Methods and apparatus to diagnose a valve using electric valve actuators

A method comprising:

• monitoring a distance travelled by a drive shaft associated with an electric motor of an electric valve actuator used to operate a valve;
• monitoring a position of a flow control member of the valve via a valve position sensor associated with the actuator;
• and
• generating an alert based on the distance travelled by the drive shaft and the position of the flow control member, the alert associated with a failure of the valve.

A tangible machine readable storage medium comprising instructions that, when executed, cause a machine to at least:

• monitor a distance travelled by a drive shaft associated with an electric motor of an electric valve actuator used to operate a valve;
• monitor a position of a flow control member of the valve via a valve position sensor associated with the actuator;
• and
• generate an alert based on the distance travelled by the drive shaft and the position of the flow control member, the alert associated with a failure of the valve.