🔍 Key Concepts

• Chemical feed line location in a steam drum and how chemicals are distributed inside the water space • Difference between feedwater inlet, blowdown/surface blow, and chemical feed arrangements in boiler drums • How an internal perforated distribution pipe is usually shown in sectional boiler drawings

💭 Think About

• Look closely at items B, E, J, and L and ask: which one is connected to a relatively small external line that could come from a chemical feed pump, then runs inside the drum as a distribution pipe? • Among the labeled items, which one lies in the water space (not up in the steam space nor right on the bottom) and appears designed to mix its contents quickly with the boiler water along most of the drum’s length? • Compare the item you think is the chemical feed line with the parts that clearly look like bottom blowdown or continuous blow: which item looks least like a drain or blow valve and more like a gentle distribution system?

✅ Before You Answer

• Verify which of B, E, J, and L is a relatively small-diameter internal pipe with multiple outlets (small holes or nozzles) running along the drum. • Confirm that the item you select is submerged in the water space and not mainly in the steam space or at the very bottom where sludge would collect. • Check whether the item is not directly connected to the obvious bottom blow/bottom drain connection at the lowest point of the drum. The chemical feed line should introduce chemicals, not discharge them.