Home brew nitrox

[rjack321]

Use a full synthetic like Chemlube 751. Do a couple oil changes with a small amount of running in between if you are currently running a mineral oil. The food grade oils are no better - they are meant to potnetially eat, not breath. They get alot of marketing hype (unwarranted IMO)

You will probbaly want a second filter tower. I have 2 in my system. (You don't clean the compressor, I'm sure you know this)

 

[MNawman]

rjack, did your compressor come with two filters or did you add one? Mine is an early 90s model Nautica that only came with one filter. I want to add another one. Do you know where I can find one? I have only been able to find the filter, but not the metal housing.

 

[Hoosier]

rjack, did your compressor come with two filters or did you add one? Mine is an early 90s model Nautica that only came with one filter. I want to add another one. Do you know where I can find one? I have only been able to find the filter, but not the metal housing.

No... He added it. The stock one only came with the small size chamber.

You can't have the chamber and all parts from here

http://www.scubacompressor.com/shop/index.php/cPath/46?osCsid=cd1f06a17b1677029bceae906c17a822


Rechard,

I should get some tips to make a DIY booster like yours...Yours looks great.

Two more projects to go

Thumbler and Booster....

 

[rjack321]

Try http://www.surpluscenter.com for a double acting, tie-rod style, hydraulic cylinder with a 3000+ psi rating. Not necessarily the cheapest place but they usually have some for $50-75. Be prepared to clean a smelly mess, I used powdered laundry detergent, then simple green.

I used 1/8" hoses and check valves from an hydraulic shop. I needed a couple of SAE to NPT adapters which I got from Mcmaster.

Its starting to use more drive gas now that my supply pressure has dropped to about 1400. Still manageable, I use an AL80 and a AL63 and as long as one of them is >2200 psi I can boost up to 3000 in the little 6cf argon bottles quite easily.

Here's some pics of Jeff Kruse's, I modeled my booster after his. His page explains the system with pics:
http://www.seanet.com/~katrinakruse/argon_booster.htm

I do recommend adding a on-off valve between the DIN fitting and the hose going to the booster. I think Jeff has added one, the pics might be old. Prevents you having to darin the whole system when removing the 6cf bottle.

Fire away on any questions you have.

 

[Hoosier]

Try http://www.surpluscenter.com for a double acting, tie-rod style, hydraulic cylinder with a 3000+ psi rating. Not necessarily the cheapest place but they usually have some for $50-75. Be prepared to clean a smelly mess, I used powdered laundry detergent, then simple green.

I used 1/8" hoses and check valves from an hydraulic shop. I needed a couple of SAE to NPT adapters which I got from Mcmaster.

Its starting to use more drive gas now that my supply pressure has dropped to about 1400. Still manageable, I use an AL80 and a AL63 and as long as one of them is >2200 psi I can boost up to 3000 in the little 6cf argon bottles quite easily.

Here's some pics of Jeff Kruse's, I modeled my booster after his. His page explains the system with pics:
http://www.seanet.com/~katrinakruse/argon_booster.htm

I do recommend adding a on-off valve between the DIN fitting and the hose going to the booster. I think Jeff has added one, the pics might be old. Prevents you having to darin the whole system when removing the 6cf bottle.

Fire away on any questions you have.

Thank you so much for your info as usual...


I will get back to you when I am in trouble...

 

[pescador775]

Nawman, extra cleaning of the compressor air is not required. Remember, you will not be pumping pure oxygen, not more than 40%, ever. However, adding extra filtration to any compressor can sometimes improve the air quality and reduce condensation or rusting in a steel tank. Find a Parker Hannifin hydraulic accumulator which is about a foot long and 25 ci capacity. These are aircraft type, stainless and sell on EBay for $30. Stuff with dessicant and charcoal plus dacron filter pads and you are in business, a hyper man.

A blending stik is easy to make. The Airspeed mod is kind of complicated. All you need to do is buy a length of 2 inch PVC pipe, some caps and a quantity of Gottschalk stainless steel sponges. Drill some holes, make an intake filter, screw in a 1/8 inch hose fitting, stuff in the spun stainless pads, plug in an oxygen analyzer and it's done. Insert a foam pad in the bottom to prevent any particles from drifting into the compressor intake line.

Use an oxygen regulator calibrated in liters or psi. The medical regulator is a single stage unit, simple and cheap. These are pressure reducing valves which regulate output by use of a constricter attached to the output. This constricter is drilled out with a #73 drill. This needs to be opened with a #60-62 drill depending on the compressor output. A regulator with 60 psi range should be drilled with #62 when using the Nautica 3cfm. Drill with #61 or 60 when using a 5 cfm compressor. If using a 100 psi regulator, then the hole should be about #62. The idea is to have the needle on the gauge setting about mid-range when pumping 36% NITROX. All this will become clearer when you reread the appropriate chapter in the "Hacker" book.

Use food grade oil in your air compressor. The type to use is sold under the NUVAIR brand, Nuvair 455. This type of oil has much higher resistance to oxidation when exposed to NITROX, much higher than diesters or triesters (751). 751 is thick as mud, anyway. Do not use EZ 1000 sold by Dnax. This is a "mystery" oil and I cannot verify its characteristics such as corrosion resistance and wear test results.

Argon will generate heat in a RIX compressor. However, this effect is less of a problem in an oil lubed compressor especially when considering that only small amounts need to be pumped.

 

[pescador775]

I took a look at the Brit's hydraulic pumper/cum booster. He did a credible job and it looks like it would be fun to do (once). Listen up, when you first undertake to pump argon through your compressor do an O2 check on the argon bottle afterwards. You may notice that the bottle contains some oxygen meaning that residual air in the condensators has been blown into the bottle along with argon. Some argon will remain unused in the condensator. A small amount of air shouldn't hurt the insulation properties of the argon but I've never used the diluted stuff, so don't know. If you purge the condensator with argon before filling there will also be some loss of gas because not all the argon in the condensator will be used. Some will remain in the canister and lines. I would suggest that the any extra "hyper" filter be bypassed for this operation thus minimizing loss. In the end, the loss in the compressor would probably be about as much as with the booster, so, no advantage compressor. However, a compressor will jam a small argon bottle in a heart beat. It will get hot but that's life. No problemo, right? Well, you might want to put the little guy in a bucket of water while filling. I like the compressor setup but it is probably a toss up. The amount of gas to be pumped is small and with the booster some of this can be simply transfilled so maybe that route is not so tedious as it looks.

 

[rjack321]

Use an oxygen regulator calibrated in liters or psi. The medical regulator is a single stage unit, simple and cheap. These are pressure reducing valves which regulate output by use of a constricter attached to the output. This constricter is drilled out with a #73 drill. This needs to be opened with a #60-62 drill depending on the compressor output. A regulator with 60 psi range should be drilled with #62 when using the Nautica 3cfm. Drill with #61 or 60 when using a 5 cfm compressor. If using a 100 psi regulator, then the hole should be about #62. The idea is to have the needle on the gauge setting about mid-range when pumping 36% NITROX. All this will become clearer when you reread the appropriate chapter in the "Hacker" book.

Use food grade oil in your air compressor. The type to use is sold under the NUVAIR brand, Nuvair 455. This type of oil has much higher resistance to oxidation when exposed to NITROX, much higher than diesters or triesters (751). 751 is thick as mud, anyway.

1) Just get yourself a 2-15 l/min med O2 reg from ebay for $8 to 25. The gauge is calibrated, the orifice is drilled already, nothin' left to futz with except hooking it up and gradually turning up the flow to the needed percentage. You'll make a mystery tank first time, after that you'll be plus-minus 0.5% easy breezy.

2) There are plenty of people that will disagree with you on the food grade oils. Chemlube being one of them. Show my some independent tests or something from Bauer - they are worth listening to.

 

[pescador775]

"Plenty of people" rjack? LOL, anonymous bashers. Look, the little Nautica is made by Aerotechnica Coltri and the Italian company's guidelines specify "food grade" oil for NITROX. A year ago, I pulled that info from the company website. However, I didn't file it because this practice is common knowledge. I kind of wish I had done so but I can't be burdened by storing references to counter every possible objection which is floated. Ultrachem is the manufacturer of Nuvair 455. Do you think that Nuvair is buying drums of their Omnilube food grade oil on a whim? Do you think that Ultrachem knows more about NITROX than Nuvair? Hardly, but they know a lot about "rotary bomb" tests and 455 has the highest oxygen stability of any of their compressor products. According to a phone conversation I had with Ultrachem, they do not endorse or object to food grade oil for this purpose. When I told an Ultrachem rep that I was using their food grade PAO for my compressor, the guy said "great". Bauer is mostly silent on the subject of food grade (PAO) oil versus heavy diester or triester oil. However, I am told that they use this food grade oil in their own commercial B-TROX system. Bauer got stung by reports of contaminated air with their big compressors while using diesters like 501. These oils contain trace toluene which is used by the manufacturers to disolve some components of the additive package. When the big, honking Bauers are run continuously in tropical temperatures it is was discovered that some toluene can boil off and enter the air stream. Moreover, if the compressor heads are hot enough this stuff can partially combust producing carbon monoxide. This effect is usually unnoticed because the filtration traps or converts these poisons. Bauer's response was to change the oil recommendation to the extremely heavy triester known as 750 or 751 which also contains this distillate. It is well known that a heavier viscosity, 40W oil has a higher flash point than 30W, and Bauer appears to believe that heavier oil and a temperature switch reduces the problem. On the other hand, the general oxidation rate of this oil when exposed to NITROX remains rather high and oxidized oil is not a good sign for lubrication or for safety reasons and so this kind of oil remains suspect, IMO. For all but the biggest compressors, the 30 weight Nuvair 455 should be fine. Test results of 455, not to mention the non toxic status on the MSDS sheet are excellent.

BTW, a standard 15 lpm medical regulator does not have enough flow to produce NITROX for a 5 cfm compressor so, rjack, your statement needs to be tested. Depends on the compressor output. In many cases, the medical unit will need to be drilled. Takes 5 minutes to unscrew the restricter and drill it.

 

[rjack321]

Pescy, I don't know who raised you but you need a new attitude.

Discussion over.