Applied to differential, liquid level, flow, pressure, thermostatic valve, regulating valve, such as volume thermal compensation, automatic mechanical servo device, switch and counter, its advantage lies in the high working reliability, compound, working life is long, the cost is low.The rubber diaphragm has a long service life, which can be used to synchronize the operation with other control components to ensure the pulse compression air.Even under extremely poor working conditions, it can ensure its normal operation and long service life.