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Saturday, July 21, 2018
The Automation Safety Community Forum.
Barriers for Pressure Sensors, Temperature Sensors, and Solenoids.
Requirement of barriers in control panel (safe area) for instruments (sensors & solenoids) which are in gas group IIA/IIB. (application compressor)


refer my below query regarding requirement of barriers in safe area.
Suppose Compressor system will be kept in hazardous area (gas group IIA/IIB) & relay based starter cum control panel will be in safe area. Pressure sensors, temp sensors & solenoids will be mounted on compressor system.

Do I need to use safe area barriers for the pressure & temp.sensors (4-20mA) at panel incoming? reason? & whether these are also required for solenoid valves (24 v dc) reason?

please guide me.

Thanks in advance.


1 out of 1 members thought this post was helpful...

If you have any machine in a hazardous area then you need to prevent any possibility of explosion by way electrical energy.
There are various ways of achieving this - using intrinsically safe barriers being one of them.

I get the impression you need a Hazop Study to determine the best solution.

1 out of 1 members thought this post was helpful...

I think using barriers assumes the field device can be made intrinsically safe, I'm not sure solenoids fall into that category.

90% of my work is in Hazardous locations but I haven't bought a barrier in years.

ASCO solenoid valves have I/S models

or EX models

You should make sure that you only use barriers and sensors together whose safety-related data and function-related data match each other.