How does a water storage tank work?

Water storage tanks are used domestically and in various industries to keep large quantities of water contained and healthy for several months, or even years if treated properly. Water tanks are generally made from steel or concrete, as the properties of those materials allow for water to be stored without immediate risk of corrosion and leaks. 

But you might be asking yourself how a water storage tank works?

The process isn’t quite as simple as pouring water into a box and the water staying pure and usable. This article will teach you how a storage tank works.

How does a water storage tank work?

Water storage tanks have pipes that allow water to enter the tank and another for water to exit. The pipe that allows the water to enter the tank (depending on the type of tank) could be sourcing water from mains water, rainwater, etc. The water flows into the tank and will not leave until you operate the exit pipes. 

Depending on the intended purpose of the water, you could have multiple exit pipes. Domestic and drinking water tanks have pipes that feed the water to cold-water taps and a separate set of pipes that send the water to your hot water system and taps.

There are two ways that your water could exit your storage tank, depending on the kind of tank you have. Your water could expel using pressure or the outer atmosphere of the tank. 

  • Pressure Tanks. 

Pressure tanks don’t use pumps. Instead, they compress the air around the water, which creates a large amount of pressure. The more compressed air, the greater the water pressure. This amount of stress causes the water to be forced out of the pipes when it is needed.

  • Atmospheric Tanks. 

Unlike pressure tanks, atmospheric tanks don’t use air pressurisation at all. Atmospheric tanks keep the water inside at a normal pressure, which means that pumps must be used to get the water out of the tank.

The water tank will contain a ball valve to monitor the water level and prevent overflow. One of the most common reasons for water tank overflow is a faulty ball valve. 

There needs to be a check valve connected to the water pump to ensure that the water will only flow in one direction. The check valve ensures that the water will not be sent back to the source if the tank is overflowing.

There should also be a boiler drain, which drains the tank of its water. 

Water storage tanks also use pressure switches to communicate with the water source to decide when to turn the water flow on and off.


Water storage tanks work with pipes that feed water in and out of the tank. Water is introduced through a one-way check valve.

The water expelled to the exit pipes is sent either with pumps or through monitored air pressure. This process uses pressure switches to communicate with the check valve. 

Tanks can be drained using a boiler drain, and the tank is likely to overflow if the ball valve is faulty.