what size oxycon help ?

[deadheadkev]

So I'm looking for what I will need oxycon wise for a national 8m with rider top torch .. would an ex-20
be enough to keep up with hours of melting with the rider torch and or the bottom torch?
If not what size would or any good ideas only have about
1200 to spend to get operational this way... already have tanks and did the filling thing.. then went to
dewars but local oxy guys are assclowns and would rather lose a customer instead of making a lost half
tank right .. so I will oblige them one way or another ..

thanks for any help!

[DickFarm Glass]

I purchased an "extreme oxygen mega 40" recently.

While I was in the buying process, Paul at extreme oxygen answered the phone and emails immediately. Answered all questions.

Second I paid and he received my money he stopped answering the phone. It took 3 weeks just to get them to finally ship it even though he told me it would ship "tomorrow" when I was paying.

It came crushed, and he refuses to answer the phone or emails to answer any questions I have about the machine or the problems that have started to occur with it within the 1st few months. It comes with a 3 year warranty, but the machine doesn't seem like it's going to last 1/2 that, and the seller now refuses to even answer any form of contact.

Just a heads up if you decide to deal with extreme oxygen aka moreoxy.com

[Nomad]

An ex-20 should work for a national with top torch.


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[Nomad]

I went to Dave at available oxygen. He hooked me up. One broke and he shipped it back and replaced it for free too. Ups does damage on them.


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[MpVpRb]

I'm a total noob glassblower, but a very experienced engineer

I would never trust a system with no storage tank(s). If the capacity is more than you need, it's wasted, if it's less, you run out

It appears that there are two common choices. High and low pressure

The high pressure (homefil, medical) systems have pumps that can reach high pressure (more than 1000 psi). The higher the pressure, the more the problems. High pressure stresses equipment

The low pressure systems use an oilless air compressor (usually Gast), to compress to lower pressures (~100 psi)

The medical systems have the additional costs of medical products, although most sold to the glasswork world seen to be substantially discounted (something about selling used equipment after a patient dies)

The low pressure concentrator market seems small, with all of the problems of small markets and hand-built products

It looks to me that there is no, one, perfect solution

Some day, I may decide to work on this..or not

[Mute]

give them both a try, thats the only way to find out which ones for you.

i've done both, and both work well.

If you're looking for more experienced glassblower's opinions than your own, you could let some veterans try out what you got, and see what they think. I had only been blowing a couple years when i started tinkering with homefills. A couple of glassblowers i know and are more experienced than myself, told me what they thought of the performance. Helped me gauge just how well things were working.

[Nomad]

Depends on what torch you use. My bravo runs nice on two oxycons with no breathing etc...


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[legallyblindglass]

If anyone could please tell me what I should be looking for in a homefill compressor, or what types would work for me it would help me out a ton. I have 2 unlimited oxygen M -20's and an extreme oxygen EX-20 linked together and am trying to fill my 2 T tanks without overloading the machines. I've found some homefill systems for sale at what seem to be good prices for machines with low hours, but not sure if they will fit the specs needed to run with the concentrators I have currently. I tried to post my own thread about this, but the site seems to only let me reply existing ones

Any help I can get would be greatly appreciated!!

[Cosmo]

Any of those machines will run a homefill no problem. Mine runs off one 5lpm concentrator. I run it at 1.5lpm. The problem is it takes a while. I'd say 48 hours to fill a K tank all the way. I never let it go that high. I own 4 tanks so I just fill it all day then swap it out and fill a new one to however much it fills. The homefill is designed to fill the small portable oxygen tanks for breathing. So it doesn't need to fill very fast because they don't hold much. There are people who have modifed the homefills to run at higher pressures, but that significantly reduces the lifespan of them. The ideal situation would be to have multiple homefills. One for each concentrator. Have them all filling the same tank. Of course that isn't cheap, and by the time you spend that much you are most of the way to buying a HVLP system anyways.

[legallyblindglass]

Should I be looking for any certain type of compressor or will any of them work? And are any certain type of compressors better than others to use for filling T tanks (besides ones with low hours of use on them)?

Thanks again, I haven't been able to find this information anywhere else so this info is crucial and keeping me from making a big mistake!!

[snoopdog6502]

Should I be looking for any certain type of compressor or will any of them work? And are any certain type of compressors better than others to use for filling T tanks (besides ones with low hours of use on them)?

Thanks again, I haven't been able to find this information anywhere else so this info is crucial and keeping me from making a big mistake!!

This is just like what I use to pump up my K tanks. I found mine used for $92 Gast oilless compressors are damn good.

http://www.ebay.com/itm/381025034176

[legallyblindglass]

Thank you so much for the link! If I get one of these Gast compressors, would I still need the homefill unit or can I buy the proper fittings to connect my concentrators to compressor, then compressor to tanks for filling?

[dustyg]

If you get a Gast, you can get fittings to hook from concentrators to gast to tank to torch.

concentrator -> low-pressure-blow-off valve -> compressor -> compressor pressure switch -> check valve -> 100psi-blowoff-valve -> tank -> regulator -> check valve -> torch

You'll need some b-fitting-to-1/4"-barbs, some oxygen hose, some 1/4"-npt-to-1/4" barbs, some 1/4" NPT or barb tees, some copper tubing (to connect to the pressure switch), some hose clamps (ear-style are my favorite), and some copper-tubing-compression-fitting-to-1/4"-npt-adapters. I think that about covers it.

[legallyblindglass]

I just e-mailed mwest715 about buying his invacare homefill unit and he said that the purity coming out of my concentrators wasn't good enough to run a homefill. If you have a minute I'd love to hear your thoughts on this and do you know anyone using this setup to fill? Thanks again, I really appreciate the help!

[legallyblindglass]

Thanks Dusty! Are the prices of the pressure switch,blow off valves and other fittings high enough that I might be smart to go with a medical homefill compressor unit instead or are they all relatively cheap?

[dustyg]

You're welcome.

The parts are all relatively cheap. Also, these two types of systems are very different. The Homefills are used to compress a small tank to very high pressure (2000 psi) over a long period of time (at about 2 lpm). The HVLP set-up typically uses a larger tank, fills as fast as your concentrators can output (mine is 20 lpm, but could easily be 100lpm with a bigger compressor and more concentrators), but to a lower pressure (100 psi).

Since the HVLP fills to a lower pressure, it has less of a reserve of oxygen to work with, so you'll typically need need more/more powerful concentrators to run it, and that's where the real cost usually is. On the plus side, a system like this will easily outlast a Homefill in years of service.

[Cosmo]

I just e-mailed mwest715 about buying his invacare homefill unit and he said that the purity coming out of my concentrators wasn't good enough to run a homefill. If you have a minute I'd love to hear your thoughts on this and do you know anyone using this setup to fill? Thanks again, I really appreciate the help!

If they are in working order I would bet the purity is fine. The higher flow rate you run them, the lower the purity. But homefills are designed to use 1-2 lpm input so at that level purity shouldn't be an issue.

[BORO]

I read 20lpm's are modified 15's ?

This would lead me to believe anything over 15lpm has been hacked/tinkered with.

I read it on the internet. It could be b.s.

[Mute]

If you get a Gast, you can get fittings to hook from concentrators to gast to tank to torch.

concentrator -> low-pressure-blow-off valve -> compressor -> compressor pressure switch -> check valve -> 100psi-blowoff-valve -> tank -> regulator -> check valve -> torch

You'll need some b-fitting-to-1/4"-barbs, some oxygen hose, some 1/4"-npt-to-1/4" barbs, some 1/4" NPT or barb tees, some copper tubing (to connect to the pressure switch), some hose clamps (ear-style are my favorite), and some copper-tubing-compression-fitting-to-1/4"-npt-adapters. I think that about covers it.

I agree, but with a few tweaks.

Concentrator>blowoff valve> compressor>unloader valve>ADJUSTABLE check valve(50-150psi)> pressure switch> holding tank> regulator>flashback arrestor> torch.

The adjustable check- valve is important. Helps streamline the flow dynamics. Learned it from watching oxygenfrogs YouTube vid

[snoopdog6502]

This works as an adjustable check valve is an pressure sensor and unloader valve with an integrated check valve all in one. I have on I got at a farm store for $24.99

84949

Now as far as the homefil I say dont waste your money on those slow ,unreliable pieces of shit. Like buying k tank fills for $100.

Buy oxygen concentrators and a Gast compressor.

[Mute]

I think you're confused. That's just a pressure switch, probably has an unloader valve, but it doesn't have an adjustable check valve. So if or when the holding tank pressure drops below the psi that your compressor and concentrators are matched at( flow wise) it won't matter. This doesn't matter as much if you closely matched your flow numbers. But it will even help systems with closely matched flow numbers. Watch the YouTube video oxygenfrog made, it lays it out.

You see most check valves, such as what's in that pressure switch you showed a pic of snoop dog, have a cracking pressure of 1/3-2 psi. So if the holding tank where at zero, the compressor would be flowing its full flow(which you don't want). With the adjustable check valve you can set the pressure in which the cracking pressure is set to. So that way your compressor will never need its full amount of flow required...

[dustyg]

I read 20lpm's are modified 15's ?

This would lead me to believe anything over 15lpm has been hacked/tinkered with.

I read it on the internet. It could be b.s.

All of the "20" machines are 20 psi, 10lpm, and they're modified 8 lpm machines. David at A/O says he uses a higher quality of zeolite than they come stock with (if I understood right) and guaranteed his machines to run at 94% or whatever his standards were when running at 10lpm. I've got two of his machines and a Gast M100x, and I'm getting almost 96% purity out of the tank, but I don't know what purity I'd get if they ran at the full 10lpm, which they almost never do.

[lost nebula]

All of the "20" machines are 20 psi, 10lpm, and they're modified 8 lpm machines.

Not trying to correct you, but you make it sound like all 20psi units are modified machines. The Airsep Intensity is a stock 10lpm 20psi machine that is very good, although not used very much in the States. I understand why when the modified units are half the price.

I have never tested the purity of these machines but my manual says 90% oxygen at 10lpm.

[snoopdog6502]

Just for shits and giggles here is My snub nose Mirage on 4 oxygen concentrators. 3 5LPM on the outer and one 8LPM on the inner.

It runs real good the way its set up, it could use more. I dont recommend running any lower LPM then this and even then dont run bad flames and cook your torch.


https://www.youtube.com/watch?v=ScW-GnlMdWM

[dustyg]

Not trying to correct you, but you make it sound like all 20psi units are modified machines.

Sorry for not being more specific - I meant all of the "A/O 20", "UO 20", "EX 20", etc. machines - after-market machines with "20" in the title.

[dustyg]

I agree, but with a few tweaks.

Concentrator>blowoff valve> compressor>unloader valve>ADJUSTABLE check valve(50-150psi)> pressure switch> holding tank> regulator>flashback arrestor> torch.

The adjustable check- valve is important. Helps streamline the flow dynamics. Learned it from watching oxygenfrogs YouTube vid

I forgot the unloader valve - I've got that in my system, too - built in to the pressure switch, like the one pictured above. That's what the copper tubing and compression fittings are for.

"Adjustable check valve helps streamline the flow dynamics"? In a way that a regular check valve won't? Can you explain?

[Mute]

"Adjustable check valve helps streamline the flow dynamics"? In a way that a regular check valve won't? Can you explain?

Check valves have a "cracking" pressure. This is the pressure that the checkvalve requires to open and let air through. The pressure is usually a fraction of a psi or 1-3psi(very low). An adjustable check valve has a "cracking" pressure that is set by the user.

Why would it matter?

Compressors have what is called "free air flow" requirements. This is the amount of air that the compressor requires for flow. The number varies throughout the range that the compressor operates at. For example if you have a compressor that has a maximum pressure output of 125psi the amount of air that is flowing is going to be less at the maximum pressure of 125psi VS when the compressor is at zero psi. So if at zero psi your compressor says it can flow 100 Liters Per Minute, but at 125psi the compressor can only flow 20 Liters per minute that is a big difference. Not a big deal except if the pressure is at zero, which would only happen during the initial fill or anytime the tank was drained and refilled. Most people will error on the side of caution and get a smaller compressor and or closely match the flow being provided to what is required by the compressor at the established working pressure(s).

With the adustable check valve the pressure in which the compressor is flowing against is never zero(except for a split second the line is filled after being unloaded). There for the flow is never required to be the maximum, and actually can be set much lower. Lower flow means less concentrators, tighter flow increased purity, less heat, longer lasting components.

to put it simply. It restricts flow.

[dustyg]

Check valves have a "cracking" pressure. This is the pressure that the checkvalve requires to open and let air through. The pressure is usually a fraction of a psi or 1-3psi(very low). An adjustable check valve has a "cracking" pressure that is set by the user.

Why would it matter?

Compressors have what is called "free air flow" requirements. This is the amount of air that the compressor requires for flow. The number varies throughout the range that the compressor operates at. For example if you have a compressor that has a maximum pressure output of 125psi the amount of air that is flowing is going to be less at the maximum pressure of 125psi VS when the compressor is at zero psi. So if at zero psi your compressor says it can flow 100 Liters Per Minute, but at 125psi the compressor can only flow 20 Liters per minute that is a big difference. Not a big deal except if the pressure is at zero, which would only happen during the initial fill or anytime the tank was drained and refilled. Most people will error on the side of caution and get a smaller compressor and or closely match the flow being provided to what is required by the compressor at the established working pressure(s).

With the adustable check valve the pressure in which the compressor is flowing against is never zero(except for a split second the line is filled after being unloaded). There for the flow is never required to be the maximum, and actually can be set much lower. Lower flow means less concentrators, tighter flow increased purity, less heat, longer lasting components.

to put it simply. It restricts flow.

Ah, I see. What I'm currently doing is restricting the flow with a valve so that line pressure stays above 50psi until tank pressure reaches 50psi, then letting it fill some more before I start. It never reaches that low during actual use.

An adjustable check valve sounds like it'd be a much better solution - an actual fix instead of a hack. Question, though, just to be clear - once cracked, will it stop flow again once pressure drops below cracking pressure? Otherwise, it'll just crack, vent the line to the tank, and then my compressor will be working against a very low pressure.

[Mute]

yes it keeps the flow going in one direction. Is that what you are asking?

it is the same as a regular check valve, except that it opens at the set pressure you choose, instead of 1 psi or whatever really low psi, normal check valves are designed for.

a regular check valve doesn't leak at less than the cracking pressure, and an adjustable check valve is the same principle. It requires a certain amount of pressure to open, but that doesn't mean it is going to leak below that pressure.

[dustyg]

yes it keeps the flow going in one direction. Is that what you are asking?

it is the same as a regular check valve, except that it opens at the set pressure you choose, instead of 1 psi or whatever really low number it's designed for.


No, I mean... the check valve is closed at 45psi, but opens when the input pressure builds to 50psi (or whatever) - does it also close when the input pressure drops from 55psi to 50psi?

[Mute]

No, I mean... the check valve is closed at 1psi, but opens at 50psi (or whatever) on the way up - does it also close at 50psi on the way down?

it doesn't matter about the way down. It's a check valve, so it only flows in one direction.

the question you ask seems a little silly, lol

but yes if the check valve opens at 50 psi, it would also close a 50psi...by default

[dustyg]

it doesn't matter about the way down. It's a check valve, so it only flows in one direction

Still some misunderstanding. I edited my question above to be more clear.

[Mute]

No, I mean... the check valve is closed at 45psi, but opens when the input pressure builds to 50psi (or whatever) - does it also close when the input pressure drops from 55psi to 50psi?

why would your input pressure drop?

the input pressure coming from the compressor will always be greater than what's on the opposite side of the adjustable check valve.

So if your question is whether or not this would cause a "hiccup" in the flow, the answer is no because it always has resistance to build pressure against, therefor the line coming from the compressor would never be below 50psi.

[dustyg]

why would your input pressure drop?

the input pressure coming from the compressor will always be greater than what's on the opposite side of the adjustable check valve.

So if your question is whether or not this would cause a "hiccup" in the flow, the answer is no because it always has resistance to build pressure against, therefor the line coming from the compressor would never be below 50psi.

The check-valve is a valve that is either open or closed, right? And it's closed until the pressure behind it reaches 50psi because you don't want your system working against anything less than 50psi, right?

If input-line pressure reaches 50psi, it opens the valve and dumps into the tank faster than the compressor can fill, so the line pressure will drop down to whatever the tank's pressure is unless the valve closes again.

[Mute]

You're confusing me...lol

The pressure behind the gate will always be greater than the tank pressure. If you want to run your holding tank at less than 50 psi, than get an adjustable check valve that will work with the numbers you need.

I mean if the holding tank pressure goes below your setting on your regulator, then obviously you wouldn't have pressure.

The only way a holding tank could recover pressure faster than it is being supplied is beyond physical ability's... Lol

The holding tank would have to be smaller than the volume of the compressor head and feed line combined...

[Mute]

The check-valve is a valve that is either open or closed, right? And it's closed until the pressure behind it reaches 50psi because you don't want your system working against anything less than 50psi, right?

If input-line pressure reaches 50psi, it opens the valve and dumps into the tank faster than the compressor can fill, so the line pressure will drop down to whatever the tank's pressure is unless the valve closes again.

Again, it doesn't matter. The pressure behind the gate is greater than what's in front of it.

Just because the check valve gate opens doesn't mean all the pressure behind it is released. It is going to stay right around 50 psi.

it simply regulates the flow. You're trying to make something difficult when its really simple.

When your tank pressure is less than 50psi, the line will build pressure until the gate is opened at 50psi. At that point the gate will allow flow greater than 50 psi to pass through the gate. Simple as that. Once the pressure in the holding tank reaches 50psi the gate will still function the same. This regulates the flow going through the compressor, and the concentrators input to the compressor.

[dustyg]

I think I follow. As long as it keeps 50psi on the input side, even if the output side is allowing free-flow to an empty tank, that's what I want. Thank you.