Boiler Systems and Steam Flashcards

What is the recommended procedure when a boiler safety relief valve lifts (opens)?

Answer: Identify and correct the cause of overpressure before resuming operation

A lifting safety valve signals a potentially dangerous overpressure condition; the root cause must be found and corrected before safely resuming boiler operation.

In a steam heating system, what is 'two-pipe' piping?

Answer: A system with supply and return piping kept separate

A two-pipe steam system uses separate supply and return mains, allowing more precise control and quicker condensate return compared to single-pipe systems.

What is 'scale' in a boiler, and what problem does it cause?

Answer: Mineral deposits on heat transfer surfaces; it reduces heat transfer efficiency

Scale is mineral buildup (primarily calcium and magnesium compounds) on waterside surfaces that acts as insulation, reducing heat transfer and potentially causing overheating.

What condition is described as 'priming' in a steam boiler?

Answer: Violent water surging that carries water droplets into the steam supply

Priming occurs when the boiler water surges violently, entraining water droplets in the steam, which can cause water hammer and damage downstream equipment.

What is the purpose of a feedwater economizer in a boiler system?

Answer: To preheat feedwater using waste heat from flue gases

An economizer recovers heat from exhaust flue gases to preheat incoming feedwater, improving overall boiler efficiency and reducing fuel consumption.

The boiler horsepower (BHP) rating is defined as the evaporation of how many pounds of water per hour from and at 212°F?

Answer: 34.5 lbs/hr

One boiler horsepower equals the evaporation of 34.5 pounds of water per hour from and at 212°F, equivalent to approximately 33,475 BTU/hr.

What does 'TDS' stand for in boiler water treatment, and why is it monitored?

Answer: Total Dissolved Solids; to prevent scale and foaming by controlling blowdown

Total Dissolved Solids (TDS) measures the concentration of minerals and impurities in boiler water; high TDS causes scale, foaming, and carryover, controlled through blowdown.