Emerson Bettis RPX Series User manual

DOC.IOM.BRX.EN Rev. 2
May 2021
Installation, Operation and Maintenance Manual
Bettis RPX-Series
Rack and Pinion Pneumatic Actuators

Installation, Operation and Maintenance Manual
May 2021 DOC.IOM.BRX.EN Rev. 2
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Installation, Operation and Maintenance Manual
DOC.IOM.BRX.EN Rev. 2 May 2021
Table of Contents
Table of Contents
Table of Contents
Section 1: Introduction
1.1 General Pneumatic System Recommendations .............................................. 1
1.1.1 Operating Media ................................................................................. 2
Section 2: Construction
2.1 Construction ................................................................................................. 3
2.2 Storage ......................................................................................................... 3
Section 3: Standard Installation
3.1 Buttery Valve Application ............................................................................ 4
3.2 Ball Valve Application .................................................................................... 4
3.3 All Quarter Turn Valve Types .......................................................................... 5
3.4 Non-standard Installation - Double-Acting and Spring-Return Actuators ....... 6
Section 4: Disassembly Procedure
4.1 Double-Acting Actuators ............................................................................... 7
4.2 Single-Acting Actuators ................................................................................ 8
Section 5: Assembly Procedure
5.1 Assembly Double-Acting Actuators ............................................................... 9
5.2 Assembly Spring-Return .............................................................................. 11
5.2.1 FAIL - CLOSE - Clockwise to CLOSE ..................................................... 11
5.2.2 FAIL - OPEN - Counterclockwise to OPEN ........................................... 11
5.2.3 End Cap Bolt Torque Values .............................................................. 12
5.3 Spring Allocation ......................................................................................... 13
5.4 Setting of Internal Travel Stops .................................................................... 14
5.4.1 Double-Acting Actuator ................................................................... 14
5.4.2 Spring-Return Actuator FAIL - CLOSE ................................................. 15
5.4.3 Spring-Return Actuator FAIL - OPEN .................................................. 16
Section 6: Maintenance
6.1 Maintenance ............................................................................................... 17
6.2 Troubleshooting .......................................................................................... 17
6.3 Pneumatic Air Connection ........................................................................... 17
Section 7: Parts and Materials
Parts and Materials ................................................................................................ 18

Installation, Operation and Maintenance Manual
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Installation, Operation and Maintenance Manual
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Section 1: Introduction
Introduction
Section 1: Introduction
This Section explains:
• General pneumatic system recommendations
1.1 General Pneumatic System Recommendations
All Bettis RPX Pneumatic Actuators are factory lubricated with Castrol LMM grease,
and unless the operating environment is extremely harsh, do not require relubrication.
For applications where the environmental temperature ranges from -40 °C to +65 °C
(-40 °F to +149 °F), a low temperature version is available with L-NBR O-ring seals and
Cassida Grease LTS 1 grease or Castrol Opti temp TT 1 + TT 1 EP.
For applications where the environmental temperature ranges from -52 °C to +65 °C
(-62 °F to +149 °F), an extreme low temperature version is available with L-NBR O-ring
seals and MolyKote®33 Extreme Low temperature grease.
For applications where the environmental temperature ranges from -15 °C to +150 °C
(+5 °F / +302 °F), a high temperature version is available with FKM O-ring seals and Castrol
Premium Heavy Duty grease.
To maintain maximum efciency with this actuator, we advise that the following basic
system recommendations are followed:
1. For maximum cycle life, the air quality of compressed air should be 2.4.1 as per
ISO 8573-1 standard.
2. Where pipelines are subjected to extremes of temperature, the system should
be tted with suitable air drying equipment.
3. When working at low temperatures, it is important that the compressed air has
been dried to a dew point of less than the ambient temperature. If this is not the
case, water will be condensed from the compressed air and freeze causing damage
to the seals inside the actuator, which could result in actuator failure.
4. Air control lines should be tted in accordance with a “Recommended Piping
Practice” and should not have loops, which may trap condensate.
5. All air connection pipe ends should be thoroughly cleaned and deburred after
cutting, to ensure that the pipeline is clear of debris.
6. If pipelines are hydraulically tested, then the lines should be “blown down” with
pressurized air to clear all traces of water, prior to connecting lines to the actuator.
7. Where pipe tting sealants are used, they should be applied to the male threads
only, to avoid excess compound being forced into the actuator control lines.
8. Where air lter equipment is used, the air lters should be situated in positions
that allow easy access to maintain and/or drain.
9. Where pneumatic valve positioners or pneumatic controllers are tted to the
valve actuator assemblies, oil mist lubricated air should not be used unless
the manufacturer states specically that the controllers are compatible with
lubricated air.

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Section 1: Introduction
Introduction
1.1.1 Operating Media
1. Use clean, dry or lubricated air or inert gas.
2. Maximum Operating Pressure (MOP) = 8.3 barg / 120 psig.
MOP is the pressure required to produce the maximum rated torque at the break
position for all actuators. Pressure should not exceed MOP during valve rotation.
MOP should be the maximum pressure regulator setting.
!WARNING
Do not exceed specications. It can be assured that the housing will not rupture or burst
when applying 10 bar / 145 psi of pressure but the cycle function cannot be guaranteed as
it totally depends on the time span to which actuator is subjected at 10 bar / 145 psi and
the frequency at which these pressure peaks occurs. Every time this peak occurs will, for
sure, have a signicantly negative effect on the life expectancy of the actuator.
!WARNING
For safety reasons, do not “air assist” Single-Acting Pneumatic Actuators.

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Section 2: Construction
Construction
Section 2: Construction
This Section explains:
• General construction principles and storage recommendations
2.1 Construction
Bettis RPX Actuators are designed to be mounted to quarter turn valves either directly
or using the correct mounting brackets/adapter and sizing products.
All models are of the opposed piston type. Each piston incorporates an integral rack
which engages with a one piece pinion drive shaft. The drive shaft is Zinc + Nickel plated
for maximum protection. The actuator body is of extruded aluminium, and tted with
“engineered polymer” bearings at the drive shaft locations. Bearing and piston seals are
dynamic “O-ring” type.
The drilling pattern and drive of the actuator valve ange complies to EN ISO 5211.
The drive is by means of a double square (star-drive) and most actuator size have 2 ISO
drilling patterns.
The top mounting interface and solenoid mounting interface complies to the
VDE/VDI 3845 (NAMUR) standard.
Adjustable travel stops are provided for each end of travel to ensure that the actuator
will open and close the valve precisely.
2.2 Storage
All actuators leave the factory tested and in excellent working condition and nish. In order
to maintain these characteristics until the actuator is installed in the plant, it is necessary
to observe the following rules and take appropriate measures during the storage period.
1. Make sure that the transport plugs remain tted in the air connections. These
plastic plugs close the air inlets, but do not have a waterproof function, as they
are a means of protection against the entry of foreign matter during transport.
For long term and specically outdoor storage, these plastic plugs need to be
replaced with plugs providing a complete weatherproof protection.
2. If the actuators are supplied separately from the valves, they must be placed onto a
wooden pallet in order to prevent damaging the valve coupling. For long term out-
door storage it is advised to coat the coupling parts with protective oil or grease.
3. In case of long term storage, it is advised to keep the actuators in a dry place or to
provide some means of weather protection.

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Standard Installation
Section 3: Standard Installation
Section 3: Standard Installation
This Section explains how to install the Bettis RPX actuators in most comon applications like:
• "In-line" installation on quarter turn valves.
• "Transverse" (a.k.a. across line) installation on quarter turn valves.
The RPX Actuator can be used for buttery valves, ball valves and all quarter turn devices,
in Double-Acting or Spring-Return conguration. Single-Acting Actuators are supplied
as FAIL - CLOSE (CW) as standard. Reverse acting (FAIL - OPEN; CCW) must be specied at
the time of order. Alternatively, it is possible to change an actuator from FAIL - CLOSE to
FAIL - OPEN by a trained and certied mechanical engineer using the assembly/disassembly
instructions as described in this document.
These installation instructions assume that the actuator is installed with the cylinder axis
parallel to the axis of the valve bore ("In-line" mounting). Please ensure that you have an
actuator with the correct drive, and that the valve and actuator are in the following positions:
1. Double-Acting units and Spring-Return units in FAIL - CLOSE position: valve closed,
actuator fully clockwise.
2. Double-Acting units and Spring-Return units in FAIL - OPEN position: valve open,
actuator fully counterclockwise.
3.1 ButteryValveApplication
Mounting to buttery valves:
1. Screw the actuator mounting studs tightly into the actuator base.
2. Install the correct shaft adapter if required.
3. Mount the actuator onto the valve top ange and secure using a lock washer
and nut on each mounting stud.
3.2 BallValveApplication
Mounting to ball and high performance buttery valves using a bracket:
1. Screw the actuator mounting studs tightly into the actuator base and secure
the mounting bracket to the underside of the actuator using four nuts and
washers as shown in Figure 1.
2. Install the appropriate coupling onto the valve stem. The coupling should
be lightly tapped or pressed onto the valve stem. The use of a lubricant
is recommended.
3. Mount the actuator and bracket onto the valve top ange using the
appropriate bolts.

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Standard Installation
Section 3: Standard Installation
3.3 AllQuarter-TurnValveTypes
1. Before installing the valve/actuator assembly in a piping system, the disc
travel should be veried and adjusted if necessary using the travel stop screws
(see Section 5.4, Setting of internal travel stops).
2. When installing the valve/actuator assembly into the pipeline, ensure that the
specic instructions relating to the valve installation are followed.
NOTE:
Some valves may require to be tted into the pipeline prior to mounting the actuator.
Rubber lined buttery valves are an example of this.
3. For valves which need to be installed in the pipeline prior to tting the actuator,
ensure that the valve is operated into its failsafe position before mounting the
actuator onto the valve.
Figure 1 Actuator Mounting
Typical Butterfly valve mounting Typical Ball valve mounting
Pneumatic
actuator
Stud
Lockwasher
Valve
Adaptor
(if required)
Nut
Pneumatic
actuator
Stud
Lockwasher
Nut
Lockwasher
Bracket
(if required)
Bolt
Coupling
(if required)
Nut
Ball valve
Pneumatic
actuator Pneumatic
actuator
Adaptor
(if required)
Bracket
(if required)
Coupling
(if required)
Bolt
Lockwasher
Lockwasher
Lockwasher
Nut
Nut
Nut
Stud
Stud
Valve Ball valve
TypicalButteryValveMounting TypicalBallValveMounting

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Section 3: Standard Installation
Standard Installation
3.4 Non-standard Installation - Double-Acting and
Spring-Return Actuators
In circumstances where the actuator is required to be installed in the transverse position
i.e. at right angles to the valve bore ("across line" mounting), the actuator must be rotated
through 90°. This is achieved in the following manner.
All quarter turn valve types:
1. Remove the actuator from the valve or the bracket by removing the 4 xing bolts/
nuts, and withdraw it vertically from the valve.
2. Reposition the shaft insert 90° for Double-D connections. Bored-keyed and star
drives do not require this action.
3. Rotate the actuator 90°.
4. Ret the actuator to the top of the valve or to the bracket. Pay attention to the
output drive of the actuator to be in line with the valve shaft and/or shaft insert.

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Section 4: Disassembly Procedure
Disassembly Procedure
Section 4: Disassembly Procedure
This Section explains:
• How to disassemble an actuator safely.
4.1 Double-Acting Actuators
!WARNING
Remove air pressure and observe normal safety precautions, including the use of
eye protection.
1. Remove the indicator assembly (25) from the top of the actuator.
2. Remove both travel stop bolts (21), after slackening the lock nuts (23).
3. Verify that the end caps are for Double-Acting actuator (at), and loosen end
cap xing screws evenly (22).
4. Remove the end caps (4).
5. Using a suitable wrench in the top of the pinion shaft (2), turn the shaft counter
clockwise to drive the pistons apart. Remove the pistons (3) complete with back-
ing pads/O-rings, etc.
6. Remove circlip (24) from the bottom bore of the actuator including thrust
washer (13).
7. Protect the actuator bore during pinion disassembly, and tap pinion shaft
downward. The travel stop cam (5) is rmly attached to the pinion and needs
to be released before removing the pinion from the actuator body (1).
8. Remove the pinion, but take care to protect the actuator bore.
9. Remove top and bottom O-rings (16 and 17) from the pinion shaft.
10. Remove top and bottom bearings (10 and 11) from the pinion shaft.

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Section 4: Disassembly Procedure
Disassembly Procedure
4.2 Single-Acting Actuators
!WARNING
Observe safety precautions. Remove air pressure and observe normal safety precautions,
including the use of eye protection. Always ensure that Spring-Return actuators are in
fail safe position before attempting any maintenance. Pay particular attention to this
requirement when manual operators are tted.
1. Remove the indicator assembly (25) from the top of the actuator.
2. Remove both travel stop bolts (21), after slackening the lock nuts.
3. Loosen end cap xing screws evenly (22) until the spring load is relaxed (3 - 5 mm).
!WARNING
High spring force. If after loosening the screws by 5 mm there is still compression on the
spring pack re-tighten the end cap screws and return the unit to the factory for service.
4. Remove end caps (4) and spring packs. In order to avoid the springs falling out
place the actuator with the end cap on top.
!WARNING
High spring force. Do not disassemble the precompressed spring packs, as the springs are
under high force.
5. Using a suitable wrench in the top of the pinion shaft (2), turn the shaft counter
clockwise to drive the pistons apart. Remove the pistons (3) complete with
backing pads/O-rings, etc.
6. Remove circlip (24) from the bottom bore of the actuator including thrust
washer (13).
7. Protect the actuator bore during pinion disassembly, and tap pinion shaft
downward. The travel stop cam (5) is rmly attached to the pinion and needs
to be released before removing the pinion from the actuator body.
8. Remove the pinion, but take care to protect the actuator bore.
9. Remove top and bottom O-rings (16 and 17) from the pinion shaft.
10. Remove top and bottom bearings (10 and 11) from the pinion shaft.

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Section 5: Assembly Procedure
Assembly Procedure
Section 5: Assembly Procedure
This Section explains:
• How to reassemble a complete actuator.
• How to set the stroke adjustment bolts after reassembly.
5.1 Assembly Double-Acting Actuators
1. Clean all disassembled items and replace all items as O-rings, bearings,
and backing pads as provided in the soft good kit.
2. Liberally grease the body bore with the grease specied.
3. Coat all O-rings and seals with the grease specied.
4. Output shaft assembly:
a. Fit the top bearing assembly (10) on the top of the pinion shaft (2)
with the top O-ring (16) uppermost.
b. Fit the bottom bearing assembly (11) on to the bottom of the pinion
shaft with the bottom O-ring (17) at the bottom.
c. Fit the top thrust washer (12).
5. Carefully insert pinion shaft assembly from underside of the actuator.
6. While inserting, t the travel stop cam (5) on top of the pinion shaft from
within the actuator bore and monitor the position of the NAMUR-slot in the
shaft top and the travel stop cam as shown in Figure 2. Finish with a rm push
to ensure full location.
Figure 2 Standard direction of Rotation
NAMUR
slot
Piston guideCamPinion Body Piston O-ring
Stopper bolt
Direction of movement
Gear mark
indication
45°±2°
Body Piston O-ring
Direction of movement
Gear mark
indication
Stopper bolt
PinionCamPiston guide NAMUR
slot

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Piston
Cam
Pinion Body Piston guideO-ring
Stopper bolt
Direction of
movement
Gear mark
indication
45° ±2°
NAMUR
slot
Section 5: Assembly Procedure
Assembly Procedure
7. Fit bottom thrust washer (13) and internal circlip (25) to bottom recess of body
to locate the shaft assembly.
8. Fit the O-ring seals (18) on the pistons (3), and grease the rack.
9. Orientate the output shaft at 45° as in Figure 2.
10. Insert pistons completely with backing pads (9) with piston legs on left hand side
of the bore when viewed from the O-ring end of the piston (Figure 2), until racks
engages with the pinion and then push gently inward. The actuator is now in the
fully closed position, and the shaft indication should be at -5° (pointing slightly
to the right).
11. Turn the pinion shaft counterclockwise until it is orientated in line with the major
axis of the actuator body. The shaft is now in the closed position.
12. Insert the right (close) travel stop bolt (21) together with the O-ring (19), washer
(14) and lock nut (23) until the bolt hits the travel stop cam. Tighten the lock nut.
13. Turn the shaft counterclockwise through 90° to bring it in line with the center line
of the actuator bore. The actuator is now in the open position.
14. Insert the left (open) travel stop bolt (21) together with the O-ring (19),
washer (14) and lock nut (23) until the bolt hits the travel stop cam. Tighten
the lock nut. The position of the travel stop bolts need to be veried after valve
assembly and adjusted if required.
15. Fit end cap gaskets (20) to the end caps (4) using a light smear of grease.
16. Fit Double-Acting end caps (at model) to body evenly and tighten the end cap
screws with the recommended torque (Table 1).
17. Fit position indicator assembly (25) to top of the actuator.
18. Operate the actuator to open and close positions using compressed air and note
the actual positions. Adjust the travel stops if required following the routine
described in this document. If the required travel is not achieved, refer to the
troubleshooting guide.
Figure 3 Non-standard direction of rotation
Body O-ring
Direction
of movement
Gear mark
indication
Stopper bolt
Pinion
Cam
Piston Piston guide
NAMUR
slot

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Section 5: Assembly Procedure
Assembly Procedure
5.2 Assembly Spring-Return
5.2.1 FAIL - CLOSE - Clockwise to CLOSE
1. Follow the steps 1 to 14 of the Double-Acting assembly procedure.
2. For Spring-Return actuators, the following additional actions are required:
a. Turn the pinion (2) clockwise to the close position.
b. Position the actuator vertically with the piston top in a horizontal plane
(make sure that the lower part is placed on a clean surface).
c. Locate the correct number of spring packs (6) in the cavities on the
piston head. For durability, make sure to divide the number of springs
evenly on both sides, with a maximum difference of 1 spring, and use the
conguration as indicated in Figure 4 based on the number of springs.
d. Fit the rst end cap as described in the following description and repeat
the sequence for the other side.
3. Fit end cap gaskets (20) to the end caps (4) using a light smear of grease.
4. Place end cap on top of the spring packs and make sure that the springs are
located in the spring pockets (cavities). Fit end cap to body evenly using end cap
screws (22) and washer (15). Tighten the end cap screws with the recommended
torque (Table 2). Make sure that the springs remain in position during assembly
of the end cap.
5. Fit position indicator (25) to top of the actuator.
6. Operate the actuator to open and close positions using compressed air and note
the actual positions. Adjust the travel stops if required following the routine
described in this document. If the required travel is not achieved, refer to the
troubleshooting guide.
5.2.2 FAIL - OPEN - Counterclockwise to OPEN
1. Follow the steps 1 to 8 of the Double-Acting assembly procedure.
2. Orientate the output shaft at 45° as in Figure 3.
3. Insert pistons completely with backing pads (9) with piston legs on right hand side
of the bore when viewed from the O-ring end of the piston (Figure 5), until racks
engages with the pinion and then push gently inward. The actuator is now in the
fully open position, and the shaft indication should be at 95°.
4. Turn the pinion shaft clockwise until it is orientated in line with the center line
of the actuator bore (90° position). The shaft is now in the open position.
5. Insert the left (open) travel stop bolt (21) together with the O-ring (19), washers
(14) and lock nut (23) until the bolt hits the travel stop cam. Tighten the lock nut.
6. Turn the shaft clockwise to 0° to bring it in line with the major axis of the actuator
body. The actuator is now in the close position.
7. Insert the right (close) travel stop bolt (21) together with the O-ring (19), washer
(14) and lock nut (23) until the bolt hits the travel stop cam. Tighten the lock nut.
The position of the travel stop bolts need to be veried after valve assembly and
adjusted if required.

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Section 5: Assembly Procedure
Assembly Procedure
8. For Spring-Return actuators the following additional actions are required:
a. Turn the pinion counterclockwise to the open position.
b. Position the actuator vertically with the piston top in a horizontal plane
(make sure that the lower part is placed on a clean surface).
c. Locate the correct number of springs in the cavities on the piston head.
Use the conguration as indicated in Figure 6 based on the number of
springs. For durability, make sure to divide the number of springs evenly
on both sides, with a maximum difference of 1 spring.
d. Fit the rst end cap as described in the following description and repeat
the sequence for the other side.
9. Fit end gap gaskets (20) to the end caps (4) using a light smear of grease.
10. Place end cap on top of the spring packs, and t end cap to body evenly using
end cap screws (22) and washer (15). Tighten the end cap screws with the
recommended Torque Table. Make sure that the springs remain in position
during assembly of the end cap.
11. Fit position indicator (25) to top of the actuator.
12. Operate the actuator to open and close positions using compressed air and note
the actual positions. Adjust the travel stops if required following the routine
described in this document. If the required travel is not achieved, refer to the
troubleshooting guide.
5.2.3 End Cap Bolt Torque Values
As the end caps are pressurized during normal operation, it’s important to x them
correctly and not damage the threading due to excessive torque. Please use the torque
values as indicated in Table 1.
Table 1. End Cap Bolts Tightening Torque
Actuator size Bolt size Tightening torque
(Nm)
Tightening torque
(lbf-in)
003 M5 3 27
004 M5 3 27
006 M5 3 27
009 M6 9 80
014 M8 15 133
020 M8 15 133
032 M10 28 248
052 M12 40 354
084 / 085 M12 40 354
140 / 141 M16 110 974
240 M16 110 974

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4 springs
5 springs
6 springs
7 springs
9 springs
10 springs
11 springs
12 springs
8 springs
Left RightLeftRight
Section 5: Assembly Procedure
Assembly Procedure
5.3 Spring Allocation
In Spring-Return applications, the number of springs used to determine the torque provided
for fail safe applications. For optimal performance, the number of springs used is based on
the valve type used using the RPX Actuator Torque Table (normally closed applications):
• Ball valves: use spring torque level which matches the spring torque at 90° with
the supplied air starting torque at 0°.
• Buttery valves: use spring torque level which matches the spring torque at 0°
with the supplied air torque at 0°.
The number of springs used can vary between 4 and 12 pieces. For durability, make sure to
divide the number of springs evenly on both sides, with a maximum difference of 1 spring,
and use the conguration as indicated in Figure 4 based on the number of springs.
Figure 4 Spring Allocation
Left
5 springs 10 springs
6 springs 11 springs
7 springs 12 springs
8 springs
4 springs 9 springs
LeftRight Right

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Pinio
n
O-ring
Piston open adjustment bolt
Ca
m
Plain washer
Spring washer
Actuator
body
Locking nut
Piston close adjustment bolt
Pinion
O-ring
Cam
Plain washer
Spring washer
Actuator
body
Locking nut
Section 5: Assembly Procedure
Assembly Procedure
5.4 SettingofInternalTravelStops
The Bettis RPX-Series Actuator is tted with integral travel stops to enable setting of exact
travel for the valve being operated. These stops allow over and under travel adjustment
of ± 5° on each end.
!WARNING
Under no circumstances the travel stop bolts should be completely withdrawn from the
actuator while compressed air is being applied.
Travel stop bolts should not be used for manual override actions.
After setting the travel stops, accessories mounted to the top of the actuator must be
re-adjusted accordingly.
5.4.1 Double-Acting Actuator
1. Operate the valve/actuator assembly to the closed position.
2. Remove air supply.
3. Slacken lock nut on the close travel stop (right).
4. Turn the travel stop clockwise to reduce travel or counterclockwise to
increase travel.
5. Re-tighten lock nut.
6. Reconnect air supply and check that the close position is correct. If not,
repeat from instruction 2.
7. Apply air to the open position.
8. Remove air supply.
9. Adjust open travel stop bolt (left) as per instruction 3 to 6 above.
Figure 5 Cam adjustment (standard direction of rotation)
O-ring O-ring
Pinion Pinion
Cam Cam
Actuator
body
Actuator
body
Plain washer Plain washer
Locking nut Locking nut
Piston close adjustment bolt Piston open adjustment bolt
Spring washer Spring washer

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Pinio
n
O-ring
Piston open
adjustment bolt
Ca
m
Plain washer
Spring washer
Actuator
body
Locking nut
Piston close
adjustment bolt
Pinion
O-ring
Cam
Plain washer
Spring washer
Actuator
body
Locking nut
Section 5: Assembly Procedure
Assembly Procedure
5.4.2 Spring-Return Actuator FAIL - CLOSE
1. Remove air supply and check actual close position.
2. Apply air to operate the actuator to the open position.
3. Whilst the air supply is maintained, slacken lock nut on the close travel stop (right)
as the close position is now able to be adjusted.
4. Turn the travel stop clockwise to reduce travel or counterclockwise to
increase travel.
5. Re-tighten lock nut.
6. Remove air supply to close the actuator. If correct close position is not achieved
repeat from instruction 2.
7. Apply air to drive the actuator to the open position and check actual open position.
8. Remove air supply so that actuator closes, and the open travel stop bolt (left) can
be adjusted.
9. Adjust open travel stop bolt as per instruction above.
10. Re-tighten lock nut.
11. Apply air and check open position. If correct open position is not achieved, repeat
from instruction 7.
Figure 6 Cam Adjustment (Non-standard direction of rotation)
O-ring O-ring
Pinion Pinion
Cam Cam
Actuator
body
Actuator
body
Plain washer Plain washer
Spring washer Spring washer
Locking nut Locking nut
Piston close
adjustment bolt
Piston open
adjustment bolt

16
Installation, Operation and Maintenance Manual
May 2021 DOC.IOM.BRX.EN Rev. 2
Assembly Procedure
Section 5: Assembly Procedure
5.4.3 Spring-Return Actuator FAIL - OPEN
1. Remove air supply and check actual open position.
2. Apply air to operate the actuator to the close position.
3. Whilst the air supply is maintained, slacken lock nut on the open travel stop (left)
as the open position is now able to be adjusted.
4. Turn the travel stop clockwise to reduce travel or counterclockwise to increase travel.
5. Re-tighten lock nut.
6. Remove air supply to open the valve. If correct open position is not achieved
repeat from instruction 2.
7. Apply air to operate the actuator to the close position and check actual close position.
8. Remove air supply so that actuator opens, and the close travel stop bolt (right)
can be adjusted.
9. Adjust close travel stop bolt as per instruction above.
10. Re-tighten lock nut.
11. Apply air and check open position. If correct close position is not achieved,
repeat from instruction 7.