Adding Very Large Pressure Tank?

Would it be possible to add a 4500gal pressure tank to my system? I currently have 2 80 gal tanks which give me about 20 gal of water with the booster pump set at 40/55psi. The pump currently runs only about a minute per cycle. If I put the 4500 gal tank in-line it would give me about 700gal of water under pressure, and with a digital pressure switch, I could set the cut in at 50psi and cutout at 55. Also, this pump is supplied by a 2500 gal tank feed by its own well pump. Would this work?

Of course this will work, this is how municipality water systems are designed.

4,500 gallons of course is a real overkill, and a drawdown of 700 gallons is a bunch, but then you didn't tell us what you were trying to solve. Why change the pump pressure cycle to 50/55, if you want constant pressure use a pressure regulator.

And of course where are the CSV guys when you need them...

Rancher

The only way you get 700 gallons of draw down from a 4500 gallon pressure tank is to use the full 40 to 60 bandwidth on the pressure switch. With only a 5 PSI differential you would only get about 175 gallons from the 4500 gallon tank. If cycling is your problem, then you need a Cycle Stop Valve. A 4500 gallon pressure tank that is up to code is probably going to cost around $10,000.00. It still won’t give you the constant pressure you would get from a $90.00 CSV.

With large tanks you should have an air controls system so they operate with the same drawdown as a bladder tank.

With proper air charge for a 40 to 55 psi setting you should get about 20% drawdown, or about 32 gallons with 160 gallons of tanks. With a 4500 gallon tank that would be about 900 gallons of drawdown.

With a 50 to 55 psi setting your drawdown should be about 7% of the tank volume.

If you really need a lot of water at constant pressure, then you need to start with your requirements and get a system designed to deliver your needs. A 4500 gallon tank is probably not the best way to do it.

Appreciate the input. Thanks.