Adjustment of the outlet valve of the water pump
Thread Content
Adjust the outlet valve of the water pump; when the flow rate increases, does the outlet pressure decrease? Does the head change as well? Thank you!
For centrifugal pumps, when adjusting the outlet valve of the pump, as the flow rate increases, the outlet pressure decreases, and the head also decreases.
The 700X water pump control valve is capable of regulating the check valve of the water pump. Before the pump stops operating, 90% of the main valve is closed first due to the inlet pressure, which causes the pump to stop automatically; the remaining 10% is closed by the return flow, thereby completely preventing water hammer effects. It is suitable for use in industrial and mining enterprises, high-rise buildings where water is supplied directly by pumps, as well as in domestic water supply systems. Product images and typical installation diagrams can be viewed by clicking the link: http://www.enine-pv.com/CH_web/valve/hydroelectric_control9.html. Technical support available
Read more relevant materials and you’ll understand
For centrifugal pumps, when the outlet valve of the water pump is adjusted, the flow rate changes accordingly, while the head remains unchanged. This is because the head of a centrifugal pump is determined by the diameter of its impeller and the speed at which the pump rotates, and it has nothing to do with the size of the pump’s outlet.
The pump’s head remains unchanged, but the outlet pressure decreases as the flow rate increases
According to the characteristic curve of a centrifugal pump, as the flow rate increases, the head decreases.
According to the characteristic curve of a centrifugal pump, as the pump flow rate increases or decreases, its head will decrease or increase accordingly, and its efficiency will also change. The pump achieves its highest efficiency when the flow rate and the corresponding head are at a certain operating condition. During the performance testing of centrifugal pumps, the flow rate is controlled by adjusting the valve opening, thereby regulating the flow rate, head, and efficiency values.
The characteristic H~Q curve of a centrifugal pump shows that its head generally decreases as the flow rate increases (with possible exceptions at very low flow rates). This indicates that the flow rate of the centrifugal pump has increased, while the head (or lift) has decreased.
The head will not change, but the pressure will decrease
I feel that everyone is discussing at a theoretical level. In fact, when the opening degree of the outlet valve is not too large (within a certain range), the outlet pressure should remain stable. Moreover, when operating the pump, it is also necessary to pay attention to maintaining stable outlet pressure when adjusting the valve opening. When the opening is too large, it’s as if the outlet pipeline is directly connected to the back path without any throttling, so the pressure will definitely drop. Under normal operation, the valve opening does not become very large.
The flow rate of the pump increases as the valve opening becomes larger; correspondingly, the pressure before the valve decreases, the pressure after the valve increases, and the pump’s head decreases.