SIST EN 17955:2024
(Main)Industrial valves - Functional safety of safety-related valves and actuators
Industrial valves - Functional safety of safety-related valves and actuators
This standard defines procedures and methods with which all relevant mechanical components of automated industrial valve packages that are used as final elements in a safety instrumented system can be evaluated according to the rules of EN 61508 Parts 1, 2, 4, 6 and 7 in order to integrate them into a safety instrumented system (SIS). It provides a method to determine all relevant factors, associated with the product, to be fully taken into account and thereby meet the specific needs of users of the product.
The basic prerequisite for the application of this standard is that the intended use is known. This standard describes a system to avoid systematic faults conforming to the targeted Safety Integrity Level.
The standard applies to automated industrial valve packages that are used as final elements in a safety instrumented system. It can be applied to single components (e.g. valve, actuator or mechanical parts of solenoid valves) or to assemblies of several of these components and interconnecting parts (e.g. gears, adaptors, brackets, etc.). Electrical, electronic or programmable electronic parts have to be assessed according to EN 61508.
This standard does not apply to:
• Manually operated valves,
• Components in safety systems or risk-reducing devices that are not assessed and operated according to the principles of functional safety. (E.g. automatic safety valves like pressure relief valves).
The methods described can also be used for other mechanical components in a final element of the safety instrumented system if the applicability is confirmed by appropriate expert knowledge. (E.g dampers, brakes, clutches, …).
Industrieamaturen - Funktionale Sicherheit sicherheitsbezogener Industriearmaturen und Antriebe
Dieses Dokument legt die Anforderungen für die Bewertung konformer mechanischer Objekte in einem Stellglied nach den Grundsätzen von EN 61508 für ihre Integration in ein sicherheitsbezogenes System fest. Es bietet ein Verfahren zur Bestimmung aller relevanten Faktoren, die mit dem Produkt in Verbindung stehen, um so den spezifischen Bedürfnissen der Anwender des Produkts gerecht zu werden.
Die grundlegende Voraussetzung für die Anwendung dieses Dokuments ist die Kenntnis der bestimmungsgemäßen Verwendung. Dieses Dokument beschreibt ein System zur Minimierung von systematischen Fehlern, um den angestrebten Sicherheits-Integritätslevel (SIL) zu erreichen.
Dieses Dokument wird auf einzelne konforme Objekte (z. B. Armatur, Aktor oder mechanische Teile von Magnetschaltern) oder auf Baugruppen aus mehreren dieser konformen Objekte und konformen Verbindungsobjekten (z. B. Getriebe, Adapter, Halterungen) angewendet. Elektrische, elektronische oder programmierbare elektronische Bauteile werden nach EN 61508 bewertet.
Dieses Dokument gilt nicht für:
- handbetätigte Armaturen;
- Objekte in Sicherheitssystemen oder risikomindernde Einrichtungen, die nicht nach den Grundsätzen der funktionalen Sicherheit bewertet und betrieben werden (z. B. automatische Sicherheitsventile wie Druckbegrenzungsventile).
Die beschriebenen Verfahren können auch für andere konforme mechanische Objekte in einem Stellglied des sicherheitsbezogenen Systems verwendet werden, wenn die Anwendbarkeit durch entsprechendes Fachwissen bestätigt wird (z. B. Dämpfer, Bremsen, Kupplungen).
Robinetterie industrielle - Sécurité fonctionnelle des appareils de robinetterie et actionneurs liés à la sécurité
Le présent document définit les exigences relatives à la manière dont les articles conformes mécaniques d’un élément final peuvent être évalués conformément aux principes de l’EN 61508 afin de les intégrer dans un système relatif à la sécurité. Il fournit une méthode pour déterminer tous les facteurs pertinents, associés au produit, et répond ainsi aux besoins spécifiques des utilisateurs du produit.
La condition préalable basique pour l’application du présent document est que l’utilisation prévue soit connue. Le présent document décrit un système permettant de minimiser les anomalies systématiques afin d’atteindre le niveau d’intégrité de sécurité ciblé (SIL).
Le présent document s’applique à des articles individuels conformes (par exemple, appareil de robinetterie, actionneur ou parties mécaniques des électrovannes) ou à des assemblages de plusieurs de ces articles conformes d’interconnexion et des composants (par exemple, engrenages, adaptateurs, supports, etc.). Les composants électriques, électroniques ou électroniques programmables sont évalués conformément à l’EN 61508.
Le présent document ne s’applique pas aux :
- appareils de robinetterie à commande manuelle ;
- articles des systèmes de sécurité ou des dispositifs de réduction des risques qui ne sont pas évalués et exploités conformément aux principes de la sécurité fonctionnelle (par exemple, soupapes de sécurité automatiques telles que les soupapes de décharge).
Les méthodes décrites peuvent également être appliquées à d’autres articles conformes mécaniques appartenant à un élément final du système relatif à la sécurité, si l’applicabilité est confirmée par une expertise adéquate (par exemple, amortissements, freins, embrayages).
Industrijski ventili - Funkcionalna varnost varnostnih ventilov in pogonov
General Information
Standards Content (Sample)
SLOVENSKI STANDARD
01-oktober-2024
Industrijski ventili - Funkcionalna varnost varnostnih ventilov in pogonov
Industrial valves - Functional safety of safety-related valves and actuators
Industrieamaturen - Funktionale Sicherheit sicherheitsbezogener Industriearmaturen und
Antriebe
Robinetterie industrielle - Sécurité fonctionnelle des appareils de robinetterie et
actionneurs liés à la sécurité
Ta slovenski standard je istoveten z: EN 17955:2024
ICS:
23.060.01 Ventili na splošno Valves in general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EN 17955
EUROPEAN STANDARD
NORME EUROPÉENNE
August 2024
EUROPÄISCHE NORM
ICS 23.060.01
English Version
Industrial valves - Functional safety of safety-related
automated valves
Robinetterie industrielle - Sécurité fonctionnelle des Industriearmaturen - Funktionale Sicherheit
appareils de robinetterie automatisés assurant une sicherheitsbezogener automatisierter
fonction de sécurité Industriearmaturen
This European Standard was approved by CEN on 7 July 2024.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists 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, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2024 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 17955:2024 E
worldwide for CEN national Members.
Contents Page
European foreword . 4
Introduction . 5
1 Scope . 6
2 Normative references . 6
3 Terms, definitions and abbreviations . 7
4 Relationship and conformity with EN 61508-1, −2, −4, −6 and −7. 12
5 Basic requirements for development and production . 14
5.1 Evaluation of systematic capability . 14
5.2 Documentation management . 14
5.3 Functional safety management . 14
5.4 Safety lifecycle requirements for development and production of safety-related automated
industrial valves . 14
5.4.1 Objectives and requirements . 14
5.4.2 Mechanical requirements specification . 19
5.4.3 Mechanical validation planning . 20
5.4.4 Mechanical design and development. 21
5.4.5 Mechanical system integration . 23
5.4.6 Mechanical system installation, commissioning, operation and maintenance procedures
............................................................................................................................................................................. 24
5.4.7 Mechanical system safety validation . 26
5.4.8 Production . 26
5.4.9 Modification of compliant items . 27
5.5 Verification . 28
5.5.1 Objective . 28
5.5.2 Requirements . 28
5.6 Functional safety assessment . 30
5.6.1 Objective . 30
5.6.2 Requirements . 30
6 Classification of the compliant item . 30
6.1 Demand mode and utilization rate . 30
6.2 Type of final element/compliant item . 33
7 Field failure data . 33
7.1 Field failure data analysis procedure . 33
7.2 Use of field failure data for pre-existing compliant items . 34
8 Qualification testing . 34
8.1 General. 34
8.2 Test planning/test conditions . 34
8.3 Pre-conditioning of test samples . 35
8.4 Cycle testing and B values . 35
10D
8.5 Environmental testing . 35
9 Determination of failure rates . 35
10 Operational testing, maintenance and time restrictions . 36
10.1 Online diagnostic tests . 36
10.2 Proof test. 36
10.3 Proof test coverage (PTC) . 36
10.4 Maintenance . 37
10.5 Useful lifetime . 37
10.6 Storage time . 37
11 Safety manual in addition to an installation, operation, and maintenance manual . 37
Annex A (normative) Techniques and measures to avoid and control systematic failures . 39
Annex B (normative) List of failure rates for common compliant items . 46
Annex C (normative) FME(D)A to identify and evaluate the effects of different failure modes . 49
C.1 FME(D)A . 49
C.2 Input information to carry out an FME(D)A. 49
C.3 FME(D)A procedure . 49
C.4 FMEDA example . 52
C.5 List of functional units and their failure rates with a low utilization rate (LUR) . 54
C.6 List of functional units and their failure rates with a high utilization rate (HUR) . 56
Annex D (informative) Safety manual . 58
Annex E (informative) Examples for the evaluation of the mechanical design . 60
E.1 General . 60
E.2 Examples . 60
E.2.1 Bolting connections . 60
E.2.2 Force-locked connections . 61
E.2.3 Form-locked connections (structural component strength) . 62
E.2.4 Springs . 62
E.2.5 Bearings . 62
E.2.6 Gears and force transmission linkages . 63
Annex F (informative) Estimation of random failure rates with Bayesian integration between
“basic” failure rates and field feedback . 64
F.1 General . 64
F.2 Procedure . 64
F.3 Formula . 65
F.3.1 General . 65
F.3.2 Estimation of the verisimilitude factor V . 66
Bibliography . 68
European foreword
This document (EN 17955:2024) has been prepared by Technical Committee CEN/TC 69 “Industrial
valves”, the secretariat of which is held by AFNOR.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by February 2024, and conflicting national standards shall
be withdrawn at the latest by February 2024.
Attention is drawn to the possibility that some of the e
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