Blowback is the ___ in a boiler that occurs after the safety valve has opened.

___ and waist belts are used to reduce injuries from falling.

During the combustion process, fuel mixed with air is burned to produce the heat necessary to operate a boiler.

___ and waist belts are used to reduce injuries from falling.

A check valve is used when fluid flow needs to be restricted or regulated through the valve.

The three states of ___ are solid, liquid, and gas.

If fuel oil is not properly blended, it may stratify in a tank.

The ___ valve should be closest to the boiler.

A ___ is used to reduce utility water pressure to prevent overpressure in a system.

An electric spark igniter is a device located at a burner that uses a small piece of silicon nitride, which produces high temperatures when electric current passes through it.