🔍 Key Concepts

• Trace the piping connected to device O in both the side and rear views to see where that line goes. • Distinguish between the feed water line and the brine discharge/recirculation line on this type of low‑pressure evaporator. • Think about what a device must do if its purpose is to regulate/measure flow versus providing suction head for a pump.

💭 Think About

• From device O, follow the pipe: does it lead toward the evaporator shell inlet, the brine pump suction, or a discharge/overboard point? • Ask yourself: is device O placed where it could actually change the amount of fluid entering the evaporator, or does it affect fluid leaving the unit? • Consider the vertical position of O relative to the brine pump—could its location realistically create a positive suction head, or is it more suited to controlling flow in a line?

✅ Before You Answer

• Verify which labeled line carries incoming feed water and which carries brine; check their connections at the shell and pumps. • Confirm whether device O is installed upstream or downstream of the evaporator body on that particular line. • Look for any indication (symbol/shape) that O is a valve or control device rather than a simple pipe or fitting; this will help decide between regulating entry vs. exit flow.