When water and sulfur combine, they react to form ___, which corrodes boiler metal.

A boiler is an open metal container in which water is heated to produce steam or heated water.

A ___ hazard on the NFPA Hazard Signal System indicates the degree of susceptibility of a material to burning based on the form or condition of the material and its surrounding environment.

Diverter fittings are used to supply cold water to a heating unit while maintaining the required flow of cold water to the next heating unit.

A(n) ___ is a cooling system that uses direct expansion of the refrigerant in the evaporator coil to cool a building’s interior air.

Diverter fittings are used to supply cold water to a heating unit while maintaining the required flow of cold water to the next heating unit.

A quick-open bottom blowdown valve is located ___.

To prevent damage to a brick refractory, the furnace ___.

An evaporation test is performed by blowing down the low water fuel cutoff.

If the automatic makeup water feeder on the surge tank fails to supply water to the tank, the ___ will shut off the feedwater pump in order to protect the pump.