The electric expansion valve is used for converter air conditioning system to automatic control of refrigerant flow rate to realize save energy. Environment temp: -30~+60(energized rate less than50%) Fluid temp: -30~+70(energized rate less than50%) Action model: 4phase permanent-magnet stepping motor Environment humidity: less than95%RH Refrigerant: R22, R40C7, R410a Power: DC12V, rectangle wave Fluid direction: bi-flow Max working pressure: 4.15MPa life: 100000times