The influence of atmospheric pressure on the suction height of self-priming pump
Atmospheric pressure has a significant impact on the suction height of self-priming pumps. Here is a detailed analysis of this impact:
1. Basic principles
The basic principle of a self-priming pump is to use the high-speed rotation of the impeller to generate a low-pressure area in the pump body, so that the liquid enters the pump body under the action of atmospheric pressure. When the pump body is filled with liquid, the impeller continues to rotate, pushing the liquid toward the outlet pipe. In this process, atmospheric pressure plays a vital role as it is the main driving force for pushing liquid into the pump body.
2. Influence mechanism
The relationship between atmospheric pressure and suction height:
When the saturated vapor pressure of the liquid delivered by the self-priming pump and the resistance loss of the liquid entering the impeller are constant, the greater the atmospheric pressure, the greater the allowable suction vacuum height of the pump, that is, the higher the suction height; conversely, the smaller the atmospheric pressure, the higher the suction height of the self-priming pump. The allowable suction vacuum height is smaller, and the suction height is also reduced accordingly.
Effect of altitude:
Atmospheric pressure decreases with increasing altitude. Therefore, under the same conditions, the atmospheric pressure in plateau areas is lower, resulting in the allowable suction vacuum height of the pump being smaller than that in plain areas. This is why when using a self-priming pump in high altitude areas, special attention needs to be paid to the limitation of its suction height.
3. Specific performance
In practical applications, the influence of atmospheric pressure on the suction height of a self-priming pump can be expressed in the following ways:
In high altitude areas, due to the lower atmospheric pressure, the suction height of the self-priming pump will be reduced accordingly. Therefore, when selecting and installing a self-priming pump, it is necessary to determine the appropriate suction height based on the local altitude and atmospheric pressure conditions.
In low altitude areas, where the atmospheric pressure is high, the suction height of the self-priming pump is relatively high. But even so, care must be taken not to exceed the designed suction height limit of the pump to avoid cavitation or failure to suction water.
4. Countermeasures
In order to deal with the influence of atmospheric pressure on the suction height of self-priming pumps, the following measures can be taken:
When selecting, fully consider the local atmospheric pressure and altitude conditions, and select the appropriate self-priming pump model and specifications.
During installation and use, pay attention to maintaining good sealing of the pump body to avoid air leakage resulting in a reduction in suction height.
Regularly inspect and maintain the self-priming device and liquid storage chamber of the self-priming pump to ensure that they are working properly and can increase the self-priming height.
