Re filling 02 systems

[YPJT]

Posting on behalf of a mate who recently purchased a TB20 from USA with a factory fitted O2 system. The cylinder/s are fixed into the airframe and cannot be removed, except by a LAME. Most suppliers in Australia seem to work on cylinder exchange rather than refill and they don't have this specific type of cylinder anyway.

Does anyone know of airports around Oz that have the equipment to refill these systems as my mate can only top up when he is back at his home airport from a cylinder he gets from BOC gas.

[ForkTailedDrKiller]

It will probably come as no surprise that I know a bit about this stuff!

In my experience, getting O2 refills around the countryside varies from difficult to impossible, and is always expensive.

I can't get a refill in Townsville at all and I can't get one in Cairns unless I supply an adaptor that fits my cylinder.

My answer to that problem was to set up my own refilling station at home. With fixed clyinders in the aeroplane you would need to fit out your own trolley.

One cylinder to refill from does not work well as once the pressure in your main cyclinder equals the pressure in your aeroplane cylinder, you can't get anymore O2 into your aeroplane cylinder. You need to have at least two cylinders - which is why you see O2 refill carts with a bank of maybe 4 cylinders.

You always start your refill from the lowest content (ie pressure) cylinder, then top up to your final fill pressure from the second one. When you can't get anymore useful pressure out of Cylinder #1 you get a new one and rotate your cylinders one place to the left! ie the fullest cylinder is used last to bring your aeroplane cylinder up to final working pressure.

You can buy an adapter for filling onboard O2 systems.

Cost me a couple of grand to get set up, but refills cost me next to nothing - compared with about $90 for the last one I paid for on an aerodrome.

I can generally go out and back to most places I want to go with myself and Mrs Dr on O2.

I use Aviation O2 but you can use welders O2 - its the same stuff! But it is hard to get the same pressure (ie fill) with welders O2 cause the cylinders are filled to a lower pressure.

Aviation oxygen cylinders from BOC are at Extra High Pressure = 25,000 kPa.

Dr :8

[Ovation]

The Doctor is 100% right with the set-up and procedures to refill (as you would expect).

Most of the refilling fittings needed are not available in Australia - here is a link to where you'll find everything you need, and the service is prompt.

Oxygen equipment (continued) (http://www.wingsandwheels.com/page36.htm)

[YPJT]

Cheers guys,
will pass this on.:ok:
My mate's dilemma is that he often spends many weeks away, usually up around FNQ / Darwin. Is there any facility anywhere up there for re-fills assuming he had the adaptors?

Might be just as easy to have the installed system removed and go back to portable cylinders with canulas, which would be a bit of a shame.

[zlin77]

Instead of refilling cylinders, why not get a portable oxygen generator, F.A.A. TSO approved units are now available in Australia, about the size of a small flightbag and I believe they can deliver 4 litres/minute, they also can be run off their own battery supply for 3 hours ......

[ForkTailedDrKiller]

As far as I know you can't get a fill in Townsville. You can probably get a fill in Cairns from Hawkers if you have the right adaptors - but you will pay and arm and a leg for it.

Bro can get a fill in Maroochydore.

Dr :8

[YPJT]

Thanks Doc, I'll let him know.

Zlin77, any idea of make / model / suppliers? My mate did mention these but didn't know too much about them.

[NOSIGN]

I have refilled O2 in Darwin from many maint facs, most recently from the Cessna dealer who has the shiny DC3 parked out front (can't remember the name of the fac, SAE perhaps?

As the Dr says, price ranges from a carton of beer to about $90.

I used to refill extensively and I cant recall ever removing the bottle from the plane. Carried our own adapter in the plane.

Hawkers used to do ours when in TV, but i dont think that they are there any more and so, the maint place opposite blue water did ours a few times - can't remember the name... the engineer who looks like David Hughes from ch10.:E
:ok:

[ForkTailedDrKiller]

can't remember the name... the engineer who looks like David Hughes from ch10

Now that is funny - and true!

No, the Dave Hughes look alike can't do it - he sub-contracted to Hawkers.

Dr :8

[Rich-Fine-Green]

Regulatory/Insurance issue?.

Last I heard a maint. approval from CASA is/was required in order to top fixed O2 bottles in an aircraft.

Has this changed?.

Filling O2 can be hazardous if done too quickly or with oily rags in close proximity etc.

Same kind of maint. approval was required when I used to have a Beech and changed single and dual controls.

Comments please from any LAMEs?.

[blackhand]

Maintenance of oxygen systems does not fall into the category of approved pilot maintenance on Class B aircraft.

I use Aviation O2 but you can use welders O2
Really??? :eek::eek::eek:
Perhaps this is why a qualified LAME should look after oxygen systems.
BH

[Josh Cox]

Blackhand is correct, you'll need a maintenance authority under Reg 33B(1)(a) to fill the bottles fitted to the aircraft.

If you carry an external bottle, this is different, it is then considered baggage/freight, and due to the contents being over the 30 odd psi magic number it is a DG, but talk to the CASA DG guru, I believe there is either an exemption, instrument or ruling to carry these without consignment.

[bushy]

Our national airline proved that.

[baron_beeza]

Civil Aviation Safety Authority - AWB 12-1 Issue 2 - Aircraft servicing and ground handling tasks (http://www.casa.gov.au/scripts/nc.dll?WCMS:STANDARD::pc=PC_90648)

Note: The servicing of liquid and gaseous oxygen systems is to be carried out only by an appropriately rated LAME.

[TURIN]

Sorry to butt in from the Northern hemisphere, but for what it's worth, I came across this. DECANT FILLING OF CYLINDERS WITH HIGH PRESSURE OXYGEN (http://www.hse.gov.uk/foi/internalops/hid/din/555.pdf)

No mention of welders oxygen. :ok:

[ForkTailedDrKiller]

Some of you need to get out more!

Look here:

Pelican's Perch #13:Getting High on Welder's Oxygen (http://www.warmkessel.com/jr/flying/td/jd/13.jsp)

Pelican's Perch #13:Getting High on Welder's Oxygen
Having problems finding Aviator's Breathing Oxygen to refill your bottle? Upset about the rip-off prices some FBOs charge for an O2 fill? Don't put up with it, says AVweb's John Deakin, who explains why it's perfectly safe ? and perfectly legal ? to use cheap welder's oxygen, and tells you exactly what you need to know to buy it in bulk and do your own refills.

Oxygen is oxygen. It is the substance that matters, not the intended purpose. These days, welding, medical, and aviation oxygen are exactly the same. All three come from the same tank of liquid oxygen (LOX). The liquified form is the cleanest, purest, driest form of oxygen (or any substance) you'll find anywhere.

Dr :8

[blackhand]

From Pelicon Perch #13
Those Blessed Rules
Readers should be aware some of this advice may violate various rules of your hangar landlord, your airport, the EPA or others. It is pretty clear to me that nothing here violates any FAA rules, but your FSDO may have a different interpretation (as FSDOs are inclined to do). So proceed at your own risk.


And you feel that this is approved maintenance data??:eek:
BH

[Tex37]

I feel I have to reply to this before someone gets killed.

It is true to say that the O2 source is the same for all 3 commercial grades of O2, that is Welding (industrial), Medical and Aviator grade, this is where the similarities cease.

For medical and aviator grade, the cylinders are drawn into a vacuum before refilling and with the case of aviator grade it is also further dried.

The big hazard with using welding grade is that any contaminants, such as CO, CO2 and N2 remain in the cylinder as well as the big no no which is water.

The aviator and medical grade are certified and analysed to be minimum 99.5% O2, we have seen welding grade produce results of 94% O2 (we did not want to know what the other 6% was.

The main problem is the water in the system, so far as aviation is concerned. This can and will turn to ice when pressure is released, particularly at the low temperatures experienced at altitude and will result in poor performance of downstream regulators or even stop them functioning totally.

Coupled with this you also have the long term risk of corrosion etc.

I hope that this is clear!

Tex

[ForkTailedDrKiller]

I use Aviation O2 :O

[YPJT]

So in the absence of suitably certified FBOs or LAMEs to do the job propberly in Australia, has anyone had experience with the O2 generators? I read some are approved inside pressurised cabins but what about non pressurised?

I assume these would only meet the requirements of a "supplemental oxygen" system and at best be approve up to about FL180?

Does CASA have any position on them either way?

[Chimbu chuckles]

You mean apart from them being a fire hazard?

[YPJT]

Chimbu,
dunno mate, that's why I'm asking the question. I heard, ableit second hand, that there are approved devices out there. Maybe these are only the ones approved for medical purposes in pressurised cabins.

[zanzibar]

Does CASA have any position on them either way?

You bet they do. Ask one CASA bloke and he'll say "this" Ask another and he'll say "that". You won't be able to pin them down .................

[blackhand]

Does CASA have any position on them either way?

They sure do, refer::ok:
Section 108.26
System specification — oxygen systems

BH