1、December 2013 Translation by DIN-Sprachendienst.English price group 12No part of this translation may be reproduced without prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale for German Standards (DIN-Normen).I
2、CS 13.240!%*z4“2078717www.din.deDDIN EN ISO 4126-4Safety devices for protection against excessive pressure Part 4: Pilot operated safety valves (ISO 4126-4:2013);English version EN ISO 4126-4:2013,English translation of DIN EN ISO 4126-4:2013-12Sicherheitseinrichtungen gegen unzulssigen berdruck Tei
3、l 4: Pilotgesteuerte Sicherheitsventile (ISO 4126-4:2013);Englische Fassung EN ISO 4126-4:2013,Englische bersetzung von DIN EN ISO 4126-4:2013-12Dispositifs de scurit pour protection contre les pressions excessives Partie 4: Soupapes de sret pilotes (ISO 4126-4:2013);Version anglaise EN ISO 4126-4:2
4、013,Traduction anglaise de DIN EN ISO 4126-4:2013-12SupersedesDIN EN ISO 4126-4:2004-05www.beuth.deIn case of doubt, the German-language original shall be considered authoritative.Document comprises 22 pages12.13 DIN EN ISO 4126-4:2013-12 2 A comma is used as the decimal marker. National foreword Th
5、is document (EN ISO 4126-4:2013) has been prepared by Technical Committee ISO/TC 185 “Safety devices for protection against excessive pressure” in collaboration with Technical Committee CEN/TC 69 “Industrial valves” (Secretariat: AFNOR, France). The responsible German body involved in its preparatio
6、n was the Normenausschuss Armaturen (Valves Standards Committee), Working Committee NA 003-01-10 AA Sicherheitseinrichtungen gegen Druckber-schreitungen. Amendments This standard differs from DIN EN ISO 4126-4:2004-05 as follows: a) Clause 3 “Terms and definitions” has been extended; b) Subclause 5.
7、2 “Valve end connections” has been modified; c) Table 2 “Minimum duration of hydrostatic test” has been updated; d) Subclause 6.4.2 “Safety requirements” has been editorially revised; e) Clause 7 “Type testing” has been renamed; f) Subclause 7.1.1 “Application” has been modified; g) Subclause 7.2.3
8、“Test equipment” has been technically revised; h) Subclause 7.3.3 “Test procedure” has been technically revised; i) Clause 7 “Type testing” has been renamed and technically revised; j) Subclause 7.3.5 “Records and test results” has been extended; k) Clause 8 “Determination of pilot operated safety v
9、alve performance” has been technically revised; l) Clause 9 “Sizing of pilot operated safety valves” has been technically revised; m) Annex A has been deleted. Previous editions DIN EN ISO 4126-4: 2004-05 EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 4126 4 July 2013 ICS 13.240 Supersedes
10、 EN ISO 4126-4:2004English Version Safety devices for protection against excessive pressure -Part 4: Pilot-operated safety valves (ISO 4126-4:2013) Dispositifs de scurit pour protection contre les pressions excessives - Partie 4: Soupapes de sret pilotes(ISO 4126-4:2013) Sicherheitseinrichtungen geg
11、en unzulssigen berdruck - Teil 4: Pilotgesteuerte Sicherheitsventile (ISO 4126-4:2013)This European Standard was approved by CEN on 28 December 2012. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status
12、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, Germa
13、n). 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,
14、 Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and Unite
15、d Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: Avenue Marnix 17, B-1000 Brussels 2013 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 4126-4:20
16、13: E-Contents Page Foreword . 3 1 Scope . 4 2 Normative references. 4 3 Terms and definitions 4 4 Symbols and units . 8 5 Design . 8 5.1 General 8 5.2 Valve end connections 9 5.3 Minimum requirements for springs 9 5.4 Materials 10 6 Production testing 10 6.1 Purpose . 10 6.2 General . 10 6.3 Hydros
17、tatic testing . 10 6.4 Pneumatic testing 11 6.5 Adjustment of set or cold differential test pressure . 11 6.6 Seat leakage test 12 6.7 Pressure seals 12 7 Type testing 12 7.1 General 12 7.2 Tests to determine operating characteristics . 13 7.3 Tests to determine flow characteristics. 15 7.4 Determin
18、ation of the coefficient of discharge . 17 7.5 Certification of coefficient of discharge 17 8 Determination of pilot operated safety valve performance . 17 9 Sizing of pilot operated safety valves 17 10 Marking and sealing . 17 10.1 Marking 17 10.2 Sealing of a pilot operated safety valve . 18 Annex
19、 ZA (informative) Relationship between this International Standard and the Essential Requirements of EU Directive 97/23/EC (PED) 19 Bibliography 20 DIN EN ISO 4126-4:2013-12EN ISO 4126-4:2013 (E) 2This document (EN ISO 4126-4:2013) has been prepared by Technical Committee ISO/TC 185 Safety devices f
20、or protection against excessive pressure in collaboration with 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 la
21、test by January 2014, and conflicting national standards shall be withdrawn at the latest by January 2014. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all
22、 such patent rights. This document supersedes EN ISO 4126-4:2004. This document has been prepared under a mandate given to CEN by the European Commission and the European Free Trade Association, and supports essential requirements of EU Directive(s). For relationship with EU Directive(s), see inform
23、ative Annex ZA, which is an integral part of this document. According to the CEN-CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
24、 Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. Endorsement notice The text
25、 of ISO 4126-4:2013 has been approved by CEN as EN ISO 4126-4:2013 without any modification. Foreword“”DIN EN ISO 4126-4:2013-12EN ISO 4126-4:2013 (E)31 ScopeThis part of ISO 4126 specifies general requirements for pilot operated safety valves, irrespective of the fluid for which they are designed.
26、In all cases, the operation is carried out by the fluid in the system to be protected.It is applicable to pilot operated safety valves having a valve flow diameter of 4 mm and above which are for use at set pressures of 0,1 bar gauge and above. No limitation is placed on temperature.This is a produc
27、t standard and it is not applicable to applications of pilot operated safety valves.2 Normative referencesThe following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the
28、 referenced document (including any amendments) applies.ISO 4126-7:2013, Safety devices for protection against excessive pressure Part 7: Common data3 Terms and definitionsFor the purposes of this document, the following terms and definitions apply.3.1pilot operated safety valveself-actuated device
29、comprising a main valve and an attached pilotNote 1 to entry: The pilot responds to the pressure of the fluid without any other actuating energy than the fluid itself and controls the operation of the main valve. The main valve opens when the fluid pressure that keeps it closed is removed or reduced
30、. The main valve re-closes when the pressure is re-applied.Note 2 to entry: See Figure 1 for a list of main components.3.2main valveparts of a pilot operated safety valve, through which the discharge capacity is achieved3.3flowing pilotpilot which discharges the fluid throughout the relieving cycle
31、of the pilot operated safety valveDIN EN ISO 4126-4:2013-12EN ISO 4126-4:2013 (E) 4Key1 equipment to be protected 9 disc (or piston)2 main valve 10 seat3 pilot valve 11 main valve body4 sensing line 12 main valve inlet5 loading/unloading line 13 main valve outlet6 pressure chamber 14 pilot outlet7 c
32、over (or cap) 15 connection of the sensing line (see Note)8 guideNOTE The sensing line from the pilot can be either connected to the main valve inlet or connected directly to the equipment to be protected. In cases where the sensing line is not connected to the main valve inlet, considerations shoul
33、d be given to the length and to the protection from damage of the sensing line.Figure 1 Nomenclature of main components of a pilot operated safety valve3.4non-flowing pilotpilot in which the fluid flows only during the opening and/or closing of the pilot operated safety valve3.5ON/OFFaction characte
34、rized by stable operation resulting in fully open or fully closed main valve positionNote 1 to entry: This is an action of the pilot operated safety valve.DIN EN ISO 4126-4:2013-12EN ISO 4126-4:2013 (E)53.6modulatingaction characterized by a gradual opening and closing of the disc of the main valve
35、which is a function of the pressure, proportional but not necessarily linearNote 1 to entry: This is an action of the pilot operated safety valve.3.7set pressurepredetermined pressure at which the main valve of a pilot operated safety valve under operating conditions commences to openNote 1 to entry
36、: It is the gauge pressure measured at the main valve inlet at which the pressure forces tending to lift the main valve disc for the specific service conditions are in equilibrium with the forces retaining the main valve disc on its seat.3.8maximum allowable pressurePSmaximum pressure for which the
37、protected equipment is designed3.9opening sensing pressurepressure at which the pilot commences to open in order to achieve the set pressure3.10overpressurepressure increase over the set pressure, usually expressed as a percentage of the set pressure3.11reseating pressurevalue of the inlet static pr
38、essure at which the main valve disc re-establishes contact with the seat or at which the lift becomes zero3.12cold differential test pressureinlet static pressure at which a pilot operated safety valve is set to commence to open on the test benchNote 1 to entry: This test pressure includes correctio
39、ns for service conditions, e.g. back pressure and/or temperature.3.13relieving pressurepressure used for the sizing of a pilot operated safety valve which is greater than or equal to the set pressure plus overpressure3.14back pressurepressure that exists at the outlet of a safety valve as a result o
40、f the pressure in the discharge systemNote 1 to entry: The back pressure is the sum of the superimposed and built-up back pressures.3.15built-up back pressurepressure existing at the outlet of the main valve caused by flow through the main valve and the discharge system3.16superimposed back pressure
41、pressure existing at the outlet of the main valve at the time when the device is required to operateNote 1 to entry: It is the result of pressure in the discharge system from other sources.DIN EN ISO 4126-4:2013-12EN ISO 4126-4:2013 (E) 63.17blowdowndifference between set and reseating pressuresNote
42、 1 to entry: Blowdown is normally stated as a percentage of set pressure except for pressures of less than 3 bar when the blowdown is expressed in bar.3.18liftactual travel of the main valve disc away from the closed position3.19flow areaminimum cross-sectional flow area (but not the smallest area b
43、etween disc and seat) between inlet and seat which is used to calculate the theoretical flowing capacity of the main valve, with no deduction for any obstruction3.20flow diameterdiameter corresponding to the flow area3.21theoretical discharge capacitycalculated capacity of a theoretically perfect no
44、zzle having a cross-sectional flow area equal to the flow area of the main valve of a pilot operated safety valveNote 1 to entry: It is expressed in mass or volumetric units.3.22coefficient of dischargevalue of actual flowing capacity (from tests) divided by the theoretical flowing capacity (from ca
45、lculation)3.23certified (discharge) capacityportion of the measured capacity permitted to be used as a basis for the application of a pilot operated safety valveNote 1 to entry: It may, for example, equal the: a) measured flow rate times the de-rating factor; or b) theoretical flow rate times the co
46、efficient of discharge times the de-rating factor; or c) theoretical flow rate times the certified de-rated coefficient of discharge.3.24DN (nominal size)alphanumeric designation of size that is common for components used in a piping system, used for reference purposes, comprising the letters DN fol
47、lowed by a dimensionless number having an indirect correspondence to the physical size of the bore or outside diameter of the component end connectionNote 1 to entry: The dimensionless number does not represent a measurable value and is not used for calculation purposes.Note 2 to entry: Prefix DN us
48、age is applicable to components bearing PN designations according to ISO 7268.Note 3 to entry: Adapted from ISO 6708:1995, definition 2.1.DIN EN ISO 4126-4:2013-12EN ISO 4126-4:2013 (E)74 Symbols and unitsTable 1 Symbols and their descriptionsSymbol Description UnitA Flow area of a safety valve (not
49、 smallest area between seat and disc) mm2KdCoefficient of dischargeaKdrCertified de-rated coefficient of discharge (Kd 0,9)an Number of tests qmTheoretical specific discharge capacity kg/(hmm2)qmSpecific discharge capacity determined by tests kg/(hmm2)aKdand Kdrare expressed as 0,xxx.5 Design5.1 General5.1.1 The design shall incorporate guiding arrangements necessary to ensure consistent operation and seat tightness.5.1.2 The seat of the main valve, other than when it is
