ASTM A1047 A1047M-2005 Standard Test Method for Pneumatic Leak Testing of Tubing.pdf

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1、Designation: A 1047/A 1047M 05Standard Test Method forPneumatic Leak Testing of Tubing1This standard is issued under the fixed designation A 1047/A 1047M; the number immediately following the designation indicates theyear of original adoption or, in the case of revision, the year of last revision. A

2、 number in parentheses indicates the year of lastreapproval. A superscript epsilon (e) 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 involvesmeasuring the c

3、hange 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 beequivalent

4、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 This standard does not

5、 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-bility of regulatory limitations prior to use.1.4 The values stated in either inch-poun

6、d or SI units are tobe regarded separately as standard. Within the text, the SI unitsare shown in brackets. The values stated in each system are notexact equivalents; therefore, each system shall be used inde-pendently of the other. Combining values from the two systemsmay result in nonconformance w

7、ith the specification.2. Referenced Documents2.1 ASTM Standards:2A 1016 Specification for General Requirements for FerriticAlloy Steel, Austenitic Alloy Steel, and Stainless SteelTubes3. Terminology3.1 DefinitionsThe definitions in SpecificationA 1016 areapplicable to this test method.3.2 Definition

8、s of Terms Specific to This Standard:3.2.1 actual starting pressure (P0actual)the actual star-ing pressure at time zero on each test cycle.3.2.2 calibration holea device (such as a crimped capil-lary, or a tube containing a hole produced by laser drilling)certified to be of the specified diameter.3.

9、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 sys-tem to accumulate input from limit switches and transmittersproviding corresponding outputs to solenoid valves, acoustical

10、arm devices, and visual displays3.2.5 pressure change (DP)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 inpressure, either between two tubes

11、, 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 pressure (P0)the test starting pr

12、essure 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 must becrossed to determine reject

13、 status. PT= P0actual DP forpressure decay, and PT= P0actual + DP for vacuum decay.4. Summary of Test Method4.1 Procedure 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 tub

14、e against a control volume at identical pressure. (SeeRefs (1) and (2)4.2 Procedure B, Pressure Decay, measures the drop 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 inp

15、ressure caused by gas entering the tubing.1This 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 Dec. 1, 2005. Publishe

16、d December 2005.2For 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 Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbo

17、r Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5. Significance and Use5.1 When permitted by a specification or the order, 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) con

18、trols all opera-tions of the test method by accepting inputs from limit switchesand transmitters, and by providing corresponding pass/failoutputs to solenoid valves, acoustic alarm devices, and visualdisplays. The pass/fail determination is achieved by a compari-son of the data input from pressure t

19、ransducers with a standardaccept/reject criterion measured over the set test time.6.2 The test apparatus may have the capability for single- ormulti-tube testing. It shall be designed to detect a smallpredetermined pressure change during the testing cycle. It isintended that the apparatus be fully a

20、utomated and equippedwith suitable instrumentation for the purpose of the test. Thisinstrumentation may include, but is not limited to the follow-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

21、 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 Automatic shutdown capability.7. Hazards7.1 WarningIn addition to other precautions, high pres-sure air is employed during the testing process.8. Calibration8.1 A

22、pparatus calibration shall be performed using a refer-ence standard, with adjustments of Starting Pressure (P0),Pressure Change (DP), and test time. Test time is dependentupon starting pressure, allowed pressure change, tube internalvolume, hole diameter, and is calculated using the equation inAppen

23、dix X1. Actual test time may be longer than thecalculated value and shall be adjusted as necessary for theapparatus to cross the threshold pressure and cause the systemto automatically shut down.8.2 Verify that all failure lights are illuminated during thecalibration.8.3 Unless otherwise specified,

24、apparatus calibration shallbe made at twelve month intervals maximum.8.4 Recalibrate the test apparatus prior to use whenever anypressure sensing component is replaced or modified.8.5 Calibrate the calibration hole at twelve month intervalsmaximum. It is recommended that the device containing thecal

25、ibration hole be stored in an inert atmosphere and cleanedwith high pressure nitrogen.8.6 Calibrate all pressure gauges and pressure transducers attwelve month intervals maximum.8.7 Unless otherwise agreed to by producer and purchaser,the minimum calibration hole size in the reference standardshall

26、be 0.003-in. diameter. Calibration with smaller holes maynot be repeatable due to fouling and plugging. (See Ref (5)9. Procedure9.1 Perform pneumatic leak testing after all process opera-tions, including cold work, heat treatment, and straightening.9.2 Clean and dry the tubes before testing. Remove

27、loosescale from the inside and outside surfaces of the tubes.9.3 Actual test time is calculated in accordance with theparameters of the test using 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 c

28、ontrol volume, to a pressure greater than 33 psia withclean and dry compressed air.9.4.2 Allow the system to stabilize and measure the actualStarting 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= P0a

29、ctual DP.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. Thetubes 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

30、 or tube have failed. When a failureoccurs while testing tubes in pairs, the individual tubes may betested with other tubes to determine which tube 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.

31、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 apparatus is to calculate and set the ThresholdPressure where PT= P0actual DP.9.5.4 Measure the pressure at the end of the test cycle. Thetube has passed th

32、e test if the pressure has not crossed thethreshold pressure PT.9.6 Test Cycle for Procedure C, Vacuum Decay:(See Refs (3) and (4)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

33、 10 % ofP0for a valid test.9.6.3 The apparatus is to calculate and set the ThresholdPressure where PT= P0actual + DP.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 infor

34、mation:10.1.1 Tubing identification, 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 capabili

35、tysince the test is non-quantative.A 1047/A 1047M 05212. Keywords12.1 leak testing; pneumatic testingAPPENDIX(Nonmandatory Information)X1. EXAMPLE CALCULATIONS AND APPLICATIONSX1.1 NomenclaturePa= absolute atmospheric pressure, in psia = 14.69 psiaP0= initial absolute pressure inside the tube, in ps

36、iaPf= final absolute pressure inside the tube, in psiaDP = 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 ti

37、me, in secondsT = absolute air temperature inside the tube, in R = F +460; T may be assumed to be 70 F = 530 RM = mass of air contained in a tube, in lbmDM = mass change inside the tube during the test period, inlbmm= mass flow rate of air leaking through a hole, in lbm/secra= density of air at stan

38、dard conditions = 0.0765 lbm/ft3R = gas constant for air = 53.3 ftlbf/lbmRX1.2 Theoretical Time EquationsX1.2.1 Pressure Differential and Pressure Decay Time:t 5 1.65 3 1024Vd2UlnP0 DPP0U(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 3 1024Vd2DPPa(X1.2)wit

39、h units V 5 in.3, d 5 in.,and assuming T 5 530 RNOTE X1.1The vacuum equations can be used for the pressureequations by substituting P0for Pawith the provision that DP is less than1 psi.X1.3 DerivationX1.3.1 From Fliegners Formula (see Ref (6), page 85):m=TAP5 0.532 or m50.532AP=Twith units A5 ft2, P

40、5lbfft2(X1.3)X1.3.1.1 Boundary condition for 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:dPdt5RTVdMdt5RTVm(X1.6)X1.3.3.1 Substituting Fliegners formula:

41、dPdt5RTV0.532AP=T528.36AP=TV(X1.7)dPP528.36A=TVdt 5t dt*1PdP 5*t dtt 5V28.36A=TUlnP0 DPP0Uwith V in ft3, A in ft2, P can be any unitt 5 1.65 3 1024Vd2UlnP0 DPP0Uwith 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 t

42、he atmo-sphere and is of infinite quantity, pressure in a control volumeincreases at a linear rate.t 5DMm(X1.8)DM 5 VDrr05P0Para, rf5PfPara, Dr 5DPPara5 0.0765DPPaX1.3.4.2 Again using Fliegners formula:m50.532APa=Twith units A5 ft2, Pa5lbfft2(X1.9)A 1047/A 1047M 053t 5DMm50.0765VDPPa0.532APa=T5 0.14

43、38V=TAPaDPPaUsing Pa5 2115 psfa 14.69 psia!t 5 6.8 3 1025V=TADPPawith units V 5 ft3, A 5 ft2, T 5 R,and P can be any unitt 5 1.65 3 1024Vd2DPPawith 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

44、 a 1 in. OD by 0.050 in. wall by 60ft long tube with a 0.003 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 3 1024Vd2UlnP0 DPP0U(X1.10)V 5 458 in.3d 5 0.003 in.P05 110 1 14.69 5 124.69 psiaDP

45、 5 0.031 psiat 5 1.65 3 10244580.0032Uln124.69 0.031124.69U51.65 3 10243 458 3 2 3 10249 3 10265 1.7 secX1.5 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.F

46、IG. X1.1 Pressure Differential Standardization 110 psig 0.031 Threshold 0.003 in. Leak DiameterA 1047/A 1047M 054REFERENCES(1) An Improved Method for Testing 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).A 1047/A 1047M 055