Regarding standby pumps

Of course! The purpose of having backup equipment is to deal with sudden failures of the equipment that is in operation.

Having two backups and one primary is a guarantee; it’s very necessary

The 2-in-use-1-backup approach can be considered; since having only 1 unit means the equipment operates alone, and in some cases devices that require high flow rates and high head pressure have very high power consumption. If a 1-in-use-1-backup setup is used, it leads to significant waste of resources on the idle device. At this point, the advantage of using 2 with 1 as a backup can be seen. For example, in the project at Sideli (Jiangxi) Chemical Fiber Company, with a flow rate of 1200 cubic meters per hour, the power requirement for a single pump was 285 kW. I opted to provide them with a setup of two pumps in operation and one as a backup, which reduced the unused power consumption to 180 kW. When it’s actually in use, its power consumption is roughly the same as 285, as long as it operates within its efficient range. This was tested by the owner recently, so it’s guaranteed.

I have seen situations where there is one backup for one unit, one backup for two units, and one backup for three units. The purpose of the backup pump is to prevent sudden failures of the operating pump; as long as it can achieve this goal, that’s sufficient.

Especially for pumps that operate for long periods of time, it is very necessary to have spare pumps, as this facilitates maintenance and helps prevent emergencies; as for the ratio of operating pumps to spare pumps, it depends on the operating conditions and design

Using two backups for one unit is quite common; for systems that require high traffic volumes, this setup is typically employed to protect the equipment. The outlets of the 3 pumps are connected in parallel, each equipped with its own check valve and outlet control valve; when in use, 2 of the pumps are activated while the other outlet is closed as a backup. In any case, important pumps should have backup pumps available to prevent greater losses in the event of sudden emergencies. At the very least, the warehouse should have a spare pump; even if a pump stops working and cannot be repaired, it is possible to connect the entire system directly and replace the pump.

To ensure normal production in the event of pump failures, the design must provide at least one spare unit for each pump.

Equipment with high value often comes with an extra unit as a spare; however, high-value equipment with an extremely low failure rate may not require a spare unit, such as centrifugal compressors and screw compressors.

If it’s valuable, then one needs to consider the failure rate of the pump. For example, the diaphragm pumps imported by our company cost over 20 million each; who would dare to use them as spare units? They are all operated as single units.