The doctor is in. Industries that need to do more diagnostics with fewer people and want better operational outcomes, the cure is the FIELDVUETM DVC6200 smart valve positioner. This prescription comes from Emerson’s self-proclaimed valve MD Steve Hagen.
While smart valve positioners may be coming the new standard, he believes that most users are not leveraging their full potential. This single-instrument solution performs above and beyond traditional valve positioners with multiple benefits but like any prescription, instructions for proper use brings the most benefits.
Comparing a traditional valve positioner with a smart positioner is like the difference between using a landline phone and a smart phone Hagen says – they both make calls. However, your smart phone has now replaced your watch, your calendar, your alarm clock, your calculator and can do so much more.
While a valve positioner is the interpreter between the control valve assembly and the control system, the smart valve positioner with its built-in computer performs the same basic functions along with a range of additional capabilities. It takes the basic positioning functionality and makes it more accurate and reliable by providing controls to get closest to set point for optimum process control. Auto-calibration means less reliance on the skilled on-site technicians -- a time and cost savings.
Some of the in-service diagnostics include monitoring, friction analysis, troubleshooting and air consumption tests. The out-of-service diagnostics include valve signatures and step-response tests.
Hagen estimates that only about 10 percent of the smart valves’ positioning capabilities are used. “Typical reasons why operators are not able to take full advantage of the smart valves include bandwidth, personnel or procedures in diagnostic alert response,” he said. “To get the most value out of the smart valves, users must understand exactly what tasks can be accomplished and how to use that data without getting overwhelmed.”
A smart valve positioner performs multiple functions that can enhance plant function and:
Then, to leverage all the good diagnostic information and control functions available, Hagen recommends six steps to start a control valve monitoring program – find a long-term owner to take charge of the process; determine how to collect all the information; prioritize valves to be monitored; start small with three key alerts; pilot a program in one area as a trial for work through the process details; and track your costs.
By following these steps, valve MD Hagen predicts the long-term prognosis for operators using Emerson smart valve positioners is excellent. For more information on Valve diagnostics, you can read this article from the American Institute of Chemical Engineers.