When the medium is a liquid, how is the test pressure value determined?
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This post was last edited by zhangjuhua on 2018-10-17 at 11:47. Question: During a pressure test, assuming that the temperature compensation factor is not taken into account, how is the test pressure value determined when the medium is a liquid? For example, if the height of the liquid column is 10m and the design pressure is 1 MP, what is the pressure for a horizontal hydrostatic test: 1.25x1+0.1, or 1.25x(1+0.1)+0.1? I just checked 4.6.2.1 a) of 150.1; it should be 1.25x1+0.1, regardless of whether the medium is gas or liquid. Thank you
During the horizontal test, the test pressure is 1.25x1+0.1
Pay attention to the medium in question; if the density of your liquid medium is higher than that of water, you also need to include the factor of density ratio > 1*0.1
This post was last edited by zjq1962 on 2018-10-17 at 12:36. The medium mentioned by the original poster is a gas – does this refer to the medium used in the experiment or the medium used during operation? The pressure for the withstand test is independent of whether the medium is a liquid or a gas during operation. If it refers to the medium during testing, then the test pressure is the same for vertical and horizontal tests. Only hydraulic testing requires consideration of the liquid column height. When the static pressure of the liquid column of the internal filling medium under operating conditions is greater than that during the hydraulic test, appropriate consideration should be given to increasing the test pressure accordingly.
Why can’t it be edited? I checked just now – it’s 150. When the medium is gas, the pressure for a horizontal hydrostatic test should be 1.25; when the medium is a liquid, it should be 1.35. Is that okay?
This post was last edited by 754210465 on 2018-10-15 at 19:55. I think what the original poster meant is a vertical container: if the working medium is a liquid with a density of 1.0 (the same as water), and the liquid level filling the container is 10 m high, then what is the hydrostatic test pressure required for a horizontal test? (Without considering temperature compensation) My understanding is: 1.25*P+0.1 ； Here, P represents the design pressure or the maximum allowable operating pressure (excluding the height of the liquid column); the pressure used in the calculations for the equipment includes this liquid level height. Another scenario involves wall-mounted equipment, where the hydrostatic head of the liquid column during operation is greater than that of the container itself; in such cases, it is necessary to increase the water pressure.
This post was last edited by gn_1984 on 2018-10-16 09:48. When the densities of the medium and water differ, the test pressure during a horizontal hydrostatic test should be 1.25P1+P2 (the higher value of the static pressures resulting from the liquid columns of both the medium and water). (Without considering temperature compensation) P1 is the design pressure or the maximum allowable operating pressure.
If the medium is a gas with no liquid column, is it still necessary to apply P2 during the hydrostatic test?
Unless you conduct a pressure test, you need to consider it at heights above a certain level.
It should be calculated as 1.25P1 + P2, where P1 refers to the design pressure or the maximum allowable operating pressure, and P2 is max (the hydrostatic pressure of the working medium, or the hydrostatic pressure of the fluid used for hydraulic testing). The test pressure for this calculation is the minimum test pressure. The actual test pressure must be greater than or equal to this value, and the strength calculation for the equipment shall be verified through a hydraulic pressure test based on the actual values used.
OP, it’s filled with liquid during operation – isn’t this a pressure vessel? How is the pressure maintained?