The diluter demand and pressure demand masks are not "required" by regulation to my knowledge, but are recommended for above 25,000 feet.

Cannulae are approved only for up to 18,000 feet. Above that you are required to use a mask.

The Nelson systems all include the adjustable flow meters inline, where each user can see and adjust as necessary without messing with any flow control at the regulator.

It seems that one can dump the pressurization on a P model and safely take it higher than 20,000 with an oxygen system and masks. The trick would be the legal argument about certification. If anything happend I bet lawyers would have a heyday.

pressurization help!!
 

Overhauled front engine, had combustion heater checked and was returned from C & D Associate's as not repairable--we re-installed --now we can get nowhere near Max differential at altitude, rechecked seals on heat ex changer, what are we missing????---work perfectly before we overhauled front engine---1973 Pressurized T337G??
A. any suggestions as to where to look---service manual not much help
B. Where is a good Skymaster shop -- we are located ion West Virginia??

Jim Bennon

Jim, some may miss this post because of the thread title (Oxygen). Consider putting it in a different or new thread under Pressurization. Also, in one post the combustion heater came back as repairable but in the next post as non-repairable; which is it?

Ernie Martin