Hydrants are valve types that are used to take the fluid from the main pipeline. They are connected to the pipeline from only one side, that has a body end free to the atmosphere to enable the release of fluid. They are operated by a handwheel or a key, that is turning a spindle attached to a valve mechanism. They can be categorized in to two main groups in terms of their application:
Used to fight against fire especially in high risk areas. Can be categorized into two groups in terms of their installation:
Stand post fire hydrant
Installed above ground, where that the body and connecting ends outside.
Underground fire hydrant
Installed under ground, where that the body and connecting ends are located inside a valve box.
Used to take water from the pressurized main line in farmlands. Generally, they have a pressure regulator, flow regulator and metering device in addition to a valve mechanism.