Do You Know Your Manual Valve’s Position?

I don’t want to admit how long I’ve know Emerson’s Kurtis Jensen, but it does goes back to the pre-Emerson days at Fisher Controls. Kurtis is an instrument product manager for the Fisher Valve and Valve Automation businesses. He’s penned a great article for Valve magazine, A Bright Future for Wireless Technology. He encapsulates his thoughts:

Industry has a watchdog that can save costs, provide reliability and allow more confidence that our valves are in good health and operating at peak capacity. The technology can also work toward a safer work environment and provide more information for improving processes.

The watchdog of course is wireless. Just as how it has become indispensible in our homes and given us the freedom to connect from anywhere, Kurtis describes its benefits to process manufacturers. It eliminates:

…the time and effort it takes for manual audits; the amount of occasions in which someone is sent into undesirable conditions; and product variances, which when reduced can improve product quality.

In most processes, manual valves can be found in many places. One example is their use in maintenance cleanout activities. Adding wireless valve position feedback can:

…improve process reliability: it protects product quality, it protects against scrap or rework, and it protects against clean-up actions. The end result is a more reliable process and greater confidence that all is well.

Without this valve position feedback, more operational resources are required to follow standard operating procedures to verify that the valves are in their correct open or closed position.

Kurtis reminds the reader why manual valves are automated:

First, moving the valve may require too much manual effort. Second, it may be desirable to eliminate having personnel in dangerous conditions such as precarious heights or hazardous environments. Third, it might be necessary to reduce complexity and time needed to coordinate valve adjustments during plant operations.

For the on-off variety of automated valves, many today are driven from the automation system by a solenoid. The command is issued but there is no feedback from the valve that it went from open to close or close to open. Traditionally, this feedback required two sets of wiring on the valve positioner side and two discrete input (DIN) channels on the automation system side. This may not be a big issue if spare pairs of wire are available and spare DIN channels are available. Usually though, if it’s not a big issue and knowing its state is important, the valve position feedback is already present. Kurtis notes:

Knowing more about a valves’ health enables better decisions and faster maintenance. It is just as simple and easy to achieve significant improvements on these old valves as with new projects. Facilities that implement wireless feedback have the competitive advantages of operating cost reductions, improved product quality, increased production volumes and increased levels of safety.

Beyond more feasible valve monitoring, Kurtis closes with a thought from the automation system control strategy perspective:

Designers of control strategies will take advantage of wireless valves to enable greater control as well as greater process and equipment health awareness, all of which results in greater confidence in operations and processes.

Kurtis summed up his thoughts on wireless even beyond valves to me in an email, “If it moves you can monitor it!” If you have manual valves or others without position feedback that has caused operational or safety-related issues, this might be an article worth your time to read.

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