Ahmed Adly, Marlin Inn DC(Offline)

I would really like to know if it would be OK to run deco 50 through a compressor.
I know for a fact that a friend of mine ran 60 through his by mistake once for a few minutes with nothing at all happening.

The thing is, that membranes can produce 50%. So if it can be established that we can run it through the old clunker, then we will fix a lot of troubles in the world.

Imagine filling 30 50's a day on a live aboard for a whole 10 days!!! even with a membrane using 40 as a top up gas, it will still be a hell of a lot of J's.

So lets share how many times all of you have also made nitrox 50 or 60 by mistake while continuous blending.

Ahmed

Teppo (Online)

How clean is your compressor? ie are you running fomblin oil? or vegetable oil

You need to consider what the O2 will do to the O-rings

T

__________________
Teppo
http://koti.welho.com/tlallukk/

caverkevin(Offline)

There is a little more to be concerned with than just a massive failure. Also need to be worried about CO production. If you are thinking about running high PPO2's in a old clunker. Think about the how much CO could be produced in the gas that you are compressing. I would want to make sure you are running a product like LF's monoxycon to convert the CO to CO2.

Personally at home, I am transfilling some pure O2 then topping with 35% to make 50%

Much more than 35% scares the poop out of me. As I am usually next to the equipment. There was some NASA studies on FO2 and auto-ignition. If I recall correct, they were able to get ignition of hydrocarbons with rapid pressurization of 50%.

I also have some friends that are running greater than 40%. I have heard about two compressor problems so far. So I would advise to be very cautious and think of the risk v benefit.

Cheers!!

Kevin

tanto(Offline)

I pump 50% through a small Coltri compressor that has been slowed down with the adoption of a smaller pulley. As a consequence the compressor runs colder than usual. As a lubricant I use the polyolefin synthetic EZ1000. So far no problems, keeping my fingers crossed!

Ahmed Adly, Marlin Inn DC(Offline)

I have heard of this CO production thing before. But I think if the analyzer reads 50% at both ends, then I suppose there is no CO production going on.

Also, all my 80's have rubber neck O-rings, no problems and no wear for years and years.

The oil I run is EZ2000. Some funky American food grade compressor oil. (or at least that is what the local dealer says it is)

I wouldn't mind hearing more of what the failures where for your frineds compressors.

My compressor is old, but not decrepid. I like the idea of slower filling. I have a second compressor I could do that pulley thing on and let that one be my deco 50 factory.

Keep the suggestions coming, we are creating a tresure trove here.

TobinGeorge(Offline)

There a guy selling a watercooled head and I think water cooled intercoolers for Bauer Compressors. I have his info at the shop, I'll post it later.

I don't think I'd rely on O2 analysis on each end to ensure no CO. It only takes a little, and the resolution of an O2 analyser just isn't fine enough to catch small amounts.

You might want to consider a CO analyser, and the monoxycon.

If you slow down your compressor too far it may not be adequately cooled, many are "splash" oiled.


I know I'd be standing back aways if I was trying to compress 50%


Tobin

Ahmed Adly, Marlin Inn DC(Offline)

I need some one who undersgtands to do some scientific research on tis matter. What we need is real evidence backed up by facts.

The trouble is, I always get the feeling that the whole 40% thing is real bull. Or, that the n itrox 40 is dangerous stuff too.

You all see what I mean right?

Ahmed

NIMROD CHEN(Offline)

Ahmed ,
the onwer of the last dive shop i was working for also repairs compressors
the last time i checked there were 4 units in the trash area waiting to be sunk at sea , all of them were using a stick (up to 40 % ) - it works for a while and than the piston comes out to see the sun .
use a rix or do PP to bank 50% and boost it to the tanks .

Nimrod

rjack(Offline)

How much do you want to roll the dice? It unpredictable, that's part of the problem. If you blow up the liveaboard, you're really hosed.

One issue: Oil of different ages is going to flash at different temps. From what I've heard, PAOs like the EZ-2000 you're running have a high load of volatile hydrocarbons with the base additives. So presumably you might have a higher CO production than a compressor running say an ester synthetic. The consequences of small amounts of CO at depth are death. We're talking parts per million - your O2 analyzer is only working in the parts per hundred scale.

I wouldn't want to create an environment were I knowingly have conditions ripe for more CO production and then try to "manage" CO by 1) using monoxycon and 2) hoping the analyzer is working correctly.

Getting more whips to PP fill O2 into more deco bottles at a time would be way safer if you're looking to speed up the filling of multiple bottles.

What problem are you trying to solve again?

TobinGeorge(Offline)

As promised here's the link to the water cooled goodies. http://www.nitroxtech.com/nitrox.html

Not a lot of info there, but at least there's an email and phone number.

I have not used any of these goods, but what I saw at DEMA looked pretty nice.


Tobin