🔍 Key Concepts

• Boiler water salinity and dissolved solids and how they affect foaming and carryover • The purpose of a blowdown (what it removes and what it does NOT add) • Typical role of phosphate or carbonate treatments in boiler water chemistry

💭 Think About

• After you lower salinity by blowing down, what condition in the boiler water have you changed, and what might now need to be re‑balanced? • Which of the options actually adds something to the water versus changing how the boiler is fired, and does that logically follow a blowdown done to correct water chemistry? • Think about which chemicals are commonly used to react with hardness (calcium/magnesium) to form soft sludge that can be removed, rather than hard scale.

✅ Before You Answer

• Verify which choice is a water treatment chemical and which are operating adjustments (firing rate) • Ask yourself: does changing the firing rate directly lower salinity, or is that handled by blowdown and treatment? • Confirm which treatment (carbonates vs phosphates) is more commonly associated with conditioning hardness and preventing scale in marine boilers.