Simon
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| posted on 20/1/07 at 10:34 PM |
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Physics Q - water pressure/versus depth!
Peeps,
I'm gonna need to pressure test my nearly finished intercoolers, and reckon the easiest way will be to fill with water and have a tall hose.
Should be able to pressurise quite acurately and spot leaks at the same time
Question is, how much height do I need?
Cheers
ATB
Simon
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Volvorsport
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| posted on 20/1/07 at 10:38 PM |
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have you got an air compressor ?
www.dbsmotorsport.co.uk
getting dirty under a bus
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Liam
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| posted on 20/1/07 at 10:44 PM |
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Will have to be a tall hose!
It's about 100 mbar per meter, so you need 10 metres to test to 1 bar/14.5 psi.
Liam
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Simon
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| posted on 20/1/07 at 10:48 PM |
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quote:
Originally posted by Volvorsport
have you got an air compressor ? [/quote
Yep, but didn't want to accidentally chuck 130psi in i/cooler, though as Liam has mentioned (and I've just found out) I'll need a 33
foot hose, and a way of lifting it!
Looks like it'll be the electric tyre pump. Slow and steady at least!!
Cheers chaps. Plan B it is
ATB
Simon
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gazza285
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| posted on 20/1/07 at 11:14 PM |
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Have you got an air compressor with a regulator?
DO NOT PUT ON KNOB OR BOLLOCKS!
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RazMan
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| posted on 20/1/07 at 11:27 PM |
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You shouldn't need much air to get it to pressurise so a footpump with integral gauge would be safer - certainly not a compressor anyway.
Just bring it up to 25psi or so and use soapy solution around the suspect areas or dunk the whole lot in the bath when swmbo is not looking 
Cheers,
Raz
When thinking outside the box doesn't work any more, it's time to build a new box
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Wadders
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| posted on 21/1/07 at 12:49 AM |
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We dry pressure test underfloor heating installations to 3 bar with a footpump, takes a while, but not too bad. If you fill with water first it will
be easy.
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silex
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| posted on 21/1/07 at 05:18 AM |
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If I remember correctly,
Pressure = Density of Water x Gravity x Height
and I am fairly sure the density of water is 1000Kg/m^3
and opefully there will will be an engineer or physics guru along any minute to agree or disagree with that..........
Murphy's 2 laws
1. If it can go wrong it will
2. In case of emergency - refer to rule 1.
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907
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| posted on 21/1/07 at 08:33 AM |
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Hi
Block off connections bar one.
Fill it with water.
Connect the air line to the last connection.
Fire up the compressor (or foot pump) and SWITCH OFF when the compressor reaches say, 20 psi.
Hth
Paul G
p.s. I tested the output of a calor gas reg the other day with a loop of tube part filled with water. (37mb)
1mb = 10mm, so, 1bar = 10M as stated above.
[Edited on 21/1/07 by 907]
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iiyama
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| posted on 21/1/07 at 09:46 AM |
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Mains pressure is around 4-6 bar sometimes a little more. 1 bar = 10m of head, so youll get far more pressure in there using the mains! However as
others have suggested, using compressed air is probaby the best way to go.
If its broke, fix it. If it aint broke, take it apart and find out how it works!
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dave r
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| posted on 21/1/07 at 11:37 AM |
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water supply can be as low as 1 bar
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akumabito
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| posted on 21/1/07 at 02:49 PM |
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I've got a tiny 12V air compressor (used for inflating bicycle tires), which would be perfect for something like this. The gauge is reasonably
accurate, and the thing stops immediately when you release the button.
Also: if you keep it connected, you can test for tiny leaks by keeping connected for a longer period of time, the gauge will keep displaying the
pressure inside the thing, so if it shows a lower pressure after a while you know you've got a small leak somewhere..
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