DP Xmtrs on Towers
DP Xmtrs on Towers
(OP)
Our process group would like DP's on the Atmospheric Crude Tower around every section. All DP's are in the vapor space of the tray. All the xmtrs are mounted above the taps with the sensor lines sloping toward the taps. I have steam traced the sensor lines, but we are still having problems with (we think) condensables building up in the tubing, causing erroneous measurements. Are there any alternatives to purging the sensor lines? I would like to keep the DP xmtrs I have purchased (in lieu of buying sealed leg diaghrams.)





RE: DP Xmtrs on Towers
Good luck.
RE: DP Xmtrs on Towers
The majority of places I work use 1/2" tubing for impulse lines so this problem surfaces.
The past few years I have run into more installations where two transmitters are installed, one at the top and one at the bottom. A subtracting block is used in the DCS to calculate the difference in pressure. You need very accurate transmitters for this. I wouldn't do it with two pneumatic transmitters.
Mark
RE: DP Xmtrs on Towers