ASME A112.18.3:2002 pdf download PERFORMANCEREQUIREMENTS FORBACKFLOWPROTECTION DEVICES AND SYSTEMS IN PLUMBING FIXTUREFITTINGS
laborafory fitting: a fitting terminating with a serratedhose tip.
potable wafer: water which is suitable for drinking andfree from impurities present in amounts which are sufficient to cause disease or harmful physiological effects
randon sanple: a sample taken in a manner which giverevery item in the lot, or every portion of the lot for bulkmaterials, an equal probability of being selected as parof the sample.
sample: the number of specimens selected from a production lot as representative of that lot.
samnpling schenne, nultiple: a sampling method in whichafter each sample is inspected, the decision is made tcaccept a lot, to reject it, or to take another sample, the testresult of which shallbe added to that of the previous oneshampoo fitfing: a hose and spray assembly for attachment to a wall outlet or lavatory fitting.
specimen: an individual component which combinedwith others makes up a required sample.
upper confidence limif: the maximum probable percentageof individual safety devices subject to backflow in thefield under those conditions defined in the life test.
vacuum breaker: a device or means to prevent backsiphonage by allowing air to enter a fitting.
venf fo air: a backflow prevention device which opens afitting or part of a fitting to the atmosphere.
5 APPLICATION OF BACKFLOW PREVENTIONDEVICES
5.1 Minimum Level of Protection
Fixture fittings which are not protected against backflow by an air gap in accordance with ASME A112.1.2under all conditions of usage shall incorporate backflowprotection by means d6 throueh 16 or1n Daras.use a system or devicein compliance with the followingstandards:NSL/ASSE 1001ANSI/ASSE 1011.ASSE1012，ASSE 1013/ASSE 1014.ASSE 1019.ASSEANS摊矽壁袄版备跋扒北熬昆卑芭1035，ASSE 1052，ASSE 1056，AWWA C511，CSA B64or CSA B125 dependent on their application and codeinstalation requirements with no further testing to thisStandard.
5.2 Application
(a) Backflow prevention devices or systems not covered by the standards listed in para. 5.1 shall complywith paras,6 and 7
(b) Fittings with internal backflow prevention devicesor systems complying with paras.6 and 7 shall be tested
to para. 8.(c) Fittings with internal backflow prevention devicesor systems not complying with paras. 6 and 7 shallcomply with para.9.
GENERAL REQUIREMENTS FOR BACKFLOW6PREVENTION DEVICES
6.1 Functional
Backflow prevention devices shall be designed to prevent pollution and contamination of the potable watersystem.
6.2 Materials
Materials in contact with potable water shall complywith the requirements of ASME A11218.1M.
6.3Environment
6.31 Working Pressure. Backflow prevention devicesshall be designed to function at water working pressuresup to 125 psig (861 kPa gage).
6.3.2 Working Temperature. Backflow preventiondevices shall be designed to function at water supplytemperatures ranging from 40°F to 160”F(44%C to 71C)
6.4 Reliability
Backflow prevention devices shall be resistant tomechanical wear, deposition of minerals, aging, and corrosion of the materials as determined by the test procedure of para.7.The manufacturer shall establish thereliability of the individual backflow prevention deviceand it shall be confirmed by durability tests in accor-dance with para.7.
EVALUATION OF BACKFLOW PREVENTION7DEVICES
7.1 Sample Size
The minimum initial sample size per set shall be sevenspecimens.The incremental increases and cumulativesample sizes shall be as shown in Table 1.
7.2 Test Methodology
7.2.1 Facilities The backflow prevention devicesshall be tested individually in fittings or test fixturesrepresenting the dimensions and tolerances specified bythe device manufacturer.
7.2.2 ProtocolThe functional performance of thedevice shall be determined before and after the durabil.ity test sequence.The functional performance of a device
ASME A112.18.3:2002 pdf download
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