Series and parallel connection of water pumps

The series of the pump
 
The series of pumps mainly solve the problem of insufficient head, after the series of pumps, its flow unchanged, head is the sum of the two pumps.In practice, in order to avoid the water inflow of the downstream pump to the upstream pump is not enough, the downstream pump flow is usually adjusted to the best condition to ensure that the upstream pump water inflow is sufficient.
Of the pump in parallel
 
Pump parallel refers to a number of pumps share a common outlet pipe.Each pump has a separate check valve.Pump parallel operation, the same head under the flow added.