I just purchased a new bladder tank and its not filling with water how do u get water in it?

A bladder tank does not fill up with water. The bladder is located at the upper portion of tank.There is air in that section that is compressed until the shut off pressure is reached. The reading at the tank should be the same as or close to the pressure of the shut off pressure.

To set the pressure in tank, system has to be shut off and the tank drained. Then take a reading at the air valve on top of tank. It should be set 2 PSI lower then shut of PSI. If shut off pressure is set at 30PSI then tank is set at 28PSI.

Chuck

Another great answer Chuck!
Lexy, Let me show you how a bladder tank operates. Good luck, Tom