We are on our third purge valve Part # RAP6354 and it just failed again. I grabbed my tools of mass destruction and went for it. I promptly broke the corroded return tube in my desiccant bowl (Parker PS721P) but fortunately, my local Granger toy store carries that equivalent, Wilkerson, part # X06-02-000 for about $115.
At the end of my journey, there was a joy and my old purge valve was cleaned and provided great joy when it worked properly.
HWH Purge Valve RAP6354
Compressor with the new desiccant bowl element and the dissembled purge valve for those interested. Art & Polly 2003 U320 40′