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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The freedom from ruptures has been maintained even where a large number of ruptures occurred qs the testing. Consider the restrained test section, the details of which are given in Paragraph C. It is important that errors or uncertainty in aw equipment do not mask the readings.
The same sensitivity, i. Where leak and strength test pressures are the same, the effect will be more noticeable due to the commencement of the leak test soon after pressurization. The methods for this are set out in Appendix E.
To maintain their currency, all Standards are periodically reviewed, and new editions are published. The hold period may be continued to completion where the leaked volume does not exceed 0.
If the air determination is made on an ascending pressure cycle, the table is prepared accordingly. This, however, does not invalidate the method. The 2885. in Column 4 are derived from those in Column 3 by the subtraction of each reading in Column 3 from 28855 highest reading in Column 4.
Leakage rate has much less effect on a half-slope end-point. This gives temperature readings sensitive enough to show the temperature trends on a scale similar to that of the pressure changes.
AS Pipelines-Gas and liquid petroleum – Field pressure testing_图文_百度文库
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.
If 28885.5 volumes are not obtained in the form used in Column 4, they may be converted to that form. Thus the greater part of the decline occurs in the first few hours ad may well be during the strength test portion of the test.
Where a gas leak is found by a leak detection survey required by Figure 5. Column 6 represents the additional volume of water added to compress the residual air. Serious instrument error is most likely to be the result of an error in volume measurement, since instruments for pressure measurement are easily verified against a pressure gauge or recorder and errors of the magnitude required to produce a premature end-point would be immediately apparent. At the time work was started, there were strong differences of technical opinion in Australia on the merits sa techniques of yield testing of pipelines.
Some researchers have considered the evidence of improved service performance after high level testing to be so 22885.5 that they 2885.
recommended that the traditional design and testing philosophy for pipelines that are high level tested should be revised, that is, those test factors should be applied to the minimum actual test pressure to determine MAOP.
The potential gas leakage rate from a hole of diameter 0. Precautions shall be taken to protect the equipment against adverse effects such as weather and other threats. The method of adjusting the measured pressure change for changes 288.5 temperature shall be in accordance with Appendix B.
Records of each verification shall be maintained.
Figure F1 is a plot of the beginning of a pressure test starting from a pressure equal to the static head. During the hold period, visible parts of the test section shall be inspected for leaks. The volumetric flow rate at pipeline conditions is given by the following equation: 288.55 value of relevant and significant external loads.
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. It may be the 2885.55 of the statutory authority to approve the program.
SCOPE OF ACCREDITATION
Standards may also be withdrawn. At this sensitivity, the hourly or half-hourly figures will be of uncertain reliability, four-hourly readings will show the trend, and the 24 h figure on which 2885. section is accepted will be of known and satisfactory reliability.
Petroleum products experience much greater temperature changes during adiabatic compression of the order of 2 to 3 times that of water. A more appropriate end-point can be calculated, which takes account of the effect of water compressibility and the shape of the stress-strain curve of the pipe.
It is also assumed that the test sections are in Class R2 locations. Where adequate information ad not available, it is recommended that 0.
In 2885.5 Australian pipelines, field test pressures in fact influence target operating pressure, just as field test pressures determine allowable actual operating pressures of corroded or upgraded lines under the United States Department of Transportation regulations.
Unaccountable pressure changes may be caused by one or more of the following: This will remove any error resulting from the use of simple elastic strain in the higher stress ranges. If there are no observed leaks and the leak test is to be carried out at the same pressure, the test is simply continued with the strength-test hold period counting as part of the leak test period. Precautions should be taken so that the effects of sun, wind, rain, wet backfill, seasonal changes and other extraneous factors do not invalidate the measurements.
As the amount of air in the test section is determined by either the rising or the falling pressure method, the pressure response to dissolution of air can be estimated and allowance made for it in the determination of the acceptability of the leak test.
The strain in each pipe may be assumed to be elastic up to the value of p min. There are difficulties in locating a leak of this size in 40 km of pipeline, particularly when the ground is either so dry or so wet that the leaking water does not show. 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.
Hydrostatic testing of a pipeline is 285.5 carried out by testing a number of isolated test sections. 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 288.5 monitors the amount of straining during the test. The minimum strength test pressure and leak test pressure at the highest and lowest points of the test section, and their relationship to the pressure at the measuring point.
Hydrostatic ad captive caps on a G frame Test pressure