Start working at zero differential pressure, the ESV series valves are small sizes 3/2 way solenoid valves with orifice sizes from 1.5mm to 3mm. There’re 3 different kind of valves in this series valve, the main difference are the flow direction when energized or de-energized. The ESV1 and ESV2 has different directions, while ESV3 valves are dual-directions.