1、BRITISH STANDARDBS EN 1797:2001Incorporating corrigendum November 2008Cryogenic vessels Gas/material compatibilityICS 23.020.40g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g6
2、0g53g44g42g43g55g3g47g36g58BS EN 1797:2001Committee on28 August 2001 BSI 2008ISBN 978 0 580 63473 4National forewordThis British Standard is the UK implementation of EN 1797:2001. It supersedes BS EN 1797-1:1998 which is withdrawn. The UK participation in its preparation was entrusted to Technical C
3、ommittee PVE/18, Cryogenic vessels.A list of organizations represented on this committee can be obtained on request to its secretary.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Compliance with a British S
4、tandard cannot confer immunity from legal obligations.Amendments/corrigenda issued since publicationDate Comments30 November 2008Addition of supersession information to nationalforwordThis British Standard waspublishedunder the authorityof the Standards Policy andStrategy EUROPEAN STANDARDNORME EURO
5、PENNEEUROPISCHE NORMEN 1797July 2001ICS 23.020.40 Supersedes EN 1797-1:1998English versionCryogenic vessels - Gas/material compatibilityRcipients cryogniques - Compatibilit entre gaz etmatriauxKryo-Behlter - Vertrglichkeit von Gas/WerkstoffenThis European Standard was approved by CEN on 9 June 2001.
6、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 app
7、lication 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 s
8、ame 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, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STA
9、NDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centre: rue de Stassart, 36 B-1050 Brussels 2001 CEN All rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 1797:2001 EEN 1797:2001 (E)2ContentspageForeword31Sco
10、pe42Normative references43Compatibility of materials with gases other than oxygen.44General requirements for oxygen service.54.1 Evaluation of materials for oxygen service.54.2 Evaluation of metallic materials.54.3 Evaluation of non metallic materials.64.4 Test methods and acceptance criteria64.4.1
11、Ignition tests.64.4.2 Mechanical impact test in liquid oxygen (LOX)7Annex A (normative) Spontaneous ignition test (Bomb test).8Annex B (normative) Pressure surge test13Annex C (informative) Ignition test - Advantages and disadvantages of the two alternative methods16Annex ZA (informative) Clauses of
12、thisEuropean Standard addressing essential requirements orother provisions of EU directives.17Bibliography18BS EN 1797:2001EN 1797:2001 (E)3ForewordThis European Standard has been prepared by Technical Committee CEN/TC 268, “Cryogenic vessels“, thesecretariat of which is held byAFNOR.ThisEuropean St
13、andardshall begiven the statusofa national standard, eitherbypublication of an identical text orby endorsement, at thelatestbyJanuary2002, and conflicting national standards shall be withdrawn at the latestby January 2002.This document replaces EN 1797-1:1998.For relationshipwith EU Directives, see
14、informative annex ZA, which is an integral part of this document.Thisdocument has been prepared under a mandate given to CEN by the European Commission and the EuropeanFree Trade Association, and supports essential requirements of EU Directives.According to the CEN/CENELEC Internal Regulations, the
15、national standards organizations of the followingcountriesare bound to implement this European Standard: Austria, Belgium,Czech Republic, Denmark, Finland,France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden,Switzerland and the United Kingdom.BS
16、EN 1797:2001EN 1797:2001 (E)41 ScopeThis European Standard specifies requ irements for gas/materials compatibilityfor cryogenic vessels (such aschemical resistance) but it does not cover mechanical properties (e.g. for lowtemperature application).It givesguidance for compatibilitywith gases other th
17、an oxygen and it givesdetailedrequirementsforoxygenandoxygen enriched atmosphere compatibility and defines the testing methods for establishingoxygencompatibility ofmaterials (metallic and non-metallic) to be used for cryogenic ve ssels and associated equipment.It mainlydealswith materials that are
18、normallyor could be in contact withliquid/gaseousoxygene.g., materialsforcryogenicvessels used for the storage and/or transport of liquid oxygen.It alsodeals with the materials which can be in contact with oxygen enriched environment e.g. insulating materialsused for nitrogen, neon, hydrogen and hel
19、ium cryogenicvessels in case of air condensation.2 Normative referencesThis European Standard incorporates bydated or undated references provisions from other publications. Thesenormative references arecited at the appropriate places in the text, and the publications are listed hereafter. Fordated r
20、eferences, subsequent amendments to or revisions of any of thesepublication applyto this EuropeanStandard only whenincorporated in it byamendment or revision. For undated references, the latestedition of thepublication referred to applies (including amendments).EN 849: 1996, Transportable gas cylind
21、er Cylinder valves - Specification an d type testing.EN 12300, Cryogenic vessels - Cleanliness for cryogenic service.EN ISO11114-1, Transportable gas cylinders - Compatibility of cylinder and valve materials with gas contents -Part 1 : Metallic materials (ISO11114-1:1997).prEN ISO11114-2:1997, Trans
22、portable gas cylinders - Compatibility of cylinder and valve materials with gascontents -Part 2 : Non-metallicmaterials (ISO/DIS 11114-2).3 Compatibility of materialswith gases other than oxygenThe cryogenic vessels are used in a range of temperature from verylow temperature toambienttemperature. Th
23、eproblemsofcompatibility withgases other than oxygen such as corrosion, hydrogen embrittlement normally occurat ambient temperature and become negligible at cryogenic temperature.So, in caseof gases other than oxygen, EN ISO 11114-1 and prEN ISO11114-2:1997maybeusedasa guide forcryogenic vessels.BS
24、EN 1797:2001EN 1797:2001 (E)54 General requirements for oxygen service4.1 Evaluation of materials for oxygen serviceThe selection ofa material for use with oxygen and/orin an oxygen enriched atmosphere is primarilya matter ofunderstanding the circumstances that cause oxygen to react with the materia
25、l. Mostmaterials in contact withoxygen willnot ignite without a source of ignition energy. When an energy input rate, as converted to heat, isgreaterthantherate ofheat dissipation, and the resulting heat increase is continued for sufficient time, ignition andcombustion will occur. Thus, two things s
26、hall be considerednull the materials minimum ignition temperature ;null the energy sources that will produce a sufficient increase in the temperature of the material.These should be viewed in the context of the entire system design so that the specific factorslisted belowwillassume the proper relati
27、ve significance.The specific factors are :null the properties of the materials, including the factors affecting ease of ignition and the conditions affectingpotential resulting damage (heat of reaction) ;null the operating conditions : pressure, temperature, gas velocity, oxygen concentrations and o
28、xygen state(gaseous orliquid), surface contamination in accordance with EN 12300 ;null the potential sourcesofignition (friction, heat of compression, heat from mass impact, heat from particleimpact, static electricity, electrical arc, resonance, internal flexing etc.) ;null the reaction effect (con
29、sequence on the surroundingsetc.) ;null additional factors (performance requirements, prior experience, availabilityand cost).CAUTION This European Standard specifies the minimum acceptance requirements for materials in oxygen and enriched airservice. In the cases of severe conditions and when the o
30、perating pressure is above 40bar, additional tests to those specifiedshould be considered.The use of materials in cryogenic vessels which do not pass the tests outlined in 4.4.1 and/or 4.4.2 shall besupported byafavourablerisk assessment and/or documented evidence of previouslong term satisfactory s
31、ervicein use.4.2 Evaluation of metallic materialsMetallic materials normally used for the construction of cryogenic vessels i.e. low alloysteels,nickel steels,stainless steels,copper and copper alloys, aluminium and aluminium alloysdo not normallypresent anyincompatibilitywhen in contact with oxygen
32、.The cases in which some ignitions orviolent reactions may occur arewhenverythin materialsare usedwith highsurface/volumeratio,and when high ignition energyis available e.g. pump failure. Thin materialse.g. thinner than0,1 mmshall be testedinaccordance with4.4.2in conditions as close as possible to
33、the real operational conditions(e.g. for multi-layerinsulations use similar number of layersand configuration). Materialstobeused in applicationswhere the ignition energyis potentially high should be subjected to special consideration.For cryogenicvesselsintended for oxygen service the test shall be
34、 performed with oxygen. For cryogenic vesselsintended fornitrogen, hydrogen or helium service, when materials are located in an area where contact withcondensed enriched airisa risk, the test described in 4.4.2 shall be performed with cryogenic O /N mixturescontaining at least 50 % oxygen.BS EN 1797
35、:2001EN 1797:2001 (E)64.3 Evaluation of non metallic materialsNon metallic materials include, for example, plastics, elastomers, lubricants, ceramics,glassesand glues. Someofthese materials present a high ris k of ignition when in contact with ox ygen and should be avoided or ca refullyselected and
36、used in limited quantity.Somefully oxidised materials such as ceramics and glass present no risk of ignition provided they are notcontaminated.Any non metallic materials, other than fully oxidised materials,in contact with liquid oxygen shallbe testedinaccordance with 4.4.1 and 4.4.2.Consideration s
37、hall begiven to testing materials used in those parts of the systemwhere liquid oxygen accumulation m ay incidentally occur (e.g. in the insulation).For cryogenicvesselsintended for oxygen service the test shall be performed with oxygen. For cryogenic vesselsintended for nitrogen, hydrogen or helium
38、 service, when materials are located in an area where contact withcondensed enriched airisa risk, the test described in 4.4.2 shall be performed with cryogenic O /N mixturescontaining at least 50 % oxygen.Any non metallic materials, other than fully oxidised materials,in contact with gaseousoxygensh
39、all be tested inaccordance with 4.4.1. Consideration shall be given to testing materials used in those parts of the system wheregaseousoxygen accumulation may incidentally occur (e.g. in the insulation).4.4 Test methods and acceptance criteriaEachmaterialto be tested shall be clearly identified, nor
40、mally by the commercial name and the manufacturersname.4.4.1 Ignition testsTwo alternative test methods are described in 4.4.1.1 or 4.4.1.2. The advantages and disadvantages of each aregiven in annexC.Materials not satisfying the requirements of 4.4.1.1 or 4.4.1.2 can still be used providing they su
41、ccessfullypass, intheir actualoperating configuration, the “Oxygen pressuresurge test“ described in 5.3.8 of EN 849:1996 (e.g. for avalve sealing material, the entirevalve ora representative assembly shall be tested).4.4.1.1 Spontaneous ignition test (“Bomb test“)4.4.1.1.1 Test procedureThe test pro
42、cedure is given in annex A.BS EN 1797:2001EN 1797:2001 (E)74.4.1.1.2 Acceptance criteriaThe spontaneous ignition temperature determ ined in accordance with 4.4.1.1.1 shall be not lessthan the valuesgiven in Table 1.Table 1 Minimum spontaneous ignition temperatureMaximum workingpressureBar (gauge)Min
43、imum SpontaneousIgnition Temperature(SIT) CRemark320010 23020 25040 300100 350150 375207 400Above 207 up to 345 400Complementarytest maybe advisable (see 4.1)NOTE Intermediate values can be determined by linear interpolation.4.4.1.2 Pressure surge test4.4.1.2.1 Test procedureThe test procedure is gi
44、ven in annex B.4.4.1.2.2 Acceptance criteriaNo reaction shall be observed during 5 consecutive pressure surge impacts at the intended maximum workingpressure.4.4.2 Mechanical impact test in liquid oxygen (LOX)4.4.2.1 Test procedureThe mechanical impact test shall be performed at atmospheric pressure
45、in liquid oxygen generally asdescribedinthe bibliography. This is an example of preferred test equipment but the details are not mandatory. The test shall beconducted :null on material with the surface condition that is intended for use ;null on material in a physical form delivered for use (i.e. so
46、lid, powder etc.) ;null at an impact energy per unit contact area of 79 J/cm.4.4.2.2 Acceptance criteriaNo reaction shall be detectedwithin a series of 20 tests.BS EN 1797:2001EN 1797:2001 (E)8Annex A(normative)Spontaneous ignition test (Bomb test)A.1 GeneralThis annex defines a test method to deter
47、mine the spontaneous ignitiontemperature of non-metallic materials inpressurised gaseousoxygen.Spontaneousignitiontemperature isa criterion for the comparison and the classification of materials, and can beused as an aid in the choiceofmaterialsused in the presence of pressurised gaseous oxygen.A.2
48、PrincipleA small quantity ofthe test material is slowlyheated in oxygen under pressure. The continuous recording ofpressure and temperature is used to determine spontaneous ignition, which is seen as a sudden increase intemperature and pressure.A.3 Preparation of test piecesTest pieces shall be prep
49、ared byprocedures that prevent contamination.Test pieces can be in liquid or solid form. In the case ofsolids, the materials shall be cut into a minimum of 6pieces. The total mass of the pieces used in each test shall be at least 60 mg.A.4 Test equipmentFigure A.1showsthe basicprinciple of the testequipment. When others methods of heating are used the heatingrate of the specimen should be less than 20C/min. If inductivelyheated furnace are used, the temperature ratecan be up to 110C/min.A thermocouple inside a glove finger positioned as close as possible to the
