A clean gauge glass is the only way to accurately determine boiler water level.

When replacing the flange cover in a duplex fuel oil strainer, the ___ must be carefully replaced to prevent air from entering the system.

Atmospheric pressure is the sum of gauge pressure and vacuum pressure.

A clean gauge glass is the only way to accurately determine boiler water level.

The ___ line is a refrigerant line that carries low-pressure refrigerant between an evaporator and a compressor.

A steam system is a boiler system that supplies the proper amount of water to a boiler.

A ___ is a burner accessory that opens when energized by contacts in the programmer to allow fuel oil to flow to a burner nozzle.

A ___ is a burner accessory that opens when energized by contacts in the programmer to allow fuel oil to flow to a burner nozzle.

Gate valves offer no restriction to flow when wide open.

Gate valves offer no restriction to flow when wide open.