Device "27" shown in the illustration is...

🔍 Key Concepts

• Follow the piping connected to device 27 and notice where it leads (to atmosphere, to suction, or to another part of the system). • Think about the normal operating condition of this unit: it works under vacuum inside the shell above the heater bundle. • Compare device 27 with the nearby devices (like 25 and 26) to decide which one is meant for protection versus routine operation.

💭 Think About

• Ask yourself: if the shell is normally under vacuum, which of the listed functions would be critical for protecting the shell if something goes wrong? • Which function would require a connection directly to the top of the evaporator shell rather than into the feed or brine lines? • Look at whether device 27 appears to be a spring‑loaded valve venting out of the system or a small line that returns back into the system—how does that match the choices?

✅ Before You Answer

• Verify whether device 27’s outlet goes out of the system (to atmosphere or a safe discharge) or back into the process piping. • Check if any other numbered item in the illustration is already clearly labeled or shaped like a pressure/vacuum gauge or regulating valve so you don’t confuse their functions. • Confirm that the function you choose would logically be placed on the very top of the shell, where gases or overpressure would naturally collect.

Device "27" shown in the illustration is used to __________. Illustration MO-0111

purge the unit of non-condensable gases

add de-scaling chemicals as needed

regulate maximum vacuum during normal operation

relieve excess pressure

🔍 Key Concepts

💭 Think About

✅ Before You Answer