How is pressure controlled when testing vertical pipes?
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For example, when performing a hydrostatic test on a vertical pipe at a height of 100 meters, a pressure gauge is installed at the highest point, and another pressure gauge is placed on the temporary pipeline. Water is introduced starting from a height of 0 meters. If the pipe is to be pressurized to 7 MPa, due to the static pressure difference caused by water, by the time the pressure gauge at the top reaches 7 MPa, the actual pressure at the bottom will already be close to 8 MPa. How should such a situation be handled during the pressurization process? How much pressure should be applied?
Choose the higher option; there’s almost no difference between water pressures of 8 and 7
Just follow the design requirements. During pressure testing, test under the most severe conditions within the specified parameters – a device that doesn’t fail under such testing is a good one; P
Install a pressure gauge at the low point and operate according to the test pressure.
This post was last edited by we11we11 on 2021-6-10 at 19:55. Generally, for long-distance pipelines, the operation is such that the high points reach the strength test pressure, while the low points do not exceed 95% of the minimum yield limit
Refer to 8.6.4.8 of GB50235-2010; it is stated there
During design, it should be designed for 8 MPa; during pressure testing, the pressure should be increased to 1.2 times the design pressure
As stated above, the pressure at the lowest point must not exceed the tolerance capacity of the pipeline components. What does this tolerance capacity mean?
It refers to the maximum allowable test pressure value for the pipeline components themselves; once the test pressure at the lowest point exceeds this value, it can cause damage to the pipeline system.
It can’t be understood that way, right? The highest point reaches the test pressure; at a height difference of 100 meters, the lowest point must exceed the test pressure. If the test pressure is based on the lowest point, then the highest point won’t reach that level