction Manual
D200137X012
3570 Positioners
September 2011
The connection marked VENT (see figure 4) should be left open if the actuator is installed in the vertical position.
However, the vent must be protected against the entrance of any foreign material that could plug it. Check the vent
periodically to be certain it is not plugged.
If the actuator is mounted in other than the vertical position, be sure there is a vent and drain at the lowest point of the
positioner. To do this, remove the pipe plug (key 36, figure 11) from the cover. Then, position the cover in such a way
that the hole in the cover is at the lowest point. Plug the vent connection because the positioner is now vented
through the cover.
Note
A remote vent is not possible with 3570P, 3570PC, 3571, 3576, and 3577 positioners.
If a remote vent is required, the vent line must be as short as possible with a minimum number of bends or elbows.
Vent line piping should have a minimum inside diameter of 19 mm (3/4‐inch) for runs up to 6.09 meters (20 feet) and
a minimum inside diameter of 25.4 mm (1‐inch) for runs from 6.09 to 30.5 meters (20 to 100 feet).
Supply Pressure Connections
WARNING
Personal injury or property damage may occur from an uncontrolled process if the supply medium is not clean, dry, oil‐free
air, or noncorrosive gas. While use and regular maintenance of a filter that removes particles larger than 40 micrometers in
diameter will suffice in most applications, check with an Emerson field office and industry instrument air quality standards
for use with corrosive air or if you are unsure about the proper amount or method of air filtration or filter maintenance.
WARNING
To avoid personal injury or property damage resulting from the sudden release of pressure, do not install the valve
assembly where service conditions could exceed the limits given in this manual or on the appropriate nameplates. Use
pressure‐relieving devices as required by government or accepted industry codes and good engineering practices.
WARNING
If the supply pressure medium is corrosive, make sure the tubing and instrument components that contact the corrosive
medium are of suitable corrosion‐resistant material. The use of unsuitable materials might result in personal injury or
property damage due to the uncontrolled release of the corrosive media.
The connection marked SUPPLY (see figure 4) must be provided with clean, dry air or a noncorrosive gas. Install a
40‐micrometer filter and suitable equipment to dry the supply medium. Establish a maintenance cycle to ensure that
the regulator and filter are working correctly.
CAUTION
The maximum allowable supply pressure to prevent damage to the components of the positioner, actuator, and valve is
normally stamped on the actuator nameplate. Use a suitable supply pressure regulator to reduce the supply pressure
source to the value stamped on the nameplate.
9
3570 Positioners
September 2011
If this maximum supply pressure value is not available, use a supply pressure that does not exceed any of the following:
D The maximum supply pressure for the positioner as shown in table 1.
D The maximum pressure rating of the actuator, from the appropriate actuator instruction manual.
D The maximum allowable valve plug stem load for the specific valve body assembly being used. Contact your
Emerson Process Management sales office for valve plug stem load information, if required.
D For diaphragm actuators, refer to the actuator instruction manual for the recommended supply pressure and use
the larger value of the range listed.
The recommended supply pressure for use with piston actuators is the highest available supply pressure between 3.4
bar (50 psig) and the maximum limit determined by the actuator and positioner specifications. Selecting the highest
pressure within the limits will minimize load error and will maximize stroking speed and thrust. For the lowest supply
pressure that will assure satisfactory performance, the factors of valve plug unbalance force, valve plug seating force,
and frictional force must be considered in the following relationship:
Instruction Manual
D200137X012
(Valve
unbalance,
Supply
pressure, = 98
bar
or
Supply
pressure, =
psig
Consult your Emerson Process Management sales office for the appropriate values for specific actuators, valves, and
service conditions. The 0.7 bar (10 psig) is added to the equation to account for an approximate 0.7 bar (10 psi)
differential pressure loss in the positioner. For spring‐return piston actuators, the pressure required to compress the
actuator spring completely must also be considered.
[
kg)
(Valve
unbalance,
[
pounds)
(Area of the actuator piston,
(Area of the actuator piston,
(Seating
+
force,
kg)
in square mm)
(Seating
+
force,
pounds)
in square inches)
(Frictional
+
force,
kg)
(Frictional
+
force,
pounds)
]
]
+ 0.7 bar
+ 10 psig
Cylinder Connections
1. The connection marked CYLINDER (see figure 4) is connected at the factory to the lower part of the cylinder
(bottom) or to the lower diaphragm casing if the positioner is used with a pneumatic diaphragm actuator.
2. The cylinder top connection is a pressure passage located in the bottom of the positioner base (key 1, figure 11). On
3570 and 3570C positioners, an O‐ring (key 33, figure 11) is used between the bottom of the positioner and the top
of the actuator. On 3570P, 3570PC, 3571, 3576, and 3577 positioners, a mounting bracket (key 55, figure 13) is
required. This mounting bracket connects to the bottom of the base. An O‐ring (key 33, figure 11) is placed
between the base and mounting bracket. This mounting bracket provides a 1/4 NPT connection for the positioner
output. This connection is made at the factory if the positioner is ordered mounted to the actuator or if the
mounting bracket is installed.
Instrument Connection
The connection marked INSTRUMENT (see figure 4) connects to the output signal connection of the control device.
The positioner operates only on a pneumatic input signal; the input signal range is marked on the nameplate (key 23,
10
Instruction Manual
D200137X012
figure 11). The maximum allowable input signal for positioners with standard or optional bellows is in table 1 (bellows
pressure rating). The instrument connection is made at the factory when a complete control valve assembly with a
valve‐mounted control device is ordered. Otherwise, make field connections to the positioner from an appropriate
control device. Refer to table 1 and the nameplate for input signal pressure ranges.
3570 Positioners
September 2011
Operating Information
Initial Adjustments
Normally, no adjustments are necessary upon initial installation. The positioner is set at the factory for the travel, input
signal range, and action specified in the order. Adjustment is necessary when operating conditions are changed, when
the unit has been dismantled and reassembled, or when the control valve travel does not correspond to the desired
input signal range. If the operating conditions have not changed but the positioner requires adjustment, refer to the
adjustment procedures in this section. If the operating conditions have changed, first, refer to the signal range code
descriptions, then, refer to the adjustment procedures.
Signal Range Codes
The range spring and the bias spring are matched to a specific input signal range and length of travel. Also, the spring
retainer length is matched to the application on the 3570, 3570C, 3572, and 3573 positioners. Refer to figure 2 for
location of parts.
The signal range codes in table 4 are based on the following applications:
D Codes for valve travels up to and including 50 mm (2 inches) are used for actuators that have a 50 mm (2 inch)
maximum travel. If the actuator maximum travel is greater than 50 mm (2 inches), an additional retainer spacer
(key 235, see figure 2) is required. Refer to the parts list for the additional spring retainer spacer (key 235) part
number.
D Codes for valve travels greater than 50 mm (2 inches), up to and including 105 mm (4‐1/8 inches), are used for
actuators that have a 105 mm (4‐1/8 inch) maximum travel, except the 480‐12 or 480‐15 Size 20 actuators which
have a 54 mm (2‐1/8 inch) maximum travel. If the actuator maximum travel is greater than 105 mm (4‐1/8 inches),
an additional retainer spacer are required. Refer to the parts list for the additional spring retainer spacer (key 235)
part numbers.
D Codes for valve travels greater than 105 mm (4‐1/8 inches), up to and including 206 mm (8‐1/8 inches), are for
actuators that have a 206 mm (8‐1/8 inch) maximum travel. If the valve travel is 105 mm (4‐1/8 inches) or less, two
additional spring retainer spacers are required. Refer to the parts list for the additional spring retainer spacer (key
235) part numbers.
If the input signal range and travel do not match any of the selections in table 4, consult your Emerson Process
Management sales office for information. To change the springs, refer to the range and bias spring procedures in the
Maintenance section.
From table 4, select the signal range that matches your application. Find the travel length for the application under the
signal range selected, then use the code (from the direct or reverse column) that matches the direct or reverse
operation of the positioner.
The first number in the code is used to identify the range spring, the letter in the code is used to identify the bias
spring, and the second number (after the letter) is used to identify the spring retainer. For example, from table 4, for a
11
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