The chief or principal part; the main or most important thing.
principal duct or pipe, as distinguished from lesser ones; esp. (Engin.), a principal pipe leading to or from a reservoir; as, a fire main.
Principal; chief; first in size, rank, importance, etc.; as, the main reason to go; the main proponent.
In shipbuilding, the adjective applied to the most important timbers, or those having the greatest cross-sectional area.
a principal pipe in a system that distributes water or gas or electricity or that collects sewage
most important element; "the chief aim of living"; "the main doors were of solid glass"; "the principal rivers of America"; "the principal example"; "policemen were primary targets"
a large diameter water supply pipe that has many smaller
pipe or duct for distributing fluids such as air, water, or steam to various branch ducts and collecting fluids from various branches
a large pipe sized to carry the water for the irrigation system. Usually sprinklers are not connected directly to the main. Main pipe lines are usually under pressure at all times unless drained during the winter.
the piping that provides pressurized water to the sprinkler sections.
A large pipe that carries the steam, gas or water from the power plant.
A continuous pipe used for the conveyance of gas from points of supply, generally running within the road corridor and from which individual service pipes or other parts of the distribution network are supplied.
A large pipe which carries either water or sewage through our system
Principal drain pipe to which all branches connect, directly or indirectly.
Pressurized piping running from point of supply (pump etc) to the solenoid control valves.
The chief pipe, duct, or cable in any electrical, water, gas, sewer, vent or other utility system.
the primary distribution and collection pipes for non-wired utilities, such as gas, steam, water, and sewer; typically 12 to 20 inches in diameter
"Main" means the principle pipe artery to which branches may be connected.
1. The largest and most important of something. 2. The primary piping run to which other pipes are connected.