PADI's manual merely states that if partial pressure blending is used, a cylinder must meet oxygen service standards because it is exposed to 100% O2 during the filling/blending process. The PADI manual does not mention "membrane" because the course does not detail all processes by which nitrox is prepared.
Even though my LDS banks nitrox, I have all my cylinders O2 cleaned because I may get a fill from a LDS who blends rather than banks. Also, if I want something other than 32% or 36%, the LDS will likely have to PP blend the mix. The cleaning isn't difficult, and you can do it yourself. Or pay the LDS the few bucks it costs at the time of your annual visual inspection.
Even though my LDS banks nitrox, I have all my cylinders O2 cleaned because I may get a fill from a LDS who blends rather than banks. Also, if I want something other than 32% or 36%, the LDS will likely have to PP blend the mix. The cleaning isn't difficult, and you can do it yourself. Or pay the LDS the few bucks it costs at the time of your annual visual inspection.
