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Posted: Sat Jan 03, 2009 9:27 am
by ALIHISGREAT
... but 100 bar is 1450 psi?!?! and you've tested it to 1000?

Posted: Sat Jan 03, 2009 9:38 am
by maggotman
this is with it being fed compressed air

on its owen it wouldent go more than 1000
but with being fed air like i just done this morning i got it up to 1800psi then it went pop and i have now just cut it open to see what failed on it

read the post at the top of this page

Posted: Sat Jan 03, 2009 9:42 am
by john bunsenburner
A fride compressor is 90% of the time a scroll pump...

Posted: Sat Jan 03, 2009 9:45 am
by ALIHISGREAT
oh my mistake! where did you get the pump from?

Posted: Sat Jan 03, 2009 10:24 am
by maggotman
A fride compressor is 90% of the time a scroll pump...


scroll pumps are onleay used on large air con units have you ever seen how expensive a scroll compressor is like one for air tools

near were i live there is a house letting agency and thay always have friges and the crap pepole leave behin when thay move

the fail was due to an internal gasket ripping not surprised at 1800psi lol

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the case is about 3mm thick

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not sure if you can see in the pic but notice the blueing of the reed valve

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the missing pice of the gasket is wear it blew out

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Posted: Sat Jan 03, 2009 1:47 pm
by john bunsenburner
sorry, for my mistake your compressor is obviously piston operated, though i still doubt you should take it that high...What is the brand?

Posted: Sat Jan 03, 2009 1:48 pm
by POLAND_SPUD
so it turned out it is possible to increase output pressure by supplying pressurised air to the air inlet...

does it increase flow as well ??


I must say I am really surprised that you managed to get 1000 psi with just a fridge compressor itself... I've never tried to get more than 600 psi but you managed to get 3 times that...

well I hope you know it's not the safest thing to do and that an average spudder can't even use such pressures safely becasue most easily available materials are rated to much lower pressures...
I wouldn't feel safe using a 1/2" malleable iron fittings and pipes at anything above 1000 psi or even 600 psi

I hope you are fully aware how dangerous it is and you will normally use lower pressures...

but overall I appreciate that you tested the idea and I am really really impressed with the results.... KUDOZZZ :wink:

Posted: Sat Jan 03, 2009 2:42 pm
by maggotman
i would never think of using a copper gun at them pressures unless it was made to take them

Posted: Sat Jan 03, 2009 2:49 pm
by Gippeto
It would seem that your case was not pressurized. I wonder if I got it figured backward when I dissected mine.

Seems likely at this point.

I'm amazed at how much lighter yours was built though.

Makes me wonder what mine would have done. Ah well, I turfed it so it doesn't matter.

Sorry you buggered your compressor, but I appreciate you sharing the results.

Out of curiosity, can you measure the bore and stroke on yours and post them?

Thanks.

Posted: Sat Jan 03, 2009 3:11 pm
by maggotman
bore is 20.50 mm
stroke is 16.50mm

the last one i tore apart was alot bigger and more heaver made but woud not reach above as much pressur this one is not very old or had much use buy the look of it still has got honing marks on the barrel

the onleay reason i wouldent put them in series is i wouldn't trust the case
if the cases. if were stronger i reckon you coud probably get 3000psi witch is liquid pressure i think

Posted: Sat Jan 03, 2009 7:27 pm
by rp181
now that ive seen what pressure's youve reached, im gonna have to read the thread =p
Hows lubrication?

Posted: Sat Jan 03, 2009 9:02 pm
by maggotman
"Hows lubrication?"
im not sure what you mean

Posted: Sun Jan 04, 2009 12:52 am
by D_Hall
Gippeto wrote:You want the easy way? :)

Here ya go. Scroll to the bottom.

http://www.engineersedge.com/calculator ... t_calc.htm
Note: The equations listed on that page are NOT ACCURATE FOR ALL SYSTEMS. They are the classic "thin walled vessel" equations. Basically, if your wall thickness is 1/10 of your diameter or less, they're really friggin' close. As your wall thickness increases, the accuracy of the equations decreases. And worse, they indicate burst pressures that are higher than the actual burst pressures.

Posted: Sun Jan 04, 2009 12:59 am
by D_Hall
Oh, and the OP might want to look up something called "critical temperature."

Short version: Unless you want to go cryo, you'll NEVER liquify air. Or... If you do, prepare your Nobel Prize acceptance speech because you will almost certainly be giving it.

Posted: Sun Jan 04, 2009 10:56 am
by maggotman
what do divers breathe then ?