Number of desk selection

1. For the normal operation pump, only one is usually used, because one large pump is equivalent to two small pumps working in parallel (referring Select a large pump instead of two small pumps, but when there is the following situations, two pumps can be considered and jointly works: the traffic is large, and one pump does not reach this traffic.

2. For large pumps that need 50%of the spare rate, two smaller pumps can be changed, and two spares (four in total)

3. For some large pumps, a pump with 70%flow requirements can be used. There is no backup pump. When one pump is maintained, the other pump still undertakes 70%of the transportation.

4. For pumps that need to be continuously operated for 24 hours, three pumps should be set aside, one operation, one spare, and one repair