Do you know how to choose a centrifugal pump?When selecting a centrifugal pump,if capacity is bigger,it is better to choose bigger head or small.Today let us talk together.
If In general, when the centrifugal pump is designed, the flow head is a curve. The flow head of centrifugal pump has the minimum and maximum limits. If the limit is exceeded, the performance of the centrifugal pump will decline. When selecting water centrifugal pumps, the selected flow and head should preferably be the rated flow head or the similar water pump designed by the water pump, so as not to affect the efficiency of the water centrifugal pump.
Many customers usually think that the lower the head of centrifugal pump is, the smaller the motor load is. Under this misunderstanding, when purchasing a pump, they often choose a high head of the pump. In fact, for centrifugal pumps, when the centrifugal pump model is determined, its consumption power is proportional to the actual flow of the centrifugal pump. The flow of the centrifugal pump will decrease with the increase of the head, so the higher the head is, the smaller the flow is, and the smaller the power consumption is. On the contrary, the lower the head, the greater the flow, and the greater the power consumption. Therefore, in order to prevent motor overload, it is generally required that the actual pumping head of the centrifugal pump shall not be less than 60% of the calibrated head. Therefore, when the high head is used for pumping water with low head, the motor is easy to overload and heat, and it can burn down in serious cases. In case of emergency use, a gate valve (or block the small water outlet with wood, etc.) must be installed on the water outlet pipe to regulate the water output, so as to reduce the flow and prevent the motor from overloading. Pay attention to the temperature rise of the motor. If the motor overheats, turn down the water outlet flow or shut down in time.
It can be seen from the above that why the outlet gate valve of centrifugal water pump needs to be closed when it starts and stops is to prevent the motor from over current, which causes the motor to burn out.