🔍 Key Concepts

• Understand how automatic combustion control normally regulates the fuel/air ratio in a boiler • Difference between fan inlet dampers, fan discharge dampers, and crossover dampers in a forced draft system • Importance of maintaining proper air flow and furnace pressure during manual operation

💭 Think About

• Think about which damper location (inlet vs discharge vs crossover) gives you the most direct and stable control of air volume when automation fails • Consider which control point is normally used for manual adjustment of combustion air on most marine boiler systems • Ask yourself: if the automatic system is gone, where would you safely and accurately adjust air without causing sudden changes in furnace pressure?

✅ Before You Answer

• Confirm which damper is typically tied to the automatic combustion control system for modulating air flow • Check which damper adjustment is best for fine control of air quantity rather than just changing fan operating conditions • Verify that your choice would allow you to manually match air flow to firing rate while keeping furnace pressure within safe limits