IMI STI RTQH Series User manual

Quarter turn hydraulic actuator
RTQH Series
Single acting version type RTQHS
INSTRUCTION MANUAL 5400

_____________________________________________________________________________________
STI S.r.l. –Via Dei Caravaggi 15, 24040 Levate (BG) –ITALY www.imi-critical.com
Manual 5400, rev. 05 02/2018 –RTQHS i
Date
Revision
Description
Compiled
Approved
06/02/2018
5
Revised § 5.1
M. Bozzarelli
F. Tondolo
06/12/2017
4
Revised §1.6 / added §7.3
M. Bozzarelli
F. Tondolo
15/02/2016
3
Revision
M. Bozzarelli
D. Lamoure
02/10/2015
2
Revision
M. Bozzarelli
D. Lamoure
24/10/2013
1
Revision
G. Alfieri
D. Lamoure
01/07/2013
0
Issue
E. Montagna
D. Lamoure
STI S.r.l has taken every care in collecting and verifying the documentation contained in this Instruction
Manual. The information herein contained are reserved property of STI S.r.l.

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Manual 5400, rev. 05 02/2018 –RTQHS ii
INDEX
1GENERAL INFORMATION.............................................................................................................................1
1.1 GENERAL WARNINGS..................................................................................................................................1
1.2 GENERALITIES ...........................................................................................................................................1
1.3 MANUFACTURER ........................................................................................................................................1
1.4 TERMS AND CONDITIONS .............................................................................................................................1
1.5 MANUFACTURER’S LIABILITY ........................................................................................................................1
1.6 APPLICABLE STANDARDS AND DIRECTIVES .....................................................................................................2
1.7 SYMBOLOGY USED.....................................................................................................................................2
2DEVICE DESCRIPTION..................................................................................................................................3
2.1 GENERAL DESCRIPTION ..............................................................................................................................3
2.2 IDENTIFICATION OF THE MAIN PARTS .............................................................................................................4
2.3 ACTUATOR CODING DESCRIPTION..................................................................................................................5
3TECHNICAL DATA ........................................................................................................................................6
4IDENTIFICATION PLATE...............................................................................................................................6
5INSTALLATION..............................................................................................................................................7
5.1 TRANSPORT ..............................................................................................................................................7
5.2 RECEPTION...............................................................................................................................................8
5.3 STORAGE .................................................................................................................................................8
5.4 REQUIREMENTS OF STABILITY......................................................................................................................8
5.5 INTERFACE DOCUMENT AND DIMENSIONAL DRAWING.........................................................................................8
5.6 INSTALLATION............................................................................................................................................9
5.7 DISASSEMBLING....................................................................................................................................... 12
6OPERATION AND USE................................................................................................................................ 13
6.1 OPERATION DESCRIPTION..........................................................................................................................13
6.2 INTENDED USE.........................................................................................................................................13
6.3 REASONABLY FORESEEABLE MISUSE ...........................................................................................................13
6.4 OPERATING LIMITS ...................................................................................................................................14
6.5 RESIDUAL RISKS......................................................................................................................................14
7INSTRUCTIONS FOR THE OPERATOR.......................................................................................................15
7.1 START UP...............................................................................................................................................15
7.2 STROKE ADJUSTMENT...............................................................................................................................15
7.3 MANUAL OVERRIDE ..................................................................................................................................18
8MAINTENANCE ...........................................................................................................................................20
8.1 PERIODIC INSPECTIONS.............................................................................................................................20
8.2 SPECIAL MAINTENANCE .............................................................................................................................21
8.3 REPAIRS.................................................................................................................................................25
8.4 MECHANISM LUBRICATION .........................................................................................................................26
8.5 HYDRAULIC FLUID ....................................................................................................................................26
9TROUBLESHOOTING..................................................................................................................................27
10 PARTS LIST GENERAL ASSEMBLY .......................................................................................................28
11 SPARE PARTS ........................................................................................................................................34
12 DECOMMISSIONING................................................................................................................................35
13 DECLARATION OF INCORPORATION .................................................................................................... 36

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Manual 5400, rev. 05 02/2018 –RTQHS iii

_____________________________________________________________________________________
STI S.r.l. –Via Dei Caravaggi 15, 24040 Levate (BG) –ITALY www.imi-critical.com
Manual 5400, rev. 05 02/2018 –RTQHS 1
1 GENERAL INFORMATION
1.1 General Warnings
Important
This Instruction Manual is an integral part of the machine, it should be carefully
read before carrying out any operation and it should be kept for future references.
This Instruction Manual covers the RTQHS actuators in the base version without
any accessories and/or control panel.
In case accessories and/or control panel are foreseen mounted on the actuator an
additional Section to this Instruction Manual will be attached to the specific
actuator.
This Instruction Manual is realized in accordance with the Directive 2006/42/CE.
1.2 Generalities
STI S.r.l. actuators are conceived, manufactured and controlled according to the Quality Control System in
compliance with EN ISO 9001 International Standard.
STI S.r.l. Via Dei Caravaggi 15
24040 Levate (BG) Italy
Tel. [phone]
Fax [phone]
[e-mail]
1.3 Manufacturer
With respect to Machinery Directive 2006/42/EC the Manufacturer of the described RTQHS actuator series,
is STI S.r.l. as specified on the machinery label.
1.4 Terms and conditions
STI S.r.l. guarantees each single product to be free from defects and to conform to current goods
specifications. The warranty period is one year from the date of installation by the first user, or eighteen
months from the date of shipment to the first user, whichever occurs first.
The warranty does not cover special products or components not covered by warranty in their turn by
subcontractors. No warranty is given for products which have been subject to improper storage, improper
installation, misuse, or corrosion, or which have been modified or repaired by unauthorised personnel.
Repair work due to improper use will be charged at standard rates.
1.5 Manufacturer’s Liability
STI S.r.l. declines all liability in the event of:
- use of the actuator in contravention of local safety at work legislation
- incorrect installation, disregard or incorrect application of the instructions provided on the actuator
nameplate and in this manual
- modifications without STI’s authorisation
- work done on the unit by unqualified or unsuitable persons.

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Manual 5400, rev. 05 02/2018 –RTQHS 2
1.6 Applicable Standards and Directives
- EN ISO12100: 2010:Safety of machinery-General principles for design. Risk asses and risk reduction.
- IEC 61508-1/7 (Ed.2010)
- IEC 61511-1 (Ed. 2016)
- 2006/42/EC Machinery Directive.
- 2014/68/EU Pressure Equipments Directive (PED)
- 2014/35/EU Directive for Low Voltage Equipment (LV)**
- 2014/30/EU Directive relating to the Electromagnetic Compatibility (EMC)**
- 2014/34/EU Directive concerning equipment for use in potentially explosive atmospheres (ATEX)
** Applicable only when electrical control panel is supplied integrate with the actuator
1.7 Symbology Used
1.7.1 Signs of warning and/or danger
Please pay the maximum attention to the signs shown here below when they are present.
They indicate a potentially hazardous situation and they warn that, if the displayed indications are not
properly observed, the failure to observe them could cause serious injuries, death or long-term risks
to the health of exposed persons.
1.7.2 Sings of obbligation
General
obligation (with
the possible
supplementary
signboard)
Must wear
protective
clothing.
Obligation to
wear
protective
footwear.
Is required to
wear a helmet.
Is required to
protect the
eyes.
Obligation to
protect your
hearing.
GENERAL DANGER
DANGER POWER SUPPLY
CRUSHING HAZARD

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Manual 5400, rev. 05 02/2018 –RTQHS 3
2 DEVICE DESCRIPTION
2.1 General Description
RTQHS single acting hydraulic actuators, are suitable for the operation of quarter turn valves (ball valves,
butterfly valves, plug valves,...) for ON-OFF and modulating heavy-duty services.
The actuator is made up of a weatherproof scotch yoke mechanism transforming the linear movement of the
hydraulic cylinder (on closing or opening direction) or the linear movement due to the force of a spring (on
opposite direction to the hydraulic cylinder) into the rotary movement, which is necessary for valve
operation.
The travel stroke of the yoke is adjustable between ± 4 degree at both ends of the nominal travel by means
of the external mechanical stops arranged into the end flange of the spring cartridge and into the end flange
of the hydraulic cylinder.
The cover of the centerbody of the scotch yoke mechanism is machined to provide the assembly pattern for
any required accessories (i.e. positioner, signalling limit switches, position transducer, etc.) by means of
proper matching units. The above mentioned accessories are operated by the actuator drive sleeve.
Actuator centerbody bottom wall is machined with threaded holes to allow actuator mounting on top of valve
top-work either directly or, when required, with the interposition of an adaptor flange or a mounting bracket.

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Manual 5400, rev. 05 02/2018 –RTQHS 4
2.2 Identification of the Main Parts
The RTQHS actuator is composed by six main parts identified in the attached Fig. 1:
1) Scotch yoke mechanism.
2) Hydraulic cylinder
3) Spring cartridge
4) Stopper screw assembly for cylinder
5) Seal kit
6) Position Indicator
7) Stopper screw assembly for spring cartridge.
Fig. 1: Main parts for RTQHS actuator series (Spring to Close configuration)

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Manual 5400, rev. 05 02/2018 –RTQHS 5
2.3 Actuator coding description
- - - -
V
M
01 05
02 06
03 07
04 08
Y
S
C
C
60 200
75 235
100 280
135 300
160
R
A E
B F
C G
D H
S
1
2
3
4
A
CL
OP
H
HW
HWR
HP
RTQHS
Model 02
Manual handwheel
Y
-
S
Spring size
Version
Model 05
Model 06
Model 07
Model 08
Diameter = 235 mm
Diameter = 280 mm
Spring pack model
Diameter = 100 mm
Diameter = 135 mm
Diameter = 160 mm
Diameter = 300 mm
Diameter = 75 mm
R
C
Diameter = 200 mm
Single acting
Canted
Symmetric
V
Model
Model 03
Model 04
Yoke type
M
Model 01
Cylinder diameter
Diameter = 60 mm
Model 04
Model 05
Model 06
Model 07
Model 08
Manual handwheel with reduction
Accessories
Hydraulic hand pump
H
Fail action
Fail Close
Fail Open
Spring Size 2
Spring Size 1
Spring Size 3
Spring Size 4
A
Model 01
Model 02
Model 03

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Manual 5400, rev. 05 02/2018 –RTQHS 6
3 TECHNICAL DATA
DATA
Supply medium
Hydraulic fluid (see Section 8.5)
Operating temperature ranges
Standard : -30°C +100°C
Optional : -60°C +100°C (*)
(*) for SIL applications T° amb. min ≥ -40°C
PED applications:
Standard : -20°C +100°C
Optional : -50°C +100°C (*)
(*) for SIL applications T° amb. min ≥ -40°C
Cylinder design pressures
103, 207 or 345 bar
Operating pressure range
Depending on customer requirements and
specifications.
(Data are available on actuator nameplate)
Max operating torque (MOT)
RTQHS 01 models: up to 12.000 Nm
RTQHS 02 models: up to 22.000 Nm
RTQHS 03 models: up to 40.000 Nm
RTQHS 04 models: up to 70.000 Nm
RTQHS 05 models: up to 125.000 Nm
RTQHS 06 models: up to 220.000 Nm
RTQHS 07 models: up to 350.000 Nm
RTQHS 08 models: up to 500.000 Nm
Applications
On-Off
Modulating service (on request)
The nameplate fastened on the actuator contains the main actuator operating condition.
It is forbidden to modify the information and the marks without previous written authorization by STI S.r.l.
4 IDENTIFICATION PLATE

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Manual 5400, rev. 05 02/2018 –RTQHS 7
5 INSTALLATION
5.1 Transport
Warning
The lifting and handling must be made by qualified staff and in compliance with the laws
and provisions in force.
Lift the actuator as shown in Figure 2 taking care that the maximum opening angle
between the chains remains below 90°.
The lifting points are appropriate for the lifting of the actuator alone and not for the valve +
actuator assembly.
Avoid that during the handling, the actuator passes above the staff.
The actuator should be handled with appropriate lifting means considering the mass of
actuator. The mass is printed on the label of the actuator.
The mass is also reported on the delivery bill and on overall-dimensions drawings
furnished with the documents accompanying the actuator.
In case the information regarding the weight is missing consult www.stiactuation.com for
base actuators or ask this information at [e-mail]
Fig. 2 –Lifting points for RTQHS actuator series
Important
Not performing the following procedures will invalidate the product guarantee.
90° max

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Manual 5400, rev. 05 02/2018 –RTQHS 8
5.2 Reception
- Check that the model, the serial number of the actuator and the technical data reported on the
identification plate correspond with those of order confirmation (Sect. 4).
- Check that the actuator is equipped with the fittings as provided for by order confirmation.
- Check that the actuator was not damaged during transportation: if necessary renovate the painting
according to the specification reported on the order confirmation.
- If the actuator is received already assembled with the valve, its settings have already been made at the
factory.
- If the actuator is delivered separately from the valve, it is necessary to perform the setting after the
assembling on the valve according to the following Section 7.2.
5.3 Storage
All the actuators RTQHS leave the factory in perfect condition. Performances of each unit are guaranteed by
individual test and data reported on a specific test certificate issued for each unit.
In order to maintain these characteristics until the RTQHS actuator is installed on site, proper attention must
be observed for preservation during the storage period.
If the actuator needs storage, before installation follow these steps:
- Place it on a wood surface pallet or on metallic support, so that they are not in direct contact with the
ground, in order not to deteriorate the area of valve coupling, later it must be packed with appropriate
covering.
- Make sure that plastic plugs are present on the hydraulic and electrical connections (if present).
- Check that the limit switch box (if any) is properly closed.
-
If the storage is long-term or outdoor:
- Keep the actuator protected from direct weather conditions.
- Replace plastic plugs of hydraulic and electrical connections (if any) with metal plugs that guarantee
perfect tightness.
- Coat with oil, grease or protection disc, the valve coupling area.
- Periodically operate the actuator (Sect.6).
5.4 Requirements of Stability
- Conditions in which the machinery meets the requirement of stability during use, transportation,
assembly, dismantling when out of service, testing or foreseeable breakdowns, are shown in Fig.2.
- The actuator must be put, with extreme caution, in a right position on a plane surface and with adapted
capacity to the load to support.
- Do not use actuator eye bolts lifting of valve-actuator package.
- Concerning the requirement of stability during installation and disassembling it ‘s possible to refer to the
next chapters 5.6 and 5.7.
5.5 Interface document and dimensional drawing
- Hydraulic diagrams, wiring diagrams and dimensional drawing are furnished with document
accompanying the actuator.

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STI S.r.l. –Via Dei Caravaggi 15, 24040 Levate (BG) –ITALY www.imi-critical.com
Manual 5400, rev. 05 02/2018 –RTQHS 9
5.6 Installation
Warning
It is assumed that the installation, setting, commissioning, maintenance and repair
works are carried out by qualified personnel and checked by responsible
Specialists.
Any repair work other than the operations outlines in this Instruction Manual will
be strictly reserved to qualified STI srl personnel or to personnel directly
authorised by the Company itself.
Warning
Before proceeding with any Installation the following instructions must be
respected:
- Always wear protective clothing, gloves, and eyewear to prevent personal
injury.
- Use the lifting point foreseen on the actuator to move the actuator: if
different instructions are not well specified the lifting points foreseen on
the actuator must be used only to move the actuator.
- Check with your process or safety engineer for any additional measures
that must be taken to protect against process media.
5.6.1 Checks to be performed before installation
If the RTQHS actuator is purchased separately, proceed as follows before assembling it onto the valve:
- Check that the coupling dimensions of the actuator/coupling block flange and stem meet the specified
coupling dimensions.
- Prepare the necessary tools for the assembly and setting of the unit.
- Check that the outer surface of the actuator is free from dust and dirt.
- Clean the actuator flange and remove anything that might prevent a perfect adherence to the
actuator/coupling block flange and joint especially all traces of grease.
5.6.2 Assembling of the actuator on the valve
The actuator can be assembled on top of the valve flange either by using the actuator-housing flange with
threaded holes, or by the interposition of a proper mounting hardware.
The actuator drive sleeve is generally connected to the valve stem by an insert bush or a stem extension.
The assembly position of the actuator, with reference to the valve, must comply with the plant requirements
(cylinder axis parallel or perpendicular to the pipeline axis).
To assemble the actuator onto the valve proceeds as follows:
- Move the valve and the actuator to their fails position
- If an insert bush or stem extension for the connection to the valve is supplied separately, assemble it
onto the valve stem and fasten it by tightening the proper stop dowels.
- Connect a sling to the support points of the actuator and lift it: make sure the sling is suitable for the
actuator weight
- Lower the actuator onto the valve in such a way that the insert bush, assembled on the valve stem,
enters the actuator drive sleeve; this coupling must take place without forcing and only with the weight
of the actuator.
- When the insert bush has entered the actuator drive sleeve, check the holes / pin of the valve flange
meet the actuator holes and pin, otherwise rotate the mounting bracket to obtain a right assembling.

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Manual 5400, rev. 05 02/2018 –RTQHS 10
Fig. 3 –Assembling of the actuator on the valve
Important
To guarantee the correct transmission of torque from the actuator to valve
stem without phenomena of slip it is important to remove any trace of oil
and/or grease from the mating surfaces of valve and actuator or bracket and
tighten the nuts fixing the bolts with the torque specified into the following
Table 1
Table 1
Threading
Tightening torque (Nm)
Threading
Tightening torque (Nm)
M8
20
M24
550
M10
40
M27
800
M12
70
M30
1200
M14
110
M33
1400
M16
150
M36
1800
M20
300
The torque values in Table 1 have been calculated considering the materials ASTM A320 grade L7/ASTM
A193 grade B7 for screws or tie rods and ASTM A194 grade 4 for the nuts.
Alternative bolting permitted i.e. ASTM A193 B8M (or B8M3) for tie rods and ASTM A194 grade 8M for the
nuts, provided that yield strength of screws or tie rods is higher than 450 MPa.

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Manual 5400, rev. 05 02/2018 –RTQHS 11
5.6.3 Hydraulic Connections
Warning
Check that the values of hydraulic supply available are compatible with those
reported on the identification plate of the actuator.
Use pipes and connections appropriate as for type, rating, material and dimensions.
The connection should be made by qualified staff.
-Properly deburr the ends of rigid pipes.
-Properly clean the interior of pipes sending through them plenty of the supply fluid used in the system.
-Mould and fasten the connection pipes so that no irregular strains at entries or loosening of threaded
connections occur.
-Make the connections according to the operating diagram.
-Check the absence of leakages from hydraulic connections. If necessary tighten the nuts of the pipe-
fittings.
5.6.4 Electrical Connections (If any)
Warning
Before carrying out electrical connections, switch off any power and control lines.
Use components appropriate as for type, material and dimensions.
The connections should be made by qualified staff.
-Introduce connection cables.
-Make the connections in compliance with applicable wiring diagrams on the documentation supplied.
-Screw the cable gland.
-Replace the plastic plugs of unused entries with metal plugs.
5.6.5 Earting connection
If the hearting connection is not guaranteed trough mechanical parts where actuator is mounted, it is
necessary ensure a directly hearting connection on provided point of actuator.

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Manual 5400, rev. 05 02/2018 –RTQHS 12
5.7 Disassembling
Fig. 4 –Disassembling of the actuator from the valve
Warning
Before starting the disassembly operations it is mandatory to disconnect the
hydraulic power and to exhaust the cylinder and any other pressure retaining
component mounted on the actuator.
Before removing the screws between actuator and valve or adaptor flange or mounting
bracket, the actuator should be connected with appropriate lifting means. Lift the actuator
as shown in Fig.3. The lifting points are appropriate for handling the actuator alone and
not for the valve + actuator assembly.
During the disassembling take care that the mounting coupling block is fix on the valve
stem to avoid any dangerous situation.

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Manual 5400, rev. 05 02/2018 –RTQHS 13
6 OPERATION AND USE
6.1 Operation description
The RTQHS is a hydraulic actuator designed for on-off and control service and is applicable over a wide
range of pressure, temperatures and environments.
The scotch yoke mechanism converts the linear motion of hydraulic piston or spring into valve rotation by
the actuator shaft. The symmetric scotch yoke mechanism generates high torque at start (0° degree) and
the end (90° degree) of the valve stroke, typically valve torque figure of ball valve. The canted scotch yoke
mechanism generates very high torque when valve is closed, typically valve torque figure of butterfly valve.
For Single acting actuator RTQHS the spring cartridge is located on the other side of actuator housing. The
spring provides the required safety function, the valve either opens or closes if the hydraulic supply is
interrupted Safe spring design ensures proper functionality and safe maintenance, preventing any
accidental hazards due corrosion of bolting.
6.2 Intended use
The machinery covered in this Instruction Manual is single acting hydraulic RTQHS actuator series
designed to operate a quarter turn industrial valve (ball valves, butterfly valves, plug valves,
dampers,...) for ON-OFF or modulating heavy duty service.
This RTQHS actuator is produced by STI srl [Manufacturer] and identified by a label with a product
designation code. STI srl will not be liable for any possible damage or physical injury resulting from use in
other than the designated applications or by lack of care during installation, operation, adjustment and
maintenance of the machine. Such risks lie entirely with the user. Depending on the specific working
conditions, additional precautions may be requested. Considering that STI srl has no direct control over
particular applications, operation or maintenance conditions, it is the operator’s responsibility to comply with
all applicable safety rules. Please inform STI srl urgently if you face unsafe situations not described in this
Instruction Manual. It is the sole responsibility of the operator to ensure that the local health and safety
regulations are adhered to.
RTQHS actuator is designed in accordance with the applicable International Rules and Specifications, but
the following Regulations must be observed in any case:
- the general and safety regulations
- the plant specific regulations and requirements
- the proper use of personal and protective devices (glasses, clothing, gloves, etc)
- the proper use of tools, lifting and transport equipment.
Warning
It is severely forbidden to use the RTQHS actuators series for purpose or
application other than those for which it was designed and here above specified
6.3 Reasonably foreseeable misuse
A short list of reasonably foreseeable misuse :
- Installation in ambient with not planned conditions: i.e. climatic conditions different from the specified
conditions;

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Manual 5400, rev. 05 02/2018 –RTQHS 14
- Insert incorrect fluid into the system;
- Supply pressure out of required range;
- Lifting of the actuator with valve through eye bolts.
6.4 Operating limits
Operating conditions are described in paragraph 3, the nameplate fastened on the actuator contains the
main actuator operating condition for the specified application.
Warning
It is severely forbidden to use the actuator under conditions other than those
provided on the nameplate.
6.5 Residual Risks
Warning
The actuator has parts under pressure: use the due caution.
Use individual protections provided for by the laws and provisions in force.
- Risk due to movements of loads during load displacements, assemblage and maintenance servicing.
- Electrical risk due to an incorrect application of the instruction.
- Crushing during assemblage and maintenance servicing.
- Extreme metal temperature at high (over than 80°C) or very low values as consequence of ambient
temperature as to be considered as a risk of person injury in case of contact.
- Emissions of hazardous substances where natural gas is used as motive energy.

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Manual 5400, rev. 05 02/2018 –RTQHS 15
7 Instructions for the operator
7.1 Start Up
During the start-up of the actuator, proceed as follows:
-Check that the pressure and quality of the air supply (filtering degree, dehydration) are as prescribed.
-Check that the feed voltage values of the electric components (solenoid valve coils, micro-switches,
pressure switches, etc.) are as prescribed.
-Check that the actuator controls work properly (remote control, local control, emergency controls, etc.)
-Check that the required remote signals (valve position, air pressure, etc.) are correct.
-Check that the setting of the components of the actuator control unit (pressure regulator, pressure
switches, flow control valves, etc.) meet the plant requirements.
-Check that there are not leak in the hydraulic connections. If necessary tighten the nuts of the pipe
fittings.
-Remove all rust and, in accordance with the applicable painting specifications, repair paint-coat that has
been damaged during transport, storage or assembly.
7.2 Stroke adjustment
Important
It is assumed that the following instructions are executed in the workshop
using air as the power fluid.
Instructions are applicable when the actuator is already installed on the valve.
It is important that the mechanical stops of the actuator (and not those of the valve) stop the rotary stroke at
both extreme valve positions (fully open and fully closed), except when different configuration is required by
the type of thevalve (i.e,: eccentric butterfly valves,..).
The setting of the open/closed valve position is performed by adjusting the setting screws foreseen
into the end flanges of the cylinder and spring cartridge (see Fig. 5 and Fig. 6) following the
instructions listed on the next paragraphs 7.2.1 and 7.2.2.
7.2.1 Spring to Close version
7.2.1.1 Setting of the stopper on the cylinder side (Fig. 5)
Start this operation with the air in the hydraulic cylinder exhausted and valve in closed or intermediate
position.
Loosen the nut (5.3) from the setting screw (5.2) and unscrew the setting screw (5.2) until it remain only a
few threads engaged on the end flange of the cylinder.
By pressurizing the cylinder or by using the manual override, move the valve until it reach the correct setting
in open position. Fix then the valve position by screwing the setting screw (5.2) until it stops on the end part
of the internal piston.
Taking care not to damage it, reinstall the sealing washer (5.4) and screw until it blocks against the surface
of the end flange; put then in place the protection washer (5.1) around the sealing washer (5.4) and block all
the system with the nut (5.3).
To avoid the risk of unsetting the setting screw (5.2) during this last operation, keep the setting screw (5.2)
blocked by using an Allen wrench engaged on the on the hexagonal receptacle.

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Manual 5400, rev. 05 02/2018 –RTQHS 16
7.2.1.2 Setting of the stopper on the spring side (Fig. 6)
Start this operation with valve in open or intermediate position.
Loosen the nut (6.3) from the setting screw (6.2) and unscrew the setting screw (6.2) until it remain only a
few threads engaged on the end flange of the spring cartridge.
By releasing the air in the cylinder or by using the manual override, move the valve until it reach the correct
setting in closed position. Fix then the valve position by screwing the setting screw (6.2) until it stops on the
end part of the internal spring stem.
Taking care not to damage it, reinstall the sealing washer (6.4) and screw until it fit into the groove of the
spring cartridge bushing (6.1), then block all the system with the nut (6.3).
To avoid the risk of unsetting the setting screw (6.2) during this last operation, keep the setting screw (6.2)
blocked by using an Allen wrench engaged on the on the hexagonal receptacle.
Fig. 5 –Stroke adjustment detail Fig. 6 –Stroke adjustment detail
7.2.2 Spring to Open version
7.2.2.1 Setting of the stopper on the cylinder side (Fig. 7)
Start this operation with the air in the hydraulic cylinder exhausted and valve in open or intermediate
position.
Loosen the nut (7.3) from the setting screw (7.2) and unscrew the setting screw (7.2) until it remain only a
few threads engaged on the end flange of the cylinder.
By pressurizing the cylinder, move the valve until it reach the correct setting in closed position; fix then the
valve position by screwing the setting screw (7.2) until it stops on the end part of the internal piston.
Taking care not to damage it, reinstall the sealing washer (7.4) and screw until it blocks against the surface
of the end flange; put then in place the protection washer (7.1) around the sealing washer (7.4) and block all
the system with the nut (7.3).
To avoid the risk of unsetting the setting screw (7.2) during this last operation, keep the setting screw (7.2)
blocked by using an Allen wrench engaged on the on the hexagonal receptacle.
7.2.2.2 Setting of the stopper on the spring side (Fig. 8)
Start this operation with valve in closed or intermediate position.