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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Records of each verification shall be maintained. It should be realised that retests of existing petroleum pipelines and distribution systems are regularly made 2858.5 or near the maximum allowable operating pressure. If the converted pressure is lower than the mill test 2885.5, and no errors are detected in the calculations, it is almost certain that at least one wrongly identified length of 2885.
has been included in the test section. It was published on 4 April It is not anticipated that such a test would ever be conducted as a failure could result in significant personal danger and environmental damage could result. Copies of the verification or calibration records for the — i ii primary pressure measurement instrument; device used for measurement of added volume in volume-strain tests; and iii devices used for measurement of temperature in temperature-correlated leak tests.
Strength tests may be carried out by raising the pressure to a predetermined level and holding for a fixed time.
Where sections of pipe are tested prior to field testing i. Records of the initial and all subsequent pressure tests shall be retained for the life of the pipeline.
The leak test sensitivity can be improved by extending the test period. During the hold period of the leak test, changes of temperature that would result in volume changes in a free state will result in pressure changes in the constrained state of a leak test. The elevations of the points in the test section where the reported pressures apply. This exponential-like fall in pressure is mostly due to dissipation of the heat produced during pressurization. Use of the actual slope is preferred.
The highest degree of certainty approaching absolute certainty is achieved when the factor is at least 1. The values in Column 4 are derived from those in Column 3 by the subtraction of each reading in Column 3 from the highest reading in Column 4. If either of the above conditions is not met, Figure 5. The offset volume excludes the volume of water added to compress residual air.
F1 The total water added may be measured volumetrically in a test of either increasing or decreasing pressures. The pressure instrument alone cannot distinguish between these conditions.
Industrial grade gauges The following applies to industrial grade gauges: Time-dependent straining takes place for some time, often for several hours in yield tests. Obtain the volume of the test section by calculation from the pipe dimensions or actual volume measurements during filling if more accurate. Unless significant lengths of the test section have been pressured well above the SMYS pressure see Paragraph E5a premature end-point is likely to indicate substantial quantities of under-strength pipe in the test section.
However, a clear definition of what constitutes a successful test is required. This Section defines the minimum requirements for accuracy, sensitivity and repeatability of test equipment and the practices to be observed to ensure that readings of test instruments reflect test section parameters and avoid spurious influences.
Procedures and precautions for the safety of the general public, operating personnel and testing personnel, and operating and testing equipment see also Clause 2. The acceptable volume should be calculated and included in the test program.
AS Pipelines-Gas and liquid petroleum – Field pressure testing_图文_百度文库
The testing liquid is normally water, but provision is made for the use of certain hydrocarbon liquids that do not vaporize rapidly. Fully restrained conditions normally only occur in long buried pipelines restrained by soil friction, or in pipe between two or more anchors that are much stiffer than the pipe and only when the pipe is free of substantial changes in direction.
Column 6 represents the additional volume of water added to compress the residual air. A pipe section is considered to be fully restrained when axial movement is prevented. It further appears that the industry has settled, through long experience rather than scientific forethought, on the use of a pressure strength at least 1.
The duration of strength tests is defined to verify the strength of the test section by allowing time for any near critical defects to grow to failure. The instrument measures precisely both pressure and pressure change. The date or dates on which the test was conducted.
SCOPE OF ACCREDITATION
The traditional method of reducing the pressure following the strength test for the start of the leak test reduces the overall temperature rise. If the 28885.5 at the lowest point in the test section is less than SMYS, the calculated offset volumetric strain will 28855.5 be less than 0. An offset strain end-point best reflects the gradual increase of strain with stress, which is characteristic of non-expanded pipe and is recommended for non-expanded pipe.
With minor exceptions, it is intended for application to all transmission pipelines. The slower strain rate cancels approximately one third of the von Mises effect. The straining rate 2885.5 be considered to approach zero during any hold period.
Normal pipeline filling practices should reduce the air content to acceptable sa but, if the filling practice is not normal or something goes wrong, and the air content is unacceptable, it will be apparent during pressurizing for the strength test. The accurate location of the temperature-measuring points.
It is rare for a leak test to be conducted in conditions that are fully stabilized, so a very careful examination of temperature trends at each measuring point is essential. It is also assumed that the test sections are in Class R2 locations.
The actual unaccountable pressure loss measured during the test. 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. Alternatively, both organizations publish an annual printed Catalogue with full details of all current Standards.