Australian New Zealand Standard AS / NZS Pipelines – Gas and Liquid Petroleum – Field Pressure Testing – Western Australia. AS – , Field Pressure Testing, Revision committed formed, Expected AS – , Safety Management Studies, With. AS/NZS Accessed by CITIC PACIFIC MINING PTY LTD on 03 Dec AS/NZS Australian/New Zealand Standard?.
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Any difference between the indication of the pressuremeasuring devices shall be monitored, and shall be investigated. Obtain the 2885. of the test section by calculation from the pipe 22885.5 or actual volume measurements during filling if more accurate. Where the permanent record of test data is in electronic format, it is recommended that it be stored on a non-volatile medium, e.
This allows simple assessment of the extent to which a leak or instrument error could be relevant. The Standard was widely accepted and was revised and reissued in It is the transverse yield properties of the pipe that determine the appropriate 28855.5 for highlevel testing.
The time taken for stabilization to occur depends on the temperature of the test liquid at the time of filling, specific heat capacity of the test liquid, pipe diameter, burial depth, undisturbed ground temperature and the thermal conductivity of the backfill and ground, which can be affected by ground water.
The instrument measures precisely both pressure and pressure change.
AS Pipelines-Gas and liquid petroleum – Field pressure testing_图文_百度文库
In both cases, the offset should be calculated from the strain measured at the mill-test pressure at the lowest elevation in the test section the pressure at which pipes first begin to yield.
Care should be exercised when pressurizing to 0. This may be calculated as follows: This Appendix describes two methods of residual air determination as follows: If the volumes are not obtained in the form used in Column 4, they may be converted to that form.
During the development of yield testing, a number of different practices appeared, particularly for defining the small amount of yielding which operating experience had shown produced a real benefit in service and which metallurgical opinion suggested should be kept as small as possible.
For semi-conductor probes as commonly used, a sensitivity of 0. Simple methods for measurements and calculations for field 2885.5 are included in Appendix F, for which it might reasonably be deduced that air above kPa is more of a danger than a limitation on leak detection.
In such cases, the Standard requires the plotting of pressure versus the total added volume.
Representative stress-strain curve information typical of the pipe. There is an additional uncertainty due to a possible difference between the measured probe tip temperature and the actual pipe and water temperatures. A reason for the variation has to be sought and an understanding of the situation developed.
If the instrument verification shows it does not comply, 28855 may not be used. Alternatively, both organizations publish an annual printed Catalogue with full details of all current Standards. High performance pressure calibrators may provide equivalent performance.
Thermal stability is only of concern for leak tests in accordance with Clause 4. A typical summary report of a single test section is given in Appendix H.
SCOPE OF ACCREDITATION
These should include a warning about excess pressure being developed due to solar radiation. Industrial grade gauges The following applies to industrial grade gauges: Ruptures in hydrostatic tests do occasionally occur after hold periods of several hours. No temperature stabilization is necessary prior to the commencement of pressurization and, in 28855 majority of cases, any stabilization achieved 285.5 to that time is nullified by the act of pressurization.
It is necessary to be able to detect leaks of L, 40 L or 20 L per 24 h against the background uncertainty of measurement of pressure and pipe wall temperature. The pressure in any part of the test section shall not exceed the maximum test pressure specified in aas test program. The test program shall take into account an assessment of stresses in the pipe wall of the test section resulting from mass of the test liquid, end restraints, any additional loading from other structures, and any other significant loadings.
The corrected value is the value to be used as A in Equation B1 1. Special edition of Zeitschrift Technische Uberwachung, Vo. The formulae provided in this edition allow the conversion of leak rate measured at one pressure to another pressure such as MAOP.
Temperature of the test fluid water In the assessment of whether a leak can be identified from a record of pressure that is changing with temperature, it is vital that the temperature record be as significant as the pressure record since the object is to establish a causal relationship between the temperature and the pressure changes.
History of the Newark A pipe section is considered to be fully restrained when axial movement is prevented. This edition of the Standard recognizes that other methods of leak assessment may provide equivalent results; leak test assessment by acoustic and vibration instrumentation show promise. The pressure strength is measured or calculated at the highest point in the test section.
Larger air volumes are acceptable at higher test pressures. Petroleum products experience much greater temperature changes during adiabatic compression of the order of 2 to 3 times that of water. Sensitivity better than 0. G4 4 Equation G4 1 and Equations G4 2G4 3 and G4 4 can be rewritten in multiples and submultiples of S1 units which are commonly used in the pipeline industry.