Samson 3241 User manual

Competence in Functional Safety
Functional safety of globe
valves, rotary plug valves, ball valves and butterfly valves
MANUAL
SMART IN FLOW CONTROL.

2
Competence in Functional Safety
Functional safety of globe valves, rotary plug valves, ball valves and butterfly valves
SAMSON
AIR TORQUE · CERA SYSTEM · KT-ELEKTRONIK · LEUSCH
PFEIFFER · RINGO · SAMSOMATIC · STARLINE · VETEC
Founded in 1907, SAMSON has since become a worldwide
leader in the manufacture of expertly engineered control
valves.
SAMSON has over 50 subsidiaries, amongst them noted
manufacturers of special valves.
With these subsidiaries, SAMSON is represented in over
80 countries to assist its customers on all continents.

3
Competence in Functional Safety
Functional safety of globe valves, rotary plug valves, ball valves and butterfly valves
Table of contents
1 Scope ...............................................................................................................................................................4
2 Validity of this manual ........................................................................................................................................4
3 Intended use of this manual.................................................................................................................................5
4 General aspects of functional safety.....................................................................................................................6
4.1 Standards, terms and abbreviations .............................................................................................................6
4.2 Determining the safety integrity level ............................................................................................................8
4.3 Hardware fault tolerance ............................................................................................................................9
5 Intended use of control valves in safety-instrumented systems................................................................................10
5.1 General control valve requirements............................................................................................................12
5.2 Globe valve requirements.......................................................................................................................... 13
5.3 Ball valve requirements .............................................................................................................................15
5.4 Butterfly valve requirements.......................................................................................................................16
5.5 Rotary plug valve requirements..................................................................................................................18
5.6 Proof tests and service life .........................................................................................................................18
6 Installation, piping and wiring ...........................................................................................................................19
6.1 Mechanical and pneumatic installation.......................................................................................................19
6.2 Electrical installation .................................................................................................................................20
6.3 Installation of control valves.......................................................................................................................20
7 Applicable device documentation ......................................................................................................................22
8 Appendix 1 – Manufacturer‘s declarations .........................................................................................................22
9 Appendix 2 − Example of a checklist for a final element......................................................................................30

4
Competence in Functional Safety
Functional safety of globe valves, rotary plug valves, ball valves and butterfly valves
1 Scope
Valves and the associated actuators are used to isolate pipelines in safety-instrumented systems. Alternatively, they can
also be used for pressure relief, i.e. by completely opening valves.
2 Validity of this manual
This manual applies to control valves manufactured by the following companies within SAMSON:
 SAMSON AG
 LEUSCH GmbH Industriearmaturen
 PFEIFFER Chemie-Armaturenbau GmbH
 VETEC Ventiltechnik GmbH
Refer to the manufacturer‘s declarations in Appendix 1 of this manual for the valve models concerned.
The individual versions of the valves can be identified by their nameplates
10 EB 8310-7 EN
Markings on the device
2 Markings on the device
2.1 Actuator nameplate
The nameplate is stuck on the diaphragm casing. It includes all details required to identify the
actuator:
2 Conguration ID
3 Serial number
4 Actuator area
5 Bench range in bar
6 Bench range in psi
7 Operating travel in mm
8 Operating range in bar
9 Operating range in psi
10 Permissible supply pressure pmax in bar
11 Permissible supply pressure pmax in psi
12 Symbol indicating fail‑safe action
Actuator stem extends (FA)
Actuator stem retracts (FE)
Manual override
14 Connecting thread
15 Diaphragm material
16 Date of manufacture
7
4
14
15 12 6
5
8
9
10 11
SAMSON 3271
Made in Germany
Var-ID
3
2
Serial no.
16
Fig.1: Nameplate
Example of a nameplate for a Type 3241
Valve with Type 3271 or Type 3277 Pneumatic
Actuator manufactured by SAMSON AG
12 EB 8015 EN
Markings on the control valve
2 Markings on the control valve
2.1 Valve nameplate
6 8
12 13
10 11
14 15 16 17 18
1…5 9
SAMSON
20
21
19
Fig.1: Valve nameplate
1…5 PED (Pressure Equipment Directive), "Art. 4, Abs. 3"
ID of the notied body, uid group, and category
6 Type designation
8Material
9Year of manufacture
10 Valve size:
DIN: DN · ANSI: NPS· JIS: DN…A/B
11 Pressure rating:
DIN: PN · ANSI: CL · JIS: K
12 Order no. with modication index
For after-sales service orders: AA prex
13 Position in order
For after-sales service orders: conguration ID
14 Flow coefcient:
DIN: KVS · ANSI: CV · JIS: CV
15 Characteristic:
%: equal percentage · Lin: linear · NO/NC: quick opening
16 Seat/plug seal:
ME: metal (see section3.3)
HA: carbide metal
ST: Stellite® facing
KE: ceramic
PT: soft seal with PTFE
PK: soft seal with PEEK
17 Seat code (trim material) · On request
18 Pressure balancing:
DIN: D · ANSI: B · JIS: B
19 Flow divider:
1: StI · 3: StIII
20 Country of origin
21 PSA version

5
Competence in Functional Safety
Functional safety of globe valves, rotary plug valves, ball valves and butterfly valves
3 Intended use of this manual
This manual is intended to assist planners and operators during the integration of control valves into a safety loop as
part of the safety function and to enable them to safely operate control valves.
This manual contains information, safety-related data and warnings concerning the functional safety in accordance
with IEC 61508 and concerning the application in the process industry in accordance with IEC 61511. It does not con-
tain any particular details on other safety requirements, such as explosion protection or electrical safety.
Safety-instrumented systems are to be commissioned and maintained by qualified personnel only. Refer to the corre-
sponding mounting and operating instructions of the valve.

6
Competence in Functional Safety
Functional safety of globe valves, rotary plug valves, ball valves and butterfly valves
4 General aspects of functional safety
4.1 Standards, terms and abbreviations
Abbreviation Designation Description
SIL Safety Integrity Level One of four discrete levels for specifying the safety integrity requirements
of the safety functions to be allocated to the E/E/PE safety-related systems,
where SIL 4 has the highest level of safety integrity and SIL 1 has the lowest.
MTBF Mean Time Between Failures Mean time between two failures
MTTR Mean Time To Restoration Mean time between the occurrence of a failure in a device or system and its
repair
HFT Hardware Fault Tolerance Capability of a functional unit to continue executing the demanded function
in case of faults or deviations.
λsd Failure rate for all safe detected
failures
λsu Failure rate for all safe undetected failures
λdd Failure rate for all dangerous detected failures
λdu Failure rate for all dangerous undetected
failures
SFF Safe Failure Fraction Fraction of non-hazardous failures, i.e. the fraction of failures without the
potential to set the safety-related system to a dangerous or impermissible
state.
PFDavg Average Probability of Failure on
Demand
Average likelihood that a dangerous safety function failures occurs on
demand.
TITest Interval between life testing of the safety
function
Average likelihood that a dangerous safety function failures occurs on
demand.
Low demand
mode
Low demand mode of operation Low demand mode is where the frequency of demands for operation made
on a safety-related system is no greater than one per year and no greater
than twice the proof test frequency.

7
Competence in Functional Safety
Functional safety of globe valves, rotary plug valves, ball valves and butterfly valves
Abbreviation Designation Description
MooN Voting “M out of N“ (e. g. 2oo3) Classification and description of the safety-related system regarding redun-
dancy and the selection procedure used.
• “N“ indicates how often the safety function is carried out (redundancy).
• “M“ determines how many channels must work properly.
Example: Pressure measurement in 1oo2 architecture
A safety-instrumented system decides that a specified pressure limit has
been exceeded if one of two pressure sensors reaches this limit. In a 1oo1
architecture, there is only one pressure sensor.
MooND Voting “M out of N“ with diagnostics
Relevant standards
Norm Designation
IEC 61508
Parts 1 to 7
Functional safety of electrical/electronic/pro-
grammable electronic safety-related systems
IEC 61511
Parts 1 to 3
Functional safety – Safety instrumented systems
for the process industry sector
VDI 2180
Parts 1 to 5
Safeguarding of industrial process plants by
means of process control engineering
Terms and definitions
Term Definition
Dangerous failure Failure with the potential to set the safety-related system to a dangerous or inoperative state.
Safety-related system A safety-related system carries out the safety functions needed to establish or maintain a safe state,
e.g. in a plant.
Example: Pressure measuring instrument, logic unit (e.g. limit switch) and valve form a safety-related system.
Safety function A defined function carried out by a safety-related system in order to establish or maintain a safe state of
the plant, under consideration of a specified dangerous incident.
Example: Pressure limit monitoring

8
Competence in Functional Safety
Functional safety of globe valves, rotary plug valves, ball valves and butterfly valves
4.2 Determining the safety integrity level
The achievable safety integrity level (SIL) is determined by the following safety-related data:
 Average probability of failure on demand (PFDavg)
 Hardware fault tolerance (HFT)
 Safe failure fraction (SFF)
The following table in accordance with IEC 61508 and IEC 61511 shows how the safety integrity level (SIL)
depends on the average probability of failure on demand (PFDavg). It is based on low demand mode of
operation, i.e. the frequency of demands on a safety-related system is no greater than once per year.
Safety integrity level (SIL) PFDavg (low demand mode)
4≥10-5 to <10-4
3≥10-4 to <10-3
2≥10-3 to <10-2
1≥10-2 to <10-1
PFDavg in low demand mode of operation according to IEC 61508-1, Table 2
The sensor, logic unit and final element form a safety-related system that performs a safety function.
Sensor
e.g. pressure
measuring instrument
PFDavg ≤X % ≤X % ≤X %
Logic unit
e.g. PLC
Final element
e.g. valve
The average probability of failure on demand (PFDavg = sum of sensor, logic unit and final element failures) must be within
the range of the demanded safety integrity level (SIL) in case of demand as listed in the above table.

9
Competence in Functional Safety
Functional safety of globe valves, rotary plug valves, ball valves and butterfly valves
4.3 Hardware fault tolerance
In the process industry, the achievable SIL classes for sensors, final elements and non-programmable logic modules,
such as isolating amplifiers and relays, are restricted in accordance with IEC 61511 as shown in the following table.
Safety integrity level (SIL) Minimum required hardware failure tolerance (HFT)
1 0
2 1
3 2
4 Special requirements (refer to IEC 61508)
Minimum required hardware failure tolerance (HFT) according to IEC 61511-1, Table 6, for the process industry
The minimum required hardware failure tolerance can be decreased by one if the following requirements are met:
 The device is proven in use.
Take this into account when selecting devices!
 The device only allows process-relevant parameters to be set, e.g. measuring range, upscale or downscale function
in case of failure.
Final elements do not have any configurable functions.
 The process-relevant parameters of the device are access-protected, e.g. by jumper or password.
Final elements do not have any configurable functions.
 The function requires a SIL less than 4.
A final element has a single-channel design, resulting in a hardware failure tolerance (HFT) = 0. This results in a single-
channel application up to SIL 1 or up to SIL 2 for proven-in-use devices.
At least two redundant devices are required for SIL 3 with proven-in-use devices.
At least three redundant devices are required for SIL 3 without proven-in-use devices.

10
Competence in Functional Safety
Functional safety of globe valves, rotary plug valves, ball valves and butterfly valves
5 Intended use of control valves in
safety-instrumented systems
Responsibility
The reliability of mechanical components is significantly affected by the operating condi-
tions and, as a result, by systematic failures. This needs to be taken into account when
selecting and sizing devices.
Safety-instrumented function
During normal operation, the signal pressure is applied to the pneumatic actuator. To
meet the requirements of the safety-instrumented function, the actuator is usually vented
by a solenoid valve. The force of the actuator springs moves the valve to its end position,
i.e. the valve is either completely opened or closed.
The end position of the valve must not be impeded by mechanical equip-
ment, such as travel stops or handwheels, under any circumstances.
When the signal pressure is applied to the actuator again, the valve moves to the corre-
sponding position. If the actuator is to be locked after a case of demand, this must be
ensured by the operator using suitable means.
Operator
Features of final elements
 Contact with the process media may cause systematic failure and, as a result, affect the
safety-related availability of the safety-instrumented systems. The influence of specific
process conditions must be analyzed and taken into account during sizing and main-
tenance.
These conditions arise from process requirements. To rule out systematic failure, we re-
commend creating a loop data sheet according to the German standard VDI 2180-5,
section 4 (recommendations for final elements).
In case of doubt, consult the manufacturer for valve sizing.
To reduce systematic failure, diverse redundancies may be advantageous (e.g. globe
valve and ball valve).
Operator

11
Competence in Functional Safety
Functional safety of globe valves, rotary plug valves, ball valves and butterfly valves
Responsibility
 The joint use of a control valve within the safety loop by a control loop of a basic
process control system makes it possible to increase the diagnostic coverage of the
safety-instrumented system. This joint use can lead to additional risk. This aspect must
be taken into account in the risk analysis.
 Online tests, such as the partial stroke test and other diagnostic processes integrated
into the valve positioner, can be regarded as state-of-the-art test methods. They can
be used to lengthen the proof test interval or to improve the safety margin (discovery
of undetected systematic failures).
VDI 2180-5, section 4 provides special instructions.
Avoiding systematic failure
To avoid systematic failure, the user must take into account the following application-
specific factors besides the manufacturer specifications:
 Corrosion (destruction primarily of metals due to chemical and physical processes)
 Material fatigue, e.g. in bellows seals
 Wear induced by the process medium
 Abrasion (material removed by solids contained in the process medium)
 Medium deposits
 Aging (damage caused to organic materials, e.g. plastics or elastomers, by exposure
to light and heat)
 Chemical attack (organic materials, e.g. plastics or elastomers, which swell, leach out
or decompose due to exposure to chemicals)
If no experience data exist for the devices used, a visual inspection of the safety equip-
ment must be performed after a short time in operation.
Operator

12
Competence in Functional Safety
Functional safety of globe valves, rotary plug valves, ball valves and butterfly valves
5.1 General control valve requirements Responsibility
For each application, the user must specify the following conditions:
 Maximum/minimum transit time OPEN CLOSED or CLOSED OPEN
 Permissible leakage rate
 Maximum/minimum supply pressure of the compressed air network
 Air capacity available in relation to pressure
Connecting pipe cross-sections must be adhered to.
Operator
Nominal size (connection length ≤2 m)
KVS coefficient
0.16 · 0.32 1.4 4.3 –
Connection
Pressure (bar) 4 1 and 3 4 9
≥ 1.4 ≥ DN 6 ≥ DN 8 ≥ DN 10
≥ DN 4≥ 2.5 ≥ DN 4 ≥ DN 6 ≥ DN 8
≥ 6≥ DN 4 ≥ DN 6
Note: A larger nominal size is needed when the connection length exceeds 2 m. 
Example: Connecting pipe cross-sections required for SAMSOMATIC Type 3963 Solenoid Valve
Manufacturer
SAMSON uses calculation methods to predict the transit time and to size the pneumatic
hook-up. SAMSON can support users in selecting devices on request.
The seat shut-off performance (leakage rate) must be tested at regular intervals by
 performing plausibility checks while the process is running or
 measuring it on a leakage test bench.
The type of test depends on the application.
The external leakage (fugitive emissions) must be tested at regular intervals, e.g. by spray-
ing with foaming agent.
The conditions depend on the process requirements.
Manufacturer
Operator

13
Competence in Functional Safety
Functional safety of globe valves, rotary plug valves, ball valves and butterfly valves
5.2 Globe valve requirements Responsibility
 If there is a risk of solids contained in the process medium causing blockage,
a strainer must be fitted.
Safety equipment with fail-open action must not be operated with
strainers.
 To reduce friction, it is preferable to use spring-loaded stem packings. Adjustable stem
packings are to be tightened by qualified staff only to prevent the stem from beco-
ming blocked.
 To prevent corrosion of the actuator springs, measures must be taken to prevent water
or moisture from entering the actuator. Such measures include fitting a venting pipe or
air purging of the actuator‘s spring chamber.
Operator
Operator

Example:
Control and quick-acting shut-off valve with air purging of the
actuator‘s spring chamber
Example:
On-off valve with air purging of the actuator‘s spring chamber
 Suitable measures must be taken to ensure that the venting port of the solenoid valve
is kept open.
Example: Venting pipe on the solenoid valve
Manufacturer/
operator

14
Competence in Functional Safety
Functional safety of globe valves, rotary plug valves, ball valves and butterfly valves
Responsibility
 It is essential to check the actuator forces to ensure that the valve can overcome
the process pressures to reach its fail-safe position.
This can be checked by the manufacturer if requested.
 The actual actuator forces must not close the valve against a pressure which is 1.5
times above the nominal pressure (PN) of the plant or valve.
If this actuator force restriction cannot be implemented, an excess pressure valve is
necessary for valves connected in series to prevent that the permissible operating
pressure is exceeded.
Manufacturer/
operator
Example: Valves connected in series
 It is essential to observe the prescribed direction of flow (arrow on the valve body) of
globe valves.
Operator

15
Competence in Functional Safety
Functional safety of globe valves, rotary plug valves, ball valves and butterfly valves
5.3 Ball valve requirements Responsibility
 Note for ball valves that higher initial breakaway torques arise as the differential pressure
of the process medium rises, requiring higher actuator torques.
Manufacturer
Differential pressure ∆p (bar) 03610 16 40
DN Mdmax
(Nm) Md(Nm) Mdl (Nm)
15 60 3 5558911
25 240 510 10 10 14 18 28
40 450 10 20 20 20 26 35 52
50 450 15 30 30 33 36 42 73
80 750 25 60 60 66 72 86 144
100 750 40 90 90 105 120 140 251
150 3160 60 120 120 160 210 290 450
Max. permissible torque, required torques and initial breakaway torques
Example: Torque specifications for a ball valve
 Media, especially degreasing, swelling and fibrous media, may affect the torque.
 The operating conditions, e.g. switching interval and the medium temperature, have
an effect on the torques.
 The mounting of the valve and actuator is of vital importance.
 The permissible torques for the ball valve shaft, shaft adapter and bridge have been
verified by the manufacturer. As a result, the max. torque of the actuator (air or spring
torque) must not exceed these torques under any circumstances.
The corresponding specifications in accordance with DIN EN ISO 5211/DIN EN 15081
(NAMUR Recommendation NE 14) must be observed
Operator
Manufacturer
Flange type F03 F04 F05 F07 F10 F12 F14 F16 F25 F30 F35 F40 F48 F60
Maximum torque of the
attachment flanges (Nm) 32 63 125 250 500 1000 2000 4000 8000 16000 32000 63000 125000 250000
Maximum torque of the attachment flanges according to DIN EN ISO 5211

16
Competence in Functional Safety
Functional safety of globe valves, rotary plug valves, ball valves and butterfly valves
5.4 Butterfly valve requirements Responsibility
 On sizing actuators for butterfly valves, note that the actuator must provide suf-
ficient torque to overcome the breakaway torque and closing torque in closed
position as well as the dynamic torque in open position.
 On mounting the actuator on the butterfly valve, the breakaway torque of the but-
terfly valve in relation to the differential pressure and the permissible torque of the
butterfly valve shaft must be observed.
Manufacturer
Nominal size Perm. torque
Mdmax (Nm)
Perm. torque Mdl in Nm at a differential pressure
∆p (bar)
DN NPS 0 bar 5 bar 10 bar 16 bar
80 3280 40 43 45 51
100 4280 48 54 59 67
150 6505 91 106 114 157
200 8785 190 219 269 288
250 10 785 320 364 433 480
300 12 1591 370 467 578 654
400 16 3215 690 903 1089 1239
Example: Required manufacturer specifications
 Note that high dynamic torques can arise at high differential pressures in the process
medium, pushing open the butterfly disc.
Operator
Dynamic torque of butterfly valves in relation to the opening angle

17
Competence in Functional Safety
Functional safety of globe valves, rotary plug valves, ball valves and butterfly valves
Responsibility
 Media, especially degreasing, swelling and fibrous media, may affect the torque.
 The operating conditions, e.g. switching interval and the medium temperature, have
an effect on the torques.
 The mounting of the valve and actuator is of vital importance.
 The permissible torques for the butterfly valve shaft, shaft adapter and bridge have
been verified by the manufacturer. As a result, the max. torque of the actuator (air
or spring torque) must not exceed these torques under any circumstances.
The corresponding specifications in accordance with DIN EN ISO 5211/DIN EN 15081
(NAMUR Recommendation NE 14) must be observed. See section 5.3 on ball valve
requirements.
Operator
Manufacturer

18
Competence in Functional Safety
Functional safety of globe valves, rotary plug valves, ball valves and butterfly valves
5.5 Rotary plug valve requirements Responsibility
 On sizing actuators, note that the actuator must provide sufficient torque to over-
come the closing torque in closed position as well as the dynamic torque in open
position.
 Adjustable stem packings are to be tightened by qualified staff only to prevent the
stem from becoming blocked.
 To prevent corrosion of the actuator springs, measures must be taken to prevent water
or moisture from entering the actuator. Such measures include fitting a venting pipe
or air purging of the actuator‘s spring chamber.
 The proper mounting of the valve onto the actuator is of vital importance.
 The permissible torques for the valve shaft, shaft adapter and bridge have been
verified by the manufacturer. As a result, the max. torque of the actuator (air or
spring torque) must not exceed these torques under any circumstances.
The corresponding specifications in accordance with DIN EN ISO 5211/DIN EN 15081
(NAMUR Recommendation NE 14) must be observed. See section 5.3 on ball valve
requirements.
Operator
Manufacturer
5.6 Proof tests and service life
 The proof test interval and the extent of the test lie within the operator‘s responsibility.
This must be documented correspondingly.
 During the proof test, suitable means must be used to test the control valve to ensure
its proper functioning. Worn components must be replaced by original spare
parts from the manufacturer.
 The maximum service life must be specified.
 It is recommended to summarize the requirements of the proof test in a checklist.
Refer to Appendix 2 for an example.
Operator

19
Competence in Functional Safety
Functional safety of globe valves, rotary plug valves, ball valves and butterfly valves
6 Installation, piping and wiring Responsibility
6.1 Mechanical and pneumatic installation
 During mechanical and pneumatic installation, the mounting and operating instructions
of the corresponding device must be observed.
The pneumatic connection must only be connected to instrument air networks that meet
the quality requirements in accordance with ISO 8573-1:2001, Class 3 or 4.
Operator
Compressed air quality according to ISO 8573-1
Particle size and quantity Oil content Pressure dew point
Class 4 Class 3 Class 3
≤ 5 μm and 1000/m³ ≤ 1 mg/m³ –20 °C or at least 10 K below the lowest ambient tem-
perature to be expected
 The required minimum cross-sections of the supply air lines must be observed. Refer to
section 5.1 (General control valve requirements).
After mounting, the position of the filters or filter check valves on the valve accessories,
e.g. pilot valves, must be checked and, if necessary, corrected.
Example: Pilot-controlled Ex i solenoid valve (SAMSOMATIC)
 The prescribed mounting position of the devices must be observed.
 Booster valve ports not connected by pipe or hose must be protected properly against
dirt, water etc. from entering the device by using appropriate filters.
Operator

20
Competence in Functional Safety
Functional safety of globe valves, rotary plug valves, ball valves and butterfly valves
6.2 Electrical installation Responsibility
 Only cables with the prescribed outer diameter of the cable glands may be used.
 For EExi circuits the electrical cable data must comply with the data taken as
the basis during planning.
 Cable glands and cover screws must be fastened tightly to ensure that the degree of
protection is met.
 Only devices with suitable equipotential bonding may be connected.
 The installation regulations for the respective explosion protection measures must be
observed.
 Prior to start-up, the voltage must be checked to ensure that it meets the permissible
range.
 Prior to start-up, the necessary verifications (verification of intrinsic safety) must be
available.
 The effect of disturbances to lines must be checked, especially
– disturbance caused by EMC influences and
– disturbance caused by capacitance influences when long lines are used (risk that
a solenoid valve remains energized).
 The special conditions specified in the explosion protection certificates must be
adhered to.
Operator
6.3 Installation of control valves
 Control valves must be installed free of stress and with low degrees of vibration.
 After installation, the flange joints must be checked for leaks.
 The pipeline must be rinsed prior to installing the control valve.
Operator