Throttle valve
Is the regulation of pump outlet valve opening change method of centrifugal pump flow is most simple, while the horizontal multistage centrifugal pump speed constant (generally rated speed), its essence is to change the pipeline characteristic curve to change the location of pump operating point. Pump characteristic curve Q-H and characteristic curve of Q- sigma h intersection of the operating point limit valve fully open water pump. When the valve is closed, the local resistance of the pipeline is increased, the working point of the pump is shifted to the left, and the corresponding flow rate is reduced. The valve is fully closed, the equivalent resistance is infinite, the flow rate is zero, the pipeline characteristic curve and vertical coordinates coincide.
Thus, to close a small valve to control the flow, the multi-stage centrifugal pump water supply capacity itself is the same, the head characteristics of the same, the resistance characteristics of the valve will be changed with the change of the valve opening. This method is easy to operate, continuous flow, can be between a maximum flow and zero random adjustment, and no additional investment, the application is very wide. But the throttle adjustment is to consume the excess energy of the centrifugal pump to maintain a certain amount of supply, the efficiency of the centrifugal pump will also decline, the economy is not reasonable.
