A low water fuel cutoff is located slightly below the NOWL.

A back-pressure burner is a burner consisting of tubes with drilled holes that allow pressurized gas to escape into the furnace where the gas is burned.

A back-pressure burner is a burner consisting of tubes with drilled holes that allow pressurized gas to escape into the furnace where the gas is burned.

A negative pressure reading in a manometer is indicated if the level of the liquid in the leg connected to the breeching is ___ to the atmosphere.

A negative pressure reading in a manometer is indicated if the level of the liquid in the leg connected to the breeching is ___ to the atmosphere.

___ is the amount of fuel a burner is capable of burning in a given unit of time.

Flame failure can cause a furnace explosion from the buildup and ignition of fuel.

Flame failure can cause a furnace explosion from the buildup and ignition of fuel.

Class ___ fires are fires that burn combustible metals such as zirconium, titanium, magnesium, sodium, and potassium.

Class ___ fires are fires that burn combustible metals such as zirconium, titanium, magnesium, sodium, and potassium.