Normally closed: This is a normally close type electric solenoid valve, power on to open it and power off to close it. Its N/C(normally closed), meaning it is closed when power isn't supplied. Connect to DC 12V voltage and the suggested input current is more than 2A to ensure a stable performance. Safe: This solenoid valve is designed to installed indoors horizontally in a dry environment. If used outdoors, the coil part should be well protected from water. Application fields: Suitable for use with pipelines in water, air, gas and low viscosity non-corrosive fluid applications. Both cables can be used as positive or negative. Irrigation controls (garden, farm,etc.), liquid controls ( pipeline, artificial river etc. and air controls ( lab, factory, etc.) Parameter: The high quality zinc alloy valve body would hold a press up to 0.8Mpa, 1/2" BSPP (DN15) Thread Size and liquid temperature from -10℃ to 100℃.There is an arrow sign on valve showing direction, please follow the sign to connect pipes. Intermittent work: Better for intermittent short time work, single continuous power on time is better to be less than 30 minutes. To ensure its work is efficient and its service life is extended