Article Index

Gas analysis- Determination of ingredients of a gaseous blend.

Gas burner- Is a device to generate a flame to heat up products using a gaseous.

Gas pressure regulator- Gas pressure regulator is a valve that automatically cuts off the flow of a liquid or gas at a certain pressure to the burner supply line.

Gauge cock- A valve attached to a water column or drum used to ascertain the water level.

Gauge glass- The gauge glass or sight glass is a transparent tube through which the operator of a boiler can observe the level of water contained within.

Gauge pressure- Is the additional pressure in a system relative to atmospheric pressure.

Grade- Oil classification according to quality, generally based on ASTM specifications.

Grain- Unit of measure used in water analysis measuring impurities in water (17.1 grains = 1 part per million - ppm).

Handhole- Access opening in a boiler usually not larger than 6inches.

Handhole cover- A handhole closure.

Hardness- Is the amount of dissolved calcium and magnesium in the water. Usually expressed as grains per gallon or ppm as CaCO3.

Hard water-Is water that has high mineral content (in contrast with "soft water"). Hard water is formed when water percolates through deposits of calcium and magnesium-containing minerals such as limestone, chalk and dolomite.

Header- A distribution pipe or manifolds that tie multiple steam mains to one boiler or multiple boilers to one or more steam mains supplying a number of smaller lines tapped off of it. .

Heat exchanger- A vessel in which heat is transferred from one medium to another.

Heating surface- Surface exposed to fire or to the heated products of combustion on one side and water on the other for absorption and transfer of heat to the heat medium per American Boiler Manufacturers Association (ABMA)

Heat release rate- Heat release rate is a measurement of heat energy released over a specific unit of time, expressed in Btu per hour per cubic foot of furnace volume or square foot of heating surface.

Heating value- Is the amount of heat produced by the complete combustion of a unit quantity of fuel. It is commonly expressed in Btu per lb., per gallon, or cu-ft.

High fire- The input amount of a burner at or near maximum.

High gas pressure control- A control to stop the burner if the gas pressure is too high.

High gas pressure switch- A switch to stop the burner if gas pressure is too high.

High oil presser control- A control to stop the burner if the oil temperature is too high.

Hot well- A tank used to receive condensate from various sources on its passage back to a boiler through the feedwater system. It usually is vented to the atmosphere.

Hydrocarbon- A chemical compound of hydrogen and carbon.

Hydrostatic test- strength and tightness test of a closed pressure vessel by water pressure.