A ___ check valve is a check valve that prevents backflow through the use of a conical or cylindrical brass disc held in place by a spring.

A ___ check valve is a check valve that prevents backflow through the use of a conical or cylindrical brass disc held in place by a spring.

A power burner is a burner ___.

Natural draft produces greater amounts of draft in the winter than in the summer.

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

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.