🔍 Key Concepts

• Think about what the boiler wrapper sheet is on a marine boiler – it is the plate that wraps around and forms the outer wall of the furnace/combustion chamber, not the steam space inside the drum and not the tube bank itself. • Compare the arrows that point to drums or openings (like the steam drum and manhole) versus those that point to flat or curved plates forming the furnace enclosure. • In this sectional view, identify the area where the combustion space is, then look for the plate that separates that hot furnace from the water/steam space and tubes – that plate is the wrapper sheet.

💭 Think About

• First, locate the furnace/combustion chamber in the illustration. Which side of the boiler shows the burner and flame path? • Which labeled arrow is pointing to the metal plate that surrounds that furnace, rather than to a drum, tube bank, or manhole cover? • Of the answer letters given (A, B, C, H, I), which one is pointing directly at a sheet or wall around the furnace, instead of the interior of the steam drum or a group of tubes?

✅ Before You Answer

• Verify that your chosen letter points to a sheet/plate forming a wall, not a round drum, manhole cover, or tube bank. • Confirm that the part you pick is in the area surrounding the furnace/combustion zone, where the burner is located in the illustration. • Make sure the arrow is not indicating individual tubes or the main generating bank, since the wrapper sheet is a continuous plate, not separate tubes.