I worked with PW at R&D, in the pilot plant, in the 1970s & 1980s.  PW was smart, a hard worker, very patient, and easy to work with.  You count always count on PW to get the job done, and to do it right.  He also was knowledgeable about the equipment and I learned a lot from him.  I'm really sorry to hear about his passing.  I think I last saw him at an R&D Christmas party.  A great guy!