# How long to fill a 12,000 gal tank with 5psi of air

by Al
(Boston,Ma )

I have to test an underground tank 12,000 gal with 5psi of air for a test. I only have a typical dewalt 5.0 cfm at 90psi and 160psi max out of my 110 v. Air compressor. How long would it take to fill that 12,000 gal tank with air. Thank you

### Comments for How long to fill a 12,000 gal tank with 5psi of air

 Feb 06, 2015 Filling a large tank by: Doug in s.d.ca A test at only 5 PSI? Hmm. Anyway:12,000 gallons to 5 PSI(g) at 5 CFM is the question, apparently.12,000 Gal = 1604.17 cubic feet, per google.5 PSI = 0.344737865 bar (google)0.344737865 * 1604.17 = 553.018140897 Cu Ft of air.Rounding off a bit, we get553cf / 5 cfm = 111 Minutes or nearly 2 hours.That assumes continuous run, and that the temperature of the air going into the pump is about the same as the ambient in the tank.It might hit 5 PSI sooner, but the tank will likely be cooler, so you'll lose pressure as the air cools.Most likely your compressor rated 50 percent duty cycle, so you'll want to put it on a timer or something so it runs maybe 15min on then 15min off, for nearly 4 hours.