New air tank / Compressor recommendations

So this past week i saw a air tank at an auction and picked it up for 65 bucks
its a 20 gallon 175 psi industrial air tank before i had a 3 gallon tank . The tank is really nice and pressure never drops under 110psi but it does tank a long time to fill it back up to 145. I have the equivalent to a viair 350c and was wondering what would be a good set up for that tank. I was thinking maybe 444c duals or 380c duals. also would i have to run a wire from the battery to the second compressor relay or could i piggy back off the original power wire to the second relay.

thanks here’s a pic of the new tank

Great find at that price. It looks like a nice sturdy old unit but I’d still get it pressure tested to make sure it won’t fail on you. That much air can be a serious hazard.

As to compressors - tank that size needs an EDC or an Oasis. Any 12V compressor from Viair will only fill up to 5 gallons (per compressor) to stay within warranty limitations.

the tank was certified last year by the company that sold it there was a tag on it and the max psi will never probably get over 145 psi.

An Oasis can fill it from 0 to 150 PSI in about 3.5 minutes.

I would think that you would need a deep cycle battery or two of them plus heavy alternator also? I always used big-rig engine water-cooled, belt-driven 2-cylinder compressors. Running at highway speeds these would fill a 60 gallon tank from 0 - 145PSI in only a few minutes. Great for blowing the real big horns. This Cummins 500 compressor is like the one I used, but was belt-drive, not direct drive.

^^ Haha, that thing looks like a trans axle.

OP - Great find. I agree about the Oasis or some sort of EDC. It will take a bank of the smaller 12v compressors that cost about the same, consume similar amperage, and busy up the wiring and plumbing. Ask me how I know.

Hahahahaha!! Some like this one have their own oil sump. Others used your engine’s oil, pumped up from the engine’s sump. I always used those with their own sump and kept their oil changed for superior performance and no oil in the lines, plus I had bottom mounted drains on my receiver and high capacity flow-through air filters in the airline to the valve, also with moisture drains for the cleanest air possible.

TRAIN RANGER: Looking at your new receiver, I saw the tag, but could not read it. I am assuming that it is ASME coded? Yes, you should get it hydro-statically tested. This is the safe way to test the rigidity and safety of an air receiver. If your tank were to suddenly burst at 145lbs of compressed air, then it would be like a bomb and easily totally destroy your car or truck and kill you in the process.

Hydro-static testing is safe. Your tank is filled with water under pressure until it reaches the receiver’s maximum rating. Then it is compressed 10% higher. Should the tank suddenly burst, it would just crack open and the water come out, no explosion, because the compressed water is not stored energy like air is.

If ASME code, there will be a bottom port on the tank. Install a globe valve on the bottom and use it to drain the tank at least daily if heavily used, weekly if light use, and your discretion for occasional use. With that big twenty gallon tank you can get blows out of the biggest locomotive horns like the mighty M5 or Leslie S5T/RS5T. Good luck!!!

Nathanh5-- yes it is ASME codded and when i bought it they said they had tested it before they put it in the auction. also after getting it i did pressure test at our shop. And yes its loads of fun now having 20 gallons