The pump transmits the mechanical energy or other external energy of the prime mover to the liquid to increase the liquid energy, which is mainly used to transport the liquid including water, oil and acid-base liquid. Pumps are divided into different categories according to different conditions, and each pump has its own unique method of use. Now we will explain why the centrifugal pump to close the valve start, and axial flow pump to open the valve to start. The reasons are as following:
1.Centrifugal pump power performance curve is a slow rise of the approximate straight line, the minimum shut-off power, in order to start and stop light load, solid start and shut down before shutting down the first outlet valve;
2.The axial pump power performance curve is a rapid decline of the convex convex parabola, the maximum power to turn off the death, in order to avoid wrong operation caused serious overloading of the power machine, axial pump pumping device does not allow any valve.
