First I list the proof / recommendation I found in the vendor literature and also in one of the projects this vendor recommendation was for a complete vacuum condition. As always, it is not good to accept anything without reason and logic, so I have gathered the possible reasons I can find for such an installation or recommendations.
Remote Diaphragm Seal Transmitter
1) Let’s start with the BADOTHERM recommendation
See the bottom of the catalog page and the diaphragm seal installation snap
2) EMERSON next recommendation
Emerson Seller Recommendations / Literature There is a reference link here.
Now the best part is why? When it comes to doing this, they are related but a little different, so I have listed all the reasons I can possibly find.
# Reason 1 (Highlights of pressure drop in pressure)
For example, water boils at 100 ° C at atmospheric pressure (101325 kPa). In absolute vacuum, it boils at 0 ° C. This effect is a combination of pressure and temperature for all liquids and is a key factor in choosing a diaphragm filler fluid.
A hard vacuum also boils the sealed fluid in the surface transmitters (remember that the boiling point depends on the pressure – as the pressure decreases, the boiling point also decreases) and bubbles in the capillaries.
# Reason 2 (to maintain positive pressure on the transit side)
If our bottom nozzle is at the bottom of the tank, but our transmitter is less than 50 inches below, take this sample for the DP level transmitter. So at level zero when there is no pressure in the lower nozzle, the receiver is still calibrated for it (zero suppression). Similarly, when a complete vacuum is created, positive pressure is still applied to the transmitter
(Personally, I’m not entirely convinced of this, but regardless of what I mentioned.) . So what follows from this explanation is that the positive title is retained and opposes the spread of these bubbles. PS: To my best understanding it still has a long way to go, but it is an effort to share in the way I learn. If anyone is clear about this concept, please comment, correct or message it if it needs correction, thank you very much!
# Reason 3 (packages tend to expand significantly by reaching zero)
(Personally, I’m not entirely convinced of this, but regardless of what I mentioned.) . So what follows from this explanation is that the positive title is retained and opposes the spread of these bubbles. PS: To my best understanding it still has a long way to go, but it is an effort to share in the way I learn. If anyone is clear about this concept, please comment, correct or message it if it needs correction, thank you very much!