How Does a Pressure Tank on a Well Work?

Frank Whittemore

Because wells rarely have positive pressure, equipment is required to draw the water from the well. Well systems generally consist of the well itself, a pump, a pressure switch for automatic activation of the pump and a pressure tank. The pump sends water from the well to the pressure tank for temporary storage.

How Does a Pressure Tank on a Well Work?

Well System Components

The pressure tank then holds the water until it is needed in the house. Pressure tanks generally come in three different forms, those with an air-filled bladder, those with a wafer between the water and the air inside and those with no bladder or wafer at all.

How the Pressure Tank Works

In the pressure tank, compressed air bears down on the water in the tank. When a valve, such as a faucet, is turned on in the house, the pressure in the tank pushes the water out of the tank, through the plumbing and out of the faucet. The pump does not turn on until a pressure switch connected to the tank detects that the pressure has dropped to the point where more water is needed in the tank. When this occurs, the pump will activate and refill the pressure tank. When the tank is full again, the switch will then turn the pump off.

Benefits of Having a Pressure Tank

The pressure tank provides immediate access to well water without having to manually turn on the pump. The pressure tank/pressure switch combination allows the pump to operate automatically in an intermittent way, running only when needed. This also reduces the amount of time the pump is running, thereby extending the life of the pump.