silvertate
Read TSO-C89 (ETSO-C89 in EASA) and CS-25 for the standards required.
If the aircraft is certified to cruise above a certain altitude it has to be fitted with pressure breathing regulators to meet the required pressure and flow rates.
I'm not going to copy paste but if you really want to know you will find them.
Last edited by FE Hoppy; 25th Mar 2015 at 12:55.
Reason: added EU ref