Linear Position Sensors for Valve Actuators

Illustration of Magnetostrictive Linear Displacement Transducer (MLDT) inserted into a gun-drilled cylinder.Today’s petrochemical and process industries, like most industries, are striving to increase their capabilities of automation & control, coupled with condition monitoring, across their entire operation.  Demands for uptime are increasing and the focus on reliability through redundancy and prediction of pending maintenance requires new control and monitoring strategies.  This is nowhere more true than in the case of the sophisticated valves that form the most critical elements of the operation or process.  Operational readiness and confirmation of operation for these valves are indispensable to assure smoother and uninterrupted production…and safety.

Christian Dow has written an interesting article in Valve Magazine that highlights the benefits of linear position sensors when installed in the hydraulic actuators of these valves.  The benefits mentioned in the article don’t apply just for valves, though.  Many of the advantages can be obtained for almost any application where a hydraulic cylinder is the prime mover.

Servo-Hydraulic Showcase

48959254_woodbannerIn a previous installment here on SENSORTECH, we explored the three M’s of linear position feedback application (Linear Feedback Sensors – The Three M’s).  One of those three M’s stands for Motion Control.  When we talk about motion control applications for industrial linear position sensors, we’re often referring to closed-loop servo-hydraulics.  In these applications, the linear position sensor, which is usually installed into a hydraulic cylinder, plays a key role in the ability to accurately and reliably control the motion of very large, heavy loads.

Nowhere is closed-loop servo hydraulics more prominently utilized than in primary wood processing – where raw logs are transformed into all manner of finished board lumber.  Applications such as saws, edgers, planers, along with many more, rely heavily on closed-loop servo-hydraulics.  In many cases, hydraulic actuators get the job done when other types -electric, pneumatic – simply can’t.

If you’d like to get a look at some of these application, or to learn more about how linear positions sensors are used in the applications, a good place to start would be at an event where many of the machinery builders and suppliers gather in one place for a few days.  Does such an event exist? (I hear you asking).

Well of course it does!  It just so happens this very thing will be taking place in Portland, OR in the middle of October 2014.  If you would like to learn more about these interesting applications in general, and how linear position sensors are used in particular, you might want visit Balluff at the Timber Processing and Energy Expo.  Click the link below for more information.

Timber Processing and Energy Expo, October 15th through October 17th

Is Your Spidey Sense Tingling?

The July 2011 issue of Hydraulics and Pneumatics magazine featured an interesting application story about how hydraulics systems were designed and used in the “Spiderman: Turn off the Dark” Broadway musical.  The article describes some of the challenges faced by motion systems designers, and how those challenges were solved.

One particularly challenging aspect of the hydraulic motion systems was the requirement that multiple hydraulically driven platforms had to be raised and lowered simultaneously.  The motion of the platforms had to be very precisely controlled, making hydraulic component selection critical.

Continue reading “Is Your Spidey Sense Tingling?”