AK Boiler Operator flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

ASME Section I

ASME Boiler and Pressure Vessel Code section governing power boilers above 15 psig steam, including design, materials, fabrication, inspection, and stamping requirements.

ASME Section IV

Code section for heating boilers limited to 15 psig steam, 160 psig water, and 250°F water temperature; covers construction and safety requirements.

MAWP

Maximum allowable working pressure is the highest pressure at which a boiler or pressure vessel may legally operate under its Code design.

NBIC

National Board Inspection Code provides rules for repairing and altering boilers and pressure vessels and for qualification of repair organizations and welders.

Safety valve function

Automatically relieves pressure when it reaches setpoint, protecting the boiler from overpressure; it must have capacity at least equal to maximum generating capacity.

Low-water fuel cutoff

Safety control that shuts off fuel to the burner when boiler water level falls below a safe limit, preventing overheating and pressure-part failure.

Gauge glass blowdown

Procedure that opens and closes gauge glass valves to prove water and steam connections are clear and that the indicated water level is accurate.

Flame safeguard control

Control that monitors flame scanner signal, proves pilot or main flame, and closes fuel valves and locks out on flame failure.

Stoichiometric air

The minimum amount of air needed to completely burn a given quantity of fuel; excess air is supplied above this amount to ensure complete combustion.

Three T's combustion

Temperature, turbulence, and time are combustion conditions needed with proper air-fuel ratio to achieve complete burning and low unburned fuel.

Flash point

Lowest temperature at which a liquid fuel releases enough vapor to form an ignitable mixture near its surface under specified test conditions.

Forced draft

A fan supplies combustion air to the furnace under positive pressure; forced-draft systems must prevent leakage of hot gases into the boiler room.

Deaerator

Feedwater heater and venting device that removes dissolved oxygen and carbon dioxide, reducing corrosion pitting in feedwater lines and boiler.

Ion exchange softening

Process that replaces calcium and magnesium hardness ions with sodium ions, reducing scale formation; it does not remove dissolved solids.

Boiler blowdown

Removal of boiler water from the bottom or surface to control dissolved solids, sludge, and contamination; excessive blowdown wastes heat and water.

Priming and foaming

Priming is carryover of boiler water into steam; foaming is unstable foam on the water surface. High solids, alkalinity, or oil can cause both.

Pre-ignition purge

Period of forced airflow through furnace and flue before ignition to remove combustible gases, preventing furnace explosion during startup.

Normal boiler shutdown

Reduce load and firing, stop fuel, maintain water level, close main steam valve, and allow controlled cooling without rapid temperature change.

Bottom blowdown timing

Bottom blowdown is performed at light load with stable water level to remove sludge; blowdown at high firing can cause level instability and thermal stress.

Emergency shutdown

Trip fuel and burner, isolate fuel supply, maintain safe water level if possible, and follow site emergency procedures before any restart.

Hydrostatic test

Pressure test using water to verify strength and tightness; new construction is commonly tested at 1.5 times maximum allowable working pressure.

Lockout tagout

Isolation and tagging of energy sources before maintenance to prevent accidental startup or release of stored energy; verify zero energy before work.

Non-destructive testing

Inspection methods such as ultrasonic thickness, dye penetrant, magnetic particle, and radiography that detect defects without destroying the component.

Safety valve pop test

Test that verifies a safety valve opens at set pressure and reseats properly; adjustment is limited to qualified personnel with jurisdiction approval.

Low-water condition

Unsafe water level that can overheat tubes; fuel must be shut off, and water must not be added to an overheated boiler until it has cooled.

Water hammer cause

Sudden condensation or trapped condensate in steam lines causes slug impact; draining lines and warming slowly prevent it.

Carbon monoxide hazard

Colorless, odorless gas from incomplete combustion; it can cause poisoning, so fuel-burning areas need ventilation and CO detection.

Fire triangle

Fuel, oxygen, and heat are required for combustion; removing any one leg extinguishes or prevents fire.

Operator license limits

A boiler operator license authorizes operation only of boilers within the class, size, and pressure limits set by the jurisdiction.

Boiler operating log

Record of pressure, temperature, water level, blowdown, tests, and abnormalities used to document operation and support maintenance and inspections.

Code repair requirement

Repairs and alterations to boilers must follow ASME and NBIC requirements and be inspected before the boiler returns to service.

Operator in charge

Person responsible during a shift for safe water level, combustion, controls, emergency response, and compliance with operating procedures.