O2 Compatable air

[garygee]

Hi folks

Am changing my compresser setup to be able to blend Nitrox and later Trimix so need to have O2 compatable air.

Know what setup is needed but have had varying advise on compressor oil.
Currently using a mineral based oil which some people say not to use, must be full synthetic,some say mineral is its OK.

So what do people use in their compressors for O2 compatable air ?.
Do I really need to empty, clean and refill ?.

(Assume double filteration which is standard on my filling set already and partial pressure blending i.e. 100% is cylinder at start of blend.)

Thanks Gary

[Hazel W]

hi gary
if u decide to use mineral oil then you can no longer consider your cyls o2 clean.
I know many people use mineral oil but it is a fact that as your filters load up with hydrocarbons some will start to pass through into the mix.
This is especially a problem where 100% o2 is in the cyls at the start of a PPo2 mixing process...not only are hydrocarbons bad for you but they can act as a combustable material in the presence of high pressure o2....its generally a bad idea.
the non mineral based compressor oils or the synthetic variety are better ( and not as bad for you)

the decision is urs of course but i would strongly recomend following manufacturers recomendations if you are supplying the mixex to anyone other than yourself ......we live in the litigative society after all!


Hazel

[Spike Jackson]

I am no expert on compressors but I am assured that our club compressor set up meets all the legal requirements for our clean air (ie O2 compatible). It is an oil compressor with a double filtration system.

[garygee]

Thanks for feedback folks

Still not reached a final conclusion.

The compressor manufacturer says use mineral.
The company who does all the other bits, filters etc needed says synthetic
A very repspectable trainer who does gas blening a lot and courses says mineral
Feedback here say synthetic
Got a contact for a compressor guru, thanks, but no reply yet.

Why can it be simple !!!

Compressor is my own, not a clubs, but dont se that make s much difference as i want it right.

Regards Gary

[NeilB]

We are setting up a NitroxStick as suggested in the Oxygen Hackers book. This states that your compressor should be using synthetic oil. Our three do so we have no problems.

I assume synthetic is better as if there are problems then no hydrocarbons are coming from the oil.

[iain/hsm]

One simple solution is to write to each of the air compressor manufacturers and ask them for a response on company letter headed paper as to the air compressors suitability for the production of nitrox or oxygen enriched gas. They will either a. Not respond or b. Reply by referring you to an independent supplier of there products thus shouldering off the liability to a third party. Other responses will include verbal assurance only, or opinion.

In the cases of explosions that have occurred with air compressors being used for oxygen enriched air both by blending and partial pressure the legal defence from the manufacturers has been “Read the Label” i.e. you have an air compressor and under UK/EU standards the product is suitable for Air only. The filter manufacturer position is equally ambivalent in so far that filter’s by there very nature fail so it’s the old user error defence and the same defence in that the filter was designed for air filtration only.

The UK legal standard is that any gas with a percentage of oxygen greater than 23% shall be classed as oxygen, with the position of “Use no oil” being the legal standard. Any lubricant used must be suitable for oxygen to the pressure and temperature generated and have been tested by the manufacturer certified suitable for use with the equipment.
Oils both mineral and synthetic, food grade or diester that have an auto ignition temperature and so are unsuitable for oxygen enriched air process.