ASTM E2930-13(R2021) pdf free download

ASTM E2930-13(R2021) pdf free download.Standard Practice for Pressure Decay Leak Test Method
1. Scope
1.1 This practice describes a method for determining the leakage rate of a vessel subject to a positive pressure differ- ence. The technique is based upon evaluation of the change of mass within the test object based on a pressure decay measure- ment. The pressure decay measurement uses the ideal gas equation ofstate and the measured pressures, temperatures, and time to determine the mass loss from the vessel. This method does not apply to deformable vessels. 1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appro- priate safety, health, and environmental practices and deter- mine the applicability ofregulatory limitations prior to use. 1.3 This international standard was developed in accor- dance with internationally recognized principles on standard- ization established in the Decision on Principles for the Development of International Standards, Guides and Recom- mendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
3. Terminology
3.1 Definitions: 3.1.1 pressure decay test resolution—the resolution of the test that can be derived from the test equipment specifications and the volume of the test vessel. The test resolution is determined by evaluation of the individual resolutions of the pressure measurement, temperature measurement, and time measurement for a known vessel volume. The method for determining the test resolution is give in Annex A1. 3.1.2 pressure decay test accuracy—the test accuracy is the estimated accuracy of the test based on a combination of the measurement accuracies of contributing variables. The method for determining the test accuracy is given in Annex A2.
4. Summary of Test Method
4.1 This practice requires a known volume and the use of the pressure rate of decay technique for quantitative measure- ment of leakage rates. The practice is written to be usable over a wide range of pressures and system volumes. This method is only applicable to the test of non-deformable volumes or devices. Test devices which may have significant changes in volume due to pressurization should not be tested with this method. The method requires the measurement of the system pressure and temperature as a function of time and as such requires that these measurements be made with calibrated instrumentation. The range of the measurement technique can vary significantly but is generally applicable in the range greater than 1 × 10 -8 mol/s (2.2 × 10 -4 std cc/s)
5. Significance and Use
5.1 The equipment, test duration, and technique should be determined before commencement of the test based on the required test sensitivity or accuracy (see Annex A1 and Annex A2). If the test is used to certify that the vessel has a minimum specified leakage rate, then the test equipment and test duration should be chosen to have a resolution ten times less than the specification and an accuracy which is four times less than the specification. The test should be designed so that the total pressure change is less than 10 % ofthe starting pressure. Leak test specifications should specify the vessel test pressure or differential pressure. If the test specification does not specify a test pressure, then a safe test pressure should be used that complies with the applicable safety standards.
6. Basis of Application
6.1 The following items are subject to contractual agree- ment between parties using or referencing this practice. 6.2 Personnel Qualification: 6.2.1 If specified in the contractual agreement, personnel performing examinations to this practice shall be qualified in accordance with a national or internationally recognized NDT personnel qualification practice or standard such as ANSI/ ASNT-CP-189, SNT-TC-1A, NAS-410, or a similar document and certified by the employer or certifying agency, as appli- cable. The practice or standard used and its applicable revision shall be identified in the contractual agreement between the using parties. 6.3 Qualification of Nondestructive Agencies—If specified in the contractual agreement, NDT agencies shall be qualified and evaluated as described in Practice E543. The applicable revision ofPractice E543 shall be in the contractual agreement.