EN 14382:2002

Safety devices for gas pressure regulating stations and installations - Gas safety shut-off devices for inlet pressures up to 100 bar

This European Standard specifies constructional, functional, sizing, and testing requirements, also documentation and marking of gas safety shut-off devices:
¾ for operating pressures up to 100 bar and nominal diameters up to DN 400;
¾ used at an operating temperature range from -20 °C to +60 °C which operate with fuel gases of the 1st and 2nd family according to EN 437 in transmission and distribution networks and industrial installations.
For operating pressures higher than 100 bar or nominal diameters DN > 400 or operating temperatures outside the range -20 °C to 60 °C, this standard can be considered as a guideline.
Gas safety shut-off devices will hereafter be called SSDs except in titles.
This European Standard considers the following classes of SSD:
a) Temperature classes:
¾ class 1: operating temperature range from -10 °C to 60 °C;
¾ class 2: operating temperature range from -20 °C to 60 °C.
b) Functional classes:
¾ class A: SSDs that close when damage to the pressure sensing element occurs (applicable to overpressure SSDs only) or when external power fails;
¾ class B: SSDs that do not close when damage to the pressure sensing element occurs or are able to be opened automatically by the pressure control system (applicable to overpressure SSDs only).

Sicherheitseinrichtungen für Gas-Druckregelanlagen und -einrichtungen - Sicherheitsabsperreinrichtungen für Betriebsdrücke bis 100 bar

Diese Europäische Norm legt Bauanforderungen, Funktionsanforderungen, Dimensionierung, Prüfung, Dokumen-tation und Kennzeichnung von Gas- Sicherheitsabsperreinrichtungen fest für:
   Eingangsdrücke bis 100 bar und Nennweiten bis DN 400
   Betriebstemperaturen von   20 *C bis + 60 *C, soweit sie mit Brenngasen der 1. und 2. Familie nach EN 437 in Gasversorgungsnetzen wie auch in gewerblichen und industriellen Anlagen betrieben werden.
Für Eingangsdrücke über 100 bar und/oder DN   400 und/oder  Betriebstemperaturen außerhalb des Bereiches       20 *C bis 60 °C kann diese Europäische Norm als Leitfaden herangezogen werden.
"Gas-Sicherheitsabsperreinrichtung" wird im weiteren, außer in Überschriften, mit "SAE" abgekürzt.
Diese Europäische Norm behandelt die folgenden Klassen von SAEs:
a)   Temperaturklassen:
   Klasse 1: Betriebstemperaturbereich von   10 *C bis 60 *C;
   Klasse 2: Betriebstemperaturbereich von   20 *C bis 60 *C.
b)   Funktionsklassen:
   Klasse A: Schließen bei Schaden an der Vergleichmembran (nur bei Überdruckabsicherung) oder im Falle eines Ausfalls der externen Energiequelle;
   Klasse B: kein Schließen bei Schaden an der Vergleichmembran bzw. mögliches automatisches    Öffnen durch die Druckregelung (nur bei Überdruckabsicherung für SAEs).
ANMERKUNG 1   Einige Länder oder Vertreiber können die Verwendung einiger der o.g. Klassen einschränken.
ANMERKUNG 2   SAEs, die die Anforderungen dieser norm erfüllen, können als "in Übereinstimmung mit EN..." deklariert werden.
Die Anforderungen dieser Norm hinsichtlich Werkstoffe und Funktionsverhalten können auf SAEs angewendet werden, die thermische oder elektrische Energie für den Auslösevorgang verwenden. Die Betriebsparameter des Auslösevorgangs solcher SAEs werden nicht in dieser Norm festgelegt. Dieser Entwurf einer europäischen Norm gilt nicht für:
   SAEs vor/an/in Gasgeräte des Haushalts, die hinter Hausgaszählern installiert sind.
   SAEs zum Einbau in die Regelstrecken in Übereinstimmung mit EN 12279

Dispositifs de sécurité pour postes et installations de détente-régulation de pression de gaz - Clapets de sécurité pour pressions de service jusqu' à 100 bar

La présente Norme européenne spécifie les exigences relatives à la construction et au fonctionnement, le dimensionnement, les essais, la documentation et le marquage des clapets de sécurité :
   pour des pressions amont jusqu'à 100 bar et diamètres nominaux jusqu'à DN 400 ;
   utilisés sur une plage de température de service de - 20 °C à + 60 °C, et fonctionnant avec des gaz combustibles de la première et de la deuxième famille conformément à l'EN 437 dans les réseaux de transport et de distribution ainsi que dans les installations industrielles.
Pour des pressions amont supérieures à 100 bar ou des diamètres nominaux DN > 400 ou des températures de service extérieures à la plage   20 °C à + 60 °C, la présente norme peut être considérée comme une "ligne directrice".
Dans la suite du présent document, les "clapets de sécurité" sont désignés sous l'appellation "CS", sauf dans les titres.
La présente Norme européenne traite des classes suivantes de CS :
a)   classes de température :
   classe 1 : plage de température de service comprise entre - 10 °C et + 60 °C ;
   classe 2 : plage de température de service comprise entre - 20 °C et + 60 °C.
b)   classes de fonctionnement :
   classe A : se ferme lorsqu'un dommage se produit sur la membrane de détection de la pression (applicable uniquement aux CS de surpression) et lors d'une défaillance d'alimentation en énergie externe ;
   classe B : ne ferme pas lorsqu'un dommage se produit sur la membrane de détection de la pression ou peut être ouvert automatiquement par le système de commande de pression (applicable uniquement aux CS de surpression).
NOTE 1   Certains pays ou donneurs d'ordre peuvent restreindre l'usage de certaines de classes listées ci-dessus.
NOTE 2   Les CS satisfaisant aux exigences de la présente norme peuvent être déclarés "conformes à l'EN.....".
Les exigences relatives au fonctionnement et aux matériaux, spécifiées dans la présente norme, peuvent s'appliquer aux CS qui utilisent l'énergie thermique ou

Varnostne naprave za plinske regulacijske postaje in napeljave - Plinske varnostne zaporne naprave za vstopne tlake do 100 bar

General Information

• Status: Withdrawn
• Publication Date: 17-Dec-2002
• Withdrawal Date: 08-Mar-2005
• ICS: 23.060.40 - Pressure regulators
• Technical Committee: CEN/TC 235 - Gas pressure regulators and associated safety devices for use in gas transmission and distribution
• Drafting Committee: CEN/TC 235/WG 1 - Safety shut-off devices, safety relief devices and small regulators with or without safety devices used in gas transmission and/or distribution.
• Current Stage: 9960 - Withdrawal effective - Withdrawal
• Start Date: 09-Mar-2005
• Completion Date: 09-Mar-2005
• Ref Project: SIST EN 14382:2004 - Safety devices for gas pressure regulating stations and installations - Gas safety shut-off devices for inlet pressures up to 100 bar

Relations

• Replaced By: EN 14382:2005 - Safety devices for gas pressure regulating stations and installations - Gas safety shut-off devices for inlet pressures up to 100 bar
• Effective Date: 22-Dec-2008

Standards Content (Sample)

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Varnostne naprave za plinske regulacijske postaje in napeljave - Plinske varnostne zaporne naprave za vstopne tlake do 100 barSicherheitseinrichtungen für Gas-Druckregelanlagen und -einrichtungen - Sicherheitsabsperreinrichtungen für Betriebsdrücke bis 100 barDispositifs de sécurité pour postes et installations de détente-régulation de pression de gaz - Clapets de sécurité pour pressions de service jusqu' a 100 barSafety devices for gas pressure regulating stations and installations - Gas safety shut-off devices for inlet pressures up to 100 bar23.060.40Pressure regulatorsICS:Ta slovenski standard je istoveten z:EN 14382:2002SIST EN 14382:2004en01-februar-2004SIST EN 14382:2004SLOVENSKI
STANDARD



SIST EN 14382:2004



EUROPEAN STANDARDNORME EUROPÉENNEEUROPÄISCHE NORMEN 14382December 2002ICS 23.060.40English versionSafety devices for gas pressure regulating stations andinstallations - Gas safety shut-off devices for inlet pressures upto 100 barDispositifs de sécurité pour postes et installations dedétente-régulation de pression de gaz - Clapets de sécuritépour pressions amont jusqu' à 100 barSicherheitseinrichtungen für Gas-Druckregelanlagen und -einrichtungen - Gas-Sicherheitsabsperreinrichtungen fürEingangsdrücke bis 100 barThis European Standard was approved by CEN on 7 November 2002.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards may be obtained on application to the 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 translationunder the responsibility of a CEN member into its own language and notified to the Management Centre has the same status as the officialversions.CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece,Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMITÉ EUROPÉEN DE NORMALISATIONEUROPÄISCHES KOMITEE FÜR NORMUNGManagement Centre: rue de Stassart, 36
B-1050 Brussels© 2002 CENAll rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 14382:2002 ESIST EN 14382:2004



EN 14382:2002 (E)2ContentsForeword.41Scope.52Normative references.53Terms and definitions and symbols.73.1General terminology.73.2Functional variables.113.3Operating features.133.4Further design terminology.144Construction requirements.164.1Basic requirements.164.2Materials.214.3Strength of housings.275Functional requirements.285.1General.285.2Shell strength, external tightness and internal sealing.295.3Accuracy group.305.4Response time.305.5Relatching difference and unlatching.305.6Closing force.315.7Endurance and accelerated ageing.315.8Resistance to gas of plastic components.315.9Maximum flow with respect to the performances of the trip mechanism and the valve seat.325.10Flow coefficient.325.11Final inspection.326Testing.326.1Types of tests.326.2Selection of test samples.347Test methods.347.1General.347.2Shell strength, external tightness and internal sealing.367.3Accuracy group.387.4Response time.417.5Relatching difference and unlatching.427.6Closing force.437.7Endurance and accelerated ageing.447.8Resistance to gas of plastic components.447.9Verification of the strength of the trip mechanism, valve seat and closing member.447.10Determination of flow coefficient.457.11Final inspection.468Documentation.468.1Documentation related to type test.468.2Documentation for the customer.468.3Documentation related to surveillance.479Marking.479.1Mandatory markings.479.2Marking of connecting nipples for sensing, exhaust and breather lines.489.3Identification of auxiliary devices.48Annex A (informative)
Use of allowable pressure pzul.49Annex B (informative)
Ice formation.50B.1General.50SIST EN 14382:2004



EN 14382:2002 (E)3B.2Requirements.50B.3Tests.50Annex C (informative)
Conformity evaluation .51C.1General.51C.2Manufacturer’s conformity evaluation.51C.3Third parties’ conformity evaluation.51C.4Issue of the certificate of conformity.52Annex D (informative)
Pressure drop and flow coefficient.53D.1Calculation method for pressure drop throughout the safety shut-off device.53D.2Test method for the determination of the flow coefficient Cv.53Annex E (informative)
Alternative test method to verify the maximum flow with respect to theperformance of trip mechanism.55E.1Test method.55E.2Test method for the determination of the dynamic factor Cr.55E.3Test method for a series of safety shut-off devices.56Annex F (informative)
Sizing equation.58Annex G (informative)
Inspection certificate.59Annex H (informative)
Order specification.60H.1Minimum specifications.60H.2Optional specifications.60Annex I (informative)
Acceptance test.62Bibliography.63SIST EN 14382:2004



EN 14382:2002 (E)4ForewordThis document EN 14382:2002 has been prepared by CEN /TC 235, "Gas pressure regulators and associatedsafety devices for use in gas transmission and distribution" the secretariat of which is held by UNI.This European Standard shall be given the status of a national standard, either by publication of an identical text orby endorsement, at the latest by June 2003, and conflicting national standards shall be withdrawn at the latest byJune 2003.At the time of drafting, it has not been decided whether the devices within the scope of this European Standard willfall under the Pressure Equipment Directive 97/23/EC, also there was no network of Notified Bodies under theprovisions of the directive itself. Therefore it has been decided to establish the evaluation of conformity according tothe CEN “Guidelines for Technical Committees - Requirements in European Standards concerning the evaluationof conformity 1993-01”.When it is confirmed that pressure SSDs within the scope of this European standard fall under the PressureEquipment Directive, the Standard will be revised to ensure that it’s clauses conform with the essentialrequirements and conformity of the Directive.NOTEReferring to 4.2.2 of this standard it should be noted that at the discussion during its elaboration within WG 1, it waspointed out that in some member countries there is legislation limiting the application of some materials listed in Table 5.Creep (venting) relief devices built-into gas safety shut-off devices are dealt with in a normative annex to prEN 334Review.In this standard the annexes A to I are informative.This document includes a Bibliography.According to the CEN/CENELEC Internal Regulations, the national standards organizations of the followingcountries are bound to implement this European Standard : Austria, Belgium, Czech Republic, Denmark, Finland,France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Spain,Sweden, Switzerland and the United Kingdom.SIST EN 14382:2004



EN 14382:2002 (E)51 ScopeThis European Standard specifies constructional, functional, sizing, and testing requirements, also documentationand marking of gas safety shut-off devices:¾ for inlet pressures up to 100 bar and nominal diameters up to DN 400;¾ used at an operating temperature range from –20 °C to +60 °C which operate with fuel gases of the 1st and2nd family according to EN 437 in transmission and distribution networks and industrial installations.For inlet pressures higher than 100 bar or nominal diameters DN > 400 or operating temperatures outside therange –20 °C to 60 °C, this standard can be considered as a guideline.Gas safety shut-off devices will hereafter be called SSDs except in titles.This European Standard considers the following classes of SSD:a) Temperature classes:¾ class 1: operating temperature range from –10 °C to 60 °C;¾ class 2: operating temperature range from –20 °C to 60 °C.b) Functional classes:¾ class A: SSDs that close when damage to the pressure sensing element occurs (applicable tooverpressure SSDs only) or when external power fails;¾ class B: SSDs that do not close when damage to the pressure sensing element occurs or are able to beopened automatically by the pressure control system (applicable to overpressure SSDs only).NOTE 1Some countries or purchasers can restrict the use of some of the classes listed above.NOTE 2SSDs complying with the requirements of this standard can be declared as “in conformity with EN.“.The material and functional requirements specified in this standard are applicable to SSDs which use thermalenergy or the effects of electrical energy to trip the operation of the closing member. For these SSDs theoperational parameters are not specified in this standard.This European Standard is not applicable to:¾ SSDs upstream from/on/in domestic gas-consuming appliances which are installed downstream of domesticgas meters;¾ shut-off devices only designed for installation in service lines in accordance with EN 12279 that comply withboth of the following characteristics:¾ volumetric flow rate £ 200 m3/h at normal conditions,¾ inlet pressure £ 5 bar.2 Normative referencesThis European Standard incorporates by dated or undated reference, provisions from other publications. Thesenormative references are cited at the appropriate places in the text, and the publications are listed hereafter. Fordated references, subsequent amendments to or revisions of any of these publications apply to this EuropeanStandard only when incorporated in it by amendment or revision. For undated references the latest edition of thepublication referred to applies (including amendments).EN 287, Approval testing of welders - Fusion welding.SIST EN 14382:2004



EN 14382:2002 (E)6EN 288, Specification and approval of welding procedures for metallic materials.EN 334, Gas pressure regulators for inlet pressures up to 100 bar.EN 970, Non-destructive examination of fusion welds - Visual examination.EN 1349, Industrial process control valves.EN 1418, Welding personnel - Approval testing of welding operators for fusion welding and resistance weld settersfor fully mechanized and automatic welding of metallic materials.EN 10002-1, Metallic materials - Tensile testing - Part 1: Method of test at ambient temperature.EN 10045-1, Metallic materials - Charpy impact test - Part 1: Test method.EN 10204, Metallic products - Types of inspection documents.EN 12627, Industrial valves - Butt welding ends for steel valves.EN 12732, Gas supply system - Welding steel pipework - Functional requirements.EN 13787, Elastomers for gas pressure regulators and associated safety devices for inlet pressures up to 100 bar.prEN 13906-1, Cylindrical helical springs made from round wire and bar - Calculation and design - Part 1:Compression springs.prEN 13906-2, Cylindrical helical springs made from round wire and bar - Calculation and design - Part 2:Extension springs.EN 60534-1, Industrial-process control valves - Part 1: Control valve terminology and general considerations(IEC 60534-1:1987).EN ISO 175, Plastics - Methods of test for the determination of the effects of immersion in liquid chemicals(ISO 175:1999).EN ISO 898-1, Mechanical properties of fasteners made of carbon steel and alloy steel - Part 1: Bolts, screws andstuds (ISO 898-1:1999).EN ISO 6708, Pipework components - Definition and selection of DN (nominal size) (ISO 6708:1995).EN ISO/IEC 17025:2000, General requirements for the competence of testing and calibration laboratories (ISO/IEC17025:1999).ISO 7-1, Pipe threads where pressure-tight joints are made on the threads - Part 1: Dimensions, tolerances anddesignation.ISO 1817, Rubber, vulcanized - Determination of the effect of liquids.ISO 5752, Metal valves for use in flanged pipe systems - Face-to-face and centre-to-face dimensions.ISO 7005, Metallic flanges.ANSI/ASME B1.20.1-1983, Pipe threads, general purpose (inch).API spec. 6D, Pipeline valves (gate, plug, ball and check valves).ASME B 16.34-1996, Valves - Flanged, threaded and welding end.ASME VIII div. 1, Rules for construction of pressure vessels.MSS SP 55 – 1985, Quality standard for steel castings for valves, flanges and fittings and other piping components(Visual method).SIST EN 14382:2004



EN 14382:2002 (E)73 Terms and definitions and symbols3.1 General terminologyFor the purposes of this European Standard, the terms and definitions given in EN 60534-1 and the followingspecific terms and definitions apply.3.1.1safety shut-off devicedevice whose function is to stay in the open position under normal operating conditions and to shut-off the gas flowautomatically and completely when the monitored pressure exceeds the pre-set values (over-pressure and/orunder-pressure)3.1.2main components of a gas safety shut-off deviceparts including normally a controller, a trip mechanism, an actuator, a closing member and a relatching devicepermitting the manual opening of the SSD. All
these parts are functionally connected. (see Figures 1, 2 and 3)3.1.3closing memberpart which shuts off the gas flow completely3.1.4trip mechanismmechanism which releases the closing member when activated by the controller3.1.5actuatordevice activated by the trip mechanism which shuts the closing member3.1.6relatching devicedevice which enables the complete opening of the SSD3.1.7SSD bodypart of the SSD which is the main pressure containing envelope. It provides the fluid flow passageway and the pipeend connections3.1.8valve seatcorresponding sealing surfaces within an SSD which make full contact only when the closing member is in theclosed position3.1.9seat ringpart assembled in a component of the SSD to provide a removable seat3.1.10controllerdevice which can include:¾ setting element to adjust the set value of the trip pressure;¾ sensing element for the control of the monitored pressure (e.g. a diaphragm);¾ unit which compares the set value of the trip pressure with the monitored pressure;¾ system which gives the energy to operate the trip mechanismSIST EN 14382:2004



EN 14382:2002 (E)83.1.11fixturesdevices functionally connected to the main components of the SSDKey1Bypass6 Controller2 Relatching device7 Sensing line3 Trip mechanism8 Actuator4 Breather line9 Sensing point5 Setting element10 Closing memberFigure 1 — Example of a direct acting safety shut-off device of the slam-shut typeSIST EN 14382:2004



EN 14382:2002 (E)9Key1 Bypass7 Sensing line2 Actuator8 External loading pressure line3 Relatching device9 Internal loading pressure line4 Exhaust line10 Breather/exhaust line5 Trip mechanism11 Sensing point6 Controller12 Closing memberFigure 2 — Example of an indirect acting shut-off device of the slam-shut typeSIST EN 14382:2004



EN 14382:2002 (E)10Key1 Bypass8 External loading pressure line2 Actuator9 Internal loading pressure line3 Relatching device (manually operated)10 Breather/exhaust line4 Exhaust line11 Sensing point5 Trip mechanism12 Closing member6 Controller13 Pressure reducer (if applicable)7 Sensing lineFigure 3 — Example of an indirect acting safety shut-off device of the cut-off type3.1.12direct acting shut-off deviceSSD in which the sensing element is directly connected to the trip mechanism (see Figure 1)3.1.13indirect acting shut-off deviceSSD in which the energy required to move the closing member or to operate the controller is supplied by an internalor external power supply (see Figures 2 and 3)3.1.14cut-off deviceSSD designed to shut off the gas flow which responds slower dynamically than a slam-shut device when themonitored pressure exceeds the pre-set valueEXAMPLESSD using actuator driven by pipeline gas or external power3.1.15slam shut deviceSSD designed to quickly shut off the gas flow when the monitored pressure exceeds the pre-set valueEXAMPLESpring or weight loaded SSD3.1.16Accessories of shut-off devices3.1.16.1loading pressure lineline connecting the controller and/or actuator with the internal or external power source3.1.16.2sensing lineline connecting the sensing point and the controllerSIST EN 14382:2004



EN 14382:2002 (E)113.1.16.3exhaust lineline connecting the controller and/or actuator of the SSD to atmosphere3.1.16.4breather lineline connecting the atmospheric side of the sensing element to atmosphere3.1.16.5bypassdevice permitting manual equalization of pressure across a closed SSD3.2 Functional variables3.2.1 Reference values3.2.1.1pressureall pressures specified in this standard are static gauge pressuresNOTEPressure is expressed in bar1).3.2.1.2differential pressureDpthe difference between two values of pressure at two different points3.2.2 Variables in the monitoring process3.2.2.1monitored pressurepressure monitored and safeguarded by the SSD, normally the outlet pressure of the pressure regulatingstation/installation3.2.2.2disturbance variablesvariables affecting the functioning of the SSDEXAMPLES:¾ flow rate fluctuations;¾ temperature changes;¾ mechanical impacts;¾ moisture influences;¾ influences by gas conditioning agents;¾ dust, condensation and others;¾
dynamic force on closing member created by gas flow3.2.2.3trip pressurepressure value at which the closing member starts to move
1)1 bar = 105 Pascal = 1000 mbar = 10-1 MPa = 105 N/m2.SIST EN 14382:2004



EN 14382:2002 (E)123.2.2.3.1upper trip pressurepoupper limit of the monitored pressure (over-pressure)3.2.2.3.2lower trip pressurepulower limit of the monitored pressure (under-pressure)3.2.3 Possible values of all variables3.2.3.1actual value of the trip pressurepio
(upper trip pressure), piu (lower trip pressure)pressure value at which the closing member of an SSD starts to move3.2.3.2maximum valuehighest value:¾ to which any variable can be adjusted or to which it is limited;¾ any variable may reach during a series of measurements, or during a certain time.It is specified by the index “max,” added to the symbol of the variable3.2.3.3minimum valuelowest value:¾ to which any variable can be adjusted or to which it is limited;¾ any variable may reach during a series of measurements or during a certain time.It is specified by the index “min“ added to the symbol of the variable.3.2.4 Terms related to the set value of the trip pressure3.2.4.1set value of the trip pressureps, pso
(for over-pressure), psu
(for under-pressure)desired trip pressure value under specified conditions.3.2.4.2set rangeWh, Who
(for over-pressure), Whu (for under-pressure)whole range of set values which can be obtained from an SSD by adjustment and the replacement of somecomponent (e.g. replacement of the setting or sensing element)3.2.4.3specific set rangeWa, Wao
(for over-pressure), Wau (for under-pressure)whole range of set values which can be obtained from an SSD by adjustment but with no replacement of itscomponents.SIST EN 14382:2004



EN 14382:2002 (E)133.2.5 Terms related to the flow3.2.5.1normal conditionsabsolute pressure of 1,013 25 bar and temperature of 0 °C (273,15 K).NOTEFor calculation purposes a value of 273 K is used in this European Standard.3.2.5.2gas volumevolume of gas at normal conditionsNOTEGas volume is expressed in m3.3.2.5.3volumetric flow rateQvolume of gas which flows through the SSD per unit time, at normal conditions.NOTEVolumetric flow rate is expressed in m3/h.3.3 Operating features3.3.1trip pressure deviationthe positive or negative deviation of the actual value of the trip pressure from its set value as a percentage of theset value (see Figure 4)3.3.2accuracy groupAGthe absolute maximum permissible value of trip pressure deviation3.3.3inlet operating pressure rangeWeAG range of inlet operating pressure for which the SSD ensures a given accuracy group3.3.4response timetatime interval between attaining the permissible limit value of the trip pressure at the sensing point and completeclosure of the closing member3.3.5relatching differenceDpWdifference between the set value of the trip pressure and the monitored pressure which is required for the correctresetting of the SSDSIST EN 14382:2004



EN 14382:2002 (E)14Key1 Set value of trip pressure (pso)2 Actual value of trip pressure (pio)3 Trip pressure deviation4 Accuracy group (AG)5 Relatching difference (DpW)Figure 4 — Monitored pressure and trip pressure3.4 Further design terminology3.4.1 Pressures3.4.1.1operating pressurepgas pressure occurring in any part of the SSD during operation3.4.1.2maximum component operating pressurepmaxthe highest operating pressure at which a component of an SSD will continuously operate within specifiedconditions3.4.1.2.1maximum inlet pressurepemaxthe highest inlet pressure at which the SSD can continuously operate within specified conditions3.4.1.3allowable pressurepzulthe highest pressure the SSD body will withstand in accordance with the specified strength and external tightnessrequirements2)NOTEAt this pressure functional performance is not necessarily required.
2)For additional explanation see also annex A.SIST EN 14382:2004



EN 14382:2002 (E)153.4.1.4loading pressurepressure of the gas from the upstream pipeline or of the gas from an external source used as an energy source forthe controller and/or actuator3.4.1.5actuator pressurepressure to provide the closing force (FS). Where the pipeline gas is used, pressure reduction may be required fordifferential strength shut-off devices3.4.1.6nominal pressurePNnumerical designation relating to pressure, which is a convenient round number for reference purposes inaccordance with
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