Another O2 question

[Eraaen]

Hi guys, I've been stalking this site since I purchased my new (to me) 305 Rocket in July.  I have been attempting to figure out this whole topic of how to I fill my own oxy tank.  I'm a diver, I have a newer dive tank (certified) But, I usually rent when traveling anyway.  So I figured why not use it to avoid $95 service tickets that never get the tank full anyway.

 

1)  I understand I can fill straight oxy from my dive shop into my clean tank.

2) I purchased a whip with gauge and the correct adaptor to fit the side of the plane (it has a built in tank)

3) The whip I purchased has a CGA-540 adaptor in the inlet side.  But, no needle valve.

4)  Should there be a needle valve or can you just crack open a dive tank VERY SLOWLY??  I realize I need to keep volume low to prevent over heating.

 

I thought I was being brilliant when I found a K valve adaptor on Amazon to fill paint gun tanks.  It is a NinjaPaintball item and is certified to 3,000 psi.  However, when it arrived today the directions specifically say "not for use with Oxygen."  Can any one explain why?

 

I don't want to start any fires or create any explosions.  So.... How are you guys that are using the dive tank trick hooking up to your tanks?  Built-in or otherwise.  I've spent a week trying to find anyone who can give me help to do it for less than a $3,000 set up.

 

Specifically I need to figure out what kind of K valve adaptor to use with O2, and were can I find an appropriate adaptor to go from said K valve to the CGA-540 whip.  How do I control flow?

 

Oh and I guess one last question.  I haven't tried yet, but I'm sure a typical dive shop is probably going to freak out when I ask for 100% O2 for fear I'm a dumb-ass diver who is going to kill himself and they'll get sued.  Anyone had any experience with this?

 

[Awful_Charlie]

Lots of questions in there, I'll try some of them:

 

Assuming you have the Scott 26875/26884 filling adaptor, then that already has a restrictor in it, so in theory you should be able to dump from your filling tank as fast as you can. However, I'm always cautious opening the valve, and can normally find something to do for a few minutes so as to avoid the need to rush.

 

If you have that filling connector, you probably need something like this overpriced gadget to put on your filling loop. I don't know what you have on your dive bottle, but I use the cylinder tap to regulate the flow.

 

As to why your adapter is marked 'not for oxygen' I can only guess - maybe the material is is made of is not suitable, of maybe it's just a product liability thing, but probably worth a bit more research.

 

I've never bought oxygen from a dive shop, so have no idea how to cope with that!

 

My filling rig:

 

[N201MKTurbo]

I would be careful with the dive tank. At a minimum it should be NITROX cleaned.

 

The reason your fitting is not oxygen compatible is probably because of the materials. It cannot have any rubber O-rings and you usually don't want aluminum in contact with high pressure oxygen.

 

Why use a scuba tank? just get a welding tank and have it filled from a clean source. The CGA 540 is the correct fitting for that. Even a NITROX tank is only certified for 45% oxygen. It would be nice to have the 3000 PSI so you could top off your tank. You could get an old scuba tank and replace the tank valve with a CGA 540.

[DonMuncy]

What kind of tank are you planning on filling from. I am assuming you are wanting to fill your built-in tank on your K model.

[Eraaen]

The overpriced gadget is exactly what I have.  I purchased the Aerox Single Cylinder Filling Station and the Scott, Aerox Filling Adapter from CGA-540.  I was under the impression I could use my Aluminum Dive Tank with standard K Valve to use as a tank to fill the tank internal to the plane.  I've never been a NITROX diver.  The mention of no rubber and/or aluminum probably kills the whole idea of using my dormant Dive Tank as a cheap supply.  I'll probably need to look for a welding tank to get my hands on.

[DonMuncy]

You have to remember that you aren't really "transferring" O2 from one tank to another. It just moves the gas from the higher pressure to the lower until it equalizes. So if you have a small tankful and attach to a larger one, it will not put much into the larger tank. You would have to then go back, refill the small tank, re-attach, and it will push a smaller amount into the larger, and so on. You would eventually get it pretty full, but it would take a bunch of attempts. With a large O2 tank pushing into a smaller one, it works much better. And this is why filling is done by "cascading", where you use multiple large tanks, hooking them to the smaller (to be filled) tank starting with the lowest pressurized (filling from) tank. Then switching to a higher pressured one.

So using a transfilling system you will never get a full tankful into your plane.

You can get a system that actually pumps the oxygen into the plane, and fill it up, but those systems go north of $3000.

So, yes, you need a large welding tank, and preferably two. A large welding tank will come close to filling your plane's tank two or three (perhaps) times before the pressure gets so low you will want to refill your welding tank. Using two, you might get better than double that(depending on how full you are satisfied with.)

As to your first post, you don't need a valve between the filling tank and your plane tank. When you attach them and open the valve, it will run by itself. HOWEVER, WHEN YOU DO THIS, LISTEN TO THE VALVE IN THE PLANE. IF IT MAKES A RATTLING SOUND, THE VALVE INTO THE PLANE TANK IS BOUNCING OPEN AND CLOSED, AND IT WILL QUICKLY RUIN IT. They are expensive to replace. If it rattles, immediately close the big tank outlet valve down low enough so it quits.

[Guest]

Lots of questions in there, I'll try some of them:

 

Assuming you have the Scott 26875/26884 filling adaptor, then that already has a restrictor in it, so in theory you should be able to dump from your filling tank as fast as you can. However, I'm always cautious opening the valve, and can normally find something to do for a few minutes so as to avoid the need to rush.

 

If you have that filling connector, you probably need something like this overpriced gadget to put on your filling loop. I don't know what you have on your dive bottle, but I use the cylinder tap to regulate the flow.

 

As to why your adapter is marked 'not for oxygen' I can only guess - maybe the material is is made of is not suitable, of maybe it's just a product liability thing, but probably worth a bit more research.

 

I've never bought oxygen from a dive shop, so have no idea how to cope with that!

 

My filling rig:

 

O2 and TKS fill.jpg

Interesting process, I've never thought of using a funnel to catch the spilled oxygen to store it in the TKS tank.

Clarence

[FBCK]

On the mapa email site there is a gent named Dave Morris and he has put together some videos on various topics and one of the was how to use and put together the system you are trying to build. I Believe they might be on YouTube or his perusal site, I'm on a

My iPad and can't find it .

[carusoam]

Try to find the safety guidelines written for aviation...

Equipment suppliers like Mountain High should have everything from fittings to complete setups...

There are some possibilities to easily light things on fire.

Could be that I missed what you typed...

It is one thing to explain to someone that you used diving equipment and saved some money...

But when it says don't use for O2 right on it because it is for a paintball application....?

There is some used, low cost O2 equipment available from the healthcare industry.

It is pretty well known that welding O2 and breathing O2 come from the same source. (Search around here for the explanation)

Just know that an uncontrolled release of O2 in the presence of flammable objects is a really unsafe problem to have.

If you didn't mean that, allow me to apologize...

It's like using a powered driver on a fuel tank access panels. It only happens to the new guy....

Best regards,

-a-

[chrisk]

Take a look at http://www.aviationoxygen.com/aerox-aviation-oxygen/oxygen-refill-station-equipment.html  I bought the FBO-1, but at a reduced price because I only needed the scott adapter.  They have a few pictures of it connected to the welding tanks, which you can rent for a relatively low price from a local welding shop.

 

As for hooking it up.  1) connect the transfill to the welding tanks. 2) connect to the plane. 3) slowly open the valve on the lowest pressure welding tank.  4) wait until the pressure is stable and close the valve on the welding tank.  5) open the valve on the high pressure welding tank.  6) Wait till the tank is full, or as full as it is going to get.  Then close the valve on the welding tank.  7) disconnect from the plane.

 

I'm very particular about the tools I use on the O2 equipment and make sure they are very clean (I only use them on the O2).  I also keep a plastic bag over the adapter when not in use. I'm probably overly cautious, but it cost nothing to be clean, but a minute or two.

[Eraaen]

You may already know this, but I'm still in the learning curve.  So I have the rest of the pieces coming to convert my Aerox Single whip into a two tank system.  I hadn't caught the fact that the system I have already has a restrictor in it.  Thanks for pointing that out.

 

My local welding supply company gave me the following quote.

 $25 each to fill a 5ft tall (approx) 220 Cubic Foot Cylinder to 1800-2000 pounds

 

I can rent the tanks for $11 per month/each or

 

Lease for 5 years for $192/each

 

The lease program doesn't sound like a bad deal to me.. any opinions?  I haven't been able to locate any used items (that I feel comfortable with)

 

So, with a system like this, I may not ever get my bottle to 2000 lbs.  But, how many 1500lb fills could I expect? Off the top of my head I'm not sure of the capacity of my bottle.. only that the gauge goes to 2000lbs

[StevenL757]

You can get a system that actually pumps the oxygen into the plane, and fill it up, but those systems go north of $3000.

 

Don, I'm also shopping around for equipment to refill the 115cf kevlar in my ship.  I have a great relationship with a gas equipment business that has been supplying me nitrogen for a few years now, and will be working with them on oxygen needs.  I was planning on a 2 or 3-tank setup linked together, and see that I can also add a booster (an OB-30 in this case) to that configuration (http://www.interfacedevices.com/products/air-driven-gas-boosters.php) to get the maximum amount of oxygen from the tanks providing the filling.

 

Are you able to point me in the direction of a system that pumps ABO into an aircraft like you describe?  I don't want to say "cost is no object", but am certainly willing to spend a few thousand on a system that does what you mention so I'm as self-sufficient as possible with the least amount of hassle.

 

Let me know if this makes sense.

 

Regards, Steven

[Guest]

Steven,

With a large oxygen cylinder costing $50, you would never recover the cost of the booster pump at $5000.

Clarence

[DonMuncy]

Steven,

I don't remember where I saw them, but the site you gave seems to have one that would work. You might also try Masterline.

I'm with Clarence, unless you are filling a bunch for other people, you will have trouble justifying a booster pump.

Frankly, I would have trouble justifying two "cascading" tanks except I got them at a real bargain.

Unless you fly high a bunch of hours, it is a pretty close call. 

I think most of the justification is in convenience; and not having to grit your teeth paying someone $75 to do something that only cost you $5. 

Plus I can fill tanks for my friends almost free.

[Awful_Charlie]

I'm with Clarence and Don too - it's rare I need to despatch from home with more than 800PSI (that gives two of us more than enough for a 2.5 hour flight out and another 2.5 back), and as my supplier provides the bottles at 3000PSI for 70CHF (near enough to 70USD), spending a load to get the last few hundred PSI just isn't worth it. I just have a single filling bottle, and that lasts me around a year.

 

Interesting process, I've never thought of using a funnel to catch the spilled oxygen to store it in the TKS tank.

Clarence

 

Ah - that's the special secret mod - you connect the masks to the TKS tank and breath the alcohol fumes, and deploy the high pressure oxygen from the wing leading edges at touchdown for ultra short stopping distance

[Two Oh One]

I trolled Craigslist for a few weeks and found a few of these K tanks. Not all listings are a good deal, but with patience you can find them from hobbyists or from people who no longer need them to fill medical tanks, for cheap. Just make sure the collar on top says "customer owned" or is blank. Dinged up paint doesn't matter, just a current hydro test.

http://indianapolis.craigslist.org/for/4791863483.html

[carusoam]

Welcome aboard, 45.

Best regards,

-a-

[StevenL757]

Thanks Don, Clarence, All.  Although we fly a lot of trips at long ranges and up as high as possible, I can't see spending booster prices to get such a small ROI.  I'm able to get two, three or more large ABO tanks from my supplier, a nice cart, plus all hoses and connectors at dealer cost, so I'll work toward that and do an affordable transfill setup.  The supplier provides training on any equipment, so I'll leverage that with others' experiences here.  Thanks everyone.

[peevee]

Gonna bump an old thread and ask if you ever got set up. After paying $85 for a "fill" and only getting 1700 of the 2050PSI I needed it's looking better and better!

[DonMuncy]

You would have to do a lot of flying in the O2 levels to break even on the cost of setting up a transfill system. But the convenience of being able to do it in your own hangar, keep your tank full rather than try to squeeze out one more flight before refilling, and earn the eternal good will of the guys that hangar near you by filling theirs free (or very cheap), makes it worth it to me. Probably the best money saving item is finding cheap large cylinder(s) for your system. Although the flexible line, and the specialized fittings are a little expensive, gauges and standard fitting are easy to cobble together an inexpensive set-up.

[amillet]

I have a client who owns a medical oxygen business and is also a pilot. I get my portable tanks filled for free. On way to KOSH refilled at FBO at KPIR for $60.

[peevee]

You would have to do a lot of flying in the O2 levels to break even on the cost of setting up a transfill system. But the convenience of being able to do it in your own hangar, keep your tank full rather than try to squeeze out one more flight before refilling, and earn the eternal good will of the guys that hangar near you by filling theirs free (or very cheap), makes it worth it to me. Probably the best money saving item is finding cheap large cylinder(s) for your system. Although the flexible line, and the specialized fittings are a little expensive, gauges and standard fitting are easy to cobble together an inexpensive set-up.

Seems to me 8 fills and you're money ahead. Maybe it isn't worth the hassle, but it's a hassle to go get it filled before a trip too.