1. Generally, only one pump is used for normal operation, because one large pump is equivalent to two small pumps working in parallel (meaning the lift and flow rate are the same), and the efficiency of a large pump is higher than that of a small pump, so from the perspective of energy saving, it is better to Choose one large pump instead of two small pumps. However, you can consider two pumps working in parallel when the following situations occur: the flow rate is very large and one pump cannot reach this flow rate.
2. For large pumps that require 50% backup rate, two smaller pumps can be used and two can be used as backup (four units in total)
3. For some large pumps, pumps with 70% flow requirements can be selected for parallel operation without a backup pump. When one pump is inspected, the other pump will still bear 70% of the production transportation.
4. For pumps that need to operate continuously for 24 hours, three pumps should be kept in standby, one for operation, one for backup and one for maintenance.