1、ASME A112.18.3-2002(Revision of ASME A112.18.3M-1996)PERFORMANCE REQUIREMENTSFOR BACKFLOW PROTECTIONDEVICES AND SYSTEMS INPLUMBING FIXTURE FITTINGSAN AMERICAN NATIONAL STANDARDIntentionally left blank AN AMERICAN NATIONAL STANDARDPERFORMANCE REQUIREMENTSFOR BACKFLOW PROTECTIONDEVICES AND SYSTEMS INP
2、LUMBING FIXTURE FITTINGSASME A112.18.3-2002(Revision of ASME A112.18.3M-1996)Date of Issuance: May 23, 2003This Standard will be revised when the Society approves the issuance of a new edition. There willbe no addenda issued to this edition.ASME issues written replies to inquiries concerning interpr
3、etations of technical aspects of thisStandard. Interpretations are published on the ASME Web site under the Committee Pages at http:/www.asme.org/codes/ as they are issued.ASME is the registered trademark of The American Society of Mechanical Engineers.This code or standard was developed under proce
4、dures accredited as meeting the criteria for American NationalStandards. The Standards Committee that approved the code or standard was balanced to assure that individuals fromcompetent and concerned interests have had an opportunity to participate. The proposed code or standard was madeavailablefor
5、publicreviewandcommentthatprovidesanopportunityforadditionalpublicinputfromindustry,academia,regulatory agencies, and the public-at-large.ASME does not “approve,” “rate,” or “endorse” any item, construction, proprietary device, or activity.ASME does not take any position with respect to the validity
6、 of any patent rights asserted in connection with anyitems mentioned in this document, and does not undertake to insure anyone utilizing a standard against liability forinfringement of any applicable letters patent, nor assume any such liability. Users of a code or standard are expresslyadvised that
7、 determination of the validity of any such patent rights, and the risk of infringement of such rights, isentirely their own responsibility.Participation by federal agency representative(s) or person(s) affiliated with industry is not to be interpreted asgovernment or industry endorsement of this cod
8、e or standard.ASME accepts responsibility for only those interpretations of this document issued in accordance with the establishedASME procedures and policies, which precludes the issuance of interpretations by individuals.No part of this document may be reproduced in any form,in an electronic retr
9、ieval system or otherwise,without the prior written permission of the publisher.The American Society of Mechanical EngineersThree Park Avenue, New York, NY 10016-5990Copyright 2003 byTHE AMERICAN SOCIETY OF MECHANICAL ENGINEERSAll rights reservedPrinted in U.S.A.Inmemoryof,anddedicatedtothelifeof,ou
10、rdearfriend,colleague,andlong-standingindustryleader,ThomasP.Konen.Hiscontributionstotheplumbingindustryatlargeandtothiscommitteewillneverbeforgotten.Intentionally left blank CONTENTSA112Dedication . iiiForeword viCommitteeRoster . viiCorrespondenceWiththeA112Committee . ix1 Purpose 12 Scope 13 Refe
11、rence Standards 14 Definitions 15 Application of Backflow Prevention Devices . 26 General Requirements for Backflow Prevention Devices 37 Evaluation of Backflow Prevention Devices 38 Fixture Fittings With Internal Devices Complying With Paras. 6 and 7 . 39 Fixture Fittings With Internal Devices Not
12、Complying With Para. 7 410 Test Methods and Performance Criteria . 511 Functional Test of Backflow Prevention Devices . 512 Functional Test of Backflow Prevention Systems . 613 Independence of Devices 714 Leakage of Protection Systems With Atmospheric Vents . 815 Durability Tests . 816 Verification
13、of the Critical Level Hose Connected Movable Outlet Faucets WithAtmospheric Vents, Paras. 8.1.1(b), (c), and (d) 10Figures1 TestProtocolforDevices 42 TestProtocolforFittingsWithoutApprovedComponents 63 FunctionalPerformanceforCheckValves . 74 FunctionalPerformanceforVacuumBreakers,Diverters,andVents
14、toAir 75 FunctionalPerformanceofBackflowPreventionSystemsWithRegardtoBackPressureBackflow 86 FunctionalPerformanceofBackflowPreventionSystemsWithRegardtoBackSiphonage(HoseConnectedMovableOutletFaucets) . 97 SchematicDrawingofTestFacility 108 VerificationoftheCriticalLevel(HoseConectedOutletFaucetsWi
15、thAtmosphericVents) 11Tables1 AcceptanceSamplingPlanDevices . 32 AcceptanceSamplingPlanFittings . 53 FormulationforASMEA112.18.3Water . 9Nonmandatory AppendixA RationaleforSamplingSchemeandStatisticalProcedures . 13vFOREWORDInNovember1987,Panel18oftheASMECommitteeA112,PlumbingMaterialsandEquip-ment,
16、initiatedworktodeveloprequirementsfortheprotectionagainstbackpressurebackflowand back siphonage in an emerging class of fittings, wherein the spout and side spray werecombinedforefficientuseandoperation.TheincreasedconcernfortheprotectionofdrinkingwaterencouragedtheCommitteetolookbeyondtraditionalpr
17、otectionmethodsanddevelopaperformance standard which excludes the contamination of potable water but gives neededfreedomtomanufacturerstoproducefittingsofcomplexdesignandconstructionasdemandedbytodaysworldwidemarkets.Whiletheprobabilityofoccurrenceassociatedwiththecontaminationofpotablewaterthroughb
18、ackflowatvariousplumbingfixturefittingsisminimal,thereremainsaneedforaprotectionsystem.ThisStandardestablishesperformancerequirementswithspecificcriteriaforacceptance,toensureahighdegreeofreliabilityforthesafetysystemthroughouttheusefullifeofthefitting.Extensive testing and engineering reviews of cu
19、rrent practice demonstrated that backflowprotectionismainlyafunctionofthecheckvalveorcheckvalveassemblyandthatrelianceonvacuum breakers is dependent on the adequacy of the air vent. In achieving this, para. 6.3 ofthis Standard requires durability testing of multiple specimens and internationally rec
20、ognizedstatisticalmethodsforevaluatingtheresults.This Standard provides for the evaluation and approval of devices which may be combinedtoformasafetysystembeingintegratedintodifferentproductswithoutfurtherdurabilitytests.In addition, this Standard provides for the evaluation of production fittings c
21、omplete with anintegratedprotection system,whichhowever doesnotexamine theperformanceof thedeviceindividually.Itisdesignedtoconfirmtheoverallreliabilityoftheintegratedsafetysystem.This Standard is written to give freedom to the manufacturer in design and technology toproduceproductswithdevicesandsys
22、temreliabilityconsistentwithgoodengineeringpracticesfortheprotectionofpublichealth.SuggestionsforimprovementofthisStandardwillbewelcomed.TheyshouldbesenttoTheAmerican Society of Mechanical Engineers; Attn: Secretary, A112 Standards Committee; ThreeParkAvenue;NewYork,NY10016.ThisStandardwasapprovedas
23、anAmericanNationalStandardonSeptember6,2002.viASME A112 COMMITTEEStandardization of Plumbing Materials andEquipment(The following is the roster of the Committee at the time of approval of this Standard.)OFFICERSP. J. Higgins, ChairS. A. Remedios, Vice ChairC. J. Gomez, SecretaryCOMMITTEE PERSONNELR.
24、 H. Ackroyd, ConsultantJ. C. Aiello, Jacuzzi Whirlpool BathJ. A. Ballanco, JB Engineering however,theyshouldnotcontainproprietarynamesorinfor-mation.Requests that are not in this format will berewritten in this format by the Committeepriortobeinganswered,whichmayinadvertentlychangetheintentoftheorig
25、inalrequest.ASMEproceduresprovideforreconsiderationofanyinterpretationwhenorifadditionalinformationthatmightaffectaninterpretationisavailable.Further,personsaggrievedbyaninterpretationmayappealtothecognizantASMECommitteeorSubcommittee.ASMEdoes not “approve,”“certify,”“rate,” or “endorse” any item, c
26、onstruction, proprietarydevice,oractivity.Attending Committee Meetings. TheA112StandardsCommitteeschedulesmeetingsas needed, which are open to the public. Persons wishing to attend any meeting shouldcontact the Secretary of the A112 Standards Committee. The A112 home page containsinformationonfuture
27、meetingdatesandlocations.ixIntentionally left blank ASME A112.18.3-2002PERFORMANCE REQUIREMENTS FOR BACKFLOW PROTECTIONDEVICES AND SYSTEMS IN PLUMBING FIXTURE FITTINGS1 PURPOSEThepurposeofthisStandardistoestablishperform-ancerequirementsandstatisticallyvalidevaluationmethodsincludingdurabilitytestsf
28、orthemanufactureofsafe,efficient,andreliablebackflowprotectiondevicesandsystemsforplumbingfixturefittings.AlternativedesignsorconfigurationswhichcomplywiththeintentofthisStandardshallbepermitted.2 SCOPEThisStandardaddressesfunctionalperformanceandrequiresphysicalcharacteristicsofdevicesandsystemswhi
29、chprovidebackflowprotectionconsistentwiththelevelofriskassociatedwiththeplumbingfixturefittingapplication.TheStandardestablishesspecificperform-ance criteria and provides the test methods to provecompliance.Itisapplicabletoallplumbingfixturefit-tingswithoutletsnotprotectedbyanairgap.3 REFERENCE STAN
30、DARDSThefollowingdocumentsformapartofthisStandardtotheextentspecifiedherein.Thelatestissueshallapply.ASTMD1193,SpecificationforReagentWaterPublisher:TheAmericanSocietyforTestingandMateri-als (ASTM), 100 Barr Harbor Drive, West Consho-hocken,PA19428ASMEA112.1.2,AirGapsinPlumbingSystemsASMEA112.18.1,P
31、lumbingFixtureFittingsASMEPTC19.2,SupplementonInstrumentsandAppa-ratus,Part2PressureMeasurementPublisher:TheAmericanSocietyofMechanicalEngi-neers(ASMEInternational),ThreeParkAvenue,NewYork,NY10016-5990ANSI/ASSE1001,PipeAppliedAtmosphericTypeVac-uumBreakersANSI/ASSE1011,PerformanceRequirementsforHose
32、ConnectionVacuumBreakersANSI/ASSE1014,PerformanceRequirementsforHand-HeldShowersANSI/ASSE1025,PerformanceRequirementsforDivertersforPlumbingFaucetsWithHoseSpray,Anti-SiphonType,ResidentialApplicationsANSI/ASSE1052,HoseConnectionBackflowPre-ventors1ASSE1012,PerformanceRequirementsforBackflowPre-vente
33、rsWithIntermediateAtmosphericVentASSE1013,PerformanceRequirementsforReducedPressurePrincipleBackflowPreventersASSE1019,VacuumBreakerWallHydrants,FrostResis-tantAutomaticDrainingTypeASSE 1035, Performance Requirements for LaboratoryFaucetVacuumBreakersASSE1056,PerformanceRequirementsforBackSiphon-age
34、BackflowVacuumBreakersPublisher:TheAmericanSocietyofSanitaryEngi-neering, 2890 Clemens Road, Suite 100, West Lake,OH44145AWWAC511,ReducePressurePrincipleBackflowPre-ventorAssemblyAWWA10079,StandardMethods fortheExaminationofWaterandWastewaterPublisher: The American Water Water Works Associa-tion (AW
35、WA), 6666 West Quincy Ave., Denver, CO80235CSAB64,BackflowPreventersandVacuumBreakersCSAB125,PlumbingFittingsPublisher:CSAInternational,178RexdaleBlvd.,Toronto,Ontario,CanadaM9W1R34 DEFINITIONSNomenclature and definitions applicable to faucets,fixture fittings, and backflow requirements shall be asf
36、ollows:acceptance sampling plan: the correlation of sample sizeandallowedfailurerate.airgap:theunobstructed verticaldistancethroughthefreeatmospherebetweenthelowestopeningfromanypipeorfaucetandtheflood-levelrimofareceptor.SeeASMEA112.1.2.approved:acceptedbytheauthorityhavingjurisdictionbackflow: the
37、 reversal of flow direction from that nor-mallyintended.Backsiphonageisonetypeofbackflow.Backpressurebackflowisanothertype.backflowpreventionsystem:anymechanicalsystem,con-sistingoftwoormoredevices,designedtoautomaticallyprevent an unintentional reversal of flow in a potablewaterdistributionsystem.A
38、backflowpreventionsys-tem prevents back siphonage and back pressurebackflow.ASME A112.18.3-2002 PERFORMANCE REQUIREMENTS FOR BACKFLOW PROTECTIONDEVICES AND SYSTEMS IN PLUMBING FIXTURE FITTINGSbackpressure:apressurehigherattheoutletofafittingthanthatattheinletorapointupstream.backsiphonage:theflowing
39、backofwaterfromaplumb-ingfixture,vessel,orothersourceintothefittingastheresultofavacuumattheinletofthefitting.bidet:afixtureand/orwallmountedfittingwithtransfervalvesforverticalsprayandrimflushing;adeckmountedfittingwithhoseconnectedoutlets.certified: indicates that testing has been conducted byanap
40、provedindependenttestingagencyinaccordancewith the applicable standard and found to be in mercial fitting: a hose and spray assembly for foodservice,dispensers,andsimilarnonresidentialapplica-tionsother thanthose wherean airgapis maintainedbydesign,suchasspring-actiongoosenecks.criticallevel:levelat
41、whichpollutedwater,enteringthroughanoutletofthe supplyfitting,willflowbacktothesupplylinesbygravityand/oranynegativepres-sureinthesupplylinewhenthewatercontrolvalveisfullyopen.crossconnection:anactualorpotentialconnectionorarrangementbetweentwoormoreseparatepipingsys-tems,oneofwhichcontainspotablewa
42、terandoneoftheothersasourceofquestionableorunknownquality.The direction of flow will depend upon the pressuredifferentialbetweenthetwosystems.deckmountedandcombinationfitting:residentialdeckmountedfittingfortubs.Itoftenincludesahand-heldorpersonalshower.device:oneoftheconstituentpartsofabackflowprev
43、en-tionsystemwhichbyitselfprovidesaformofbackflowprotection.fillvalve:awatersupplyvalve(alsoknownasaballcock),openedorclosedbymeansofafloatorsimilardevice,usedtosupplywatertoatank.fitting with side sprays: a kitchen deck mounted fittingwith integral diverter and hose connected side spray.Theprimaryo
44、utletisprotectedwithanairgap.fittingwihpull-outspout:adeckmountedfixturefittingwithaprimaryremovablespoutthatisconnectedtothebodyofthefaucetthroughaflexiblehose.Applicationsareresidentialkitchens,lowsinks,andlavatories.hand held shower: a product consisting of a hose anddischarge piece, such as a sh
45、ower head or spray; it isused in conjunction with bath and shower fittings ordedicatedwalloutlets.hosebibb:afittingterminatingwithahosethread.inspection:theprocessofmeasuring,examining,testing,gauging,orotherwisecomparingtheunitwiththeappli-cablerequirements.2laboratory fitting: a fitting terminatin
46、g with a serratedhosetip.potablewater:waterwhichissuitablefordrinkingandfreefromimpuritiespresentinamountswhicharesuffi-cienttocausediseaseorharmfulphysiologicaleffects.randomsample:asampletakeninamannerwhichgiveseveryiteminthelot,oreveryportionofthelotforbulkmaterials,anequalprobabilityofbeingselec
47、tedaspartofthesample.sample:thenumberofspecimensselectedfromaproduc-tionlotasrepresentativeofthatlot.samplingscheme,multiple:asamplingmethodinwhich,aftereachsampleisinspected,thedecisionismadetoacceptalot,torejectit,ortotakeanothersample,thetestresultofwhichshallbeaddedtothatofthepreviousone.shampoo
48、 fitting: a hose and spray assembly for attach-menttoawalloutletorlavatoryfitting.specimen:anindividualcomponentwhichcombinedwithothersmakesuparequiredsample.upperconfidencelimit:themaximumprobablepercentageof individualsafety devicessubject tobackflow inthefieldunderthoseconditionsdefinedinthelifet
49、est.vacuumbreaker:adeviceormeanstopreventbacksiphonagebyallowingairtoenterafitting.venttoair:abackflowpreventiondevicewhichopensafittingorpartofafittingtotheatmosphere.5 APPLICATION OF BACKFLOW PREVENTIONDEVICES5.1 Minimum Level of ProtectionFixturefittingswhicharenotprotectedagainstback-flowbyanairgapinaccordancewithASMEA112.1.2underallconditionsofusageshallincorporatebackflowprotectionbymeansdescribedinparas.6through16oruseasystemordeviceincompliancewiththefollowingstandards: ANSI/ASSE 1001, ANSI/ASSE 1011, ASSE1012, ASSE 1013, ANSI/ASSE 1014, ASSE 10
