I have a industrial Hyd. application using a 100vg hyd fluid. The recent analysis shows Nitration (3). There isn't a accumulator in this system. I am confused how we would be seeing Nitration. Also, the UC is stating level 4. The system shows severe varnish but the lube analysis shows the hyd fluid health is normal beside the two issues noted above?? No contaminant elements in the Spectro analysis and the Vg is within tolerance.