I have been filling my own cylinders for a couple of years now. I bought a 60 cuft Aluminum oxygen cylinder that I store in my trailer (it's large enough because I ordered the 18m trailer with my new ASH31Mi, but that's another story). I bought a simple transfill hose off of Ebay (no gauge or bleed valve). It worked OK for awhile, but started leaking gas towards the end of the first season. The problem is that when you disconnect under pressure you damage the O-ring seal. So I figured I needed a transfill hose with a bleed valve. I found one on Ebay which also had a gauge. I used this all season with no difficulty. This seller no longer is in this market, but others are available for around $100.

The reason for doing this is partly economics and partly convenience. If you fly where there is no oxygen available it is more than a convenience - it is a necessity. The economics is pretty simple: refills cost $30-40; this setup cost me about $500. It takes about 15 refills to pay for the system. For me, that is about two years. BTW, I just refilled the big cylinder at my local Oxarc with aviation oxygen; cost? $22.

Tom

On Saturday, September 18, 2021 at 11:05:16 PM UTC-5, 2G wrote:
> I have been filling my own cylinders for a couple of years now. I bought a 60 cuft Aluminum oxygen cylinder that I store in my trailer (it's large enough because I ordered the 18m trailer with my new ASH31Mi, but that's another story). I bought a simple transfill hose off of Ebay (no gauge or bleed valve). It worked OK for awhile, but started leaking gas towards the end of the first season. The problem is that when you disconnect under pressure you damage the O-ring seal. So I figured I needed a transfill hose with a bleed valve. I found one on Ebay which also had a gauge. I used this all season with no difficulty. This seller no longer is in this market, but others are available for around $100.
>
> The reason for doing this is partly economics and partly convenience. If you fly where there is no oxygen available it is more than a convenience - it is a necessity. The economics is pretty simple: refills cost $30-40; this setup cost me about $500. It takes about 15 refills to pay for the system.. For me, that is about two years. BTW, I just refilled the big cylinder at my local Oxarc with aviation oxygen; cost? $22.
>
> Tom

How much of a PITA is it replacing the o-rings? Were you able to find a local source?

> How much of a PITA is it replacing the o-rings? Were you able to find a local source?

On most transfiller adapters, the O-ring is at the very tip of the nipple where it seats in the cylinder's CGA 540 socket. It is easy to see and takes 2 seconds to inspect, and if necessary, a new one can be rolled into the groove effortlessly. There is also a "soft nose nipple" that can be used instead of an O-ring seal. This allows a gas tight seal with the transfiller and cylinder without the use of a wrench. The metal-to-metal socket and nipple requires a wrench to make a good seal, but the O-ring or soft nose can be tightened sufficiently (IF you have a large diameter "hand nut" to provide enough torque to the connection.) The soft nose provides an adequate seal, and will not be damaged when the seal is broken when loosening the connection while the line is still pressurized. At 2,000 psi, it will still take some effort to break it loose. Breaking the O-ring seal on a pressurized line often blows the O-ring out. A bleed valve is a much better solution overall. Simple brass T fittings and a 1/8 or 1/4 inch NPT ball valve (available at a decent hardware store) can be added to the transfill line to relieve the pressure and make disconnection much easier, without risking damage to an O-ring seal. (Clean any oil residue from the fittings with something like Formula 409 detergent and allow to dry before assembling.)The ball valve is not a perfect seal at the 2,000 psi pressures we normally use, but for the brief period that a typical refill takes, it is plenty good. Just remember to close the high pressure master cylinder valve and the receiving cylinder valve before bleeding or disconnecting the transfiller line.

On 9/20/2021 7:42 PM, Mark Mocho wrote:
>> How much of a PITA is it replacing the o-rings? Were you able to find a local source?
>
> On most transfiller adapters, the O-ring is at the very tip of the nipple where it seats in the cylinder's CGA 540 socket. It is easy to see and takes 2 seconds to inspect, and if necessary, a new one can be rolled into the groove effortlessly. There is also a "soft nose nipple" that can be used instead of an O-ring seal. This allows a gas tight seal with the transfiller and cylinder without the use of a wrench. The metal-to-metal socket and nipple requires a wrench to make a good seal, but the O-ring or soft nose can be tightened sufficiently (IF you have a large diameter "hand nut" to provide enough torque to the connection.) The soft nose provides an adequate seal, and will not be damaged when the seal is broken when loosening the connection while the line is still pressurized. At 2,000 psi, it will still take some effort to break it loose. Breaking the O-ring seal on a pressurized line often blows the O-ring out. A bleed valve is a much better solution overall. Simple brass T fittings and a 1/8 or 1/4 inch NPT ball valve (available at a decent hardware store) can be added to the transfill line to relieve the pressure and make disconnection much easier, without risking damage to an O-ring seal. (Clean any oil residue from the fittings with something like Formula 409 detergent and allow to dry before assembling.)The ball valve is not a perfect seal at the 2,000 psi pressures we normally use, but for the brief period that a typical refill takes, it is plenty good. Just remember to close the high pressure master cylinder valve and the receiving cylinder valve before bleeding or disconnecting the transfiller line.
>
What materials are acceptable in a ball valve used for 2200 psi oxygen? I've never looked
at them carefully enough to note the construction, but none of the bleed valves I've used
were ball valves, but seemed to be needle valves.
--
Eric Greenwell - USA
- "A Guide to Self-launching Sailplane Operation"
https://sites.google.com/site/motorgliders/publications/download-the-guide-1

> What materials are acceptable in a ball valve used for 2200 psi oxygen? I've never looked
> at them carefully enough to note the construction, but none of the bleed valves I've used
> were ball valves, but seemed to be needle valves.

Generally a stainless steel ball is used, rotating in a high density plastic cage. Seems to work. Doesn't seem to want to spontaneously combust like some of the contributors on RAS.

On 9/20/2021 8:42 PM, Mark Mocho wrote:
>> What materials are acceptable in a ball valve used for 2200 psi oxygen? I've never looked
>> at them carefully enough to note the construction, but none of the bleed valves I've used
>> were ball valves, but seemed to be needle valves.
>
> Generally a stainless steel ball is used, rotating in a high density plastic cage. Seems to work. Doesn't seem to want to spontaneously combust like some of the contributors on RAS.
>
From a catalog for oxygen service ball valves:

"TFM, PTFE or glass filled PTFE are inert in oxygen and are considered standard seat and
seal materials for oxygen service. Warning! Delrin (Acetal resin) seats and Nylatron stem
thrust seals MUST NOT BE USED IN OXYGEN SERVICE."

I'd want to know the ball seal material was acceptable for oxygen, so I'd try to get a
valve rated for oxygen service instead a hardware store "who knows what" valve.

--
Eric Greenwell - USA
- "A Guide to Self-launching Sailplane Operation"
https://sites.google.com/site/motorgliders/publications/download-the-guide-1

Or a purpose built Ox bleed valve. Works great.

https://aeroconsystems.com/cart/bleed-valves-indicators-filters-and-adapters/model-712-6000-psi-bleed-valve/

Good link. Thanks.

https://www.ebay.com/itm/Hand-Tight-CGA-540-Nut-Nipple-Oxygen-Regulator-Inlet-Bottle-Cylinder-Fittings-/252532617797

Dan
5J

On 9/20/21 8:42 PM, Mark Mocho wrote:
>> How much of a PITA is it replacing the o-rings? Were you able to find a local source?
> On most transfiller adapters, the O-ring is at the very tip of the nipple where it seats in the cylinder's CGA 540 socket. It is easy to see and takes 2 seconds to inspect, and if necessary, a new one can be rolled into the groove effortlessly. There is also a "soft nose nipple" that can be used instead of an O-ring seal. This allows a gas tight seal with the transfiller and cylinder without the use of a wrench. The metal-to-metal socket and nipple requires a wrench to make a good seal, but the O-ring or soft nose can be tightened sufficiently (IF you have a large diameter "hand nut" to provide enough torque to the connection.) The soft nose provides an adequate seal, and will not be damaged when the seal is broken when loosening the connection while the line is still pressurized. At 2,000 psi, it will still take some effort to break it loose. Breaking the O-ring seal on a pressurized line often blows the O-ring out. A bleed valve is a much better solution overall. Simple brass T fittings and a 1/8 or 1/4 inch NPT ball valve (available at a decent hardware store) can be added to the transfill line to relieve the pressure and make disconnection much easier, without risking damage to an O-ring seal. (Clean any oil residue from the fittings with something like Formula 409 detergent and allow to dry before assembling.)The ball valve is not a perfect seal at the 2,000 psi pressures we normally use, but for the brief period that a typical refill takes, it is plenty good. Just remember to close the high pressure master cylinder valve and the receiving cylinder valve before bleeding or disconnecting the transfiller line.

I've got one of those.  It was easy to install on the hose and makes
connection a snap.  It takes a bit of muscle to remove, however, but the
tank mount in the Stemme allows me to get both hands on it.

Dan
5J

On 9/21/21 8:58 AM, Dan Marotta wrote:
> https://www.ebay.com/itm/Hand-Tight-CGA-540-Nut-Nipple-Oxygen-Regulator-Inlet-Bottle-Cylinder-Fittings-/252532617797
>
>
> Dan
> 5J
>
> On 9/20/21 8:42 PM, Mark Mocho wrote:
>>> How much of a PITA is it replacing the o-rings? Were you able to
>>> find a local source?
>> On most transfiller adapters, the O-ring is at the very tip of the
>> nipple where it seats in the cylinder's CGA 540 socket. It is easy to
>> see and takes 2 seconds to inspect, and if necessary, a new one can
>> be rolled into the groove effortlessly. There is also a "soft nose
>> nipple" that can be used instead of an O-ring seal. This allows a gas
>> tight seal with the transfiller and cylinder without the use of a
>> wrench. The metal-to-metal socket and nipple requires a wrench to
>> make a good seal, but the O-ring or soft nose can be tightened
>> sufficiently (IF you have a large diameter "hand nut" to provide
>> enough torque to the connection.) The soft nose provides an adequate
>> seal, and will not be damaged when the seal is broken when loosening
>> the connection while the line is still pressurized. At 2,000 psi, it
>> will still take some effort to break it loose. Breaking the O-ring
>> seal on a pressurized line often blows the O-ring out. A bleed valve
>> is a much better solution overall. Simple brass T fittings and a 1/8
>> or 1/4 inch NPT ball valve (available at a decent hardware store) can
>> be added to the transfill line to relieve the pressure and make
>> disconnection much easier, without risking damage to an O-ring seal.
>> (Clean any oil residue from the fittings with something like Formula
>> 409 detergent and allow to dry before assembling.)The ball valve is
>> not a perfect seal at the 2,000 psi pressures we normally use, but
>> for the brief period that a typical refill takes, it is plenty good.
>> Just remember to close the high pressure master cylinder valve and
>> the receiving cylinder valve before bleeding or disconnecting the
>> transfiller line.
>

Transfilling equipment and information

http://www.craggyaero.com/mh_transfillers.htm

Richard
www.craggyaero.com

On Tuesday, September 21, 2021 at 8:35:32 AM UTC-7, Richard Pfiffner wrote:
> Transfilling equipment and information
>
> http://www.craggyaero.com/mh_transfillers.htm
>
> Richard
> www.craggyaero.com

Fill your own.
http://www.craggyaero.com/MountainHigh/5I000-0005-00-Filling-Your-Cylinder-200406.pdf

Richard
www.craggyaero.com

If you lube the o-rings, they won't shred as easily. You need to have a suitable lube that doesn't react with oxygen (can spontaneously combust). MH Oxygen has Christo lube ( https://www.mhoxygen.com/product/christo-lube-mcg-111-tube-5g/ ) which I use, and it works well (haven't lost an o-ring since I started using it). The o-rings that fit my transfil are vic1407-0175; they are $CAD4.84 at AirGas, they're 09001-0011-90 at MH Oxygen for $USD1.00. Having an extra when you are at a wave camp has proved handy.

On Tuesday, September 21, 2021 at 10:57:12 AM UTC-7, Dan Daly wrote:
> If you lube the o-rings, they won't shred as easily. You need to have a suitable lube that doesn't react with oxygen (can spontaneously combust). MH Oxygen has Christo lube ( https://www.mhoxygen.com/product/christo-lube-mcg-111-tube-5g/ ) which I use, and it works well (haven't lost an o-ring since I started using it). The o-rings that fit my transfil are vic1407-0175; they are $CAD4.84 at AirGas, they're 09001-0011-90 at MH Oxygen for $USD1.00. Having an extra when you are at a wave camp has proved handy.

Here is a transfill hose w/o a bleed valve, but also w/o o-rings:
https://www.ebay.com/itm/194020471334?chn=ps&_trkparms=ispr%3D1&amdata=enc%3A1CGy1DVrNQO2OglSOwqypCw59&norover=1&mkevt=1&mkrid=711-117182-37290-0&mkcid=2&itemid=194020471334&targetid=1262843334889&device=c&mktype=pla&googleloc=9033822&poi=&campaignid=12873833227&mkgroupid=120757694159&rlsatarget=pla-1262843334889&abcId=9300536&merchantid=6296724&gclid=CjwKCAjwhaaKBhBcEiwA8acsHLRx01efq6jbe0ebzYnw28isEUy91uKlQFnakML5TOizPwhrQq68ERoCkhIQAvD_BwE
Here is another with a bleed valve:
https://www.ebay.com/itm/224392634638?_trkparms=amclksrc%3DITM%26aid%3D1110006%26algo%3DHOMESPLICE.SIM%26ao%3D1%26asc%3D20200818143230%26meid%3D228c1fc5f6b04180ba8c8040d972cd20%26pid%3D101224%26rk%3D2%26rkt%3D5%26sd%3D194020471334%26itm%3D224392634638%26pmt%3D0%26noa%3D1%26pg%3D2047675%26algv%3DDefaultOrganicWeb&_trksid=p2047675.c101224.m-1

Hardly worth the bother of building your own.

Tom

On Wednesday, September 22, 2021 at 1:01:23 AM UTC-4, 2G wrote:
> On Tuesday, September 21, 2021 at 10:57:12 AM UTC-7, Dan Daly wrote:
> > If you lube the o-rings, they won't shred as easily. You need to have a suitable lube that doesn't react with oxygen (can spontaneously combust). MH Oxygen has Christo lube ( https://www.mhoxygen.com/product/christo-lube-mcg-111-tube-5g/ ) which I use, and it works well (haven't lost an o-ring since I started using it). The o-rings that fit my transfil are vic1407-0175; they are $CAD4.84 at AirGas, they're 09001-0011-90 at MH Oxygen for $USD1..00. Having an extra when you are at a wave camp has proved handy.
> Here is a transfill hose w/o a bleed valve, but also w/o o-rings:
> https://www.ebay.com/itm/194020471334?chn=ps&_trkparms=ispr%3D1&amdata=enc%3A1CGy1DVrNQO2OglSOwqypCw59&norover=1&mkevt=1&mkrid=711-117182-37290-0&mkcid=2&itemid=194020471334&targetid=1262843334889&device=c&mktype=pla&googleloc=9033822&poi=&campaignid=12873833227&mkgroupid=120757694159&rlsatarget=pla-1262843334889&abcId=9300536&merchantid=6296724&gclid=CjwKCAjwhaaKBhBcEiwA8acsHLRx01efq6jbe0ebzYnw28isEUy91uKlQFnakML5TOizPwhrQq68ERoCkhIQAvD_BwE
> Here is another with a bleed valve:
> https://www.ebay.com/itm/224392634638?_trkparms=amclksrc%3DITM%26aid%3D1110006%26algo%3DHOMESPLICE.SIM%26ao%3D1%26asc%3D20200818143230%26meid%3D228c1fc5f6b04180ba8c8040d972cd20%26pid%3D101224%26rk%3D2%26rkt%3D5%26sd%3D194020471334%26itm%3D224392634638%26pmt%3D0%26noa%3D1%26pg%3D2047675%26algv%3DDefaultOrganicWeb&_trksid=p2047675.c101224.m-1
>
> Hardly worth the bother of building your own.
>
> Tom
2G, the o-rings are on the MH regulator, not the transfil device (I have one, it's great - the price on your link is about half of what I paid). The problem occurs when you disconnect/connect the regulator to the bottle.
Dan

To prevent blowing the o-ring in the MH regulator, I turn the oxygen off
before entering the pattern.  I think I read in their instructions to
not leave the regulator pressurized and this is an easy to ensure that.

Dan
5J

On 9/22/21 5:33 AM, Dan Daly wrote:
> On Wednesday, September 22, 2021 at 1:01:23 AM UTC-4, 2G wrote:
>> On Tuesday, September 21, 2021 at 10:57:12 AM UTC-7, Dan Daly wrote:
>>> If you lube the o-rings, they won't shred as easily. You need to have a suitable lube that doesn't react with oxygen (can spontaneously combust). MH Oxygen has Christo lube ( https://www.mhoxygen.com/product/christo-lube-mcg-111-tube-5g/ ) which I use, and it works well (haven't lost an o-ring since I started using it). The o-rings that fit my transfil are vic1407-0175; they are $CAD4.84 at AirGas, they're 09001-0011-90 at MH Oxygen for $USD1.00. Having an extra when you are at a wave camp has proved handy.
>> Here is a transfill hose w/o a bleed valve, but also w/o o-rings:
>> https://www.ebay.com/itm/194020471334?chn=ps&_trkparms=ispr%3D1&amdata=enc%3A1CGy1DVrNQO2OglSOwqypCw59&norover=1&mkevt=1&mkrid=711-117182-37290-0&mkcid=2&itemid=194020471334&targetid=1262843334889&device=c&mktype=pla&googleloc=9033822&poi=&campaignid=12873833227&mkgroupid=120757694159&rlsatarget=pla-1262843334889&abcId=9300536&merchantid=6296724&gclid=CjwKCAjwhaaKBhBcEiwA8acsHLRx01efq6jbe0ebzYnw28isEUy91uKlQFnakML5TOizPwhrQq68ERoCkhIQAvD_BwE
>> Here is another with a bleed valve:
>> https://www.ebay.com/itm/224392634638?_trkparms=amclksrc%3DITM%26aid%3D1110006%26algo%3DHOMESPLICE.SIM%26ao%3D1%26asc%3D20200818143230%26meid%3D228c1fc5f6b04180ba8c8040d972cd20%26pid%3D101224%26rk%3D2%26rkt%3D5%26sd%3D194020471334%26itm%3D224392634638%26pmt%3D0%26noa%3D1%26pg%3D2047675%26algv%3DDefaultOrganicWeb&_trksid=p2047675.c101224.m-1
>>
>> Hardly worth the bother of building your own.
>>
>> Tom
> 2G, the o-rings are on the MH regulator, not the transfil device (I have one, it's great - the price on your link is about half of what I paid). The problem occurs when you disconnect/connect the regulator to the bottle.
> Dan

The O ring in the regulator is fine, even under pressure. You should, however depressurize the line from the regulator to the EDS unit between flights.. The seals in the EDS can eventually leak if left pressurized, even with the relatively low 15-25 psi delivered by the regulator.

What blows the O ring is when you try removing the regulator or transfill line while under the cylinder's 2,000 psi pressure and the escaping gas concentrates on the initial gap as the O ring breaks its seal. Make sure the cylinder valve is closed, and depressurize the downstream line with a bleed valve and you won't have any problems.

On Wednesday, September 22, 2021 at 4:33:47 AM UTC-7, Dan Daly wrote:
> On Wednesday, September 22, 2021 at 1:01:23 AM UTC-4, 2G wrote:
> > On Tuesday, September 21, 2021 at 10:57:12 AM UTC-7, Dan Daly wrote:
> > > If you lube the o-rings, they won't shred as easily. You need to have a suitable lube that doesn't react with oxygen (can spontaneously combust).. MH Oxygen has Christo lube ( https://www.mhoxygen.com/product/christo-lube-mcg-111-tube-5g/ ) which I use, and it works well (haven't lost an o-ring since I started using it). The o-rings that fit my transfil are vic1407-0175; they are $CAD4.84 at AirGas, they're 09001-0011-90 at MH Oxygen for $USD1.00. Having an extra when you are at a wave camp has proved handy.
> > Here is a transfill hose w/o a bleed valve, but also w/o o-rings:
> > https://www.ebay.com/itm/194020471334?chn=ps&_trkparms=ispr%3D1&amdata=enc%3A1CGy1DVrNQO2OglSOwqypCw59&norover=1&mkevt=1&mkrid=711-117182-37290-0&mkcid=2&itemid=194020471334&targetid=1262843334889&device=c&mktype=pla&googleloc=9033822&poi=&campaignid=12873833227&mkgroupid=120757694159&rlsatarget=pla-1262843334889&abcId=9300536&merchantid=6296724&gclid=CjwKCAjwhaaKBhBcEiwA8acsHLRx01efq6jbe0ebzYnw28isEUy91uKlQFnakML5TOizPwhrQq68ERoCkhIQAvD_BwE
> > Here is another with a bleed valve:
> > https://www.ebay.com/itm/224392634638?_trkparms=amclksrc%3DITM%26aid%3D1110006%26algo%3DHOMESPLICE.SIM%26ao%3D1%26asc%3D20200818143230%26meid%3D228c1fc5f6b04180ba8c8040d972cd20%26pid%3D101224%26rk%3D2%26rkt%3D5%26sd%3D194020471334%26itm%3D224392634638%26pmt%3D0%26noa%3D1%26pg%3D2047675%26algv%3DDefaultOrganicWeb&_trksid=p2047675.c101224.m-1
> >
> > Hardly worth the bother of building your own.
> >
> > Tom
> 2G, the o-rings are on the MH regulator, not the transfil device (I have one, it's great - the price on your link is about half of what I paid). The problem occurs when you disconnect/connect the regulator to the bottle.
> Dan

The first transfill hose I bought had the hand-tightening connectors on them, which I believe have o-rings. It definitely started leaking towards the end of the season, no matter how hard I tightened it.

Tom