[quote author=specker link=topic=74.msg124#msg124 date=1225570397]
Is there a commercially available ESD (fail-close) actuator with intelligent PST (datalogging) that conforms to Zone 1, Group IIA, T1?

All suggestions or alternatives appreciated.

Specker


Are you thinking of a "smart valve" such as a fieldbus or modbus type? You might start here:

http://www.westlockcontrols.com/westlock_controls.asp?product=26
http://www.fieldbus.org/index.php?Itemid=281&id=452&option=com_content&task=view
http://www.miinet.com/whatsnew/

Keep in mind that the monitoring does not have to be part of the SIS system, but the primary activation does. The SIS and the control system should be seperate and no common point of failure.