Pump in the open (open loop) is also known as single stage double suction centrifugal pump, the main features of the medium flow, working principle of pump running head: the impeller installed in the pump shell, and fastened on the pump shaft, the shaft directly driven by the motor. Pump housing in the middle of a liquid suction and suction pipe connection. The liquid through the bottom valve and the suction tube into the pump. The liquid discharge port on the pump casing is connected with the discharge pipe. When the pump speed, the pressure head, flow and impeller diameter.
When the single pump can not meet the transfer task, can be used in parallel or series operation of the pump. Use of centrifugal pumps in parallel two sets of the same type, although the pressure head changes, but increased the total transport flow efficiency, the total efficiency of the pump in parallel with the same single pump in the pump series; increase the total pressure head, flow rate changes, the total efficiency of the pump in series with a single pump efficiency is the same. Two pumps in parallel, flow and pressure head has increased, but due to the pipeline characteristic curve control, pipeline resistance increases, total throughput two pumps in parallel is equal to two times the original amount of pump. Two pumps in series, pressure head and flow rate will increase, but the total head two pumps in series is still less than two times of the original pump pressure head.
