🔍 Key Concepts

• Trace the path of the exhaust gas from the engine, through the waste heat boiler/economizer, and out to the atmosphere. • Decide which listed components must be mounted on the water/steam side of the boiler versus in the gas/uptake path. • Think about what device you would put in the uptake or stack so the engineer can monitor combustion or gas condition while the system is running.

💭 Think About

• Look closely at where location "I" is placed: is it on the water/steam drum, on the burner front, on the tube bank, or in the exhaust/uptake line? • For each choice, ask yourself: does this component need direct contact with boiler water, with fuel and flame, or simply with moving flue gas? • Which of the four options is primarily an indicator/instrument rather than an active piece of equipment like a burner or sootblower?.

✅ Before You Answer

• Confirm whether point "I" is connected to the gas side (uptake/stack) or the water/steam side of the system. • Eliminate any option that must be mounted directly on the boiler shell where water level is visible or measured. • Eliminate any option that is a large mechanical assembly normally installed at the burner front or inside the gas path, rather than a small fitting/instrument.