Bi-stable pulse valves are used for small refrigeration system just as housed double control refrigerators, cold tank, drinking fountain, etc. It can switch refrigerant flow path. It has a better energy saving effect than Mono-stable solenoid valves. The bi-stable solenoid valve is actuated impulse via an electronic impulse. Depending on the position of the required output, a signal of ≥ 4 ≤ 10 half-waves (positive or negative) is required. To switch the strained condition must have an interval more than 3s;