What determines the outlet pressure of a centrifugal pump?
Thread Content
It was found on site that when the outlet valves of some centrifugal pumps are opened, the outlet pressure decreases; for some centrifugal pumps, opening the outlet valves does indeed result in a decrease in outlet pressure, which is a bit confusing I hope the great deity Hai Chuan can provide guidance and resolve my doubts.
Please take a look at these two posts: https://bbs.hcbbs.com/thread-1764877-1-1.html https://bbs.hcbbs.com/thread-3003557-1-1.html
Your question has left me confused.....:P
This issue depends on the system pressure behind the pump’s outlet valve; if the outlet pressure of this pump is not sufficient to meet the system pressure, increasing the valve opening will reduce the pressure and increase the flow rate. As the current increases, overcurrent can also cause the system to shut down. If the outlet pressure of this pump can meet the system pressure, then the opening degree of the outlet valve should be adjusted as needed, either by fully opening it or by shutting down the pump entirely. It should be said that this valve is controlled according to the system’s requirements. Of course, if the system exceeds the flow capacity provided by this pump, pressure drop, overcurrent, or shutdown will occur. Everything depends on whether the pump meets the system’s requirements, and it must be controlled by the pump’s outlet valve. It should be reiterated here that attention must be paid to the fact that, before pressure is generated in the system, the outlet pressure of the pump (the pressure before the outlet valve) should meet the rated pressure of the pump itself. Or refer to the rated current. While ensuring the proper operation of the pump, liquid is injected into the system, and pressure is gradually generated. At this point, it is necessary to use the pump outlet valve for control, and the reference should not be the % opening degree; instead, the pump’s pressure (head) and current levels should be used as the criteria for control. Otherwise, the pump will not work. For reference.
Because your pressure gauge is installed in front of the outlet valve.
The pressure gauge at the pump outlet is usually located before the pump outlet valve; the larger the opening at the outlet, the closer it is to the back pressure. The lower the back pressure, the larger the outlet opening can be, and consequently the lower the pressure.