Originally Posted by happi
this is the old post, but can anyone explain this further, with picture or art.
For example, the Burkert 6011 solenoid has directionality. If gas flows the wrong way, then the solenoid will not work as designed.
In this particular image, CO2 must flow from "P" to "A".
Image is not mine, and is Matt F's over at The Barr Report.