G-H-I

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.