Pressure transmitter cooling element/standoff

[g.mccormick]

I need to protect some pressure transmitters from hot (120°C) oil. Does anyone have a favorite transmitter cooling element/standoff they use for this?

 

[Ken Moore]

Not sure about oil, but for steam we just used standard pigtails. I would consult your transmitter vendor for recommendations.

 

[Mickey]

Another option...

Diaphragm Seal Mounting - Google Search

 

[danw]

Plain old impulse tubing is the answer. Tubing drops a lot heat because the tube is deadheaded with no flow through it.

The conventional rule-of-thumb myth is that impulse tubing drops 100-150 Deg (F or C?) per foot, but Kulite did a study and established a evidential rule of thumb: one foot of steel tubing, any diameter, will isolate a transducer from any temperature.

Kulite did the thermo math: https://kulite.com/assets/media/2018/01/AN8401HeatTube.pdf

I have witnessed this personally - 1 foot of inconel tubing through the wall of a furnace running at 1800°F and I could touch the compression fitting on the body of the transmitter and not get burned. There was a 3'x3' galvanized sheet metal shield between the furnace and the transmitter to prevent radiated heat from the furnace from overheating the transmitter, but combustion gas was cooled by that 1 foot of tubing.

Fill the tube with oil during assembly and locate the transmitter below the elevation of the tap, so that any air/gas rises and escapes from the impulse tube and does not accumulate in the impulse tube.

 

[g.mccormick]

After getting some pricing and availability, I think pigtail siphons will work just fine. I'm only trying to protect from 120C oil.