[quote=PBrown;875564]It's not the air top that needs to be slow, its the initial decant of O2.
Upto 100%?, got any more details?, AFAIK membrane systems only go to 40%. I've heard of people getting higher by re-circulating the 40%, but I don't think that's manufacturer approved.
cheers,
Paul[/quote
Personal nitrox blending systems are made by APD
Graham.