Scuba compressor inquirey???

[lucky joe]

Hi everyone,

I am a new member here...I am a newly graduated engineer who enjoys a good dive every now and again. Now that i have escaped varsity, i will hopefully have the cash to dive more often. Anyway...the question i would like to ask is:

how does the average scuba compressor work?
Is it a single acting piston with a long stroke...or dual acting with a large bore...???

I am familiar with cylinder type compressors of the dual action and two stage type and would like to know how scuba compressors differ. Which is more efficient? and what sort of power rating is needed to obtain 34.5 MPa (approx 345 bar)

Yes yes i know that home built compressors are dangerous...and i am not contemplating iteyebrow So if any technically minded people could help me out with some info on this topic...or industry contacts...i would be soooooooo grateful.

Thanks

 

[wedivebc]

My compressor is 3 stage with 3 separate cylinder and intercooling between stages. It is rated at 7 cfm and any of the larger ones I've seen are 4 stage.

 

[rcontrera]

It takes a lot of oomph to get ambient air to 3000 psi or higher so a single stage air compressor would either have to be huge or so slow that it would be useless. Plus with only one cylinder, the heat buildup would be horrendous!

Mine is a four stage compact model (about 80 pounds) that pumps about 3 SCFM and stays fairly cool.