Pressure Transmitter

N

Thread Starter

Nimmi

Hi,
we are looking for a pressure transmitter with pressure span 0-20bar but at maximum temperature >2mpa.

* They should provide output signals with HART protocol
* Also offer gold plating of the diaphragm. For Hydrogen applications

Do you think this cannot be achieved with that temperature?

Regards
Nimmi

 
No one has any idea what temperature you're talking about because you used a pressure unit, MPa, not a temperature unit.

Pressure transmitters are generally rated to about 125 Deg C body temperature at 85 Deg C ambient.

High temperatures are usually dealt with by using a length of impulse tubing rated for the pressure.

The connection to the process through the impulse tubing is deadheaded; there is no flow through the impulse tubing. Without flow, there is a relatively high degree of cooling with minimal heat transfer by conduction through either the medium or the tubing itself. So high process temperatures are handled by cooling the medium through a length or run of impulse tubing.

Oral tradition says 1 foot drops 100 deg F and there are minor derivatives.

Kulite issued a paper, "Pressure Transducer Temperature Isolation Using Tubing"

http://www.kulite.com/docs/technical_papers/AN8401HeatTube.pdf

with a formula, but they summarized its 5 pages with the statement,"As a rule of thumb, one foot of steel tubing, any diameter, will isolate a transducer from any temperature."

I agree. There was quite a discussion on this topic back in 2009
http://www.control.com/thread/1335483783#1335483783
 
R
Exactly as Mr. David has already replied, get your specs right Nimmi. 2 MPa again means your already stated pressure of 20 bar. Get the complete specs right and post it here. There are of course solutions for any applications.
 
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