Kyle, Gerardo 

Replaced (2) each 1 1/2" check valves, (2) each  3/4" check valves, (2) each exhaust air valves + actuators, left and right tower desiccant (175lbs/tower 1/8" alumina) and the two nearest downstream filter elements.  The (2) large air valves which supply the towers during the "drying" cycle are also nearly wore out and will need replacing at the next service interval. 

Kyle, John 

As alumina dust had been generated and had been visible in the 1st downstream filter element, we made rudimentary particulate measurements from the 80 psi air (before 1 psi regulator) sampled between filter stages 3 and 4.  

For comparison, we routed nitrogen from a UHP N2 bottle+regulator via 8' of 1/2" poly tube through a 0-5 GPM (liquid) rotameter which exausted into one end of a flow box.  A particle counter was placed inside of the flow box near the opposite end.  

2 GPM indicated flow    Bottled UHP N2      sampled air 
                                     260,000 0.3u        45,000 0.3u 
                                       17,000 0.5u        12,000 0.5u 
 
3 GPM indicated flow    750,000 0.3u        50,000 0.3u 
                                       23,000 0.5u        13,000 0.5u 

30 minutes after routing the purge air supply to the LVEA Class 100 manifolds I moved the flow box apparatus to the XBM purge air connection and measured: 
 
0.8 GPM indicated flow        200 0.3u 
                                             0.0 0.5u