blending with a stick?

[gaschef]

DEar All

What a load of techobabble.

Firstly does your compressor manufactuerer accept the use of increased oxygen in the input gas. Most DO NOT, the acceptions being those manufacturers like RIX or Aminco who manufacture OIL FREE compressors. If you read the NOAA, USN, RN, or anyone elses manual who knows about the subject OIL FREE compressors are what these people are talking about.

Use high level input O2 at your own risk.

Most international Standards Agencies, Gas Producers, and Professional Diving Agencies(Military & Commercial) accept that above 24% O2 you treat it as 100% O2.

THe limit for oil in air to be mixed with O2 is 0.1mg per cubic metre.
the standards agencies who came up with this figure make no difference between mineral, vegatable or synthetic oils. If your compressor can produce air this clean you will have no trouble.
If you compressor does produce air this clean, get your air testing
done again, as it most be wrong.

If you want to mix O2 online at Low Pressure a simple baffle box is all that is required, The specific gravity of O2 and Air is so near a homogenous mix is gauranteed. in except in very cold conditions

Having spent 20 years mixing gas for the offshore industry and almost as long for the recreational diver, I still cannot believe that the recreational diver cannot accept what has been learnt (painfully in many cases by PROFESSIONAL divers)

In my career I have seen 2 oxygen fires, I pray to god I never see another one. For everyones sake follow the rules, and do not try to cut corners, Oxygen will get up and bite you.

Tim "gaschef" Stevens

Commercial Diving Senior Systems Technician
ANDI Instructor Trainer IT#30

 

[gaschef]

DEar All

Another thought crossed my mind. If you are going to play with continous blending, make sure that you have some method of isolating the oxygen supply before the compressor is started up.

I would leave it to your imagination as what would happen if the compressor was given 100% oxygen on start up. probably the con rods would get scared of the dark and come out through the crankcase or something similar.

Most commercial online mixing plants have a solenoid valve connected via a timer to the compressor start panel. This will allow the compressor to be up and running before O2 can be entrained into the input air stream. It will also prevent the unintentional escape of O2 into the mixing chamber once the compressor is switched off.

If you are still going to play with this system, please bear in mind some oil free compressors are only rated fo 50% oxygen use, and very few for 100% O2. If you want to play with 100% O2 use a compressor such as a CORBLIN diaphragm pump, which has two steel diaphragms and a crack detection system which will automatically shut the system down if a failure occurs

Any problems email me I will only be to happy to be of assistance

Tim"gaschef" Stevens

 

[MikeFerrara]

gaschef once bubbled...


THe limit for oil in air to be mixed with O2 is 0.1mg per cubic metre.
the standards agencies who came up with this figure make no difference between mineral, vegatable or synthetic oils. If your compressor can produce air this clean you will have no trouble.
If you compressor does produce air this clean, get your air testing
done again, as it most be wrong.

My air is tested once a quarter and it is always below and that's before th hyper filter. And I try to time the air testing to get it done right before I replace the filters.

 

[oxyhacker]

This is a common misconception, that because a compressor is oilless it is automatically safe to run O2 through it. However Rix says very emphatically in all its literature that the compressor is for use only with air. It's a great compressor for topping up tanks which are being PP mixed, but it isn't (in the opinion of its manufacturer at least) a nitrox compressor.

And just to confuse things further, I have seen letters from both Coltri and Bauer stating that their compressors can be used for continuous mixing up to 40%!

I agree that it takes great discipline to continuous mix, since letting the O2 spike can cause all sorts of catastrophes.

gaschef once bubbled...
Firstly does your compressor manufactuerer accept the use of increased oxygen in the input gas. Most DO NOT, the acceptions being those manufacturers like RIX or Aminco who manufacture OIL FREE compressors. If you read the NOAA, USN, RN, or anyone elses manual who knows about the subject OIL FREE compressors are what these people are talking about.

 

[Genesis]

both Bauer and Coltri/MaxAir will tell you that their warranty is void if you run ANY enriched air content through them.

At least this is what they've told me.