Who was the vendor, and what were they doing with
this valve? (It's entirely possible Festo distributors sell these on the open market, but I've never seen them in the catalogue. FIRST included them in the KOP for several years.)
By the way, to convert that 14 "cfm" rating to real units, and then to C
v, you'll have to know something about the conditions under which that rating was established. Your first stop should be to search ChiefDelphi.