Latching or Bi Stable Solenoid Valves
Latching valves utilise an internal solid magnet, so when a short electrical power pulse of 6 volts is applied this energises the magnet and lifts the armature opening the solenoid valve to allow flow and the valve will remain in the open position whilst the magnet remains active. To close the solenoid valve a reverse polarity electrical signal is required i.e. swap +ve and -ve terminals which in turn cancels the internal magnet and the armature returns to the closed position preventing flow.
Latching / bi-stable solenoid valves are ideal for battery powered applications or where valves are required to remain in the open position for long periods of time without the need for failsafe closed upon power failure. Additional benefits include reduced energy consumption and reduced heat causing limescale buildup commonly found in hard water areas.