🔍 Key Concepts

• Boiler economizer purpose – what it does with exhaust/stack gases and feedwater • Dew point of flue/stack gases – why condensing certain components can damage equipment • Relationship between feedwater inlet temperature and corrosion/acid condensation in gas-side surfaces

💭 Think About

• Ask yourself: What is the main risk if the economizer feedwater is TOO COLD compared to the exhaust gas temperature? • Which option refers directly to a property of the stack gases themselves, rather than a steam-side temperature somewhere else in the system? • Why would operators want to keep gas-side surfaces in the economizer above a certain temperature related to moisture and acidic compounds?

✅ Before You Answer

• Identify which choice is tied to the stack gas condition (not steam circuit temperatures elsewhere). • Consider which factor is directly related to avoiding condensation and corrosion in the economizer tubes. • Verify which parameter would be used as a minimum limit for feedwater temperature rather than a normal control or process temperature.