Because Owning And Flying Your Beechcraft Can Be Done Safely AND For Less Money!
 Aviation Oxygen Bottle Filling System



OK, so I retrofitted a factory Oxygen system into my B55 HERE and have found it to be a great improvement in my O2 Saturation at my usual cruise altitudes of 10,000' to 13,000' and at night. It got me from the low 80's into the low 90's with a very nice oxysaver cannula for optimizing my on-board oxygen supply.


See an in cockpit Bonanza O2 Bottle Mounting solution HERE.


Still not convinced about the benefits of O2 in the cockpit - Read about and listen to this chilling hypoxic pilot audio conversation with ATC HERE




Having price checked a few FBOs on the road for oxygen bottle top offs and/or fills, I was shocked at what I was quoted for this service. In most cases $65 or MORE! This CSOB was not about to fork over the equivalent of nearly an hours worth of 100LL for O2.


I had heard of many oxygen fill stations folks had installed in their hangars and set out to research how to safely accomplish this to do my own bottle fills in a cost effective manner.





High Pressure gasses are DANGEROUS! Do not attempt to build or operate high pressure gas or oxygen systems without proper training. If in any doubt, consult a high pressure gas professional or your A&P/IA who works with high pressure gasses on a regular basis for guidance.




Offer to pay for the components and the system and let your A&P/IA build it and work out a mutually acceptable compensation to service your system.


Check out the below video for the results of incorrect oxygen cylinder handling




Here is a hair raising story that could have had a very bad ending were it not for the sharp thinking of the owner!


So, I'm in Memphis for a couple of days visiting my daughter and her family and ask the FBO to put in the O2.


I get to the airplane the next morning to check things out and the first thing I look at is the O2 pressure. It's below 400psi. I gently back away from the aircraft and tell the others to get back as well. Clearly there was a leak (the FBO definitely had topped  it off). Apparently they didn't snug the cap back on the fill fitting and the check valve had a slight leak. They said they'd top it off again and snug it up.


They are incredulous when I tell them to leave it open for an hour before messing with it.  But I have my reasons: There is an entire aircraft interior oxygen soaked overnight. Anybody that thinks this country boy is gonna climb in and crank up is out of their ever lovin' mind. Oxygen blowing out of a line is one thing.  Combustibles long term soaked in 100% of the stuff (it's down in the gaps of the fibers and *in* the fibers) is "sort of flammable".


On reflection I wasn't sure an hour would do it, so I called them back and told them to leave it for three (with the doors open). I wasn't leaving until the next day anyway. I'm sure they still think of that crazy Texas guy. Call me chicken, but not fried!



With the above warning as a backdrop, here is a narrative on how I constructed my system.


I secured an account with a local welding supply place for two full size tanks of Oxygen for about $20 each and a $12/month cylinder rental charge. Understandably, there are different schools of thought as to Welding O2 and ABO (Aviator Breathing Oxygen). Here is a quote from Mountain High's Technical Information Manual:


Contrary to a common and published myth, there are no different grades of oxygen being produced or contained in cylinders maintained under DOT regulations. By the very nature of the state-of-the-art process in which oxygen is produced, it will be better than 99.99% pure.


In other words, it all originally comes from the same spout no matter what the purpose. In addition, oxygen for medical use does not have any more moisture than oxygen for any other purposes, nor is it added. Furthermore, because of the chemical nature of oxygen it must be as pure and dry as possible if stored under pressure or else the cylinder and equipment may be damaged, or worse, personal injury or death may occur.


Therefore, a hygiene protocol is necessary in order to prevent oxygen from being contaminated or to help keep contaminated oxygen from being used. This, perhaps, is why many believe there are different grades of oxygen.


For me, I'm satisfied that the many folks I've spoken to and the above source, that I can successfully use Welding O2 for my aviation needs without issues. I have learned that in some states if you ask for Medical O2 you will need to present an Rx or some such thing.



Each tank has about 250 cubic feet of O2 in it and is filled to about 2,200 psi. I hung a tag with a number on each tank "#1" and "#2". I start with tank #1 and use that until I can no longer get 1,850psi from it. Then I close Tank #1 and open the valve on Tank #2 and top off my bottle.


My original plan was that when bottle #2 gets to 1,850psi, bottle #1 is going back for exchange and bottle #2 will become bottle #1 and the freshly filled bottle becomes bottle #2. Beech Lister Mike T. gave me some thoughts on optimizing my oxygen cascade so I'm going to experiment with Mike T.'s thoughts below.


Here are some CSOB oxygen filling thoughts from Mike T., an experienced Baron and Bonanza owner who refills his own oxygen bottles:


You'll waste much less oxygen if you use both supply tanks each time you refill your aircraft's tank. (Except when both supply tanks are nearly full.) The idea it to first draw on your lower-pressure tank until its pressure equals that of the tank in your aircraft and then switching to the higher-pressure tank to top off the aircraft tank.


Again, this procedure is used for each refill. If your aircraft's tank is nearly empty, you'll be able to get a lot of O2 from even a partially filled supply tank. This will of course mean less is drawn from the higher-pressure tank. This is the primary reason to connect the supply tanks in a cascade. It makes drawing from several tanks during one refill much easier; fewer connections to make; just turn the handles on the valves.


Also, the economics of filling one's own tanks depends on the refill/exchange policy of the gas supplier. Some air shops charge a flat rate to exchange cylinders regardless of how much gas remains in the customer's tank. Others -- particularly those that are willing to refill a customer-owned tank, rather than exchange it -- charge only for the gas it takes to top it off, pee vee equals en are tee, etc. Any card-carrying CSOB will check with several local suppliers before choosing one.


Finally, depending on your itinerary, it's frequently OK to only partially fill your aircraft tank. You only need enough O2 for the upcoming flight. Partial refills will help you get more gas from your supply tanks as they're depleted.


Great thoughts Mike!



I got a 2-bottle oxygen cart off eBay for about $69 including shipping. It looks fine for my light duty needs in my hangar and has restraining chains and sits the bottles on a platform that rests with the 12" wheels off the ground. It was shipped UPS and was a simple nut and bolt assembly.



There are much more expensive and industrial strength carts out there but I did not think I needed that kind of commercial durability. GTS-Welco has the above cart HERE for $89



I sourced a lot of the fittings and high pressure oxygen "whips" from Applied Home Healthcare in Westlake, OH 888-327-7301.



They had most of what I needed and were CSOB priced from what I could research. For bottle connections I used the CGA540 fittings. Here is the "T" (aka Western Enterprises PN: T62) and pigtail whips I purchased:






The whips are provided with 1/4" NPT female ends and cleaned, capped and packaged for Oxygen service. I used a 1/4" NPT Male-to-Male adapter to put two of them together.


Here is my parts list:


  • (1) 1109-1010 CGA540 "T"

  • (3) 1109-9914 CGA540 Nut

  • (3) 1109-9916 CGA540 Nipple 2.5" Length

  • (3) 1110-0536 Teflon Braided Pigtail 36" (One of these could have been 24")

  • (1) 1120-0057 High Pressure Gauge 0-4000 PSIG, 2 1/2", 1/4" NPT

  • (1) 1109-5581 Metal CGA540 Nut Wrench

  • (3) 0045-1100 Adapter Connection 1/4" NPT x 1/4" NPT Male

  • (1) Parker N200B Needle Valve

  • (1) Scott Adapter Fitting (sourced from Aerox)

  • (1) 1/4" NPT "T" Female

  • (1) 1/4" NPT to 1/8" NPT Adapter (Female to Male)

  • (1) 1/8" NPT to 1/4" NPT Adapter (Male to Male)

  • (1) Two Cylinder Tank Cart w/Restraining Chains and >10" Wheels




I used three (3) of these CGA540 nuts and three (3) nipples




I thought getting a CGA540 wrench for ~$13 for my filling station was a good idea for when I have to switch tanks. The wrench can be conveniently placed in the cylinder cart tray as well as the wrench for attaching my filling adapter 11/16"






Here is the 2.5" high pressure gauge I selected @ about $15. It has a 1/4" NPT Male fitting and was placed into a 1/4" NPT Female "T" that I sourced locally



I think one of the most important pieces of my fill system is the needle valve. This allows me to control the rate of the fill so that the little bottle is not filled too quickly. My research has determined quite a number of warnings regarding too fast a fill rate which will heat the bottle being filled. The reading I have done suggests that if you can comfortably rest your hand on the bottle things are good.


My friend and Bonanza owner, Bo H. is an avid scuba man and he had a needle valve specifically for this purpose. It is Parker PN: N200B with 1/8" NPT Female Ends. It has a 3GPM flow rate, however, I opened the valve just to the beginning of flow and that was a good rate for me. I used locally sourced brass adapters to attach this to the 1/4" NPT high pressure whip and the Scott adapter fitting.


Here is a 1/4" NPT Needle Valve, the N400B that could integrate nicely into your 1/4" NPT high pressure whips with a 5GPM flow rate. For additional safety I have decided I'm going to add the N400B to my system just downstream of the pressure gauge to protect the flow rate in the long section of whips.


Click HERE for a link to all the Parker N-Series Needle Valve Specs


HERE is an Auction for a new N200B at $15 from seller: clevelandsupply


Click HERE to search for an N400B needle valve


Click HERE to search for an N200B needle valve


or at Drillspot HERE for $43



PDF Data Sheet on Parker Needle Valves HERE




Oxygen Transfiller Info HERE



The other piece of the fill system is the adapter to the Beech factory fill port which is a "Scott" fitting. This piece pictured at the left end of the photo below, was sourced from Aerox HERE





My Oxygen Fill System in Use




Check out how Peter H., an aviator in the UK, solved his O2 filling needs:





My buddy Bo H., is an O2 system and Mixed gas Blender Instructor trainer, for TDI and NAUI and here are some of his watch outs:

Cleaning is imperative, "Crystal" simple green absent of the dye and perfume or simple DAWN detergent is what the NAVY uses now. Clean till water no longer " beads" or under a "black light' after 10 minutes no petroleum florescence.

This means- don't check your oil then open a tank.


Big pressure increases - filling to a closed Scott pack valve or a sudden increase in pressure can have disastrous results

The proper O2 compatible Teflon tape is important too. Source this from your welding supply or industrial supply house.

ANY PETROLEUM PRODUCT - grease gas even cigarette tar, ignites very easily in the presense of pure oxygen - and starts a chain of more stuff burning till the O2 is gone. Possibly creating a 3,500F, 8 foot fireball. ... 00x225.jpg ... mental.jpg ... en-fi_tech -- a weak experiment -

BUT this is how simple a sudden opening of an O2 tank can get ya'

Home or Hanger


Also someone I know owns this burnt out blood splattered store ... /207290346

Below is an excerpt on Oxygen tanks and their recertification requirements by Beech owner/ABS Member Pete Tracy, which was published in the ABS Magazine in 2005. Also, HERE is an article on oxygen cylinder care and servicing.




Most pilots who use oxygen cylinders in their planes have a general sense that their cylinders need to be re-tested and re-certified every so often. But few of them actually know what is required. This article is intended to give a general overview of these requirements.

Re-testing and re-certification is technically called "requalification." Requalification of oxygen cylinders is governed by regulations of the Department of Transportation (DOT) and not by those of the Federal Aviation Administration (FAA). The DOT regulations govern cylinders used for transportation of hazardous materials.

        Compressed oxygen is a hazardous material. (49 CFR Section 172.101, Table).  Each cylinder used for the transportation of compressed oxygen must meet DOT specifications and bear DOT specification markings and be "qualified."  No one may use an unqualified cylinder in transportation.

        Such cylinders must be "requalified" at certain times and under certain conditions. Requalification must be done by a person holding DOT approval. (Section 180.205). Cylinders which are not qualified or requalified may not be refilled. And federal OSHA regulations require that anyone who works with oxygen or oxygen systems receive special training. (29 CFR Section 1910.253(a) (4).

        Regardless of time, a cylinder must be tested and inspected if:

1. The cylinder shows evidence of dents, corrosion, cracked

     or abraded areas, leakage, thermal damage, or other conditions that might render it unsafe for use it transportation;

2.  The cylinder has been in an accident and has been damaged

    to an extent that may adversely affect its lading retention

      capability, or;

3.  The cylinder shows evidence of or is known to have been

   over-heated.  (Section 180.205(d)).




This is called "conditional requalification."

        Regardless of condition, a cylinder must be tested and inspected after

the passage of a certain period of time.  This is called "periodic requalification."  How often a cylinder needs requalification depends on the kind of cylinder-and there are many kinds of cylinders. However, the most commonly used cylinders in aviation are Types 3A, 3AA, 3HT, 3AL and E(xxxx).

        Type 3A and 3AA cylinders are heavy steel, must be requalified every 5 years, and have an indefinite lifetime. Type 3HT cylinders are light steel, must be requalified every 3 years, and must be condemned after 24 years or 4,380 fills. Type 3AL cylinders are aluminum, must be requalified every 5 years, and have an indefinite lifetime. (Section 180.209).

        Aluminum cylinders made from type 6351-T6 alloy have special requalification requirements because they have had failure problems. (Section 180.205(f) (4)). There is a proposed regulation to prohibit the use of this alloy in cylinders.

        Type E(xxxx) cylinders are Kevlar or a similar material, must be requalified every 3 years, and must be condemned after 15 years.

These time periods may be extended under certain circumstances. For example Type 3A or 3AA heavy steel cylinders can be requalified every 10 years, instead of every 5  years, if  "removed from any cluster, bank, group, rack or vehicle each time it is filled," meets certain other specifications, and is subjected to the dreaded "hammer test" at every filling.

(Section 180.209 (b)).

        Each cylinder that is tested and inspected must be "requalified", "rejected" or "condemned." If a cylinder is rejected, the owner must be notified in writing and have an opportunity to have it requalified under more rigorous terms. (Section 180.211). If a cylinder is condemned, the tester must stamp a series of Xs over the DOT specification number and mark it "CONDEMNED." Alternatively, with the consent of the owner, the bottle may be rendered incapable of holding pressure-usually by drilling. No person may remove or obliterate a "CONDEMNED" marking. (Section 180.205(i) (2)).

A cylinder must be condemned if:

1. It fails the visual inspection;

2. It leaks through its wall, or:

3. There is evidence of cracking. (Section 180.205 (i) (1)).

        In addition to both internal and external visual inspection, each cylinder must be pressure tested. This is commonly called "Hydro-Testing" or "Hydro-Static Testing." During a hydro-static test the cylinder is placed inside a test jacket filled with water, and a specified internal pressure is applied. Most cylinders are tested to 5/3 their certified pressure. Thus, a cylinder having a service pressure of 3000 pounds per square inch would be tested to 5000 pounds per square inch. How much the cylinder expands during pressure testing is measured. And how much the cylinder has permanently expanded from the pressure testing is also measured. (Section 180.205(g)).

If a cylinder passes its requalification testing, it must be marked with the month and year of requalification. It must also be marked with the requalifier's identification number (RIN). (Section 180.213).  If a cylinder was requalified in November, 2003 by a requalifier holding a RIN of A221, the requalification mark would look like this:


                                                  B3 2   05



Cylinders are also marked with Crown Markings which are normally on the shoulder of the cylinder. Suppose for example a cylinder was marked: DOT-3AL2216 HH34087 03/01 LUXFER TC-3ALM153. These markings mean: The cylinder is a DOT approved Type 3AL aluminum cylinder with a service pressure of 2216 pounds per square inch.  It has a serial number of HH34087. It is made by LUXFER. It was made in March, 2001. It was certified by Transport Canada as a Type 3ALM aluminum cylinder with a service pressure (in bars) of 139.

Another example might be: DOT-3AL2015 NN0366194 M4002 08 02 CATALINA M15 TC-3ALM139. These markings mean: The cylinder is a DOT approved Type 3AL aluminum cylinder with a service pressure of 2015 pounds per square inch. It has serial number NN0366194. The M4002 is the DOT manufacturer's number issued to CATALINA. It was manufactured in August, 2002. It is an "M" cylinder having a capacity of 22 cubic feet. It was certified by Transport Canada as a Type 3AL aluminum cylinder with a service pressure (in bars) of 139.

So go out to the hangar and check your oxygen cylinder. You will find out a lot more than you already know. If your cylinder is out of date, you must have it requalified before it can be re-filled.  The manufacturer of your oxygen cylinder can requalify it for you for around $60, but you will have to ship your cylinder to them.  However, many fire equipment businesses and dive shops can also do the requalification for you. Usually these businesses are local, easily accessible, and will charge around $25.

Maintaining your oxygen cylinders in top-notch shape is important. A leaking oxygen cylinder can cause instant and spontaneous combustion of nearby flammable material. A catastrophic failure of an oxygen cylinder will almost certainly be fatal. There is a reason for requalification of oxygen cylinders, and given the implications of a failed oxygen cylinder, the price of admission is low.

1. Individuals should consult the regulations themselves respecting the requirements for their own cylinders.

2. All references are to specific sections of Title 49, Chapter 180 of the Code of Federal Regulations unless otherwise indicated.





High Pressure gasses are DANGEROUS! Do not attempt to build or operate high pressure gas or oxygen systems without proper training. If in any doubt, consult a high pressure gas professional or your A&P/IA who works with high pressure gasses on a regular basis for guidance.




Offer to pay for the components and the system and let your A&P/IA build it and work out a mutually acceptable compensation to service your system.


Check out the below video for the results of incorrect oxygen cylinder handling




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