We have a Foundation Field Bus installation in which solenoid valves, used for on/off control, utilize piezo technology instead a traditional coil for switching (The solenoids receive power from the fieldbus segment, thus need to be very low power). We have seen problems with this technology where after being in one state for extended period of time, the valve fails to
switch to the other state. The solenoid valves are switching instrument air to piston valve actuators. Does anyone have any experience in using piezo solenoid valves? Any ideas as to what could cause these valves to "stick"?

Thanks in advance,

Reginald Waddell
Control Engineer
BP
Cooper River Plant

 

Perhaps the problem is with the field side of the mechanical components associated with moving the valve body. I've seen plenty of people
(especially in the south) with air in their instrument water systems. (Yes, you read that correctly.) That, combined with the low power solenoid you described, might be enough to cause this problem. Perhaps you never saw the problem before because the older higher power solenoids were able to overcome the 'stiction'.

Paul Gruhn, P.E., C.F.S.E.
Safety System Specialist
Siemens
Houston, TX

 

I know of users who are experiencing the same characteristics. As I understand, the Valve contains a flexible piece called a crystal. It bends under electrical stimulation and fails to return to it's normal shape when de-energized. This failure occurs after at least 3 days of staying in the energized condition. I believe the manufacturer of the valves is "Horbinger"(sp?). However, the problem if likely not limited to them. Sources for these type valves are far and few between. Please let me know if you have found a supplier that can overcome this problem.

Thanks,
Erik Naumann
StoneL

 

We (SMAR) make a FOUNDATION(tm) Fieldbus remote-I/O that you may want to consider as another solution. This box has 16 DI and 8 DO so it is suitable for 8 on/off solenoid valves with feedback switches. The solution has some pros and cons as compared to the solution you are using now. This box has to be mounted in a safe area or possibly in a flameproof box. It has high power
outputs that you can use to drive "regular" solenoid valves consuming lots of current. It communicates FOUNDATION(tm) H1 Fieldbus. It has built in logic using a flexible function block that you can even use as part of your interlocks, or as part of your valve diagnostics.

Jonas

==================
[email protected]
www.smar.com

 

Hello Mr. Waddell,

If you’re still looking for a solution to your problem of piezo solenoids sticking in your Foundation Fieldbus installation we have a low power solenoid for use with bus systems. Our solenoids use a flapper-nozzle system that is free of friction, an electromagnetic coil and are spring detented in the fail position.

Piezo technology has been found to not be repeatable in changing temperatures and when left for long periods in the energized state.

The power requirements of our solenoids are still very low, between 6mW and 28mW depending on the voltage, and are ideal for bus installations. Our solenoids can be offered with Cv’s up to 5 for large valve actuators.

For more information, contact me at [email protected] or 780-451-4440.

Thank you,
Dave Robinson, C.E.T.
Samson Controls Inc.