Valve positioner system

A system for performing diagnostics on a valve having an actuator, comprising:

• means for positioning the valve at a first end of a test range of valve positions;
• means for incrementing a fluid pressure to the actuator until it reaches a second end of the test range and decrementing the fluid pressure to the actuator until it reaches the first end of the test range;
• means for determining if the valve is stable between increments and decrements;
• means for sampling valve position and actuator pressure data as the fluid pressure is incrementing and decrementing, wherein the data is sampled when the valve is stable;
• memory for storing the sampled position and pressure data and means for analyzing the stored data.

A method of performing diagnostics on a valve having an actuator, the method comprising:

• positioning the valve at a first end of a test range of valve positions;
• incrementing fluid pressure to the actuator until it reaches a second end of the test range;
• determining if the valve is stable between increments;
• decrementing fluid pressure to the actuator until it reaches the first end;
• determining if the valve is stable between decrements;
• sampling valve position and actuator pressure data during the incrementing and decrementing while the valve is stable;
• storing the sampled position and pressure data in memory;
• and
• analyzing the stored data.