Pneumatic control valve is not action of failure

1, no signal, no air. Reason: air not open; Air duct leakage; Duct blockage due to air water freezes in winter, or filter, pressure reducing valve block failure; Line installation errors, check the line. 2, air supply, no signal. Reason: pipe leak signal; The regulator itself fault; Adjust the omentum is damaged; Locator corrugated pipe leakage. 3, the locator without air. Reason: pipeline leak or blocked; The filter blocked; Pressure reducing valve failure. 4, the locator have gas source, no output. Reason: the locator orifice is blocked. 5, have a signal, no action. Reason: the valve core and valve seat jammed; The valve core loss; Stem bend or break. Actuator spring rust.