Aquatec's ESO is normally closed, precision solenoid valves that positively shut off feed water. They are activated by a pressure switch to either open or close at predetermined holding tank pressure settings. The ESO Series can either be used independently or mounted inline on the inlet side of a pump. Our ESO Series also includes a modular connector for plug-and-play integration with Aquatec's other system components. Technical Specifications: WETTED MATERIALS: Polypropylene, EPDM,Stainless Steel (300/400 Series) POWER REQUIREMENTS: ESO 460 - 24 VAC, 50/60 Hz, 150 mA ESO DC100 - 24 VAC or VDC, 120 mA INLET PRESSURE/ORIFICE: ESO 460 - Maximum 45 psi, .093 diameter orifice ESO 460 - Maximum 100 psi, .062 diameter orifice ESO DC - Maximum 100 psi, .093 diameter orifice STANDARD FITTINGS: John Guest 3/8" NPT ELECTRICAL CONNECTION: AMP Mate-N-LokAlternative Part Number: Alcon (04CZ003A1-1ECA)