1. Generally, only one pump is used for normal operation, because one large pump is equivalent to two small pumps working in parallel (referring to the same lift and flow rate), and the efficiency of the large pump is higher than that of the small pump, so it is better to use it from the perspective of energy saving. Choose a large pump instead of two small pumps, but in the following situations, two pumps can be considered to work in parallel: the flow rate is very large, and one pump cannot reach this flow rate.

2. For large pumps that require a 50% backup rate, two smaller pumps can be changed to work, and two backups (total four)

3. For some large-scale pumps, pumps with 70% flow requirements can be selected for parallel operation, without a backup pump. When one pump is overhauled, the other pump still undertakes 70% of the production.

4. For pumps that need to run continuously for 24 hours, three pumps should be spared, one for operation, one for backup and one for maintenance.

1. Generally, only one pump is used for normal operation, because one large pump is equivalent to two small pumps working in parallel (referring to the same lift and flow rate), and the efficiency of the large pump is higher than that of the small pump, so it is better to use it from the perspective of energy saving. Choose a large pump instead of two small pumps, but in the following situations, two pumps can be considered to work in parallel: the flow rate is very large, and one pump cannot reach this flow rate.

2. For large pumps that require a 50% backup rate, two smaller pumps can be changed to work, and two backups (total four)

3. For some large-scale pumps, pumps with 70% flow requirements can be selected for parallel operation, without a backup pump. When one pump is overhauled, the other pump still undertakes 70% of the production.

4. For pumps that need to run continuously for 24 hours, three pumps should be spared, one for operation, one for backup and one for maintenance.