Membrane system

[DennisS]

I am using an Underwater Breathing Sytems DNAX membrane set up. We are only able to get 34.xx% nitrox out of the system. Does anyone know if increasing the input pressure will a) increase O2 out b) damage the membrane. I've tried contacting the company (phone & email) without success.

 

[Hoosier]

Just out of curiosity, how much the membrane system is?

 

[pescador775]

It may be necessary to preheat the intake air. Do not run pressures higher than recommended. Do not pump oil laden air into the membrane. Just a suggestion and I don't know that anyone can do more since you told us nothing about the actual pressures, temperatures, source air or hookup, in short, nothing about anything other than the gas percentage.

 

[DennisS]

It's usually around 90-110 degrees F coming off the LP compressor, the output from the LP compressor is filtered through 3 filters and the regulator is set for 125 PSI. The membrane system has its own heater. If I increase the input pressure to the membrane to 135 psi, will this increase my O2 percentage.


Thanks

 

[pescador775]

Alright, that's better. Give a little, get a lot. Gradually increase the intake line to 140 psi and calibrate the O2 percent. Adjust slowly and carefully as you deem necessary. Do not exceed 200 psi. Do not exceed 40% oxygen as a fraction of total gas. I think you have the old style UBS membrane but it will work if you drive it harder.

 

[akscubainst]

They told me to run mine @ 165 psi, I run it about 145 and get 32% really smooth.

The thing you have to watch with the increase of pressure is that it will increase the output pressure as well. Listen to the overpressure on the compressor intake. You don't want to overpressure the intake.

Dave