ASTM_F_1394_-_92_2012.pdf

Designation:F139492(Reapproved 2012)Standard Test Method forDetermination of Particle Contribution from Gas DistributionSystem Valves1This standard is issued under the fixed designation F1394;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.INTRODUCTIONSemiconductor clean rooms are serviced by high-purity gas distribution systems.This test methodpresents a procedure that may be applied for the evaluation of one or more components considered foruse in such systems.1.Scope1.1 This test method covers gas distribution system compo-nents intended for installation into a high-purity gas distribu-tion system.1.1.1 This test method describes a procedure designed todraw statistically significant comparisons of particulate gen-eration performance of valves tested under aggressive condi-tions.1.1.2 This test method is not intended as a methodology formonitoring on-going particle performance once a particularvalve has been tested.1.2 This test method utilizes a condensation nucleus counter(CNC)applied to in-line gas valves typically used in semicon-ductor applications.It applies to automatic and manual valvesof various types(such as diaphragms or bellows),6.3 through12.7-mm(14through12-in.)size.For applications of this testmethod to larger valves,see the table in the appendix.1.2.1 Valves larger than 12.7 mm(12in.)can be tested bythis methodology.The test stand must be sized accordingly.Components larger than 12.7 mm(12in.)should be testedwhile maintaining a Reynolds number of 20 000 to 21 000.This is the Reynolds number for 12.7-mm(12-in.)componentstested at a velocity of 30.5 m/s(100 ft/s).1.3 Limitations:1.3.1 This test method is applicable to total particle countgreater than the minimum detection limit(MDL)of thecondensation nucleus particle counter and does not considerclassifying data into various size ranges.1.3.1.1 It is questionable whether significant data can begenerated from nondynamic components(such as fittings andshort lengths of tubing)to compare,with statisticalsignificance,to the data generated from the spool piece.Forthis reason,this test method cannot reliably support compari-sons between these types of components.1.3.1.2 If detection or classification of particles,or both,inthe size range of laser particle counter(LPC)technology is ofinterest,an LPC can be utilized for testing components.Flowrates,test times,sampling apparatus,and data analysis outlinedin this test method do not apply for use with an LPC.Becauseof these variations,data from CNCs are not comparable to datafrom LPCs.1.3.2 This test method specifies flow and mechanical stressconditions in excess of those considered typical.These condi-tions should not exceed those recommended by the manufac-turer.Actual performance under normal operating conditionsmay vary.1.3.3 The test method is limited to nitrogen or clean dry air.Performance with other gases may vary.1.3.4 This test method is intended for use by operators whounderstand the use of the apparatus at a level equivalent to sixmonths of experience.1.3.5 The appropriate particle counter manufacturers oper-ating and maintenance manuals should be consulted whenusing this test method.1.4 The values stated in SI units are to be regarded as thestandard.The inch-pound units given in parentheses are forinformation only.1.5This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is the1This test method is under the jurisdiction of ASTM Committee F01 onElectronics and is the direct responsibility of Subcommittee F01.10 on Contamina-tion Control.Current edition approved July 1,2012.Published August 2012.Originallyapproved in 1992.Last previous edition approved in 2005 as F139492(2005).DOI:10.1520/F1394-92R12.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 responsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.Specific hazardstatements are given in Section 6,Hazards.2.Referenced Documents2.1 Federal Standard:FED-STD-209D Federal Standard Clean Room and WorkStation Requirements,Controlled Environment23.Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 background countscounts contributed by the testapparatus(including counter electrical noise)with the spoolpiece in place of the test object.3.1.2 condensation nucleus counter(CNC)light scatteringinstrument that detects particles in a gaseous stream bycondensing supersaturated vapor upon the particles.3.1.3 control productsample component that givesconsistent,stabilized counts at or below the expected countsfrom the test components.The product is run periodically inaccordance wi