G
GAS ANALYSIS – The determination of the constituents of a gaseous mixture.
GAS BURNER – A burner that uses gas or fuel.
GAS PRESSURE REGULATOR – A spring loaded, dead weighted or pressure balanced device which will maintain the gas pressure to the burner supply line.
GAUGE COCK – A valve attached to a water column or drum for checking water level.
GAUGE GLASS – The transparent part of a water gauge assembly connected directly or through a water column to the boiler, below and above the water line, to indicate the water level in a boiler.
GAUGE PRESSURE – The pressure above atmospheric pressure.
GRADE – Oil classification according to quality, generally based on ASTM specifications.
GRAINS PER CU-FT – The term for expressing dust loading in weight per unit of gas volume (7000 grains equals one pound).
GRAINS (WATER) – A unit of measure commonly used in water analysis for the measurement of impurities in water (17.1 grains = 1 part per million – ppm).
GRAVITY – Weight index of fuels: liquid, petroleum products expressed either as specific, Baume or A.P.I. (American Petroleum Institute) gravity; weight index of gaseous fuels as specific gravity related to air under specified conditions; or weight index of solid fuels as specific gravity related to water under specified conditions.
H
HANDHOLE – An access opening in a pressure part usually not exceeding 6inches in its longest dimension.
HANDHOLE COVER – A handhole closure.
HARDNESS – A measure of the amount of calcium and magnesium salts in water. Usually expressed as grains per gallon or ppm as CaCO3.
HARD WATER – Water which contains calcium or magnesium in an amount which require an excessive amount of soap to form a lather.
HEAT AVAILABLE – The thermal energy above a fixed datum that is capable of being absorbed for useful work.
HEAT BALANCE – An accounting of the distribution of the heat input, output and losses.
HEAT EXCHANGER – A vessel in which heat is transferred from one medium to another.
HEAT RELEASE RATE – Rate that describes the heat available per square foot of heat-absorbing surface in the furnace or per cubic foot of volume.
HEATING SURFACE – Those surfaces which are exposed to products of
combustion on one side and water on the other. This surface is measured on the side receiving the heat.
HEATING VALUE – The quantity of heat released by a fuel through complete combustion. It is commonly expressed in Btu per lb, per gallon, or cu-ft.
HIGH GAS PRESSURE CONTROL – A control to stop the burner if the gas pressure is too high.
HIGH OIL TEMPERATURE CONTROL – A control to stop the burner if the oil temperature is too high.
HYDROCARBON – A chemical compound of hydrogen and carbon.
HYDROSTATIC TEST – A strength and tightness test of a closed pressure vessel by water pressure.
I
IGNITION – The initiation of combustion.
IGNITION TEMPERATURE – Lowest temperature of a fuel at which combustion becomes self-sustaining.
ILLUMINANTS – Light oil or coal compounds that readily burn with a luminous flame, such as ethylene, propylene and benzene.
INCOMPLETE COMBUSTION – The partial oxidation of the combustible constituents of a fuel.
INDUCED DRAFT FAN- A fan exhausting hot gases from the heat absorbing equipment.
INERT GASEOUS CONSTITUENTS – Incombustible gases such as nitrogen which may be present in a fuel.
INHIBITOR – A substance which selectively retards a chemical action. An example in boiler work is the use of an inhibitor, when using acid to remove scale, to prevent the acid from attacking the boiler metal.
INJECTOR – A device utilizing a steam jet to entrain and deliver feed water into a boiler.
INSULATION – A material of low thermal conductivity used to reduce heat losses.
INTEGRAL BLOWER – A blower built as an integral part of a device to supply air thereto.
INTEGRAL-BLOWER BURNER – A burner of which the blower is an integral part.
INTERLOCK – A device to prove the physical state of a required condition, and to furnish that proof to the primary safety control circuit.
INTERMITTENT BLOWDOWN – the blowing down of boiler water at intervals.
INTERNAL TREATMENT – The treatment of boiler water by introducing chemicals directly into the boiler.
ION – A charged atom or radical which may be positive or negative.
IRI – Industrial Risk Insurers.