Valve Position Monitoring Trends
Written on June 26, 2018 | Back to the overview
Valve Position Monitoring has not seen many changes in these past decades. “2 switches in a box” is still the largest volume product in the industry.
Without being too elaborate, there are still 5 trends that can be noticed within the industry.
1. The move to “engineered products”.
If an automated valve was already equipped with a valve position monitor in the early 90s, then an off-the-shelf junction box was fitted with switches. The engineered product now includes features like easy adjustment for the switches, visual indication and integral terminal points. It has become an industry standard.
2. The rise (and decline?) of fieldbus systems.
The advantage of less cabling seems obvious. The industry never embraced the implementation on a large scale. Some issues are, the complexity of getting systems to work, the lack of a clear universal standard protocol, the potential danger of losing feedback on a large scale and the relative high cost complexity for the application.
3. The increase of analogue transmitters.
Relatively rare in the 90s because it was seen as an over the top solution for the application. However, a 4/20 mA signal requires less I/O on a site than 2 limit switches.
The continuous feedback also provides information of the condition of the valve or the feedback itself.
4. Multiple feedback modes in 1 enclosure.
For example, multiple switches combined with a transmitter allows discrete feedback for a process control system and an ESD valve (Emergency Shut Down) whilst also offering an input to a diagnostic system.
5. The increased demand for condition monitoring.
Elaborating on trend 4, the feedback is being more and more used to survey the condition of the valve-actuator unit. For example in the Oil- and Gas Industry the combination of Partial Stroke Test System (PSTS) and the identification of valve issues is being used to take action before a critical situation might occur.
VACTRA offers a complete range of Valve Position Monitors. For more information, please contact our VACTRA technical sales office.