Hakkikt, the mounting I have designed use the pressure reducer wich go with the air compressed bottle, a paintball gun bottle. This one, reduce the pressure from 250 kg/cm2 to 60 kg/cm2. A second regulator, a soldering industrial pressure variable regulator, reduce from 60 to 3-4 kg/cm2, the work pressure. This mounting is very cheap and very easy to made, opposite other options.
This air compressed system is used too as a blow ballast system, with a solenoid valve.
The engine escapes went to an expansion bottle, and then to overboard.
In the first engine trials,
I’ll test if the escapes will empty the ballast tank. I thing it is possible because the external pressure is low, maximum 0,3 kg/cm2, and if it is
necessary, I can increase the feed pressure in the second regulator with a servo.