a valve installed at the supply point of the main controlling water flow into the system.
a normally closed valve located between the manual shut-off and the backflow preventor that opens only when one of the section valves in a sprinkler system comes on. This serves to keep pressure off the mainline except during operation.
An automatic or manual valve installed at the supply point that controls water flow into the system mainline piping.
1. a large valve located on the Christmas tree and used to control the flow of oil and gas from a well. Also called master gate. 2. the blind or blank rams of a blowout preventer (obsolete).
A electric valve which opens whenever any station is watering, and closes when no station valves are on, shutting off the pressure in the main line. A master valve will greatly reduce any water loss due to a leaky station valve because the leaky station valve can only leak while the master valve is providing pressure to the system. Also, if you damage the irrigation main line, a master valve will control water loss so the main can be repaired without shutting off the water supply. A master electric valve is typically the same type of valve as you would use for your station valves, but rather than being installed downstream from your main line and connected to a station output in your controller it is installed upstream at the front of the main line and connected to the "master" or "pump" connection in your controller. Not all controllers support a mater valve or pump- be sure to check the features before buying a controller. Back to glossary index.
An automatic or manual valve installed at the supply point which controls water flow into the main piping system.