🔍 Key Concepts

• Identify what device 7 is by its symbol (type of pump) and where it sends water in the system. • Recall how wearing ring wear affects a centrifugal pump’s capacity and discharge pressure (more internal leakage, less effective flow). • Relate the feed‑water flow from device 7 to the evaporation rate inside unit 23 (more/less feed, more/less evaporation).

💭 Think About

• Follow the piping from device 7: what fluid is it moving, and directly or indirectly, how does that fluid enter unit 23? • If the pump’s wearing rings are badly worn, will the pump move more water, less water, or the same water at the same speed and suction conditions? • Ask yourself whether the standby pump (8) comes on automatically just because the rings in 7 are worn, or if some action would be needed to use it.

✅ Before You Answer

• Confirm from the symbol that device 7 is not a positive displacement pump and that it would normally use wearing rings. • Verify whether evaporation rate in 23 depends on the amount of seawater/feed water delivered or only on vacuum conditions. • Decide if worn wearing rings would reduce effective discharge flow or pressure from 7, and then infer how that would influence the amount of water available for evaporation in 23.