"L" Tubing

An industry standard for copper tubing defined by the tube wall thickness and identified by a "blue" strip. Type "L" copper tube wall is approximately 50% greater thickness than Type "M"

LDO

Lint, Dust, and Oil

LP

Liquid Propane. A fuel for gas water heaters.

Laminar Flow

Streamlined flow of a fluid near a solid boundary.

Laminated Glass

Glass that has been made by uniting layers of glass in order to strengthen the glass.

Langelier's Index

A calculated number used to predict whether or not a water will precipitate, be in equilibrium with, or dissolve calcium carbonate. It is sometimes erroneously assumed that any water that tends to dissolve calcium carbonate is automatically corrosive.

Lateral Sewage Line

A sewage line that connects one sewage pipe with another.

Laundry Tray

Laundry Tub

Laundry Tub

Very deep sink used in a laundry room for soaking or washing clothing.

Lav

Lavatory

Lav Tube

Water supply tube for lavatory.

Lavatory

A fixed bowl or basin with running water and drainage for washing. Bathroom sink.

Leach Field

Porous soil area, through which septic tank leach lines run, emptying the treated waste.

Leach Lines

Pipes that carry effluent from the septic system out to the leach field.

Leakage

Loss of fluid usually due to mechanical breakdown or gasket wear.

Lean Mixture

An air-gas mixture that contains more air than needed for complete combustion of the gas.

Leader Pipe

A pipe that carries rainwater to the ground or sewer.

Lien

A legal right to hold another's property, or to have it sold, or applied for payment of a claim, especially to satisfy a debt.

Lien Release

A written document from the contractor to the owner that releases the Lien (mechanic's or material) following its satisfaction.

Lien Waiver

A written document from a contractor or material supplier having lien rights against an owner's property that relinquishes all or part of those rights.

Lifting Flame

See Floating Frame

Length

A unit of linear measure for pipes, such as 10 or 20 ft.

Life Cycle Labs

A place where water heaters are tested at an accelerated rate to simulate life expectancies.

Light Duty

Small commercial applications.

Lime

See sediment.

Limit Stop

Faucet control unit used to adjust maximum water temperature.

Lock Nut

Nut fitted into a piece of pipe and screwed onto another pipe to join the two pieces.

Low Consumption Toilet

A class of toilet designed to flush using 1.6 gallons of water or less. Also known as "Water-saving" toilets.