___ are used in boilers to direct the gases of combustion for multiple passes to obtain maximum efficiency.

A(n) ___ is a hot water boiler fitting that serves as a boiler water setpoint temperature control system with an outside air thermostat.

___ is the condition where a flame travels upwind and into the burner assembly.

A(n) ___ is a hot water boiler fitting that serves as a boiler water setpoint temperature control system with an outside air thermostat.

___ is credited with the development of the reciprocating steam engine.

Scale acts as an insulating material and reduces the transfer of heat to water.

___ is heat transfer that occurs when currents circulate between warm and cool regions of a fluid.

A ___ is a dynamic pump with a rotating impeller inside a cast iron or steel housing.

A boiler management and control system may also be known as a boiler control system (BCS) or microcomputer boiler control system (MBCS).

A ___ is a dynamic pump with a rotating impeller inside a cast iron or steel housing.