Liquid Oxygen Tanks

[jstnoldhippie]

O.K. So here's the question, how long does your liquid tanks last. I've been using Liquid for over five years. Originally I was using a small torch (m3) and would get close to six weeks out of my tanks. Then I moved from Oregon to Kentucky, switched suppliers and switched torchs. (gtt phantom)This is were my problem pops up. It took some convincing of my current supplier to supply liquid tanks. After a couple years he began to accomadate me. I have not got more than three weeks out of his liquids. The tank I currently have bled out for a week while I was on a trip, and is now almost empty. I'll be lucky to get two weeks in all out of this tank (including the week I was gone.) My supplier swears this is normal, tanks may even bleed themselves empty if left alone for a week(he claims). So I'm getting frustrated at almost $200 ($165+$25 shipping) every three weeks, it's taking a bite out of my profit margin. I'm thinking of shopping around for another supplier (easier said then done in the hills of KY), but I thought I'd throw this out there to see what other people get out of their luqid tanks first. Thanks.:bangHead:

[VED]

thats a bit rediulas, my tanks last me 4-6 weeks on a mirage with about 4-5 hrs use every day. during the summer they vent if not used but during the cold months they shouldnt vent at all. i have had one that bleed its self out in about 10 days and air gas brought me out a new one free of charge. they told me it was probably a vacume problem with the pressure builder. i dont really know or care since they replaced it for free. i have heard stories of shady oxy suppliers setting the pressure builder on high so they vent alot more and go dry quicker, so check that out and see if you cant make some adjustments to the pressure builder that might help.

[melter skelter]

I just had one bleed out in a week ... airgas came and replaced it for free as well. I run a mirage on a liquid tank, can last me over a month...

I'd definitely bitch

[broken glass]

I got so many bad tanks from my company that they stopped giving me discounts, 5 of my last 7 tanks lasted less than a week, when they normally last 4. They started to tell me in December that the weather was to blame for the quick vent, then he caught himself when he realized it was as cold as it gets here. It was like talking to computers, i would get these programed responses to lox problems. The heat.....Did you leave the pressure builder on, ...Do you know how to use thesee tanks?.....The factory specs say that it should vent in 7-10 days....It sucks when you mark bad tanks, tell the company about a bad tank, and then notice your marked tank has been refilled for you a few weeks later and returned to you and it has not been fixed.

Six weeks does sound like a lot tho.

[p.j.]

i run a delta. i get between 4-5 weeks on it 6 hrs/day 5 days/wk.

i have had one blow the ball bearing out of the pressure relief valve after it wouldn't stop building pressure even when i left the vent open to try to release the pressure. it scared the shit out of me.....

but then they gave me a free tank and i got over it

[blazemaster83]

im on a phantom and i have 180 liter liquids. they last me about 6 weeks and i work about 5-6 hours a day, 6 days a week. they should be lastin a little longer for you.

[The Lorax]

while on the topic.. has anyone ever had problems trying to get liquid in a residential area?

[n3rd]

while on the topic.. has anyone ever had problems trying to get liquid in a residential area?

of course. its different in every area of course, but lots of places have had issues delivering to residential so they're just not willing to anymore. when i asked about it in my area they said they were getting landlord / neighbor complaints of some kind, and just weren't interested.

<3 my oxygen generator!!!

[kebira]

while on the topic.. has anyone ever had problems trying to get liquid in a residential area?

Hey J,
I just swapped out tanks at ArcSource and asked at what point I could get a price break from $24(251 cf). They're actually pushing me to liquid to see any savings.I let them know I'm residential and they said" no problem".Thinking hard, the tank venting at 2 am freaks me out concerning neighbors.

Kevin

[Firekist]

you can build a muffler, search the previous threads on liquid. a hose and some brillo pad will do.

how long a tank lasts depends on your torch, and how you work. on my beth, i was going though a 4400/180L dewar in 14 work days. i think on my mirage i'd get a few more days than that.. but again.. depending on what i'm doing. big one piece i/o sherlocks use way more gas than pendants. marbles more than sherlocks.

i've been thinking, if i put a dewar on 3 normal bathroom scales, they should be able to give the weight of a dewar without breaking... haven't put that into practice. ... but..if you can weigh it, you can see exactly what's what.

---seth

[jstnoldhippie]

Thanks you'all for responding. This confirms my thoughts. Tanks from my previous supplier (Airgas) lasted at least four weeks. It wasn't until moving and changing suppliers that I ran into the blowoff problem. I have listened to every excuse, whiling keeping my cool. Yep, like a computer with lines to read off, the weather, your not using it fast enough, whatever. I'll mention changing the pressure on the release valve to my supplier, but I think I'll be looking for a new source. Sucks that $3000 a year to one company dosn't make you a preferred customer. Today I even felt they were accusing me of lying to get a discount on the tank. I guess it does get old, as this seems to happen at least every other tank. Just another headache on the dam business aspect, I just want to blow glass dammit.:wes:

[HOSS]

I've had a lot of success keeping my tanks from venting by just adjusting the "economizer" screw. Basically it lets you adjust the max pressure that the tank is trying to build to. The oxy company people usually don't even seem to know about it, or at least won't tell you, but if it is set to a higher pressure than the relief valve, its going to vent a lot more. They look a little different from one tank to another but it is usually a bolt at the end of a bell-shaped brass thing that is connected to the pressure builder. There's a thread around here somewhere with a picture of one. Turn this screw way out, so it only builds to 100 or 200 PSI. Sometimes there are numbers on the screw that will show the pressure you're setting it to, sometimes not, but just unscrewing it most of the way is usually fine for our purposes. If the pressure goes a little too low, just screw it back in a bit, or turn on the builder. Sometime last year I started doing this with every tank as soon as it arrives, and haven't had any venting problems since.

Hope this helps, good luck!

[michaeL25]

The people at abco tell me that a 230l LOX will be empty in 3 weeks "due to evaporation" whether you use it or not. They also state that their tanks have no economizer type adjustment.

[blazemaster83]

thats some bullshit. i have a 180 liter tank and at one period i didnt get much work done, shit lasted 2 months. that was in the summer, and i remember walking out there everyday and hearing it vent. a 230 liter tank should last longer. also...see if your supplier has different pressure tanks. most are 230 psi, but i have seen ones that are 500 psi. that should help with venting as well

[misticglass]

good info nemesis.

my tank lasts about a month with 4-6 hours a day usage. seems to be the average.

[n3rd]

again Nemesis with the right answer!!

http://www.thegldg.com/forum/showpost.php?p=362654&postcount=574

[HOSS]

I originally picked up that tip from someone else here, just trying to pass it on! Seems like the kind of thing all glassblowers ought to know, but few have heard.

[n3rd]

I originally picked up that tip from someone else here, just trying to pass it on! Seems like the kind of thing all glassblowers ought to know, but few have heard.

it makes perfect sense the welding jerks don't tell you about things like the economizer, more $$$ for them. never mind the impact on the environment, stupid waste!

Nemesis' point about the economizer is a fantastic example of why this forum is one of the best tools in all of our toolboxes. welding morons prey on us not knowing a fair price for oxygen, and not knowing about things like the economizer, or how long liquid should last. "should vent after 7-10 days" is blatant misinformation, classic lies from asshole welding companies. if you use liquid right, it should never vent. set the economizer and stay ahead of the built up pressure.

great thread.

[Big Jay]

we get right at 3 weeks. But thats a mirage and a large knight. I just have to think 5 weeks would be what I'd expect running a phantom at least.