We are witnessing moisture in a pressure sensing line which is constantly damaging the diaphragm and internal components of the pressure transmitter. The pressure is monitoring exhaust pressure of roughly 8inH20 and 1300 degs F. We would see pressure perturbations before the transmitter fails. We have tried installing drip legs, increasing slope and to no avail. Any recommendations? thanks

have you tried insulating the lines? The delta T is causing condensation to form. By insulating the lines you will be reducing the amount of temp change. Also you can consider reducing the length of the sensing lines. I think Rosemount makes capillaries where the diaphragm is mounted separately from the signal conditioner.

increase the slope of the tubine so the moisture runs out. also you can blow down the lines regularly to remove the moisture...best bet is to insulate the lines to avoid the change in temp which is causing the moisture. We have the rosemount capillary transmitters on site with great success. I dont know if the thought process behind using them is to avoid moisture in the sensing lines but we have no moisture issues with them.

Hi,
We were facing similar problem in our utility boiler furnace Pressure trabsmitter.
There the pressure is 4-6 INH2O and the temp is around 400-500 Deg C.
We installed a purge rotameter in the impulse line.After that the moisture problem has been resolved.