Glossary

• Primary

• Secondary

• Excess

• Convection

• Radiation

• Conduction

• Mechanical Draf - air pushed through the boiler witht

  1. Forced Draft - air pushed through the boiler with fans located in front of the boiler furnace

  2. Induced Draft - air pulled through the boiler with fans in the breeching

  3. Balance Draft - combination of forced and induced

• Natural Draft - (thermal draft) occurs when heated gases expand. A given volume of hot gas will weigh less than an equal volume of the same gas at a cool temperature.

• Firetube

• Watertube

• Cast Iron

• Incomplete

• Complete

• Perfect

• Safety valve

• Globe valve

• Check valve

• Outside screw and yoke

• Grade A - High and Low Pressure with engines, turbines and appurtenance 

  1. 1. Special

        • 50hp in charge of boilers

        • 100 hp as a shift engineer*

     2. Second Class (2-A)

        • 100 hp in charge of boilers

        • 500 hp as a shift engineer

     3. First Class (1-A)

        • 500 hp in charge of boilers

        • Unlimited hp as a shift engineer

     4. Chief (Ch-A)

        • Unlimited hp in charge of boilers

        • Unlimited hp as a shift engineer

• Grade B - High and Low Pressure

  1. 1. Special

        • 50hp in charge of boilers

        • 100 hp as a shift engineer*

     2. Second Class (2-B)

        • 100 hp in charge of boilers

        • 500 hp as a shift engineer

     3. First Class (1-B)

        • 500 hp in charge of boilers

        • Unlimited hp as a shift engineer

     4. Chief (Ch-B)

        • Unlimited hp in charge of boilers

        • Unlimited hp as a shift engineer

• Grade C - Low Pressure (15 psig or less of steam pressure, or other liquid boiler with a maximum pressure of 160 psig or temperature of 250 degrees Fahrenheit)

  1. 1. Special

        • 50hp in charge of boilers

        • 100 hp as a shift engineer*

     2. Second Class (2-C)

        • 100 hp in charge of boilers

        • 500 hp as a shift engineer

     3. First Class (1-C)

        • 500 hp in charge of boilers

        • Unlimited hp as a shift engineer

     4. Chief (Ch-C)

        • Unlimited hp in charge of boilers

        • Unlimited hp as a shift engineer

*As an apprentice in any plant under "direct supervision."

• The amount of energy required to raise the temperature of 1 lb of water, at sea level, 1 degree Fahrenheit 

• Unit for measuring the power of a steam boiler,

• For engineer license classifications only: ten square feet of heating surface is equivalent to one boiler horsepower (for conventional boilers, and five square feet of heating surface area for steam coil type generators)

• Celsius = (Fahrenheit -32)/1.8

• Fahrenheit = (Celsius x 1.8) + 32

A pressuretrol is a control used to control a steam boiler, by setting when the boiler should begin and end firing based on steam pressure. 

An aquastat is a device used in hydronic heating systems for controlling water temperature