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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In the absence of reliable estimates, a ratio of may be used. The number adjacent to each line is the diameter of the equivalent hole. This Standard also provides additional information on a number of subjects, which would assist the experienced and competent person in the preparation of the test program and the assessment of the test, and 288.5 contribute to the understanding of the testing of pipelines by approving authorities, owners, designers, and contractors.
The values in Column 6 are the results of the subtraction of the values in Column 5 from those in Column 4. It is recommended that the test be started and finished at the same time of day in order to minimize this effect of temperature. Pipelines—Gas and liquid petroleum Part 5: This level will commonly be at least 0. 28885.5 the hold period of the leak test, changes of temperature aa would result in volume changes in a free state will result in pressure changes in the constrained state of a leak test.
Unlike the hold pressure for the pressurecontrolled test, the hold pressure for the yield test is not known in advance of the test but is determined during the test from the actual behaviour of the test section 2885.5 situ. Traceable measurements of ring-expansion yield stress for each pipe based on heat testing. This Standard ad be applied for pretesting of pipe and components and for testing sections of pipe separate from the field test see Clause 4.
B1 4 Where an unrestrained pipeline or system of pipes includes pipe of different diameters, Equation B2 becomes—?
Between editions, amendments may be issued. These equations, which differ from those used in earlier editions of this Standard, take account of the fact that the compressibility and the temperature coefficient of expansion of test media vary with both temperature and pressure. Tests for which the maximum pressure has the potential to result in yielding of any pipe under test are required to be conducted in a manner that monitors the amount of straining during the test.
The graphed pressure is related to the measuring point pressure by the hydraulic pressure difference between these elevations.
AS Pipelines-Gas and liquid petroleum – Field pressure testing_图文_百度文库
Pressure change is usually measured by a deadweight tester, which is a very accurate, reliable, stable, and sensitive item of equipment.
The specification and grade of the pipes in the test section, the mill test pressure and the name s of the manufacturer s. The Standard was widely accepted and was revised and reissued in In the calculation method, this linear equation is drawn and the slope measured. Added volume required for maintenance of pressure on account of strain in the test section may be distinguished from added volume required because of a leak in the test section by the shape of the pressure decay curve.
Where the test pressure is to be used to determine the MAOP, the accuracy of the pressure-measuring-device shall be 0.
Tests that are assessed as not likely to result in yielding of pipe may be conducted to a predetermined pressure end point. Unstable liquids shall not be used.
The values in Columns 6 and 7 are plotted against each other and a line which is the best visual fit is drawn through the origin Figure F2. Uncertainty is determined according to Clause I4.
If the air is located elsewhere, it is compressed by aw static head and the plot in Figure F2 will no longer be a straight line. A guide to the selection and design of test sections is given in Appendix I. The volume of air that can dissolve is ws 20 ppm at the relevant conditions. For an illustration of the techniques and calculations that may be required in field pressure testing, see Appendix C.
SCOPE OF ACCREDITATION
Where the pipe temperature at one or more points on the test section is changing in the opposite direction to the average, extra care has to be used in assessing the results.
It is thought that a slightly less accurate result which always overestimates the product loss is preferable to one which may underestimate the loss. Where a combination of hoop stress, longitudinal stress and radial stress occurs, the cumulative effect of these shall be determined from the maximum shear stress Tresca theory.
The end-points that have been used in the Australian industry for testing under this Standard were verified against actual strain measurements on pipes in test sections.
The volume added to each pipe may be calculated from the strain in the pipe and the compressibility of the test fluid at the pressure on the pipe. Conversely, a higher sensitivity would be required to identify the same volume loss in larger test sections, but the 285.5 of the instrument cannot be increased indefinitely.