How to Set the Pressure for a Water Bladder Tank

Private residential water wells often use either captive air or an internal air bladder to maintain pressure inside a water storage tank. Either way, the pressure of the air inside the tank controls the water pressure in the system and determines when the well pump will turn on and off. Improper air pressure can cause the well pump to cycle on and off frequently, which wastes power and eventually can damage the pump through overwork. Correcting the pressure of an air bladder requires some tools and operational cycling of the water system.


Step 1

Shut off the power to the well pump.

Step 2

Drain the water system by opening a spigot at the lowest point in the system or running a hose until the tank is empty and there is no water pressure. If you have an onboard pressure gauge mounted to the pressure tank, it must read 0 pounds per square inch (PSI).

Step 3

Locate the air valve for the bladder on the water system pressure tank. The valve looks like those on a bicycle or automobile tire. Remove the cover cap of the valve.

Step 4

Press the inlet connector on the pressure gauge to the air bladder valve. Read the pressure gauge. The ideal air bladder pressure is 2 PSI below the cut-in pressure of the water system. In other words, if the system is set for a cut-in pressure of 30 PSI, the air bladder pressure should be 28 PSI.

Step 5

Add air to the air bladder by connecting your air source to the filling valve. You need a bicycle pump or air compressor to force air into the bladder. Fill the bladder the same way you would a bicycle or automobile tire. If the air bladder has too much air pressure, hold your fingernail against the small valve stem and press inward to let some air escape.

Step 6

Check the bladder pressure again with the gauge. Add or remove air as needed to reach the correct pressure setting.

Step 7

Close any open faucets. Turn on the power to the water system and allow the tank to fill with water. Open a water faucet. Run the system through a few on and off cycles to test the pressure.