EN 161:2011/FprA1
(Amendment)Automatic shut-off valves for gas burners and gas appliances - Special requirements to determine performance level (PL)
Automatic shut-off valves for gas burners and gas appliances - Special requirements to determine performance level (PL)
The intention is to add a further Annex to EN 161 regarding a method for the determination of Performance Level (PL): This Annex is only applicable to valves or valve functions which are declared to comply with performance level requirements (PL) according to EN ISO 13849-1:2008, clauses 1, 2, 3, 4.1, 4.2, 4.5, 7, 8, 9, 10, 11, and annexes C.4, E, and F. This Annex specifies a set of additional requirements to EN 161 to determine the probability of dangerous failures per hour for continuous or high demand mode (PFHD) and the performance level (PL) for electromechanical valves or valve functions used in industrial and thermoprocessing applications (e. g. EN 746-2).
Automatische Absperrventile für Gasbrenner und Gasgeräte - Besondere Anforderungen an die Bestimmung der Leistungsniveaustufe (PL)
Robinets automatiques de sectionnement pour brûleurs à gaz et appareils à gaz - Exigences spéciales permettant de déterminer le niveau de performances (PL)
Samodejni zaporni ventili za plinske gorilnike in plinske aparate - Posebne zahteve za določanje nivojev delovanja (performance level PL) - Dopolnilo A1
General Information
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Standards Content (Sample)
SLOVENSKI STANDARD
SIST EN 161:2011/oprA1:2011
01-junij-2011
6DPRGHMQL]DSRUQLYHQWLOL]DSOLQVNHJRULOQLNHLQSOLQVNHDSDUDWH3RVHEQH]DKWHYH
]DGRORþDQMHQLYRMHYGHORYDQMD SHUIRUPDQFHOHYHO3/ 'RSROQLOR$
Automatic shut-off valves for gas burners and gas appliances - Special requirements to
determine the performance level (PL)
Automatische Absperrventile für Gasbrenner und Gasgeräte - Besondere Anforderungen
zur Bestimmung des Performance Levels (PL)
Ta slovenski standard je istoveten z: EN 161:2011/prA1
ICS:
23.060.20 Zapirni ventili (kroglasti in Ball and plug valves
pipe)
27.060.20 Plinski gorilniki Gas fuel burners
SIST EN 161:2011/oprA1:2011 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
SIST EN 161:2011/oprA1:2011
SIST EN 161:2011/oprA1:2011
EUROPEAN STANDARD
DRAFT
EN 161:2011
NORME EUROPÉENNE
EUROPÄISCHE NORM
prA1
April 2011
ICS 23.060.10
English Version
Automatic shut-off valves for gas burners and gas appliances -
Special requirements to determine the performance level (PL)
Automatische Absperrventile für Gasbrenner und
Gasgeräte - Besondere Anforderungen zur Bestimmung
des Performance Levels (PL)
This draft amendment is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee CEN/TC 58.
This draft amendment A1, if approved, will modify the European Standard EN 161:2011. If this draft becomes an amendment, CEN
members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for inclusion of this amendment
into the relevant national standard without any alteration.
This draft amendment was established by CEN in three official versions (English, French, German). A version in any other language made
by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has
the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland,
Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are aware and to
provide supporting documentation.
Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without notice and
shall not be referred to as a European Standard.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2011 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 161:2011/prA1:2011: E
worldwide for CEN national Members.
SIST EN 161:2011/oprA1:2011
EN 161:2011/prA1:2011 (E)
Contents Page
Foreword .3
Annex AA (normative) Method for the determination of Performance Level (PL) .6
AA.1 Scope .6
AA.2 Normative references .6
AA.3 Terms and definitions .6
AA.4 Performance .6
AA.4.1 Operation mode .6
AA.4.2 PL and field data evaluation .6
AA.4.3 Hardware failure tolerance (HFT) .6
AA.4.4 Common cause failure (CCF) .6
AA.4.5 Safe failure fraction (SFF) .7
AA.4.6 Determination of the B value .7
10d
AA.4.7 Determination of performance level (PL) .8
AA.5 Marking, installation and operating instructions .8
AA.5.1 Marking .8
AA.5.2 Installation and operating instructions .8
AA.5.3 Warning notice .8
Annex BB (informative) Model of a FMEA for valves .9
Figures
Figure BB.1 — Example of a single seated valve . 10
Tables
Table AA.1 – Scoring result of EN 13611:2007/prA1:2009 for valves . 7
Table BB.1 — Example of a FMEA for a single seated valve to determine the SFF . 11
Table BB.2 — Failure Fields . 22
Table BB.3 — Illustration of the used terms in Table BB.1 . 24
SIST EN 161:2011/oprA1:2011
EN 161:2011/prA1:2011 (E)
Foreword
This document (EN 161:2011/prA1:2011) has been prepared by Technical Committee CEN/TC 58 “Safety and
control devices for burners and appliances burning gaseous or liquid fuels”, the secretariat of which is held by
BSI.
This document is currently submitted to the CEN Enquiry.
SIST EN 161:2011/oprA1:2011
EN 161:2011/prA1:2011 (E)
Introduce the following modification to EN 161:2011:
Foreword
th
Add the following wording after 8 paragraph of EN 161:2011, Foreword:
Primarily in industrial applications it is common practice to rate the safety of a plant based on values
describing the likelihood of a dangerous failure. These values are being used to determine Safety Integrity
Levels or Performance Levels when the system is being assessed in its entirety.
CEN/TC58 standards for safety relevant controls do go beyond this approach, because for a certain life span
for which the product is specified, designed and tested a dangerous failure is not allowed at all. Failure modes
are described and assessed in greater detail. Measures to prevent from dangerous situations are defined.
Field experience over many decades is reflected in the CEN/TC 58 standards. Requirements of these
standards can be considered as proven in practice. The PL assessment in Annex AA is only applicable to
automatic shut-off valves which are already certified to this European Standard. It can not be presumed that
any Safety Integrity Level or Performance Level assessment alone would imply that requirements of a
CEN/TC 58 standard have been met.
To be able to provide parameters to allow for any formal Safety Integrity Level or Performance Level system
assessment the Annexes AA and BB of this document define a methodology to derive the relevant parameters
from the requirements of this standard.
SIST EN 161:2011/oprA1:2011
EN 161:2011/prA1:2011 (E)
Add the following normative Annex AA "Method for the determination of Performance Level (PL)" and the
normative Annex BB "Model of a FMEA for valves" after the last Annex I and before the Annex ZA of
EN 161:2011.
SIST EN 161:2011/oprA1:2011
EN 161:2011/prA1:2011 (E)
Annex AA
(normative)
Method for the determination of Performance Level (PL)
This European Standard applies with the following supplements or modifications of the corresponding clauses:
AA.1 Scope
Shall be according to Clause 1 with the following addition:
This Annex is only applicable to valves or valve functions which are declared to comply with performance level
requirements (PL) according to EN ISO 13849-1:2008, clauses 1, 2, 3, 4.1, 4.2, 4.5, 7, 8, 9, 10, 11, and
annexes C.4, E, and F.
This Annex specifies a set of additional requirements to EN 161:2011 to determine the probability of
dangerous failures per hour for continuous or high demand mode (PFH ) and the performance level (PL) for
D
electromechanical valves or valve functions used in industrial and thermoprocessing applications (e. g.
EN 746-2).
AA.2 Normative references
Shall be according to EN 13611:2007/prA2:2009, Clause K.2.
AA.3 Terms and definitions
Shall be according to EN 13611:2007/prA2:2009, Clause K.3.
AA.4 Performance
AA.4.1 Operation mode
Shall be according to EN 13611:2007/prA2:2009, K.4.1.
AA.4.2 PL and field data evaluation
Shall be according to EN 13611:2007/prA2:2009, K.4.2.
AA.4.3 Hardware failure tolerance (HFT)
For automatic valves according to this standard the hardware failure tolerance is always 0 (HFT = 0).
AA.4.4 Common cause failure (CCF)
Shall be according to EN 13611:2007/prA2:2009, K.4.4 with the following addition:
The minimum score of 65 points is fulfilled by meeting the requirements of this European Standard (see
Table AA.1).
SIST EN 161:2011/oprA1:2011
EN 161:2011/prA1:2011 (E)
Table AA.1 – Scoring result of EN 13611:2007/prA1:2009 for valves
No. Measure against CCF Score
1 Separation/segregation
Fulfilled by requirements in this standard. 15
2 Diversity
Not fulfilled by requirements in this standard. 0
3 Design/application/experience
3.1 Fulfilled by requirements in this standard. 15
3.2 Fulfilled by requirements in this standard. 5
4 Assessment/analysis
Depending on the results of the failure mode and effect analysis: 0 or 5 points. 0 or 5
5 Competence/training
Not fulfilled by requirements in this standard. 0
6 Environmental
6.1 Fulfilled by requirements in this standard. 25
6.2 Fulfilled by requirements in this standard. 10
Total (depending on FMEA) 70 or 75
AA.4.5 Safe failure fraction (SFF)
Shall be according to EN 13611:2007/prA2:2009, K.4.5 with the following addition:
For estimation of SFF a failure modes and effect analysis (FMEA) according to Annex BB, Figure BB.1 and
Table BB.1 shall be performed with classification of failures into “dangerous” or “safe”.
AA.4.6 Determination of the B value
10d
AA.4.6.1 Requirement
Shall be according to EN 13611:2007/prA2:2009, K.4.6.1 with the following addition:
The manufacturer shall determine at which intervals (e. g. every 100 000 or 200 000) during the endurance
test, as described in 7.107.2, the valve or the safety relevant sub-assemblies shall be tested to check
conformance with 7.2, 7.3, 7.9 and 7.101 to 7.104.
AA.4.6.2 Test
Shall be according to EN 13611:2007/prA2:2009, K.4.6.2 with the following addition:
SIST EN 161:2011/oprA1:2011
EN 161:2011/prA1:2011 (E)
The B value shall be carried out according to 7.107.2 of this standard. The number of operating cycles
10d
above those required to 7.107.2 shall be carried out at maximum ambient temperature, of this 20 % at worst
case ambient temperature, if not maximum ambient temperature.
The valve shall fulfil the requirements according to AA.4.6.1.
AA.4.7 Determination of performance level (PL)
Shall be according to EN 13611:2007/prA2:2009, K.4.7.
AA.5 Marking, installation and operating instructions
AA.5.1 Marking
Shall be according to 9.1.
AA.5.2 Installation and operating instructions
Shall be according to 9.2 with the following addition:
a) hardware failure tolerance HFT;
b) common cause failure CCF in points;
c) safe failure fraction SFF in %;
d) B and T values;
10d 10d
e) probability of dangerous failures per hour, PFH or λ , in 1/h, including maximum number of operating
D D
cycles n and maximum operating time for these values;
op
f) performance level PL;
g) mean time to dangerous failure MTTF in years.
D
AA.5.3 Warning notice
Shall be according to 9.3.
SIST EN 161:2011/oprA1:2011
EN 161:2011/prA1:2011 (E)
Annex BB
(informative)
Model of a FMEA for valves
A simplified example of a FMEA based on Figure BB.1 is given in Table BB.1. This example is not complete
and only shows the method to perform a FMEA.
NOTE For simplification the solenoid is not shown in the Figure BB.1.
To perform a FMEA for a single seated valve according to Table BB.1 the following is considered:
assembly and production failures are not regarded;
failure fields: design failures, random internal and external failures with possibility of influence in design;
product: automatic shut-off valve, at least safety related sub-assemblies;
safety functions to be considered:
1) safe closure through internal energy storage in case of loss of external power supply;
2) closing time requirements for safety shut down maintained;
3) internal leak-tightness maintained;
4) external leak-tightness maintained.
SIST EN 161:2011/oprA1:2011
EN 161:2011/prA1:2011 (E)
Key
1 Housing 8 Plunger guiding parts
2 Sleeve 9 Plunger travel limit
3 Housing connections 10 Connections plunger/closing spring
4 Valve seat 11 Closing spring
5 Static sealing for housing 12 Force transmission parts
...
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