Terms Associated with Water Distribution Systems
A valve that is similar to the globe valve but can serve as both a valve and a 90-degree elbow.
The unfinished side of the inside wall, used to mount fixture risers and sub-outs behind the fixture.
Any part of a piping system other than a riser, main, or stack.
A valve that allows liquid to flow in only one direction. Pressure within the line keeps the valve open. Closure of the valve is automatically activated by the reversal of flow or by the weight of the disc mechanism.
Thickening of a liquid into a soft, semi-solid, or solid mass.
A valve installed in the building water service line to connect to the water main.
A cylindrical casing placed in the ground over the curb stop, into which a special key can be inserted to turn off the curb stop. Also referred to as a buffalo box.
A control valve installed in building water supply lines between the corporation stop and the building.
The main water supply line to which branches are connected. Also referred to as a service line.
Vertical sections of pipe located inside the wall to connect the fixture to the supply pipe beneath the flooring.
Describes the flow capacities of various valves based on the size of the valves' interior.
Corrosion caused by a weak electrical current that occurs when two different metals are joined.
A device installed in a piping system to absorb hydraulic shock waves and eliminate water hammer, a loud thumping that results when the flow of water is suddenly stopped.
A faucet with a threaded outlet used to connect a hose. Usually located on the outside of a building.
Potential of hydrogen; a measure of the acidity or alkalinity of a solution. A pH number of 7 is considered neutral; higher numbers are more alkaline, lower numbers are more acidic.
A solid that is chemically separated from a solution.
Pressure Regulator Valve
A valve used to reduce water pressure in a building. The valve is activated by changes in pressure within the system.
Pressure Relief Valve
A valve normally used for liquid service. As pressure increases it slowly closes.
A body of water collected and stored in a natural or artificial (man-made) lake.
A flow that is not restricted as it passes through a valve. The element that closes the valve is retraced entirely clear of the passage.
Supply Stop Valve
A valve that is commonly used to disconnect the hot or cold water supply to water closets and sinks. They are available in either right angle or straight design.
Temperature and Pressure (T and P) Relief Valve
A T and P relief valve is a mixing valve which senses outlet temperature and incoming hot and cold water pressure. It compensates for fluctuations in hot and cold water temperatures and / or pressures to stabilize its outlet temperatures. Also referred to as thermostatic / pressure balancing valve, combination.
The controlled rate of flow through a valve, which does not impede flow but causes some friction loss.
The task placing attachments on fixture to complete a job.
Presence of particles (sand, mud, silt) suspended in water that give the water a cloudy appearance.
A type of backflow preventer that inhibits backflow caused by low pressure in a water supply system.
A device to measure water flow, in gallons or cubic feet, into an individual building.
Water Supply Fixture Unit (WSFU)
Water Supply Fixture Unit (WSFU) is a design factor to determine the load that different plumbing fixtures produce on the supply side of a plumbing system.
The distance below the ground's surface at which the soil becomes saturated.
Outer tube or pipe sunk into the ground after drilling or driving a well.