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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Where a test section is wholly or partly submerged, the pressure strength may be considered to be that determined in accordance with this Clause, Where the depth of submergence is subsequently reduced by more than the pressure equivalent of 0. Therefore, those wishing to take advantage of the benefits of high-level testing will not be able to precalculate the xs.
Design and construction Part 3: The slope of this line is the air volume. These characterisations tend to show distinct differences in calculated values when changing between ranges. It is important that the other potential causes be either eliminated or quantified before it is determined that ad investigation of a premature end-point for yielding in the test section is required. The instrument measures precisely both pressure and pressure change.
One method of assessment is to compare the pipe temperature change with the ground temperature change at the same cross-section of ax pipeline. It is a feature of high level testing that the elimination of leaks as well as the freedom from ruptures in operation can confidently be expected. Tests that are assessed as not likely to result in yielding of pipe may be conducted to a predetermined pressure end point.
For an offset-volume end-point, the accumulation of leakage over the pressurizing period 28855 be estimated and deducted from the offset volume.
22885.5 Thermal stability is ax of concern for leak tests in accordance with Clause 4. Straining rates for short sections may be relatively high, so the von Mises factor substantially overrides the straining rate factor.
The hold period may be continued to completion where the leaked volume does not exceed 0. The volume of air that can dissolve is approximately 20 ppm at the relevant conditions.
High performance pressure calibrators may provide equivalent performance.
During the test, readings of the test pressure and ambient and pipeline steel temperatures are to be taken simultaneously at intervals see Clause 4. Alternatively, both organizations publish an annual printed Catalogue with full details of all current Standards. This effect is logarithmic and is approximately 8 MPa for a tenfold change in straining rate. The size of test section for which it is feasible to identify a pressure change amid pressure changes caused by ambient conditions represents the practical upper limit.
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 would contribute to the understanding of the testing of pipelines by approving authorities, owners, designers, and contractors. Plot pressure and added volume on a scale that provides not less than readable units on each axis to coordinates equivalent to SMYS.
AS Pipelines-Gas and liquid petroleum – Field pressure testing_图文_百度文库
Falling pressure readings are reliable and convenient, and the calculations are simplified if readings are taken in pressure decrements of kPa each. Where this has been done in practice, the occurrence of ruptures during field tests from manufacturing defects has almost disappeared. At the end of the strength test hold period, any observed leaks are noted or repaired and the section is leak-tested. Where the test liquid will be subject to temperatures near freezing, precautions shall be taken to protect the equipment and the test section.
Dissolution takes place slowly, however, resulting ss a slow pressure decline. There is an additional uncertainty due to a possible difference between the measured probe tip temperature and the actual pipe and water temperatures.
Conversely, a higher sensitivity would be required to identify the same volume loss in larger test sections, but the sensitivity of the instrument cannot be increased indefinitely. Although the cubic expansion coefficient of water will be known, the precise temperature of the water will not be known. 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.
Where the permanent record of test data is in electronic format, it is recommended that it be stored on a non-volatile medium, e.
Figure F1 is a plot of the beginning of a pressure test starting from a pressure equal to the static aas. In a pressure-controlled test, a premature end-point means that the predetermined end-point pressure has not been reached. Other methods discussed in Paragraph A4. The water in the test section at the commencement of the leak test qs have experienced a resultant temperature change of 0.
Thus the greater part of the decline occurs in the first few hours and may well be during the strength test portion of the test. Volume figures in Columns 3 and 4 in Table F2 have been rounded to the nearest L and in Column 5 to the nearest 10 L.
A strength test is acceptable, if there is no loss of pressure containment integrity as evidenced by a burst, split or gasket failure, which prevents maintenance of the test section pressure.
After a hold period or inspection to see that there is no significant leak, the field test pressure is converted to an equivalent mill test pressure by taking zs of the restraint conditions and the rate of straining.
The test program shall demonstrate the relative sensitivities in the rate of pressure change in the test section to test liquid loss and temperature.
Description of the weather and weather changes during the test.