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Posted: Sun Jan 04, 2009 11:11 am
by ALIHISGREAT
maggotman wrote:what do divers breathe then ?
an oxygen nitrogen mix i do believe.

Posted: Sun Jan 04, 2009 11:55 am
by jrrdw
No more double posting! If I see it again, I'm locking this thread.

Posted: Sun Jan 04, 2009 1:03 pm
by SpudBlaster15
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Posted: Sun Jan 04, 2009 4:27 pm
by D_Hall
maggotman wrote:what do divers breathe then ?
Air. But it isn't liquified. 'Tis merely compressed.

Or if they like going deep, Oxygen + Helium. But again, 'tis merely compressed; no liquification.

Posted: Sun Jan 04, 2009 4:33 pm
by maggotman
thanks thats what i was getting confused with i always thaught it was compressed so much it was a liquid like bottled gas

Posted: Sun Jan 04, 2009 5:05 pm
by Daltonultra
LOX isn't really that hard to make, but doing it with straight compression is the next best thing to impossible. Besides that, if a diver used a tank of LOX stored at room temperature, the heat lost during decompression to a pressure usable for breathing would freeze his lungs solid.

http://www.allatoms.com/LOXpage.htm

Still, I am incredibly impressed by the pressures you got out of that thing. I wouldn't have thought it could manage half of that.

Posted: Sun Jan 04, 2009 5:12 pm
by maggotman
if that gasgit dient fail i recon it would have got alot higher pressurs

Posted: Sun Jan 04, 2009 5:29 pm
by john bunsenburner
As i asked earlyer, do you know the brand name of you fridge, or just the compressor? I am starting to want one!

Posted: Sun Jan 04, 2009 5:52 pm
by maggotman
i think it was a lg one

Posted: Sun Jan 04, 2009 6:27 pm
by POLAND_SPUD
the thing is that it's not exactly the best idea to use it to get 1800 psi... yet you want to get even more...

I 've never reached a point where mine would just stop or break down becasue it couldn't go higher... I've been trying to use reasonable pressures with it and my reasoning here is simple - it's was not designed as a cheap source of high pressure and as such it should be used resonably. Morover I don't have parts and materials to use higher pressures than I achieve with it now


the most important thing here is that your fridge compressor has broken down at 1800 psi..so now you don't have a fridge compressor, do you ?? I suppose something would fail in it anyway after sometime even if you used it at slightly lower pressures, let say at 1500 psi...

it's exactly the same with 1000 psi that you achieved with just the compressor itself (so without feeding pressurised air to the air inlet) - you say it couldn't go any higher. Obviously this does not mean that fridge compressors are a good source of 1000 psi - normally you don't put max load on any device


at first I was impressed with your results but now I see that this thread might be potentially dangerous....first of all,if you write that you have achieved 1800 psi that's ok but at the same time it 'makes' an impression that 1500 psi would be safe to use.
secondly,there are different types of fridge compressors and you don't know how well they are built or how much they can handle


don't get me wrong I am not flaming you but you seem to be pushing limits a little bit too far... even if you are taking some safety precautions that does not mean anyone who read your thread will do so...

you can even dig a hole and put a fridge compressor there but still you can't just write 'oh I've achieved 1800 psi with it and I think it could get more' for me it's more less the same as if someone wrote 'I've built a 2X hybrid from DWV PVC and I think it could handle more' or something like that... in fact fridge compressors are similar to DWV in a way that you can never tell at what pressur they will fail - some might be good to more than 2000 some may fail at 800 psi

anyway, if someone gets injured becasue of this it's not going to help spuddign community at all

Posted: Sun Jan 04, 2009 7:39 pm
by maggotman
fair point

also remember im not storing the air. I don't ever plan on using 1800psi in a launcher. if the pump did fail its enclosed in a 3mm thick steel case
ther would not be much of stored energy not more than 3 cm3 of air
and im not telling people to do this

Posted: Sun Jan 04, 2009 8:31 pm
by CasinoVanart
Nice results maggotman, thankyou for sharing them :) Now i recommend that you make a nice small piston pneumatic that can handle around 1000psi, that WOULD be fun!!

Posted: Mon Jan 05, 2009 12:16 am
by D_Hall
Daltonultra wrote:LOX isn't really that hard to make, but doing it with straight compression is impossible.
Fixed your post.

Posted: Mon Jan 05, 2009 2:08 am
by john bunsenburner
Are you sure of that D_hall? Plainly theoretically speaking, it should be possible, though i am guessign it is not very practical or we would be using it(we as in humanity) :?:

Posted: Mon Jan 05, 2009 6:42 am
by maggotman
CasinoVanart wrote:Nice results maggotman, thankyou for sharing them :) Now i recommend that you make a nice small piston pneumatic that can handle around 1000psi, that WOULD be fun!!
i was thinking a nice coaxel for simplicity
i will have to se what s steel i can get hold of