ASTM E1066 E1066M-2012 red 6664 Standard Practice for Ammonia Colorimetric LeakTesting《氨比色法检漏的标准方法》.pdf

1、Designation:E106695 (Reapproved 2006)Standard Test Method for Designation: E1066/E1066M 12Standard Practice forAmmonia Colorimetric Leak Testing1This standard is issued under the fixed designation E1066/E1066M; the number immediately following the designation indicates the yearof original adoption o

2、r, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval.A superscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the testing of large single- and double-walled tanks,

3、pressure and vacuum vessels, laminated, lined-or double-walled parts, complex piping systems, flexible containers (such as aircraft fuel tanks), glass-to-metal seals in hybridpackages, and systems that inherently contain or will contain ammonia (such as large tonnage refrigeration systems and fertil

4、izerstorage systems).1.2 This method can be used on piping, valves and containers with welded, fitted, or laminated sections that can be sealed attheir ends or between their outer and inner walls and that are designed for internal pressures of 34.5 kPa (5 psig)5 psig or greater.1.3 Basic procedures

5、are described based on the type of inspection used. These procedures should be limited to finding leakageindications of 4.5 3 1012mol/s (1310mol/s 1 3 107Std cm3/s)/s2or larger.1.4 UnitsThe values stated in Std cm3/s or mol/s are to be regarded separately as standard. The values stated in each syste

6、mmay not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the twosystems may result in non-conformance with the standard.1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the re

7、sponsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use. (For more specific safety precautionary information see 7.4, 8.2, 9.4.1, and 10.3.1).2. Referenced Documents2.1 ASTM Standards:3E1002 P

8、ractice for Leaks Using UltrasonicsE1316 Terminology for Nondestructive Examinations2.2 Other Documents:SNT-TC-1A Recommended Practice for Personnel Qualification and Certification in Nondestructive Testing4ANSI/ASNT CP-189 ASNT Standard for Qualification and Certification of Nondestructive Testing

9、Personnel43. Terminology3.1 DefinitionsFor definitions of terms used in this standard, see Terminology E1316, Section E.4. Summary of Test MethodPractice4.1 This test method consists of testing a container already filled with ammonia or of introducing an anhydrous ammonia or anammonia-nitrogen mixtu

10、re into a container or system so that the final ammonia percentage achieved is between 1 and 100 % byvolume at a gage pressure between 34.5 and 689.5 kPa (55 and 100 psig).psig. The ammonia flows through leaks existing inwelds and connections and reacts with a developer that is applied outside of th

11、e container producing a visible indication.4.2 Two basic developer procedures are described:1This test method is under the jurisdiction of ASTM Committee E07 on Nondestructive Testing and is the direct responsibility of Subcommittee E07.08 on Leak TestingMethod.Current edition approved Dec. 1, 2006.

12、 Published January 2007. Originally approved in 1985. Last previous edition approved in 2000 as E1066-95(2000). DOI:10.1520/E1066-95R06. on Leak Testing Method.Current edition approved June 15, 2012. Published July 2012. Originally approved in 1985. Last previous edition approved in 2006 as E1066 -

13、95(2006). DOI:10.1520/E1066-12.2The gas temperature is referenced to 0C. To convert to another gas reference temperature, Tref, multiply the leak rate by (Tref+ 273)/273.3For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual

14、 Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.4Available from American Society for Nondestructive Testing (ASNT), P.O. Box 28518, 1711 Arlingate Ln., Columbus, OH 43228-0518, http:/www.asnt.org.1This document is not an ASTM standard and i

15、s intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the

16、 current versionof the standard as published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.4.2.1 Smoke-producing developers.4.2.2 Color-change developers.4.3 Methods of introducing a

17、mmonia into unfilled systems are described, together with methods of estimating the concentrationand pressure needed to achieve specific detectable leak rates.4.4 Procedures for testing large tanks and systems are described.4.5 Ultrasonic pretesting for gross leaks is described.5. Personnel Qualific

18、ation5.1 It is recommended that personnel performing leak testing attend a dedicated training course on the subject and pass a writtenexamination. The training course should be appropriate for NDT level II qualification according to Recommended Practice No.SNT-TC-1A of the American Society for Nonde

19、structive Testing or ANSI/ASNT Standard CP-189.6. Significance and Use6.1 This method is useful for locating and measuring the size of gas leaks either as a quality-control test or as a field-inspectionprocedure. It can be used to test critical parts or containers that will hold toxic or explosive g

20、ases or liquids or as a quick test forother containers.7. Interferences7.1 The interior and exterior welds and joints where leaks are often found must be free of oil, grease, flux, slag, paint, or othercontaminants that might temporarily block or mask leakage. New containers should not be painted pr

21、ior to test. Smoking duringthe test may cause false indications.7.2 Pure ammonia gas is likely to attack brass or copper metals in a humid environment. It will not if there is no water vaporpresent.7.3 Ammonia gas attacks wood fibers when the wood contains a high moisture content. Dry wood tolerates

22、 ammoniaconcentrations below 30 %.7.4 Ammonia in high concentrations can be hazardous. When working with ammonia it is recommended that anammonia-sensitive badge be worn for safety.7.4.1 The lower explosive limit (LEL) for ammonia and air is 15 %. The upper explosive limit (UEL) is 28 %.7.4.2 The ce

23、iling for limited exposure to ammonia (1 h) is about 500 ppm.7.5 If the container to be tested has parts made of stainless steel, nickel, or chromium alloys, the color-change developer residueshould have a sulfur and halogen content of under 500 ppm of each.8. Apparatus8.1 Apparatus for Precleaning:

24、8.1.1 Gloves.8.1.2 Vacuum Pump or Heat Gun, if necessary to dry container.8.1.3 Spray Gun, if aerosol cleaner not used.8.1.4 Ammonia-Sensitive Monitor, to test area contamination.8.2 Safety Apparatus:8.2.1 Mask, covering mouth and nose.8.2.2 Ammonia Monitors.8.2.3 Gas Mask, if personnel work inside

25、the tank or with high concentrations of ammonia during a test.8.3 Apparatus for Injecting Ammonia Gas:8.3.1 Pressure GageThe gage must be able to withstand normal test pressures. The gage must be accurate to within 1 % offull scale. The gage must read at least 1.53 but not more than 43 the maximum t

26、est pressure to be used. The gage must be incurrent calibration.8.3.2 Pressure-Relief Valve, if high pressures are to be used.8.3.3 Pressure-Reducing, -Control, and -Mixing Valves, for the ammonia and nitrogen circuits if not already mixed.8.3.4 High-Conductance Injection Line and Exhaust Line.8.4 A

27、pparatus for Applying Colorimetric Developer:8.4.1 Spray Gun, if an aerosol is not used.8.4.2 Temperature-Controlled Heat Gun, if a water-based developer is used.8.5 Apparatus for Post Cleaning and Inspection:8.5.1 Brush or Vacuum Sweeper, for developer powder.8.5.2 Tape, for marking and sealing lea

28、ks.9. General Procedures for Test Objects not Already Containing Ammonia9.1 Openings:9.1.1 Seal all openings using plugs or covers that can withstand the test pressure and can be completely removed after the test.E1066/E1066M 1229.1.2 Locate the test gas inlet on the bottom of the test object with t

29、he trapped air vent at the highest point.9.1.3 Components rated at pressures below the test pressure must be isolated.9.2 GagesOne or more test gages must be connected to the system. If more than one gage is used, one may be a recordinggage.All gages must have been calibrated within a specified time

30、 period. One indicating gage must be easily visible to the operatorcontrolling the pressure throughout the pressurizing cycle.9.3 Pre-Test Inspection:9.3.1 Before pressurizing is begun, inspect the outside (and inside if possible) of the test object to verify that it is dry, free ofoils, greases, sm

31、oke deposits, or slag and that all welds and connectors are exposed.9.3.2 An ultrasonic pretest (Section 12) can be used to locate gross leaks.9.4 Vacuum Drying:9.4.1 If the test object contains wood or copper parts that will be exposed to ammonia, and if the vessel is designed to be safeunder vaccu

32、m, it may be necessary to vacuum-dry the inside of the object.9.4.2 Moisture begins to evaporate at a pressure of about 3 kPa (25 torr).25 torr. Bring the test object down to a pressure of250 Pa (20 torr).20 torr. At this point water will boil off, indicated by a sudden halt in the vacuum gage needl

33、e. When the needlestarts to go down indicating a lower pressure it can be assumed that all but trace mounts of water have been eliminated.9.5 PressurizingGradually increase the pressure in the system to 50 % of test pressure during which time frequent checksshould be made for leakage. Thereafter, sl

34、owly increase the pressure to the final test pressure. The test pressure usually is between75 and 150 % of design pressure and should not violate any applicable codes. If large leaks are expected and an ultrasonic pretesthas not been conducted, stop the pressurization at 6.9 kPa (1 psig)1 psig and r

35、epair any leaks found before continuing.9.6 Leak Test:9.6.1 At the completion of test pressure holding time, examine the system for leakage. Examination of leakage shall be madeof all welds, joints, and connections.9.6.2 The inspector shall mark all accessible leaks found on the equipment using a no

36、ndeleterious distinctive tape. Themagnitude of leak shall be described in terms of the diameter of the color-change indication or the apparent density of the smokeproduced.9.7 DepressurizingAfter inspection, slowly release the pressure by venting the ammonia-nitrogen mixture to atmosphere orinto wat

37、er.Ammonia is very soluble; 1 L of water can absorb between 800 and 2000 L of gaseous ammonia.Avacuum pump maybe used to help exhaust the remaining ammonia or the tank may be purged with nitrogen or compressed air.9.8 Removing the Color-Change DeveloperRemove the test developer from the test object

38、by brushing it from the surface andcleaning with a dust-remover.10. Smoke-Developer Method10.1 SensitivityThis test is the least sensitive and least calibratable of the developer methods. Its sensitivity with pureammonia at 6.9 kPa (1 psig)1 psig is approximately 4.5 3 108mol/s (1310mol/s 1 3 103Std

39、 cm3/s).2/s.210.2 Application:10.2.1 This test is used primarily on systems that already contain ammonia or as a quick pre-test before applying thecolor-change developer.10.2.2 Where small volumes need to be pressurized and pure ammonia may be used, this method can provide rapid leaklocation.10.3 Sm

40、oke-Developer Types:10.3.1 Sulfur candles produce a hazardous gas (sulfur dioxide) and for this reason are not recommended. This gas produces avisible smoke upon contact with ammonia.10.3.2 Some dilute acid vapors produce a visible smoke with ammonia. The liquids that give rise to these vapors can b

41、e appliedby wet swab or by aerosol. An aerosol spray is the preferred technique.10.4 Process:10.4.1 If the test object does not contain ammonia, it should be pressurized slowly to between 6.9 and 69 kPa (11 and 10psig)psig with pure ammonia. If leak location rather than the leakage rate is desired,

42、a cloth saturated with ammonium hydroxidecan be placed in the pressurized space. Move the developer vapor slowly over areas of possible leaks. A white cloud will beproduced at the leak location.10.4.2 Mark and seal leak locations with tape whenever possible.11. Color-Change Method11.1 Sensitivity:11

43、.1.1 By varying the ammonia concentration, the test pressure and the development time, any leakage rate from 4.5 3 1011to 4.5 3 1012mol/s (11 to 1 3 107Std cm3/s)2/s2can be detected. The equation in 11.1.2 is usually applied by specifying thesmallest leakage rate required (MDLR), as well as the maxi

44、mum test pressure allowable. Depending on which is the moreimportant remaining variable, test time or ammonia concentration, the less critical variable is solved for.11.1.2 Leakage Rate CalculationThe following equation allows precise calculation of the test time in seconds ( t), percentageof ammoni

45、a tracer (c), and absolute pressure in pounds per square inch (psia) within the test vessel (p) for any minimum detectableE1066/E1066M 123leakage rate (MDLR). This equation is based on laboratory data using the time in seconds required to generate a 1-mm reactionspot as the diameter of the minimum d

46、evelopment area. Leakage rates are expressed in atmcm3/s.MDLR 52.53415p22 3241!c2/3!t!(1)E1066-12_1where:t = time in seconds,c = % ammonia,p = psia, andMDLR = atmcm3/s.11.1.3 The equation can be recast to solve for any of the variables. For example, a company wishing to test for leakage of4.5 3 1011

47、mol/s (1310mol/s 1 3 106Std cm3/s)/s2could proceed as follows: Assuming that 345 kPa (50 psia)50 psia was themaximum pressure their system could tolerate, it would take 4 min and 30 s to develop a reaction spot of 1 mm using a 50 %concentration of ammonia.This result is calculated as follows:E1066-1

48、2_2orE1066-12_311.1.4 It has been determined experimentally for wall thicknesses of 1 to 50 mm that for any given pressure differential, theobserved leakage rate varies inversely with the thickness of the wall being tested. Although the relationship is not linear, thedecrease in observed leakage can

49、 be approximated by adding the following numbers to the exponents of the theoretical MDLRyou wish to detect.11.1.4.1 For wall thicknesses of 2 to 10 mm (0.080.08 to 0.4 in.)in. add nothing.11.1.4.2 For wall thicknesses between 10 and 25 mm (0.40.4 to 1 in.)in. add 1.11.1.4.3 For wall thicknesses between 25 and 50 mm (11 to 2 in.)in. add 2.11.2 ApplicationThis method can be used on containers or systems that are filled or unfilled with ammonia as long as theatmosphere surrounding the test area is not contaminated with ammon