🔍 Key Concepts

• Boiler surface blow purpose (removing impurities from the water surface, not lowering level rapidly) • Relationship between water level, steam pressure, and safe operation • Which valves must be in what position before any blowdown operation

💭 Think About

• Ask yourself: Is a surface blow normally done with the boiler in operation, or completely shut down and cooled? • Which action would help remove dissolved and floating impurities from the water surface without endangering the boiler or causing thermal shock? • Which of these options, if done first, could actually create a dangerous condition instead of a safer one?

✅ Before You Answer

• Verify what a surface blow (surface blowdown) is versus a bottom blow and when each is used • Check standard procedures: the status of fires, water level, and pressure during normal surface blowdown on an operating boiler • Eliminate any step that would increase risk of low water or rapid thermal/pressure change before blowing down