Our air filter has been acting up lately. The indicator turned yellow
(wet) and our two BCU air chillers started icing up, even in this very,
very dry season in Tucson. It was not cycling at all (no "whoosh" to wake
you up every 5 minutes). I noticed that the red indicator on the input
filters was very near the top, indicating that the pressure drop across the
filters was too high. I replaced both filters (with "Grade BX") but the
pressure difference indicator did not change - more than 90% of the visible
window is filled with red. But the thing started cycling and I got the
green color back in the indicator, so it looks like we're back in
business. I'm worried about the pressure differential indicator,
however. This is the older type of dryer (installed in 1999), not like the
newer one we have (installed in 2004) which has a "rainbow" like pressure
differential indicator at the top of the first inlet filter. The filter
model no. is 75912-DX and the filter cartridges I'm using to replace are
"Grade BX" (it says 100-18 BX on the box). I'm not even sure if these are
the right kind of filter cartridge, but they look identical to the old ones
and they fit right in the housing.
My question is, does anyone have one of these older air dryers and if so,
what does the pressure indicator on top of the first inlet filter look
like? Is there red showing, and if so how much? What kind of filter
cartridges do you use for replacement?
Thanks!
Neil
Neil E. Jacobsen, Ph.D.
NMR Facility Manager
Department of Chemistry
119 Old Chemistry
1306 E. University
University of Arizona
Tucson, AZ 85721
520-621-8146
FAX 520-621-8407
Received on Fri Jun 03 2005 - 09:45:07 MST