Compressor fill time

[klaatu]

How long, approximately, should a 2 HP compressor take to fill a 50 litre tank to 8 bar, please?

 

[peterd51]

Hi,

Mine's a 2HP, 8 bar, with a 25 Litre tank and from empty it seems to take between 20 & 30 seconds to fill, although TBH I've never actually timed it.

Regards
Peter

 

[klaatu]

Mine takes exactly 3 and a half minutes, so I guess it's crap. Well, I knew that anyway.

I wondered if it was possible to work out the actual free air displacement based on that timing. 50 litres at 8 bar is 400 litres, 400/3.5 is 114 litres per minute, so almost exactly 4 cfm. That seems about right, given that the manufacturer says it's 7.34 cfm. Does any of that make sense?

Steve

 

[peterd51]

Hi,

I'm not sure...

but I bet someone else here will know how to calculate it.

Mine states something like 172 litres per minute on the side.

I vaguely recall calculating from some conversion figures on a web-site that it's about 6.3 CFM.

Maybe yours just needs a new set of 'O' rings?

Regards
Peter

 

[klaatu]

I've just noticed your plasma cutter in another thread. My compressor is from the same place!

 

[irondarren]

172 ltrs per minute. filling a 50 ltr tank to 1 bar pressure takes around takes around 17 seconds, to fill to 8 bar takes 8 times as long. 8 x 17 = 136 seconds or 2 mins 16 seconds.

one thing you have to bearing mind is manufacturers state different cfm measurements, one is displacement the other is free delivered air, on a 3hp compressor displacement is about 14.5 cfm and free delivered air is just over 10 cfm. FAD or free air delivery is the one you want to work out the fill time of the tank