Air Compressor?

[Dan Thompson]

I would like to buy a drywall dexture gun that needs do deliver
7 CFM @ 25 psi.

My compressor is not rated at the low pressure so I was wondering if there is a conversion formula for a compressor rated at 100 psi.

My compressor is rated a 4.5 CFM @ 100 psi. So what should the CFM be at 25 psi for my compressor?

TIA

 

[xlr8ngn]

You may get 5 CFM because there is some blow-by when compressing to 100 PSIG, but you will not get 7 CFM. The only way to get more CFM is to increase displacement or increase RPM. You could get a compressor curve for your pump to see if you could re-sheave and speed it up, but more than likely it is already at its maximum RPM. That would also require you to get a lower range adjustable pressure switch so you don't overload the motor. Time to get a bigger compressor or run two in parallel. Your really need a lead/lag alternator panel to make two work together properly. Also, make sure you don't run any reciprocating compressor over 80% duty cycle or you will burn it up.

 

[Dan Thompson]

thanks for the reply. I guess I will just rent one when the time comes.