1、Designation: G 131 96 (Reapproved 2002)Standard Practice forCleaning of Materials and Components by UltrasonicTechniques1This standard is issued under the fixed designation G 131; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the
2、 year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice covers a procedure for the cleaning ofmaterials and components used in systems requiring a hig
3、hlevel of cleanliness, such as oxygen, by ultrasonic techniques.1.2 This practice may be used for cleaning small parts,components, softgoods, etc.1.3 The values stated in SI units are standard.1.4 This standard does not purport to address all of thesafety concerns, if any, associated with its use. I
4、t is theresponsibility 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 precau-tionary statements are given in Note 1.2. Referenced Documents2.1 ASTM Standards:D 1193 Specification for
5、 Reagent Water2E 1235 Practices for Gravimetric Determination of Non-volatile Residue (NVR) in Environmentally ControlledAreas for Spacecraft3F 311 Practice for Processing Aerospace Liquid Samples forParticulate Contamination Analysis Using Membrane Fil-ters4F 324 Test Method for Nonvolatile Residue
6、 of VolatileCleaning Solvents Using the Solvent Purity Meter4F 331 Test Method for Nonvolatile Residue of HalogenatedSolvent Extract from Aerospace Components (Using Ro-tary Flash Evaporator)4G 121 Practice for the Preparation of Contaminated Cou-pons for the Evaluation of Cleaning Agents5G 122 Test
7、 Method to Evaluate the Effectiveness of Clean-ing Agents53. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 contaminant (contamination), nunwanted molecularand particulate matter that could affect or degrade the perfor-mance of the components upon which they reside.3.1.2 contami
8、nate, va process of applying a contaminant.3.1.3 control coupon (witness coupon), na coupon madefrom the same material and prepared in exactly the same wayas the test coupons, which is used to verify the validity of themethod or part thereof.3.1.3.1 DiscussionIn this practice, the control coupon wil
9、lbe contaminated in the same manner as the test coupons andwill be subjected to the identical cleaning procedure.3.1.4 degas, vthe process of removing gases from aliquid.3.1.5 nonvolatile residue (NVR), nresidual molecular andparticulate matter remaining following the filtration and con-trolled evap
10、oration of a solvent containing contaminants.3.1.6 particle (particulate contaminant), na piece of mat-ter in a solid state with observable length, width, and thickness.3.1.6.1 DiscussionThe size of a particle is usually definedby its greatest dimension and is specified in micrometres.4. Summary of
11、Practice4.1 A part, material or component is placed in a containercontaining the cleaning agent. This container is then placed inan ultrasonic cleaner and treated for a given period of time atthe recommended temperature for the cleaning agent. Thisresults in a solution if the contaminant is soluble
12、in the testfluid or a emulsion if the contaminant is not soluble in the testfluid. The cleaning solution combined with the rinse solutionsmay then be analyzed for particulate, NVR, or total carbon(TC).4.1.1 In the case of aqueous based agents, the parts arerinsed after the removal from the cleaning
13、bath and ultrasoni-cally cleaned in reagent water to provide a solution for TCanalysis using G TC.4.1.2 In the case of solvent based agents, the parts are rinsedwith fresh solvent, which is collected and combined with thesolvent used in the cleaning process, and the NVR determined1This practice is u
14、nder the jurisdiction of ASTM Committee G4 on Compat-ibility and Sensitivity of Materials in Oxygen Enriched Atmospheres and is thedirect responsibility of Subcommittee G04.02 on Recommended Practices.Current edition approved March 10, 1996. Published August 1996. Originallypublished as G 131 95. La
15、st previous edition G 131 95.2Annual Book of ASTM Standards, Vol 11.01.3Annual Book of ASTM Standards, Vol 15.03.4Annual Book of ASTM Standards, Vol 10.05.5Annual Book of ASTM Standards, Vol 14.02.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, Un
16、ited States.using Practice E 1235, Test Method F 324, or Test MethodF 331, as appropriate.4.1.3 Particulate analyses may be performed by filtering thefinal cleaning solution. The particles captured by the filter arethen counted using Test Method F 311.5. Significance and Use5.1 This practice is suit
17、able for the removal of contaminantsfound on materials, parts, and components used in systemsrequiring a high level of cleanliness, such as oxygen. Partsshall have been precleaned to remove visible contaminantsprior to using this procedure. Softgoods such as seals and valveseats may be cleaned witho
18、ut precleaning.5.2 This procedure may also be used as the cleanlinessverification technique for coupons used during cleaning effec-tiveness tests as in Test Method G 122.5.3 The cleaning efficiency has been shown to vary with thefrequency and power density of the ultrasonic unit. Lowfrequencies in t
19、he 20 to 25 kilohertz range have been found todamage soft metals such as aluminum and silver. Therefore, thespecifications of the unit and the frequencies available must beconsidered in order to optimize the cleaning conditions withoutdamaging the parts.6. Apparatus6.1 Ultrasonic Cleaner, with an op
20、erating frequency rangebetween 25 and 90 kHz, a typical power range between 10 and25 W/L, and a temperature controlled bath capable of main-taining a temperature between ambient and 70C with anaccuracy of 2C.6.2 Parts Pans, stainless steel container with volumesbetween 1 and 4 L.6.3 Bracket, stainle
21、ss steel device capable of supporting theparts pans in the ultrasonic bath.NOTE 1The bracket should be designed to hang in the ultrasonic bathwithout contact with the bottom.7. Reagents7.1 Solvents such as the following may be used: tetrachlo-roethylene (perchloroethylene), trichloroethylene, methyl
22、enechloride, and perfluorinated carbon fluids.NOTE 2Warning: Solvents such as tetrachloroethylene (perchloroet-hylene), trichloroethylene, and methylene chloride have relative lowthreshold limit values and the user should refer to appropriate safehandling procedures, particularly in open tanks. Many
23、 solvents are notconsidered to be compatible with oxygen and must be completelyremoved from cleaned components prior to the use of these componentsin oxygen systems. The preferred method of removal shall be determinedby the user.7.2 Purity of ReagentsReagent grade chemicals shall beused in all tests
24、. Unless otherwise indicated, it is intended thatall reagents conform to the specifications of the Committee onAnalytical Reagents of the American Chemical Society wheresuch specifications are available.6Other grades may be used,provided it is first ascertained that the reagent is of sufficientlyhig
25、h purity to permit its use without lessening the accuracy ofthe determination. Detergents used shall be identified bymanufacturer and name (registered trademark, if any).7.3 Purity of WaterThe water used shall meet the require-ments of Specification D 1193, Type II.8. Procedure8.1 Sample Preparation
26、:8.1.1 If cleanliness verification is to be performed on controlor test coupons, prepare the coupons in accordance withPractice G 121.8.1.2 If cleanliness verification is to be performed on smallparts, measure the total surface area (S) in square centimetresor the mass in grams, or both, as applicab
27、le, to the nearest tenthof a milligram (M1). Record the surface area (S) and mass(M1).8.2 Preliminary Procedure:8.2.1 If a cleaning agent is being used that requires dilutionor special preparation, carefully follow the manufacturersinstructions. Use Type II water to prepare the aqueous cleaningagent
28、 solutions or as the actual cleaning agent.NOTE 3It has been found that many common hydrocarbon basedlubricants are effectively removed to acceptable levels using Type II waterat 50 to 55C. More difficult to remove contaminants, such as fluorinatedor silicone based lubricants, have typically been fo
29、und to require the useof surface active agents. Use Practice G 122 to evaluate the cleaningeffectiveness of the proposed cleaning agent.8.2.2 Fill the ultrasonic bath to the level specified by themanufacturer with water. Place the support bracket in theultrasonic bath, heat the ultrasonic bath to th
30、e desired tempera-ture, and degas the water for 10 min.8.2.3 Clean the stainless steel sample parts pan to be used.Conduct the sampling procedure using the selected cleaningagent without parts to verify the cleanliness of the parts pan.Use the same sampling and analysis procedures that will beused o
31、n the actual parts. Determine the contamination level ofthe parts pan, the blank value (B), which shall be less than theallowable contamination level for the items being cleaned orextracted. If the contamination level of the parts pan is greaterthan that specified for the parts, reclean the parts pa
32、n until thecontamination level is less than the allowable contaminationspecified for the parts.8.3 Cleaning Procedure:8.3.1 Place the material or part(s) being cleaned in thestainless steel parts pan.8.3.2 Pour a measured amount of the cleaning agent into thestainless steel cleaning pan sufficient t
33、o cover the parts. Cover6Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For suggestions on the testing of reagents notlisted by the American Chemical Society, see Analar Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the
34、United States Pharmacopeiaand National Formulary, U.S. Pharmaceutical Convention, Inc. (USPC), Rockville,MD.G 131 96 (2002)2the parts pan with aluminum foil or a stainless steel lid, placethe parts pan in the bracket in the ultrasonic bath, adjust thewater level in the bath such that it is above the
35、 cleaning agentlevel in the parts pan, and allow the cleaning agent and bathtemperature to equilibrate to the desired cleaning temperature.Alternatively, preheat the parts pan and cleaning agent prior tothe placement of the materials or parts into the parts pan. Thencover the parts pan with foil and
36、 place into the bracket in thebath and allow the cleaning agent to equilibrate to thetemperature of the bath.8.3.2.1 Cleaning agent to parts surface area ratio shall notexceed 1000 mL/0.1 m2; the preferred ratio is 500 mL/0.1 m2.8.3.3 Clean the parts in the ultrasonic bath for 10 min. If anaqueous d
37、etergent or surfactant solution was used for cleaning,thoroughly rinse the parts with Type II water and then performthe ultrasonic procedure with fresh Type II water. Perform thesampling procedure as soon as possible within a maximumtime limit of 120 min after turning off the ultrasonic cleaner.8.4
38、Sampling Procedure for Solvent Cleaned Parts:8.4.1 Remove the parts pan from the ultrasonic bath andremove the cover. Swirl the parts pan to mix the solvent.8.4.2 After swirling, quickly decant the solvent from theparts pan.8.4.3 Wash the parts pan and parts with 500 mL of freshsolvent in three roug
39、hly equal portions and combine with thesolvent decanted from 8.4.2. Determine the particulate con-tamination analysis using Practice F 311. Use the filtrate fromthe particulate analysis as the sample for NVR analysis.8.4.4 Determine and record the mass (M2) of the nonvolatileresidue in milligrams to
40、 the nearest tenth of a milligram usingPractice E 1235, Test Methods F 324, or F 331. Ensure that thereported NVR is adjusted to subtract the NVR of an equivalentvolume of “blank” solvent.8.5 Sampling procedure for aqueous cleaned materials andparts.8.5.1 Remove the parts pan from the ultrasonic bat
41、h andremove the cover. Swirl the parts pan to mix the Type II water.8.5.2 After swirling, quickly decant the Type II water fromthe parts pan.8.5.3 Wash the parts pan and parts with 500 mL of Type IIwater in three roughly equal portions and combine with theType II water from 8.5.2.8.5.4 Use the combi
42、ned volumes of water from 8.5.3 todetermine the TC of the sample using G TC.9. Report9.1 Report the following information:9.1.1 Identification of the part or material being cleaned(including tradename, part number, serial number, properchemical name, ASTM designation, lot number, batch number,and ma
43、nufacturer),9.1.2 Cleaning reagent,9.1.3 Cleaning time,9.1.4 Cleaning temperature,9.1.5 Frequency of the ultrasonic bath, kHz,9.1.6 Power density of the ultrasonic cleaner, W/L,9.1.7 Volume of cleaning reagent used,9.1.8 Mass (M1) of parts cleaned, g, and9.1.9 Surface area, cm2, and9.1.10 Mass (M2)
44、of thr NVR, g.10. Keywords10.1 cleaning; contamination; contaminant; nonvolatileresidue; NVR; oxygen systems; TC; total carbon; ultrasoniccleaningAPPENDIX(Nonmandatory Information)X1. SELECTION OF ULTRASONIC BATHSX1.1 IntroductionThis appendix describes technical in-formation useful in the selection
45、 of ultrasonic baths foraqueous extraction and cleaning applications. The followinginformation was graciously provided by Blackstone Ultrason-ics7and is reprinted here with their permission.X1.2 Designing an immersible ultrasonic transducer systemrequires that several factors be taken into account.
46、Each case isindividual. The following list will give the reader some idea ofthe parameters that should be defined. Later, each will beconsidered as to its effect on the design of the system.X1.2.1 The Tank:X1.2.1.1 Volumecubic measure or gallons.X1.2.1.2 Shapelength, width and depth.X1.2.1.3 Interna
47、l Featuresheaters, agitators, linings, sub-mersible pumps, etc.X1.2.1.4 Cleaning Zoneparts placement and racking.X1.2.2 The Parts Being Cleaned:X1.2.2.1 Sizephysical dimensions.X1.2.2.2 Weightweight/density.X1.2.2.3 Number Per Load or Per Unit of Timeparts perrack or basket, parts per hour.X1.2.2.4
48、Complexityholes, blind holes, internal surfaces,hems, etc.X1.2.2.5 Ratio of Part Surface Area to Part SizeSolidcube versus typical heat exchanger.X1.2.3 The Contaminant Being Removed:X1.2.3.1 Removal DiffcultyLight oil versus buffing com-pound.7Blackstone Ultrasonics, P.O. Box 220, 9 North Main St.,
49、 Jamestown, NY14702-0220.G 131 96 (2002)3X1.2.3.2 Thickness of BuildupHoles plugged solid versussurface coat.X1.2.3.3 Solubility of the contaminant and its ability toabsorb ultrasound.X1.2.4 Process Parameters:X1.2.4.1 Typical cleaning time.X1.2.4.2 Temperature.X1.2.4.3 Chemical and concentration.X1.3 System design includes determination of the numberof transducers to be used and their placement in the cleaningtank for maximum cleaning effectiveness.X1.3.1 Determination of the Ultrasonic Power Required(see Fig. X1.1):X1.3.1.1 Several schemes have been
