The allowable suction height of a pump (Hg) refers to the maximum vertical distance that can be reached between the suction port of the pump and the liquid level of the suction storage tank, expressed in Hg. The allowable suction height of a pump, also known as the allowable suction vacuum degree, indicates the allowable height at which a centrifugal pump can suction liquid.
The allowable suction height (Hg) of the pump can be calculated using the formula Hg=Hs - Hf0-1, where Hs is the allowable vacuum suction height and Hf0-1 is the total resistance of the suction pipeline.
It should be noted that the Hs value given in the formula is obtained using clean water as the working medium, under operating conditions of 20 ℃ and pressure of 1.013 × 10 ^ 5Pa. When the operating conditions and working medium are different, conversion is required.
For example, when transporting clean water but the operating conditions are different from the experimental conditions, it can be converted using the formula Hs1=Hs+Ha-10.33-Hv-0.24; When transporting other liquids, a two-step conversion is required.
The significance of the allowable suction height of a pump is mainly reflected in the self-priming height, which is the maximum self-priming height that the pump can reach. Beyond this height, the medium will not be able to be sucked up or even cavitation will occur, causing damage to the pump rotor. So, in order to ensure the normal operation of the pump, it is necessary to reasonably determine the installation height and position of the pump to ensure that the liquid at the pump inlet does not vaporize and does not produce cavitation.
