# calculating compressor tank size

• posted
Does anyone have a very rough figure for the size of tank needed if you
were to connect a one inch pipe to the outlet and needed about five
seconds worth of decent flow. I know this is very vague but I am
working on a project and have been testing out friends compressors but
not with a one inch outlet just the standard quarter inch.
I am guessing that I could be looking at a tank well over 500 litres or
100 gallons in size but only a rough guess.
Thanks
• posted
" snipped-for-privacy@hotmail.com" wrote in news: snipped-for-privacy@f1g2000cwa.googlegroups.com:
Not enough info.
You can't calculate unless you have some numbers to go from. How many CFM at what pressure do you need? You gave the time. Without the other two variables, no calculation is possible.
• posted
I agree that you do not have enough information, but the site below might be helpful.
Note that at 90 psi, with an outlet of 100 feet of 1 inch pipe, the pressure drop will only be 28 pounds at 350 SCFM! (The chart stops at 350 SCFM). (In other words, if the end of the 100 foot pipe is wide open, the actual SCFM will be more than 350 SCFM). 350 SCFM is a lot of air. 5 seconds at 350 SCFM is 29 SCF, which is only 5 cubic feet at 90 PSI. My guess is that you don't need a 100 gallon air tank, that 20 gallons might be enough. Finding a 20 gallon air tank with a one inch pipe thread outlet might be a problem. My 60 gallon compressor is piped through a 1/2 inch valve, but it appears that the tank has a 2 inch outlet. A length of 6 inch pipe might have plenty of gallons for your purpose.
But of course, I don't know if 350 SCFM is enough in your application.
Richard
snipped-for-privacy@hotmail.com wrote:
• posted
Thanks for trying to assist. If I understand correctly the scfm refers to the pump filling the receiver and depending upon pump size/tank size is how long the pump operates before cutting in again. I am more interested in how long the tank will last and if I assume a typical tank has a max pressure of 150psi then I am trying to figure out how big a tank might be needed for a five second run - through a one inch pipe - say 150psi dropping to 100psi.
Thanks again
• posted
You probably will need to follow up some of the technical refs listed by other posters, but as a practical data point, 6-gallon tire bead seating tanks with 1.5" valves empty in less than a second or two. (Example pictures at