Glossary of Terms

Not familiar with a term?  We've got you covered!

M

Main

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

Main Extension

The addition of pipe to an existing main to serve new customers.

Mains, Distribution

Pipes transporting gas within service areas to the point of connection with the service pipe. 

Mains, Gas

Pipes used to carry gas from one point to another. As contrasted with service pipes, they carry gas in large volume for general or collective use. 

Major Natural Gas Company (Pipeline)

Any natural gas company with combined sales for resale and gas transported or stored for a fee exceeding 50 million Mcf at standard conditions in each of the three previous calendar years.

Make-Up Gas

The contractual right to take gas volumes at a future date that were available but not taken on their designated date as with take-or-pay contracts. 

Manufactured Gas

A gas obtained by destructive distillation of coal, by the thermal decomposition of oil, or by the reaction of steam passing through a bed of heated coal or coke. Examples are coal gases, coke or oven gases, producer gas, blast furnace gas, blue (water) gas, or carbureted water gas. The Btu content varies widely. 

Marginal Cost

The cost of the next unit if it were purchased. See INCREMENTAL COST.

Market Area

Any area in which the company feels that gas can be sold in the public convenience and necessity to the benefit of the company and stockholders.

Market-Based Pricing

The basing of a longer-term contract or rate schedule on published current market prices of competing supplies of natural gas or alternate fuels. Also known as MARKET-RESPONSIVE PRICING.

Marketer

Entity which sells natural gas it has purchased from a producer or other seller.

Materials Transportation Bureau (MTB)

An independent office reporting to the Secretary of Transportation of the United States Government, charged with enforcing the Pipeline Safety Act. MTB, among other functions, receives reports of safety-related incidents from gas system operators and periodically issues revisions and interpretations to the Minimum Federal Safety Standard (49 CFR 192).

Meter Set (Meter Installation)

The meter and appurtenances thereto, including the meter, meter bar, and connected pipe and fittings. Also called METER SET ASSEMBLY.

MMBtu

A thermal unit of energy equal to 1,000,000 Btus, that is, the equivalent of 1,000 cubic feet of gas having a heating content of 1,000 Btus per cubic foot, as provided by contract measurement terms. See DEKATHERM. 

MMcf

A million cubic feet. See CUBIC FOOT.

MMcfd

Million cubic feet per day. 

MMS

Department of Interior Minerals Management Service.