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Old 05-04-2009, 11:27 PM
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Default How to convert CFM@PSI to CFM@different PSI?

So this is more a brain exercise than anything else, but I'm curious and unsure how the math works.

Say you have a Davey MC1A or similar scuba/paintball compressor, that produces a hypothetical 15 CFM @ 3500 PSI. Say you ran this thru a pressure regulator to produce 100 PSI. It would be my understanding that the air expands some going from 3500 PSI to 100 PSI. But assuming this is straight multiplication exercise would suggest that it produces 525 CFM @ 100 PSI which is clearly wrong.

Going by a HP estimate, that assumes about 4 CFM @ 100 PSI per HP for an efficient compressor, this compressor is capable of producing about 64 CFM @ 100 PSI. So whats the actual conversion? Some searching hasn't produced an answer yet.
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Old 05-05-2009, 01:01 AM
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fifteen cfi at thirty five hundred pounds is a massive compressor.
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Old 05-05-2009, 08:36 AM
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Originally Posted by OLD MAN View Post
fifteen cfi at thirty five hundred pounds is a massive compressor.
I'd be willing to bet that it is 15CFH@3500psi, 15cfm would be a HUGE comp,,and require a massive amount of HP!
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Old 05-05-2009, 09:48 AM
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I suspect the specs mean 15 CFM of air at one atmosphere (on the intake side) can be compressed up to 3500 PSI at whatever volume on the output side.

Here's a little exercise in calculating volume:
http://answers.yahoo.com/question/in...1093438AAaYCun

EDIT: Possibly useful: http://www.truetex.com/aircompressors.htm
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Old 05-06-2009, 09:22 AM
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You could also play around with the information starting here:

http://www.chm.davidson.edu/Chemistr...aws/index.html
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