Dewar problems

[CitizenNot]

i had a tank delivered today and all i did was throw my reg on, i'm too busy to work until tonight. The tank started venting every five minutes, and the whole tank is frosty like i've been working for hours. The pressure gauge was at 50 when it got here and it reached 250 in a matter of hours just sitting there. i was thinking it was because it was on the truck in the cold weather and then came into my shop which is alittle warmer, but i've never seen a tank do this before.

just trying to see if anyone knew what was up with it before i called the welding shop.

[jes]

check to make sure the (pressure building) valve is closed all the way if its cracked a little it can build pressure....also if you ordered the tank and they filled it a couple days ago it could possibly start venting.... I write the serial number to all the tanks I get and write next to them their performance. a, b,c,d,f, scale. I want all good tanks but sometimes they will send one that isnt up to par and keeping track only takes a little bit of time and is a way to show the company you deal with that this is serious because of $$$$$$$$ and gives them feedback on their tanks as well...any tank that isnt up to par you may be able to get reinbersed or partially... if its not your fault and the tank was not doing what it should be doing.... hope this helps you can email me or ask for # and talk too. MUCH PEACE, :-j es

[n3rd]

definitely sounds like pressure builder could be open, check the economizer next to it also, if it has one.

[CitizenNot]

thanks. i always check the pressure builder because i usually have to turn it on when i get a new tank but this ones building pressure faster than any tank i've every had. it's vented about 5 times since i've made this thread. i think i'll start writing the serial numbers down.

[Mr. Whale dick]

tuen that little screw by the pressure builder counter clockwise? i think...

[Doc Holliday]

I loosen the screw all the way out and turn on the pressure builder when I need more gas...

[Dom]

Most likely you got a bad tank. Call your supplier. Until then work off as much as you can as it should be free for the next one.

[CitizenNot]

i talked to them and i should get credit. it looks like the screw is all the way out already, and they put some kinda shrink wrap plastic over it so you can't mess with it. It's driving me crazy venting every 5 minutes and the vent is starting to freeze over.

these assholes have three tanks that are not the new ones that are stainless and i keep getting them everytime. i'm about to tell them if they keep sending them to me i'm not accepting it.

couple more days of this shit and i'm dragging it outside and blowing all the 02 out...haha

dude it just vented three times while writing this post

[chayes]

I used to get one particular bad tank every once in a while, always the same tank same problem. Told em about it they never fixed it. So one day I wrote in big black permanent marker on the side of the tank. THIS TANK IS BAD. Never saw it again.

[ALIEN!]

atta boy Chayes!

[CitizenNot]

is it safe to take it outside and open the vent? i opened it twice to take some pressure off it but it won't drop below 200.

[LifeGlass]

what a fuckin hassle, I still use t's by the fukin dozen, cause my guy has the shittiest liq's you have ever seen.

Peace write on that shit like Chayes, good Luck with it.

[CitizenNot]

yeah it figures i'v been outta 02 for weeks because of the snow and now this shit. i think i will write on it.

[CitizenNot]

well it's down to about every two minutes and it openes up.

[Dom]

Start using it then dude. Do some tube pulls or some huge iso pieces or something that will take alot of heat. Maybe some 3 inch marbles.

[CitizenNot]

i'm trying to burn off pressure but this shit ain't safe. my tank sits about 5 feet away from me and it vented with i was working and the shit blew my flame sideways....FUCK THAT! shits going outside.

I"m tagging this tank so noone else gets it, thanks for the tip chris

[CitizenNot]

is it possible to over fill a dewar? goddamn i dumped a shit ton of 02 outta this thing and it's still going.

bitches better give me two credits!

[Racer X]

For one, you need a high pressure dewar. Most of the ones in the Pittsburgh area are used for tons of fast use (cutting, dumping contents) and are pretty crappy. They mostly have a low knock off on them too. See if they can get you something more appropriate for your use.

[CitizenNot]

word thanks Rex.

[Greymatter Glass]

Sounds like the vacuum is shot on the tank - nothing you can fix.

Also, check to make sure the tank pressure is at or very near the rated vent pressure - it's also possible the relief valve is broken/stuck. If the tank is venting at more than 20-30 psi lower than it's rated that could be the problem. If the valve is frozen dump some hot water on it, if it's not frozen over, but still stuck tap it with a wrench or screw driver lightly.

The only low pressure dewars I have seen are 22psi, never seen one sold to an industrial customer here. Most are 250, some are 350, I lucked out and found a 500 psi tank.

if it vents into your flame turn its vent away from your torch... easy.


And you cannot "over fill" a liquid tank. most places fill by weight which leaves a larger head space to build pressure in, but even a saturated dewer (filled to 100% capacity) shouldn't vent that often. You could open the liquid port (outside!) and drain out a few liters, see if that helps... but I doubt it will.

I would make note of the serial number, report the problem, and let the owner test the tank. If it's bad they should offer you a credit. If you get that tank again and they haven't fixed it then you should probably mark it - but as you don't own the tank marking it in any permanent way now might open up a whole new can of worms.

And put your pants on when they deliver the tank - they'll take you more seriously. Seriously.

-Doug

[CitizenNot]

nobody said i had to wear pants damnit

[dnug42]

i had a similar thing happon with my second lox tank- i was like fuc what did i do now...it was spewing out liguid and jus frosting up out the valve next to vent- i called gas folkes and he said sometime valves go on them...So he said to open valve up that was leaking and close it back down tight as possible- so it helped but i lost alot of liquid..they said they would replace...But greatly helpful post- i am going to write down numbers on tank for sure- really good idea- anyhow- how long are these puppies lasting people-? my last one was close to 2 months....and ah what about the larger size? anyone use those? i got the LT230- i was told that there is a biggers size with casters on the bottom...hummmm
goldy

[Racer X]

First step, go to Pants'nat. Second step, find out who you can get gas from. Sky isn't cheap, I don't know who else is in Pittsburgh. Like I said, if you feel adventurous, call Chris Clarke down at the glass center and see who delivers theirs. I know Sky mostly does outlying areas, maybe some Pittsburgh deliveries, I would get quotes from a few before you make any decisions and explain the difficulties that you are having.

[FiredDesires]

I'm so pissed off with my tank right now, I got it last Friday and tomorrow it will be empty...the regulator or something is stuck and all the oxy is venting out in a steady stream. I ran hard with two torches for 4hrs, got the pressure down to 160 and it STILL was hissing...sheesh. Talked to the supplier, long distance in Seattle, he had me do the warm water thing...still nothing. He's crediting me a tank, but that's just the oxy. I've lost tank rental and the barging fees up and back so I'm not real happy. I'm torching like a mad woman full boar from 10-6 trying to get some product to show for it. Yes, it was me back in Sept. that had a very bad tank, some of you might remember, I showed pics etc. and got excellent advice/info from the peeps here.
I'm seriously getting so fed up with the expense/wait of these tanks but at 80.00per greenie? I'm screwed anyway I go...when they (the LOXs) are good...they're a dream, when they're bad...it sucks worse than you can imagine. I need 8k to end all of these woes, lol.
Citizen, you have my sympathies for sure..but it could be soooo much worse!

[CitizenNot]

well a new tank should be here any minute, but if it's another old one i'm telling the driver to take it back and i'll fill my k tank

[FiredDesires]

I'll keep my fingers crossed for you Citizen...I've been eyeing the thread about the oxygen filling systems..pretty interesting.....hummm, for 2 yrs I've been looking at an industrial system at a cost of 8K, now I see there are more options ... yeehaw! My new tank will be here Monday, and I hope it turns out to be a good one.

[Skye Perry]

is it possible to over fill a dewar? goddamn i dumped a shit ton of 02 outta this thing and it's still going.

bitches better give me two credits!
Its is not possible to overfill these tanks .But when they fill them they mix nitrogen in with it to create pressure lox alone can not create pressure they have to mix it with nitrogen .It was over mixed and that is why it is pressurizing like crazy .I have one right now that is undermixed and the day i got it I could only get 18 psi out of it and I had to turn on the builder on a brand new tank .I don't know how many people you have working on your dewar but i would rage the hell out of it or a couple days and that should slow its venting to a minimum if not stop it all together .

[byron3]

..... .But when they fill them they mix nitrogen in with it to create pressure lox alone can not create pressure they have to mix it with nitrogen .

Where did this information come from? National Welders Supply states typical purity of liquid oxygen is 99.5%. How much nitrogen do you think they mix in? What do you base this info on?

[CitizenNot]

well the tank was empty in just over 24 hours. they were late bringing me another tank this morning and when it got here i looked on the truck and what did i see, another shitty rusty old tank. told the driver dont even bother i didn't want it.

i called and talked to the VP of the company and complained, told him i was gonna take my buisness elsewhere if they couldn't take care of this problem. i've been giving these assholes money for 5 years well see what they bring me monday. guess i gotta drag out the k tank for the weekend.

[Greymatter Glass]

...when they fill them they mix nitrogen in with it to create pressure lox alone can not create pressure they have to mix it with nitrogen...

Wow Skye, that's really not true.

Who on Earth told you that nonsense? I'd straighten them out if I were you.

FWIW, all cryogenic liquid gasses will build pressure on their own. It's the nature of the beast, that's why all liquid tanks have a pressure relief on them.

[Skye Perry]

Wow Skye, that's really not true.

Who on Earth told you that nonsense? I'd straighten them out if I were you.

FWIW, all cryogenic liquid gasses will build pressure on their own. It's the nature of the beast, that's why all liquid tanks have a pressure relief on them.
This is what i was told by an old shop mate .If this is not true I appologize to all of you for the misinformation . I am not one to spread rumors so know I kinda feel like and ass.

[Greymatter Glass]

naw, the one who should feel like an ass is your old shopmate. Great thing about the Internet is misinformation is harder to spread before it gets called out.

The down side is it's a lot easier to initiate misinformation, but thankfully it doesn't make it too far.

[CitizenNot]

ok so i finally got a good tank but i'm pretty damn sure it's half full. it's a 196 which is bigger than the other tank i had i think(it was an old one GP45?) well i called them on it and they told me it was full because they fill them until they spew back out? Uhhh....don't they fill them by weight. these fucking people must think i'm retarted or something. the gauge on the top says it's only half full. can i tell by the frost on the side how much is in it when i start working on it?

well i think this is the last tank i'm ordering from them and i might just file my remaining balance i have in the trash can...haha

[Dom]

The gauge on top is not always right Ive gotten plenty of full tanks that the gauge only read half full.
Best way to check how full is it is to try to rock it. Put one hand on it and try to lean it in your direction using only your body weight. When its full I can just barely nudge it.

[CitizenNot]

i know the gauges don't always work. i can barely move em when there full, but i was not here when it came, just my wife. i tilted it when i got home and instantly knew it wasn't full.

[Chris Juedemann]

I call and tell them it's a bad tank.

Chris

[CitizenNot]

or just send it back empty covered in vasoline

[Chris Juedemann]

or just send it back empty covered in vasoline

Go get 'em, Abbie Hoffman.

Chris

[Sebastian]

blah blah blah

[Chris Juedemann]

jah jah jah

:chilling:

[Greymatter Glass]

some places fill by weight, others saturate them till liquid spews out the vent port.

[full_kiln]

some places fill by weight, others saturate them till liquid spews out the vent port.

thats what she said