- First of all get the control valve is passed from operation.
- Check the lingual to the diaphragm of the control valve.
- Disconnect it possible the actuator stem from the control valve stem.
- Stroke the actuator and see whether the actuator operates or not. It not then the diaphragm may be punctured.
- If the actuator operates connect it back to the plug stem stroke the control valve. If it does not operate loosen the gland nuts a bit and see if it operates. If it does not then the control valve has to be removed from the line to w/shop.