During a hydraulic test, if the static pressure of the liquid column is less than 5% of the design pressure, can it be ignored?

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“When conducting a hydraulic test on a vertical container in a horizontal position, the test pressure should include the hydrostatic pressure of the liquid column that would be present if the container were in a vertical position. So, can this hydrostatic pressure be ignored if it is less than 5% of the design pressure? During the hydraulic test, the static pressure of the liquid column must be taken into account and cannot be ignored. Since the hydrostatic pressure of the liquid column taken into account in pressure calculations refers to the height of the liquid column under normal operating conditions, when this hydrostatic pressure is less than 5% of the design pressure, its impact on the wall thickness is minimal and can be ignored. The static pressure of the liquid column in the vertical position is taken into account when determining the hydraulic test pressure, so as to ensure that the pressure on the stressed component remains unchanged whether the test is conducted in a horizontal or vertical position, thereby avoiding inconsistencies in the pressure verification of the stressed component due to differences in the testing orientation. At the same time, it was also taken into account that when conducting a hydraulic test on upright containers in use, the test must be carried out in an upright position.