In almost all heating applications, the control valve of a heat exchanger should have a fail-closed action so that the process does not overheat if the valve fails.

Heat always flows from a material having a lower temperature to a material having a higher temperature.

A(n) ___ is a boiler condition that occurs when the flame in a boiler furnace has been unintentionally lost.

Heat always flows from a material having a lower temperature to a material having a higher temperature.

Condensate may be directed to a condensate return tank or wasted to prevent boiler water contamination.

Steam from a boiler is directed by the main steam line through the main steam stop valve and enters the steam header.

Air pollution regulations are enacted at the federal level and/or at the state and local level.

The three classifications of refrigerants most technicians work with today are chlorofluorocarbons (CFCs), hydrochloroflurorocarbons (HCFCs), and hydrofluorocarbons (HFCs).

The closed end of a Bourdon tube is attached to the steam side of a boiler.

High surface tension is a boiler water condition in which the surface of the water is strengthened by a layer of impurities.