In the combustion process, approximately 75 lb of air are required for every pound of fuel burned.

A firebox boiler is a cylindrical scotch marine boiler.

A flammability hazard on the NFPA Hazard Signal System indicates the degree of susceptibility of materials to explode or release energy by themselves or by exposure to certain conditions or substances.

A reciprocating compressor is a compressor that has reciprocating cylinders to compress refrigerant.

The location of an auxiliary low water fuel cutoff allows it to act as a backup if the primary low water fuel cutoff fails to shut the burner OFF in a low water condition.

A feedwater ___ valve is located next to a feedwater stop valve and prevents feedwater from flowing from the boiler back to the feedwater pump.

Stop valves before and after a pressure-reducing valve allow servicing of the pressure-reducing valve.

A steam strainer should be located in a steam line after a steam trap.

Stop valves before and after a pressure-reducing valve allow servicing of the pressure-reducing valve.

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