Sprinkler System Glossary Cary NC

The following was sourced from Jess Stryker.

100% Coverage
The design goal of all sprinkler system designers. Sometimes used (incorrectly) in place of the term "head to head coverage". 100% coverage is the objective of head-to-head coverage. But head-to-head coverage does not always result in 100% coverage.

Acre Foot (also acre feet)
A measurement of water quantity most often used in agriculture. The amount of water needed to cover one acre of area with water one foot deep. Enough water to drown in, but not deep enough to swim in. See the irrigation formulas web-page for conversion of acre feet to other measurements.

Acre Inch
See "acre foot" above and substitute "inch" for "foot".

Angle Valve
Refers to the water flow pattern into and out of the valve. Often used as control valves. Seldom used as isolation valves. The valve inlet is on the bottom of an angle valve and the outlet is on one side. Angle valves as a group tend to be very reliable and have lower friction losses than "globe" valves, the other common style used for control valves.

Anti-Siphon Valve
A control valve with a built-in atmospheric vacuum breaker (backflow preventer). Most commonly used in residential irrigation systems.

Atmospheric Vacuum Breaker (AVB)
A type of backflow preventer.

Automatic Valve
A valve which can be remotely operated. The remote operation method may be either electrical (the most common) or hydraulic. Automatic valves are commonly used as "control valves" for irrigation systems.

AWG-UF
The classification of the direct burial wire used for automatic sprinkler systems. Example: #14-1 AWG-UF means a 14 gauge wire, single wire cable, designed for direct burial (no conduit) in the ground. The wire should have this information stamped or printed directly on the wire's plastic insulation. The wire should be at least 18" deep for safety (in most areas this requirement is written into local law).

Backflow Preventer
A device that prevents contaminated water from being sucked back into the water source should a reverse flow situation occur. (Which happens more often than you realize!) In most places backflow preventers are required by law on all irrigation systems.

Ball Valve
This type of valve controls the water by means of a rotating ball with a hole through the center of it. When the hole is aligned with the water flow the water flows freely through the valve with almost no friction loss. When the ball is rotated so that the hole is not aligned the flow is completely shut off. Ball valves are used primarily as isolation valves.