Position feedback for process valves has always been a difficult issue.
The initial way was to have only a visual indication of valve position which was problematic as there was no electrical connection to the process and no way to control it.
Then the practice of mounting a mechanical box on the actuator that would give two positions, opened and closed, which is still in use today but also fiddly to mount with the usual mechanical problems.
Then a better solution was to offer the same feedback but with solid state proximity sensors that would basically, never break down, which are still in use extensively. Now there is the evolution of the actuator valve with feedback at a full 360-degree with 0.1-degree increments.
This gives plant continuous position feedback and diagnostics, ranging from end-position monitoring to continuous position feedback in combination with IO-Link and the corresponding possibilities of flexible parameter setting and data acquisition.
Key features of the device are:
- Valve condition monitoring and support during error diagnostics
- Preventative maintenance planning
- Full digitisation of the valve movement and higher plant up-time
- Continuous position feedback
- Individual switching windows can be set
- Highly visible status LEDs for increased effect from a distance
- The valve position can also be detected when disconnected from power
- Diagnostic functions via IO-Link
- Temperature and time monitoring
- Cycle counter
The IO-Link communication interface allows the identification of different wear conditions. On the one hand, the sensor features seal monitoring indicating a change of the closed position, which can point to deposits or wear of the seal, for example. On the other hand, the different positions can be counted and the time taken can be measured. The types of industries that will need all this functionality of valve positioning are food and beverage manufacturing, dairies, breweries, soft drinks, as well as water and waste water, not only for water authorities but local waste water for factories to know the valve position and the valve health. It can also be used with pneumatic bulk material conveying and the manufacture of paper products. Example applications include annually maintenance activities at a breweries replace more 2,000 seals, waste water with blockage due to cellulose deposits, adhesion, corrosion and seal damage.