First, the power is obtained through compressed air to make the valve stem move, and then drive the valve core to move in the valve stem to make the whole system rotate, so as to achieve the effect of access and disconnection and realize the function of switch. This is the working principle of pneumatic high-pressure ball valve. 　　　　

Third, the installation cost of light butterfly valve is much cheaper than that of heavy butterfly valve. For example, a butterfly valve with a diameter of 10 inches weighs 55 pounds, while a 10 inch cast iron gate valve weighs 490 pounds. For the whole pipeline system, the installation cost saved by butterfly valve is also considerable. In addition, the pipeline system becomes heavier and heavier, which requires the pipeline support base to be very solid, so the entire pipeline system becomes very expensive. Therefore, when you consider the weight of the electric butterfly valve, you can fully consider that the cost of the entire pipeline system will be saved due to the weight. Therefore, when selecting electric butterfly valves, do not only consider other factors, but also ignore the weight of the butterfly valve itself.