Flowserve Limitorque L120-85 User manual

Experience In Motion
USER INSTRUCTIONS
Installation
Operation
Maintenance
Limitorque
®L120-85 Actuator
FCD LMENIM1202-03-A4 – 06/15

Limitorque L120-85 Installation, Operation and Maintenance FCD LMENIM1202-03-A4 – 06/15
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1 Introduction 4
1.1 Purpose 4
1.2 User Safety 4
2 Initial Inspection and Storage Instructions 5
2.1 Inspection and Recording 5
2.2 Short-Term Storage 5
2.3 Product Identification 6
2.4 Product Description 7
2.5 Product Features 7
3 Actuator Weight 8
4 Installation Instructions 9
4.1 Actuator Mounting 9
4.1.1 Torque Only Applications (Drive 1) 10
4.1.2 Torque and Thrust Applications (Drive 2) 10
4.1.3 Mounting Bolts 11
4.1.4 Stem Cover for Rising Stem Applications 11
4.2 Verifying Motor Rotation Direction 13
4.2.1 Initial Electrical Connections 13
4.2.2 Motor rotation (phasing) and OPEN/CLOSE
pushbutton operation. 14
4.2.3 Three-Phase Motor 14
4.2.4 DC Motor 15
4.3 Limit Switch Settings 15
4.3.1 Basic Theory of Operation 16
4.3.2 Adjustment—General 17
4.3.3 Setting the OPEN Limit Switch 17
4.3.4 Setting the CLOSE Limit Switch 19
4.4 Torque Switch Setting and Wiring 20
4.4.1 Basic Theory of Operation 20
4.4.2 Setting the Torque Switch 20
4.4.3 Balancing the Torque Switch 21
4.4.4 Rewiring the Torque Switch
for Non-Standard Drive Sleeve Rotation 21
4.5 Position Indication 21
4.5.1 Local Position Indication 21
4.5.2 Remote Position Indication 23
4.5.3 Setting the Potentiometer 24
5 Operation 26
5.1 Description of Motor Operation 26
5.2 Description of Manual Operation 26
5.3 Electrical Start-up Procedure 27
6 Maintenance 28
6.1 Lubrication 28
6.1.1 Initial Inspection 28
6.1.2 Frequency 28
6.1.3 Routine Inspection 28
6.1.4 Factory Lubricants 29
6.1.5 Minimum Lubricant Qualities Required 29
7 Disassembly 30
7.1 Removal From Valve 30
7.2 Open Electrical Compartment and Disconnect Motor 30
7.3 Remove Control Wiring 31
7.4 Remove Limit and Torque Switch 31
7.5 Remove Motor Assembly 31
7.6 Remove Handwheel 31
7.7 Remove Handwheel Shaft Assembly 31
7.8 Remove Declutch Lever Assembly 32
7.9 Remove Clutch Assembly 32
7.10 Remove Clutch Pinion Assembly 32
7.11 Remove Worm Shaft Assembly 32
7.12 Remove and Disassemble Thrust Base 33
7.13 Remove Drive Sleeve 33
8 Assembly 34
8.1 Handwheel Shaft Assembly and Shimming 34
8.2 Verifying Handwheel Operation 38
8.3 Thrust Base Assembly and Shimming 38
9 Troubleshooting 39
9.1 Typical Wiring Diagram 41
Three-phase with Control Package 37
10 How to Order Parts 42
10.1 L120-85 Illustrated Parts Breakdown 43
10.2 L120-85 Parts List 48
11 Regulatory Information 50
Contents

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Figures
Figure 1: Limitorque L120-85 Actuator 7
Figure 2: L120-85 Torque Drive Nut and Retaining Ring Details 10
Figure 3: Thrust Base removal from an L120-85 10
Figure 4: L120-85 Torque Drive Nut orientation (Drive 1) 12
Figure 5: L120-85 Thrust Base Assembly orientation (Drive 2) 12
Figure 6: Electrical Compartment and Conduit Pipe Plug openings 14
Figure 7: Grounding Lug location 14
Figure 8: Limit Switch Rotor development 15
Figure 9: L120-85 Limit Switch Components 17
Figure 10: Limit Switch OPEN/CLOSED Rotor Cam orientation 18
Figure 11: Torque Switch Components 20
Figure 12: Reversing Torque Switch wiring 21
Figure 13: Aligning MDPI Pointer for Fully CLOSED Position 21
Figure 14: Remote Position Indicator Calibration Configuration 24
Figure 15: Potentiometer Calibration configuration 24
Figure 16: Loosening Potentiometer Assembly 25
Figure 17: Removing Clutch Pinion Assembly 32
Figure 18: Key components affected by Handwheel shimming 34
Figure 19: Cut-away view of L120-85 actuator
with Clutch Latch positioned on face of Clutch Bearing 35
Figure 20: Gap between Housing face and Handwheel Bushing
shown as dimension “A” 35
Figure 21: Shimming parts and their order of assembly 37
Figure 22: Shim location for gap “B” dimension/ 37
Figure 23 Three-phase with Control Package 41
Figure 24: Electrical Compartment 43
Figure 25: Motor and Motor Drive Components 44
Figure 26: Handwheel Shaft and Associated Components 45
Figure 27: Drive Sleeve Group 46
Figure 28: Thrust Base Group 47
Tables
Table 1: L120-85 Approximate Weight Chart 8
Table 2: Torque Drive Nut: Maximum Allowable
Bore and Key Sizes 10
Table 3: L120-85 Actuator/Mounting Base Tap Size 13
Table 4: Gap “A” shim thickness selection chart 36
Table 5: Gap “B” shim thickness selection chart 37

1 Introduction
1.1 Purpose
This Installation and Maintenance Manual explains how to install and maintain the L120-85 actuator.
Information is provided for installation, disassembly, reassembly, lubrication, and parts selection.
c WARNING: Read this installation and maintenance manual carefully and completely before storing,
installing, operating or troubleshooting your Flowserve Limitorque actuator. Be aware of electrical
hazards within the actuator and high-pressure hazards at the attached valve or other device when
installing or performing maintenance on your L120-85 actuator.
1.2 User Safety
Safety notices in this manual detail precautions the user must take to reduce the risk of personal injury and
damage to the equipment. The user must read and be familiar with these instructions before attempting
installation, operation, or maintenance. Work should be performed by a qualified tradesman who is familiar
with the operation and maintenance of electric actuators. Failure to observe these precautions could result in
serious bodily injury, damage to the equipment, voiding of the warranty, or operational difficulty.
Safety notices are presented in this manual in three forms:
c WARNING: Refers to personal safety. Alerts the user to potential danger. Failure to follow warning
notices could result in personal injury or death.
a CAUTION: Directs the user’s attention to general precautions that, if not followed, could result in
personal injury and/or equipment damage.
NOTE: Highlights information critical to the user’s understanding of the actuator’s installation and
operation.
Limitorque L120-85 Installation, Operation and Maintenance FCD LMENIM1202-03-A4 – 06/15
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2 Initial Inspection and
Storage Instructions
2.1 Inspection and Recording
Upon receipt of the actuator, several steps should be initially followed to ensure condition of equipment and
to establish proper record keeping.
1. Carefully remove the actuator from the shipping carton or skid. Thoroughly examine for any physical
damage which may have occurred during shipment. If you note any damage, immediately report the
damage to the transport company.
2. A nameplate with important information is attached to each actuator. Record this information
for future reference.
2.2 Short-Term Storage (less than one year)
Actuators are not weatherproof until properly installed on the valve or prepared for storage.
Store actuators in a clean, dry, protected warehouse away from excessive vibration and rapid temperature
changes. If the actuators must be stored outside, they must be stored off the ground, high enough to prevent
them from being immersed in water or buried by snow.
1. Position the actuator in storage with motor and switch compartment horizontal.
2. Connect the internal heaters (if supplied) or place desiccant in the switch compartment.
3. Replace all plastic caps or plugs with taped or doped pipe plugs and ensure that all covers are tight.
4. If the actuator is mounted on a valve and the stem protrudes from the actuator, a suitable stem cover
must be provided.
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2.3 Product Identification
The actuator nameplate is located on the back of the actuator, opposite the limit switch compartment.
The nameplate contains the following information:
• Product name
• Point of Manufacture
• Order Number
• Serial Number
• Customer Tagging
• Certification Information
The motor nameplate is located on the motor. The nameplate contains the following information:
• ID Number
• Run Torque
• RPM
• Full Load Amps
• Insulation Class
• Horsepower
• Number of Phases
• Motor Code
• Connection Diagram
• Start Torque
• Enclosure Type
• Volts
• Locked Rotor Amps
• Duty Rating
• Service Factor
• Frequency
• Ambient Temperature
Limitorque L120-85 Installation, Operation and Maintenance FCD LMENIM1202-03-A4 – 06/15
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Figure 1: Limitorque L120-85 Actuator
Thrust
Base
Handwheel
Electrical
Compartment
Cover
Conduit
Openings
(plugged; two additional openings
are supplied on the bottom of the
Electrical Compartment)
Housing
Declutch
Lever
Motor
Position
Indication
Window
2.4 Product Description
Your L120-85 actuator controls the opening and closing travel of valves or other actuated devices. OPEN and CLOSED limits of travel are
controlled by limit switches, and output torque is controlled by the Torque Switches. As a result, all valves and other actuated devices are
protected from potential damage from overload, improper seating and foreign obstructions.
Limitorque actuators may be mounted on any appropriately sized valve in almost any position or location.
Microprocessor-based controls and monitoring devices are also available for L120 actuators. Contact your local Limitorque distributor or
Limitorque sales office for further information.
2.5 Product Features
• Up to 850 ft-lb/1156 Nm torque capacity.
• Up to 45,000 lb./20250 kg thrust capacity.
• Up to 3.25"/76 mm threaded stem capacity.
• Up to 2.75"/70 mm bore capacity.
• Torque Only (Drive 1) or Torque and Thrust (Drive 2) actuators, with removable ductile iron thrust base assembly.
• Cast iron gear housing.
• All power gearing supported on anti-friction bearings.
• All gearing is alloy, heat-treated steel or bronze.
• Speed range of 24-192 RPM (60 Hz), 20-160 RPM (50 Hz).
• Declutch force independent of load on valve stem.
• Self-locking gearing available.
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3 Actuator Weight
The following table is an L120-85 representative weight chart. It provides the weight of several components
that may be incorporated into a typical package. Use the chart as a guideline to estimate the weight of your
particular actuator package.
Table 1: L120-85 Approximate Weight Chart
Components lb. kg
L120-85 with 40 ft-lb 1700 RPM Motor (Torque only) 275 125
With Minimum Integral Control
Package and Compartment 315 143
Thrust Base Assembly (Drive 2)170 32
1 Add to weights shown above for basic actuator or basic actuator with integral control package.
Limitorque L120-85 Installation, Operation and Maintenance FCD LMENIM1202-03-A4 – 06/15
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4 Installation Instructions
c WARNING: Read this Installation and Maintenance Manual carefully and completely before
attempting to store, install, operate or troubleshoot your Limitorque valve actuator. Be aware of
electrical hazards within the actuator and high pressure hazards of the attached valve or other
actuated device when installing or performing maintenance on your L120-85 actuator.
NOTE: If your actuator incorporates a rising stem application, it may be shipped with a plastic cap over
the Drive Sleeve Housing. If so, in order to store without possible corrosion occurring, install a pipe plug
or protective stem cover to protect the Drive Sleeve Housing.
NOTE: Failure to comply with recommended storage procedures could cause the warranty to be voided.
For long-term storage procedures, consult the Limitorque Customer Service Department.
4.1 Actuator Mounting
Your L120-85 is designed to perform actuation for torque only applications (drive 1) or for torque and thrust
applications (drive 2). If you are using a torque only configuration, before installing on the valve or other actu-
ated device, you will need to verify that the Torque Drive Nut (piece 95) is properly bored and keyed to fit your
valve stem. If you are using a torque and thrust configuration, you will need to verify that the Thrust Base
Drive Sleeve (piece 101) is properly threaded to fit your threaded valve stem. Use the following procedures to
check for proper fit of the Torque Drive Nut or the Thrust Base Drive Sleeve.
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Limitorque L120-85 Installation, Operation and Maintenance FCD LMENIM1202-03-A4 – 06/15
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4.1.1 Torque Only Applications (Drive 1) (Refer to Figure 27)
Remove the Torque Nut Retaining Ring (piece 98) and Torque Drive Nut (piece 95) from actuator.
Figure 2: L120-85 Torque Drive Nut and Retaining Ring Details
#95 Torque
Drive Nut
#98 Torque Nut
Retaining Ring
A) If Torque Drive Nut has been bored and keywayed by supplier, verify dimensions of keyway for proper compatibility with the valve stem.
B) If Torque Drive Nut has not been bored and keywayed by supplier, it is provided solid (blank) to allow customer to custom bore and key
up to the maximum permissible sizes as listed:
Table 2: Torque Drive Nut: Maximum Allowable Bore and Key Sizes
Key Type Maximum Bore in. (mm) Maximum Key in. (mm)
Rectangle 2.750 (69.85) .625 x .4375 (20 x 12)
Square 2.625 (66.67) .625 x .625 (20 x 20)
4.1.2 Torque and Thrust Applications (Drive 2) (Refer to Figure 28)
Remove Socket Head Cap Screw (piece 110) and Lockwasher (piece 111) that holds the Thrust Base Housing Assembly to the actuator
Housing (piece 1).
Figure 3: Thrust Base removal from an L120-85
#111 Lockwasher
#110 Socket Head
Cap Screw
#100 Thrust Base
Housing
#1 Housing
#101 Thrust Base
Drive Sleeve

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A) If the Thrust Base Drive Sleeve (piece 101) has been threaded by supplier, verify thread compatibility with the threaded Valve Stem by
screwing Drive Sleeve onto the valve stem.
B) If Thrust Base Drive Sleeve (piece 101) has not been threaded by supplier, it is provided solid (blank) to allow customer to custom thread.
Maximum threaded stem diameter is 3.25” (82.5 mm).
NOTE: If Thrust Base disassembly is required in order to thread blank Thrust Base Drive Sleeve, remove Quad Rings (piece 107) before
removing Thrust Washer (piece 104) and Thrust Bearing (piece 103). This will prevent damaging the Quad Rings (piece 107). For
details refer to Section 10.1, Figure 28.
4.1.3 Mounting Bolts
Mount the L120-85 actuator on the Actuator Mounting Adapter (Drive 1) or on the Thrust Base Assembly (Drive 2). High-strength
(minimum hex head SAE-Grade 5 or ISO Metric Class socket head cap screws) 8.8 hex head or socket head cap screws with lockwashers
are recommended. The quantity and thread size of the actuator mounting taps are as follows:
Table 3: L120-85 Actuator/Mounting Base Tap Size
Unit Type Quantity Tap Size
Drive 1 and 2
English 4¾–10 Tap x 1.0 in. Deep*
Metric 4M20 x 2.5 mm x 10 mm Deep*
*Complies with F16 IOS mounting flange criteria
NOTE: Limitorque has supplied four taps for the L120-85 English and metric actuators. All four securing bolts are required to retain
torque and/or thrust reaction on these actuators.
4.1.4 Stem Cover for Rising Stem Applications
a CAUTION: Selection and installation of a stem cover which is too short will result in damage to the valve and/or actuator.
a CAUTION: Be sure to complete each step of the installation overview before electrically operating your actuator. If your actuator is
already mounted to a valve or other actuated device from the manufacturer, verify that the actuator is mounted according to the
following overview. Failure to follow the installation procedures could result in personal injury or may allow the actuator to operate
improperly and could cause damage to your equipment.
a CAUTION: Ensure Retaining Ring (piece 98) is properly engaged in the Drive Sleeve (piece 25) to secure the Torque Drive Nut
(piece 95) in place. If the Torque Drive Nut is not properly secured, it may fall from the bottom of the actuator when removed from
customer mounting adapters.
Before putting your actuator into operational service, check the height of your valve stem at the full OPEN position and mount a suitable
stem cover to protect the valve stems and to prevent water entry into the actuator.
Installation Overview
1. Applications
A. Torque Only Applications (Drive 1)
Mount Torque Drive Nut (piece 95) in the actuator with the Torque Drive Nut axially aligned on the Drive Sleeve (piece 25) so that
the bottom of the nut is positioned inside the actuator Mounting Base. Secure Torque Drive Nut inside Drive Sleeve (piece 25) with
Retaining Ring (piece 98). Refer to Figure 27.

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B. Torque and Thrust Applications (Drive 2)
Screw the Thrust Base Assembly onto the Threaded Valve Stem and secure the Thrust Base Assembly to the Actuator Mounting
Base using Socket Head Cap Screws (piece 110) and Lockwashers (piece 111).
Figure 4: L120-85 Torque Drive Nut orientation (Drive 1)
Drive 1
Actuator
Mounting
Base
Actuator
Mounting
Adapter
Valve
Stem
#95 Torque
Drive Nut
Key
Note: Key is shown for reference.
It may be in one of several other
orientations in reference to the
actuator.
Figure 5: L120-85 Thrust Base Assembly orientation (Drive 2)
Drive 2 Actuator
Mounting Base
Actuator
Mounting
Adapter
Threaded
Valve Stem
#101 Thrust Base
(Drive Sleeve)
Thrust Base
Assembly
#110 Socket Head
Cap Screws
#111 Lockwashers
4.2 Verifying Motor Rotation Direction
4.2.1 Initial Electrical Connections
c WARNING: Hazardous Voltage. No electrical power should be connected until all wiring and Limit Switch adjustments have been
completed. Once power is supplied to actuator, exercise caution if cover is not installed.

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1. Open the Electrical Compartment Cover (piece 200-1) and remove the Conduit Pipe Plugs from the opening(s) most conveniently
located for your power leads and other cabling.
Conduit Pipe
Plug Locations
Conduit Pipe
Plug Locations
Electrical
Compartment
Figure 6: Electrical Compartment and Conduit Pipe Plug openings
2. Adjust the Limit Switches, MDPI (Mechanical Dial Position Indicator) and Potentiometer following the procedures outlined in Sections
4.5 and 4.7.
3. Ensure Torque Switch is set properly for your application. In most cases, adjustments are not needed, but if changes are required, see
Section 4.6, “Torque Switch Settings and Wiring”.
4. Connect wiring to Terminal Strips provided on the actuator. Refer to the wiring diagram supplied with your specific actuator. “Fork-
type” terminal connections are recommended.
5. Be sure any unused conduit entrances are plugged with metal Conduit Pipe Plugs.
Notes:
a) Explosion-proof actuators require approved “sealing fittings” installed in accordance with the National Electric Code.
b) Submersible actuators require approved “sealing fittings” in order to prevent water entering the actuator.
6. Attach grounding wire to Grounding Lug (piece 14).
Figure 7: Grounding Lug location
Grounding Lug

Limitorque L120-85 Installation, Operation and Maintenance FCD LMENIM1202-03-A4 – 06/15
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7. Inspect actuator for proper lubrication. Refer to “Lubrication” Section 6.1 for lubrication instructions.
8. Verify that Motor rotation is operating in the proper direction; the Motor rotation will have a direct impact on the Limit Switch and
Torque Switch functions. Follow the procedure “Verifying Motor Rotation Direction” in Sections 4.4.2, 4.4.3 and 4.4.4).
9. Close Electrical Compartment Cover (piece 200-1).
10. The actuator is now ready for electrical operation. Continue to “Electrical Start-up Procedure” in Section 5.3.
4.2.2 Motor rotation (phasing) and OPEN/CLOSE Pushbutton Operation
It is very important to check for correct motor rotation to ensure that serious damage to your valve or other equipment does not occur. If
the actuator motor rotates in the wrong direction, damage could occur by over-torquing equipment into a seated position.
Prior to being shipped from the factory, each actuator is inspected to verify proper operation of the Torque and position Limit Switch and
to ensure that they function correctly (i.e. closes when the CLOSE pushbutton is depressed, opens with the OPEN pushbutton, etc.). These
inspections are made with a properly phased power source connected as described in the actuator manual.
a CAUTION: To ensure proper operation and to prevent your actuator or other actuated equipment from damage, verify that your actuator
is properly connected to its power source.
NOTE: Your application may vary from the following standard wiring configurations for Three-phase, Single-phase and DC motors.
Refer to your actuator wiring diagram for user-specific wiring configuration.
4.2.3 Three-Phase Motor
1. Using the Handwheel, move the valve to a midtravel position (midtravel position allows electrical operation in the valve “safe” area and
keeps the OPEN and CLOSED Limit Switches from tripping while testing motor direction).
2. Be prepared to immediately remove power should the actuator run the wrong way.
3. Test motor direction by momentarily pressing the OPEN pushbutton:
A) If the actuator moves toward CLOSED, immediately turn all power OFF and reverse the motor leads T1 and T3.
NOTE: Refer to your actuator wiring diagram for user-specific wiring configuration.
B) If the actuator moves toward OPEN, the motor is wired properly for the application.
4.2.4 DC Motor
1. Using the Handwheel, move the valve to a midtravel position (midtravel position allows electrical operation in the valve “safe” area and
keeps the OPEN and CLOSED limit switches from tripping while testing motor direction).
2. Test the motor direction by momentarily pressing the OPEN pushbutton:
A) If the actuator moves toward CLOSED, immediately turn all power OFF and reverse the motor leads A1 and A2.
NOTE: Refer to your actuator wiring diagram for user specific wiring configuration.
B) If the actuator moves toward OPEN, the motor is wired properly for the application.

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4.3 Limit Switch Settings
The standard L120-85 Limit Switch has 16 contacts. The OPEN/CLOSE Limit Switch (first eight contacts) has two Rotor Sets, one for the
OPEN position and one for the CLOSED position. Each Rotor Set has four electrical contacts which can be arranged in any combination of
normally OPEN and normally CLOSED. The SPARE Limit Switch (second eight contacts) has two additional Rotor Sets with four contacts
each that can be set to operate anywhere between the OPEN and CLOSE positions. These can be used to stop the valve in mid-travel or to
interlock with other equipment such as pumps, fans, mixers, etc. Refer to Figure 8.
Figure 8: Limit Switch Rotor Development
NOTES
1. Contact Open
2. Contact Closed
3. All limit switch trip points
are fully adjustable.
.
BY-PASS CIR.
IND LIGHT
OPEN LIMIT
BY-PASS CIR
IND LIGHT
CLOSE LIMIT
SPARE
SPARE
SPARE
SPARE
SPARE
SPARE
SPARE
SPARE
FULLY
OPEN ABFULLY
CLOSED
VALVE SHOWN IN FULL OPEN POSITION
INDICATION
INDICATION
LIMIT SWITCH CONTACT DEVELOPMENT
VALVE POSITION
ROTOR
OPEN
CLOSE
INT.1
INT.2
FUNCTION
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
CONTACT
NOTE: THE LIMIT SWITCH IS NOT PRESET at the Limitorque factory, and must be set after mounting on the valve or other associated
equipment. If your L120-85 actuator has been shipped already installed on your equipment, your actuator should have the Limit Switch
set for your application. If your actuator is not already installed on your equipment or needs resetting, use the following instructions to
make the appropriate settings.
The following instructions for setting the Limit Switches are based on the typical orientation for most actuator applications (CCW to
OPEN and CW to CLOSE). Consult the applicable wiring diagram located in the actuator Electrical Compartment for your specific Limit
Switch development.
4.3.1 Basic Theory of Operation
c WARNING: Do not manually operate actuator with devices other than installed Handwheel and Declutch Lever. Using additive force
devices (cheater bars, wheel wrenches, pipe wrenches or other devices of this nature) on the actuator Handwheel or Declutch
Lever may cause serious personal injury and/or damage to the actuator or valve.
c WARNING: Hazardous Voltage. Make sure all power is OFF before opening the Electrical Compartment Cover or making the
following settings.
The Limit Switch (piece 305) is driven directly by the Worm Shaft through the Limit Switch Pinion. Therefore, the Limit Switch is directly
connected to the output of the actuator. Once the Limit Switch is properly set, it measures the position of the valve, or other equipment, in
the ELECTRIC or MANUAL operating modes.

Limitorque L120-85 Installation, Operation and Maintenance FCD LMENIM1202-03-A4 – 06/15
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The OPEN Rotor consists of contacts 1 through 4. These switches are set to change state at the full OPEN position. The switch functions are
as follows:
Contact 1 is the CLOSED Torque Switch bypass circuit. It’s purpose is to allow the electric actuator to apply its full torque to unseat a
backseated valve. When a valve is manually backseated to prevent packing leakage, it may stick momentarily when first operated. To prevent
the CLOSE Torque Switch from stopping the actuator during unseating, this momentary bypass is applied. The OPEN Rotor actuates at the
full OPEN position causing contact 1 to open as soon as the valve moves in the close direction, thus returning the Torque Switch function to
the control circuit.
Contact 2 is normally used for a Remote Valve Position Indication Lamp. As shown in Figure 8, the lamp will be turned ON when the valve
reaches the full OPEN position.
Contact 3 is for the Local Position Indication Lamp; included as part of the actuator assembly when required. This switch turns the green
lamp/LED OFF in the full OPEN position, leaving the red lamp/LED energized and indicating that the valve is OPEN.
Contact 4 is the OPEN Limit Switch which opens the control circuit to de-energize the Motor at full OPEN position.
The CLOSE Rotor consists of contacts 5 through 8. This Rotor is set to change state at the full CLOSE position. Switch functions are as
follows:
Contact 5 is the OPEN Torque Switch bypass. After the valve has been tightly closed, it may stick when it is first opened which would cause
the Torque Switch Contacts to break. To momentarily overcome this sticking, the OPEN Torque Switch is bypassed. This OPEN Torque
Switch bypass is part of the closed valve position rotor so that as soon as the valve moves in the OPEN direction, the bypass contact opens
and the OPEN Torque Switch control function is returned.
Contact 6 is normally used for a Remote Valve Position Indication Lamp. As shown in Figure 8, the lamp will be turned ON when the valve
reaches the full CLOSE position.
Contact 7 is for the Local Position Indication Lamp; included as part of the actuator assembly when required. This switch turns the red
lamp/LED OFF in the full CLOSE position, leaving the green lamp/LED energized and indicating the valve is in the full CLOSE position.
Contact 8 is the CLOSE Limit Switch that opens the control circuit to de-energize the Motor at full CLOSE position.
4.3.2 Adjustment—General
Tools required:
• The cross-slotted Intermediate Shafts A, B, C and D have been designed for use with a 6” No. 2 Phillips screw driver shank chucked into a
variable speed reversible electric drill. (See figure 9 for Limit Switch components).
• Phillips Head or Flat Head screwdriver.
c WARNING: Potential Explosion Hazard. Do not use an electric drill for setting the Limit Switch in an explosive environment.
a CAUTION: When setting Limit Switch Rotor Cams using a variable speed reversible electric drill, Do Not run drill at speeds higher
than 200 RPM. Operating drill at high speeds can cause damage to gearing within the Limit Switch.

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a CAUTION: The Worm on the Worm Shaft Assembly is available in two different ratios 19:1 and 38:1. To avoid damage to the
gearing mechanisms, be sure you change the Limit Switch Drive Pinion gear if the Worm gear ratio is changed.
NOTE: The Limit Switch is available with a 4 Gear Set or a 5 Gear Set within the Gear Frame Assembly. The number of Gear Sets built
into your specific Limit Switch will determine the number of maximum Drive Sleeve rotations required to go the full range of the Limit
Switch. A four Gear Set with 19:1 and 38:1 has a maximum rotation of 902.25 Drive Sleeve rotations. A five Gear Set with 19:1 and
38:1 has a maximum rotation of 9022.5 Drive Sleeve rotations.
Figure 9: L120-85 Limit Switch Components
Gear Frame
Assembly
Intermediate Shafts
(A, B, C, and D)
Drive Pinion
Clutch Screw
Rotor Cams
4.3.3 Setting the OPEN Limit Switch
1. De-engerize the electrical circuit to the actuator.
2. Open the Electrical Compartment Cover (piece 200-1).
3. Put the actuator into MANUAL operation by moving the Declutch Lever in the direction of the arrow on the lever until the Declutch
Lever locks in place.
4. Turn the Handwheel CCW to move the valve to the full OPEN position. While turning the Handwheel, note the direction of the
Intermediate Shaft that corresponds to the Open Rotor Group. See figure 9.
NOTE: Most applications require turning the Handwheel CW to obtain the full CLOSE position and CCW to obtain full OPEN
position. The actuator Drive Sleeve rotates in a CW direction to the CLOSE position and CCW to the OPEN position. The
Limit Switch Intermediate Shafts rotate in a CCW direction to the CLOSE position and CW to the OPEN position. If your
application is configured differently, keep in mind that the descriptions in this manual will describe rotation directions opposite of your
application.
5. Once the valve is fully OPEN, turn the Handwheel back toward CLOSE approximately one full turn. This will allow for coasting during
motor operation.
a CAUTION: Do not operate the actuator when the Clutch Screw is in a fully depressed position; loss of the contact setting will occur and
the Setting Rod will be damaged.

Limitorque L120-85 Installation, Operation and Maintenance FCD LMENIM1202-03-A4 – 06/15
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a CAUTION: For highly geared actuators, one turn of the handwheel may not be sufficient to allow for coast of moving parts. Refer to
valve manufacturer setting requirements in these cases.
6. Push in Clutch Screw and turn CW one quarter turn to latch in a depressed position.
7. Limit Switch Rotor Cams
A. If your Limit Switch Rotor Cams did not trip at the full OPEN position point, turn the Intermediate Open Shaft in a CW
direction until the Open Limit Rotor Cam rotates 90° to make an OPEN contact (OPEN limit trip point = Rotor Cam in a vertical
orientation to make an OPEN contact); see figure 10 for orientation. Once you have reached the full OPEN position point, use the
Handwheel to rotate the Intermediate Shaft slowly in the CCW direction until the Rotor just trips again.
B. If your Limit Switch Rotor Cams did trip before reaching the full OPEN position point, leave the valve at the full OPEN position
point and turn the Intermediate Open Shaft in a CCW direction until the Rotor Cam rotates 90° to make an OPEN contact
(OPEN limit trip point = Rotor Cam in a vertical orientation to make an OPEN contact). Once you have reached the full OPEN
position point, rotate the Intermediate Shaft slowly in the CW direction until the Rotor just trips again.
Figure 10: Limit Switch OPEN/CLOSED Rotor Cam orientation
OPEN
Contact
CLOSED
Contact
Contact
Plunger
Rotor
Cams
8. Before operating the actuator, depress and turn the Clutch Screw CCW one-quarter turn to the spring release position. Insert
a screwdriver into each of the Intermediate Shafts and “rock” them CW and CCW a few times to ensure all the gearing is
seated well.
4.3.4 Setting the CLOSE Limit Switch
1. De-engerize the electrical circuit to the actuator.
2. Open the Electrical Compartment Cover (piece 200-1).
3. Put the actuator into MANUAL operation by moving the Declutch Lever in the direction of the arrow on the lever until the Declutch
Lever locks in place.
4. Turn the Handwheel CW to move the valve to the full CLOSED position. While turning the Handwheel, note the direction of the
Intermediate Shaft that corresponds to the Closed Rotor Group.

19
Limitorque L120-85 Installation, Operation and Maintenance FCD LMENIM1202-03-A4 – 06/15
flowserve.com
NOTE: Most applications require turning the Handwheel CW to obtain the full CLOSE position and CCW to obtain full
OPEN position. The actuator Drive Sleeve rotates in a CW direction to the CLOSE position and CCW to the OPEN position.
The Limit Switch Intermediate Shafts rotate in a CCW direction to the CLOSE position and CW to the OPEN position. If
your application is configured differently, keep in mind that the descriptions in this manual will describe rotation directions opposite of
your application.
5. Once the valve is fully CLOSED, turn the Handwheel back toward OPEN approximately one full turn. This will allow for coasting during
motor operation.
a CAUTION: Do not operate the actuator when the Clutch Screw is in a fully depressed position; loss of the contact setting will occur and
the Setting Rod will be damaged.
a CAUTION: For highly geared actuators, one turn of the handwheel may not be sufficient to allow for coast of moving parts. Refer to
valve manufacturer setting requirements in these cases.
6. Push in Clutch Screw and turn CW one-quarter turn to latch in a depressed position. See Figure 9 for Limit Switch nomenclature.
7. Limit Switch Rotor Cams
A. If your Limit Switch Rotor Cams did not trip at the full CLOSE position point, turn the Intermediate Close Shaft in a CCW
direction until the Close Limit Rotor Cam rotates 90° to make an OPEN contact (CLOSE limit trip point = Rotor Cam in a vertical
orientation to make an OPEN contact). Once you have reached the full CLOSED position point, rotate the Intermediate Shaft slowly
in the CW direction until the Rotor just trips again.
B. If your Limit Switch Rotor Cams did trip before reaching the full CLOSE position point, leave the valve at the full CLOSE position
point and turn the Intermediate Close Shaft in a CW direction until the Close Limit Rotor Cam rotates 90° to make an OPEN
contact (CLOSE limit trip point = Rotor Cam in a vertical orientation to make an OPEN contact). Once you have reached the full
CLOSE position point, rotate the Intermediate Shaft slowly in the CCW direction until the Rotor just trips again.
8. Before operating the actuator, depress and turn the Clutch Screw CCW one quarter turn to the spring release position. Insert a
screwdriver into the Intermediate Shafts and “rock” them CW and CCW a few times to ensure all the gearing is seated well.
4.4 Torque Switch Setting and Wiring
c WARNING: Hazardous Voltage. Turn the power OFF before opening the Electrical Compartment Cover or making any adjustments
to the Torque Switch.
NOTE: Removal or modification of the Torque Switch Limiter Plate will void the actuator warranty. Do not exceed the torque setting
indicated by the Torque Switch Limiter Plate without contacting the Limitorque Customer Service Department.
The L120-85 actuator is equipped with a double-acting Torque Switch that has been factory preset according to the required torque value
provided by the valve manufacturer or other associated equipment supplier. Further Torque Switch adjustment should not be required;
however, the Torque Switch may be reset from positions 1 through 5 (5 being the highest input torque requirement) by adjusting the Torque
Switch Adjustment Screws unless it is limited by the Limiter Plate. See figure 11 for Torque Switch nomenclature.

Limitorque L120-85 Installation, Operation and Maintenance FCD LMENIM1202-03-A4 – 06/15
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4.4.1 Basic Theory of Operation
As torque is developed by the actuator, the Worm moves axially and causes compression on the Spring Pack Assembly (components of
the Worm Shaft Assembly (piece 15)). The Spring Pack Assembly is calibrated so that a given amount of spring compression equates to a
given amount of output torque. Axial Worm Shaft Assembly movement causes the Torque Switch Shaft (piece 300-13) to move, therefore
engaging the Torque Switch measurement device. Once the Torque Switch is properly set, it measures valve, or other equipment, torque
input in the ELECTRIC or MANUAL operating modes.
4.4.2 Setting the Torque Switch
a CAUTION: Installing or adjusting the Torque Switch with the actuator in a loaded condition will result in loss of torque protection.
Before adjusting or installing the Torque Switch, place the actuator in MANUAL mode and turn the Handwheel in the direction
necessary to release the torque load on the Worm Shaft Assembly.
NOTE: If Torque Switch replacement is required, be sure to use an L120-85 Torque Switch rather than replacing with an L120-10 thru
40 Torque Switch. The L120-85 Torque Switch Torque Arm is rotated 10° from the position of the Torque Arm on the L120-10 thru 40
Torque Switch (the red dot on the Torque Switch Shaft indicates an L120-85 Torque Switch).
Figure 11: Torque Switch Components
ID Limiter
Plate (not shown)
#300-4 Torque Switch
Adjustment
Screws
#300-8 Balancing
Screws Mounting
Screw Hole
Torque Arm
Red dot indicates
L120-85 Torque Switch
Typical OPEN
contact assembly
(18 & 18C)
#300-2 & 300-3
Index Arm
Typical CLOSE
contact assembly
(17 & 17C)
1. Turn all power to the actuator OFF.
2. Loosen the Torque Switch Adjustment Screws (piece 300-4) on the OPEN or CLOSED side of the Torque Switch.
3. Move Index Arm (piece 300-2 or piece 300-3) to desired torque setting. The higher number indicates an increased torque and/or thrust
output requirement.
4. Tighten the Torque Switch Adjustment Screws (piece 300-4).
5. Turn power ON and operate the valve electrically to seat the valve or other device and to ensure tight shut-off.
4.4.3 Balancing the Torque Switch
If the Torque Switch has been removed from the actuator or if you are installing a new Torque Switch, it must be rebalanced using the
following procedure: