ASTM A1047 A1047M-2005(2014) Standard Test Method for Pneumatic Leak Testing of Tubing《管道的气压泄漏标准试验方法》.pdf

1、Designation: A1047/A1047M 05 (Reapproved 2014)Standard Test Method forPneumatic Leak Testing of Tubing1This standard is issued under the fixed designation A1047/A1047M; the number immediately following the designation indicates theyear of original adoption or, in the case of revision, the year of la

2、st revision. A number in parentheses indicates the year of lastreapproval. A superscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method provides procedures for the leak testingof tubing using pneumatic pressure. This test method involvesme

3、asuring the change in pressure inside the tubing over time.There are three procedures that may be used, all of which areintended to be equivalent. It is a qualitative not a quantitativetest method. Any of the three procedures are intended to becapable of leak detection and, as such, are intended to

4、beequivalent for that purpose.1.2 The procedures will produce consistent results uponwhich acceptance standards can be based. This test may beperformed in accordance with the Pressure Differential (Pro-cedure A), the Pressure Decay (Procedure B), or the VacuumDecay (Procedure C) method.1.3 The value

5、s stated in either SI units or inch-pound unitsare to be regarded separately as standard. The values stated ineach system may not be exact equivalents; therefore, eachsystem shall be used independently of the other. Combiningvalues from the two systems may result in non-conformancewith the standard.

6、1.3.1 Within the text, the SI units are shown in brackets.1.4 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bil

7、ity of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2A1016/A1016M Specification for General Requirements forFerritic Alloy Steel, Austenitic Alloy Steel, and StainlessSteel Tubes3. Terminology3.1 DefinitionsThe definitions in Specification A1016/A1016M are applicable

8、 to this test method.3.2 Definitions of Terms Specific to This Standard:3.2.1 actual starting pressure (P0actual)the actual start-ing pressure at time zero on each test cycle.3.2.2 calibration holea device (such as a crimpedcapillary, or a tube containing a hole produced by laser drilling)certified

9、to be of the specified diameter.3.2.3 control volumefixed volume that is pressurized tocompare against an identical pressure contained in one tubeunder test.3.2.4 electronic control device (ECD)an electronic systemto accumulate input from limit switches and transmittersproviding corresponding output

10、s to solenoid valves, acousticalarm devices, and visual displays3.2.5 pressure change (P)the smallest pressure changein a tube, reliably detected by a pressure sensitive transmitter.3.2.6 pressure sensitive transmitterspressure measuringand signaling devices that detect extremely small changes inpre

11、ssure, either between two tubes, a tube and a controlvolume, or a tube and the ambient atmosphere.3.2.7 reference standarda tube or container containing acalibration hole. The calibration hole may either be in a fulllength tube, or in a short device attached to the tube orcontainer.3.2.8 starting pr

12、essure (P0)the test starting pressure set inthe test apparatus ECD.3.2.9 theoretical holea hole that will pass air at a theo-retical rate as defined by the equations given inAppendix X1.2.3.2.10 threshold pressure (PT)test ending pressure limitafter the allowed test time; the pressure value that mus

13、t be1This test method is under the jurisdiction of ASTM Committee A01 on Steel,Stainless Steel and Related Alloys and is the direct responsibility of SubcommitteeA01.10 on Stainless and Alloy Steel Tubular Products.Current edition approved March 1, 2014. Published March 2014. Originallyapproved in 2

14、005. Last previous edition approved in 2009 as A1047/A1047M 05(2009). DOI: 10.1520/A1047_A1047M-05R14.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards

15、Document Summary page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1crossed to determine reject status. PT= P0actual P forpressure decay, and PT= P0actual + P for vacuum decay.4. Summary of Test Method4.1 Procedur

16、e A, Pressure Differential, measures the drop inpressure over time as a result of air escaping from inside onetube when compared to another tube at an identical pressure, orone tube against a control volume at identical pressure. (SeeRefs (1) and (2).)34.2 Procedure B, Pressure Decay, measures the d

17、rop inpressure over time as a result of air escaping from the tube.4.3 Procedure C, Vacuum Decay, involves evacuating thetubing to suitably low pressure and measuring the increase inpressure caused by gas entering the tubing.5. Significance and Use5.1 When permitted by a specification or the order,

18、this testmethod may be used for detecting leaks in tubing in lieu of theair underwater pressure test.6. Apparatus6.1 An electronic control device (ECD) controls all opera-tions of the test method by accepting inputs from limit switchesand transmitters, and by providing corresponding pass/failoutputs

19、 to solenoid valves, acoustic alarm devices, and visualdisplays. The pass/fail determination is achieved by a compari-son of the data input from pressure transducers with a standardaccept/reject criterion measured over the set test time.6.2 The test apparatus may have the capability for single- ormu

20、lti-tube testing. It shall be designed to detect a smallpredetermined pressure change during the testing cycle. It isintended that the apparatus be fully automated and equippedwith suitable instrumentation for the purpose of the test. Thisinstrumentation may include, but is not limited to the follow

21、-ing:6.2.1 Internal transducers for calibration tests,6.2.2 Differential pressure and leak rate diagnosis,6.2.3 Control panel display for reporting digital or analogoutputs,6.2.4 Absolute or differential pressure transducers, or both,6.2.5 Internal timing device,6.2.6 Failure lamps, and6.2.7 Automat

22、ic shutdown capability.7. Hazards7.1 WarningIn addition to other precautions, high pres-sure air is employed during the testing process.8. Calibration8.1 Apparatus calibration shall be performed using a refer-ence standard, with adjustments of Starting Pressure (P0),Pressure Change (P), and test tim

23、e. Test time is dependentupon starting pressure, allowed pressure change, tube internalvolume, hole diameter, and is calculated using the equation inAppendix X1. Actual test time may be longer than thecalculated value and shall be adjusted as necessary for theapparatus to cross the threshold pressur

24、e and cause the systemto automatically shut down.8.2 Verify that all failure lights are illuminated during thecalibration.8.3 Unless otherwise specified, apparatus calibration shallbe made at twelve month intervals maximum.8.4 Recalibrate the test apparatus prior to use whenever anypressure sensing

25、component is replaced or modified.8.5 Calibrate the calibration hole at twelve month intervalsmaximum. It is recommended that the device containing thecalibration hole be stored in an inert atmosphere and cleanedwith high pressure nitrogen.8.6 Calibrate all pressure gauges and pressure transducers a

26、ttwelve month intervals maximum.8.7 Unless otherwise agreed to by producer and purchaser,the minimum calibration hole size in the reference standardshall be 0.003-in. diameter. Calibration with smaller holes maynot be repeatable due to fouling and plugging. (See Ref (3).)9. Procedure9.1 Perform pneu

27、matic leak testing after all processoperations, including cold work, heat treatment, and straight-ening.9.2 Clean and dry the tubes before testing. Remove loosescale from the inside and outside surfaces of the tubes.9.3 Actual test time is calculated in accordance with theparameters of the test usin

28、g the appropriate equation in X1.2.9.4 Test Cycle for Procedure A, Pressure Differential:9.4.1 Pressurize the tubes in pairs, or a single tube and aknown control volume, to a pressure greater than 33 psia withclean and dry compressed air.9.4.2 Allow the system to stabilize and measure the actualStar

29、ting Pressure (P0actual). P0actual must be within 10 % ofP0for a valid test.9.4.3 The apparatus is to calculate and set the ThresholdPressure where PT= P0actual P.9.4.4 Isolate the tubes in pairs or a single tube and a knowncontrol volume.9.4.5 Measure the pressure at the end of the test period. The

30、tubes or tube have/has passed the test if the pressure has notcrossed the threshold pressure PT. If the threshold pressure hasbeen crossed, then the tubes or tube have failed. When a failureoccurs while testing tubes in pairs, the individual tubes may betested with other tubes to determine which tub

31、e failed.9.5 Test Cycle for Procedure B, Pressure Decay:9.5.1 Pressurize the tube to a pressure greater than 33 psiawith clean and dry compressed air.9.5.2 Allow the system to stabilize and measure the actualStarting Pressure (P0actual). P0actual must be within 10 % ofP0for a valid test.9.5.3 The ap

32、paratus is to calculate and set the ThresholdPressure where PT= P0actual P.3The boldface numbers in parentheses refer to a list of references at the end ofthis standard.A1047/A1047M 05 (2014)29.5.4 Measure the pressure at the end of the test cycle. Thetube has passed the test if the pressure has not

33、 crossed thethreshold pressure PT.9.6 Test Cycle for Procedure C, Vacuum Decay: (See Refs(4) and (5).)9.6.1 Draw a vacuum on the tube to a pressure below 6 psia.9.6.2 Allow the system to stabilize and measure the actualStarting Pressure (P0actual). P0actual must be within 10 % ofP0for a valid test.9

34、.6.3 The apparatus is to calculate and set the ThresholdPressure where PT= P0actual + P.9.6.4 Measure the pressure at the end of the test cycle. Thetube has passed the test if the pressure has not crossed thethreshold pressure PT.10. Report10.1 Report the following information:10.1.1 Tubing identifi

35、cation, and10.1.2 Procedure used for the satisfactory results of the test.10.2 Maintain records of the test parameters and results.11. Precision and Bias11.1 No information is presented about either the precisionor bias of this test method for measuring the leak capabilitysince the test is non-quant

36、ative.12. Keywords12.1 leak testing; pneumatic testingAPPENDIX(Nonmandatory Information)X1. EXAMPLE CALCULATIONS AND APPLICATIONSX1.1 NomenclatureX1.1 Pa= absolute atmospheric pressure, in psia = 14.69psiaP0= initial absolute pressure inside the tube, in psiaPf= final absolute pressure inside the tu

37、be, in psiaP = absolute pressure change inside the tube during the testperiod, in psiaV = tube internal volume, in ft3or in.3as notedA = through wall hole cross section area, in ft2or in.2asnotedd = through wall hole diameter, in inchest = test or decay time, in secondsT = absolute air temperature i

38、nside the tube, in R = F +460; T may be assumed to be 70 F = 530 RM = mass of air contained in a tube, in lbmM = mass change inside the tube during the test period, inlbmm = mass flow rate of air leaking through a hole, in lbm/seca= density of air at standard conditions = 0.0765 lbm/ft3R = gas const

39、ant for air = 53.3 ftlbf/lbmRX1.2 Theoretical Time EquationsX1.2.1 Pressure Differential and Pressure Decay Time:t 5 1.65 31024Vd2U lnP02 PP0U (X1.1)with units V 5 in.3, d 5 in.,and assuming T 5 530 RX1.2.2 Vacuum Decay Time:t 5 1.65 31024Vd2PPa(X1.2)with units V 5 in.3, d 5 in.,and assuming T 5 530

40、 RNOTE X1.1The vacuum equations can be used for the pressureequations by substituting P0for Pawith the provision that P is less than1 psi.X1.3 DerivationX1.3.1 From Fliegners Formula (see Ref (6), page 85):m =TAP5 0.532 or m 50.532AP=T(X1.3)with units A 5 ft2, P 5lbfft2X1.3.1.1 Boundary condition fo

41、r choked flow (see Ref (6),page 84):PaPf,0.528 for pressure decay,PfPa,0.528 for vacuum decay(X1.4)X1.3.2 Ideal Gas Law:PV 5 MRT or P 5MRTV(X1.5)X1.3.3 Pressure Decaying from a Control Volume:A1047/A1047M 05 (2014)3dPdt5RTVdMdt5RTVm (X1.6)X1.3.3.1 Substituting Fliegners formula:dPdt5RTV0.532AP=T528.

42、36AP=TV(X1.7)dPP528.36A=TVdt 5 dt*1PdP 5 *dtt 5V28.36A=TU lnP02 PP0Uwith V in ft3, A in ft2, P can be any unitt 5 1.65 31024Vd2U lnP02 PP0Uwith units V 5 in.3, d 5 in.,and assuming T 5 530 RX1.3.4 Vacuum Decay into a Control Volume:X1.3.4.1 Because the high pressure source is the atmo-sphere and is

43、of infinite quantity, pressure in a control volumeincreases at a linear rate.t 5Mm(X1.8)M 5 V05P0Paa, f5PfPaa, 5PPaa5 0.0765PPaX1.3.4.2 Again using Fliegners formula:m 50.532APa=T(X1.9)with units A 5 ft2, Pa5lbfft2t 5Mm50.0765VPPa0.532APa=T5 0.1438V=TAPaPPaUsing Pa5 2115 psfa 14.69 psia!t 5 6.8 3102

44、5V=TAPPawith units V 5 ft3, A 5 ft2, T 5 R,and P can be any unitt 5 1.65 31024Vd2PPawith units V 5 in.3, d 5 in.,and assuming T 5 530 RX1.4 Application ExampleX1.4.1 For Procedure A, Pressure Differential, determinethe pressure decay time of a 1 in. OD by 0.050 in. wall by 60ft long tube with a 0.00

45、3 in. diameter hole; the test apparatusinitial pressure is 110 psig with 0.031 psig allowed pressuredrop.X1.4.1.1 Using the equation given in X1.2.1:t 5 1.65 31024Vd2U lnP02 PP0U (X1.10)V 5 458 in.3d 5 0.003 in.P05 110114.69 5 124.69 psiaP 5 0.031 psiat 5 1.65 310244580.0032U ln124.69 2 0.031124.69U

46、51.65 310243458 32 310249 310265 1.7secX1.5 GraphX1.5.1 The graph in Fig. X1.1 displays decay time as afunction of tube internal volume assuming a 0.003 in. holediameter, 110 psig initial pressure, and 0.031 psig allowedpressure drop.A1047/A1047M 05 (2014)4REFERENCES(1) An Improved Method for Testin

47、g Stainless and Titanium Tubing PWR- Vol. 34, 1999 Joint Power Generation Conference Volume 2ASME 1999. Dennis J. Schumerth or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).FIG. X1.1 Pressure Differential Standardization 110 psig 0.031 Threshold 0.003 in. Leak DiameterA1047/A1047M 05 (2014)5