Glossary of terms

Autoignition temperature
The lowest temperature at which a gas will ignite after an extended time of exposure.

British Thermal Unit (BTU)
A BTU is the amount of heat required to change the temperature of one pound of water by one degree Fahrenheit.

Cryogenic
The science of producing very low temperatures such as those required for natural gas liquefaction.

Cubic Foot
A unit of measurement of gas volume. It is the amount of gas required to fill a volume of one cubic foot under stated conditions of temperature, pressure, and water vapor.

Density
A property of a fluid equal to volume divided by weight.

Department of Energy (DOE)
The Department of Energy is the 12th Cabinet Position, and it consists of the Office of the Secretary of Energy and the Federal Energy Regulatory Commission. It was created on August 4, 1977 as a result of the Department of Energy Organization Act of 1977. There are many subdivisions within the DOE, but the Economic Regulatory Administration and Energy Information Administration are two groups which have significant bearing on gas utility operations.

Energy Information Administration (EIA)
The statistical information collection and analysis branch of the Department of Energy.

Environmental Protection Agency (EPA)
A federal agency created in 1970 to permit coordinated and effective governmental action, for protection of the environment by the systematic abatement and control of pollution, through integration of research monitoring, standard setting, and enforcement activities.

Explosion
The sudden release or creation of pressure and generation of high temperature as a result of a rapid change in chemical state (usually burning), or a mechanical failure.

Fahrenheit degrees (F)
A temperature scale according to which water boils at 212 and freezes at 32 degrees. Convert to Centigrade degrees © by the following formula: (F -32)/1.8 = C.

Federal Energy Regulatory Commission (FERC)
A U.S. government agency created by Congress in 1977. The act transferred to the FERC most of the former Federal Power Commission's interstate regulatory functions over the electric power and natural gas industries. In 1978, Congress passed the Natural Energy Act, broadening the FERC's jurisdiction and regulatory functions. The FERC now also regulates producer sales of natural gas in intrastate commerce. The FERC establishes uniform ceiling prices for each of several categories of natural gas, and these prices apply to all sales on a nationwide basis.

Lease
A contract between an owner (lessor) and a tenant (lessee), setting forth the compensation, terms, and conditions upon which the lessee may occupy or use property, real or personal, of the lessor.

Liquefaction of Gases
Any process in which gas is converted from the gaseous to the liquid phase.

Liquefied Natural Gas (LNG)
Natural gas which has been liquefied by reducing its temperature to minus 260 degrees Fahrenheit at atmospheric pressure. It remains a liquid at -116 degrees Fahrenheit and 673 psig. In volume, it occupies 1/600 of that of the vapor at standard conditions.

Main
A distribution line that serves as a common source of supply for more than one service line.

Mcf
Thousand cubic feet.

MTPA
Million Tonnes per Annum. Tonnes or Metric Ton is approximately 2.47 cubic meters of LNG.

Noncombustible
A substance or gas that will not burn.

Peak shaving LNG Facility
A facility for both storing and vaporizing LNG intended to operate on an intermittent basis to meet relatively short-term peak gas demands. A peak shaving facility may also have liquefaction capacity, which is usually quite small compared to vaporization capacity at such facility.

Pipeline
All parts of those physical facilities through which gas is moved in transportation, including pipe, valves, and other appurtenances attached to pipe, compressor units, metering stations, regulator stations, delivery stations, holders, and fabricated assemblies.

Pipeline Capacity
The maximum quantity of gas that can be moved through a pipeline system at any given time based on existing service conditions such as available horsepower, pipeline diameter(s), maintenance schedules, regional demand for natural gas, etc.

Pressure, Atmospheric
The pressure due to the weight of the atmosphere (air and water vapor) on the earth's surface. The average atmospheric pressure at sea level (for scientific purposes) has been defined at 14.696 pounds per square inch absolute.

Receiving Terminal
Coastal plant that accepts deliveries of liquefied natural gas and processes it back into gaseous form for injection into the pipeline system. Also known as regasification terminal.

Stranded Gas
Gas that is not near a market and that does not have an economic basis for development and production.

Throughput
The volume of natural gas that may be carried through a pipeline over a period of time.