sTEm–at-Work Olde But Goody Series Puzzle #41: Water Filter Performance Test

A water quality technician has collected and graphed the back flow test data for a carbon nano-tube (everybody has to do something with nano, so FLATE’s puzzle team is no exception) based membrane technology water filtering system. When the water to be sold under the companies PDS (“Purer then Driven Snow”) brand passes one way through the filter, the water is purified and then sent to the bottling facility. The tech periodically back flushes the membrane and if the filter is clogged replaces it. The tech runs the back flow test by disconnecting the forward flow and then pumps purified water through the filter in the opposite direction. If the filter is not clogged, the black flush test pattern has a similar shape as the forward flow plot but it has higher flow rate values for each pressure.
                                         
After reviewing both the forward and back flush pressure vs. flow rate plots below, the tech knows if the filter is clogged. She has determined that this specific filter is not clogged. 


The orange plot is the filter's back flush data plot.  Yes or NO.  Submit your answers below the blog, or post it at www.fl-ate.org.