Water Storage Tanks: Types, Uses, and How They Work

What Are Water Storage Tanks and How Do They Work?

Water storage tanks are designed to store water for a specific period and provide access when needed. When you turn on your kitchen faucet, water flows from the tank through pipes, offering instant availability. Reverse osmosis systems purify water slowly, so storage tanks connected to these systems ensure immediate access to clean water.

Water storage tanks come in various shapes and sizes for residential, commercial, and industrial applications. They range from small 5-liter reverse osmosis tanks to massive 120-liter well pressure tanks. Large outdoor atmospheric tanks can store thousands of liters of rainwater or well water, used for firefighting, irrigation, or household needs. These tanks are often equipped with UV-resistant coatings to prevent algae and bacterial growth.

How Do Water Storage Tanks Work?

Water storage tanks collect and store water from a source, such as a well or reverse osmosis system, until the tank reaches its capacity. When water is needed, the tank delivers it through pipes to the point of use, whether for drinking, bathing, irrigation, or industrial purposes.

Water storage tanks fall into two main categories: pressurized tanks and atmospheric tanks.

Pressurized Tanks

Pressurized tanks use compressed air to create water pressure inside the tank. These tanks have an air chamber or diaphragm and come with a pre-set internal pressure. As water fills the tank, it compresses the air, increasing pressure. Once the tank reaches the desired pressure, water intake stops. When a faucet is opened, the compressed air forces the water out, maintaining steady pressure. As water is used, the air expands again, reducing pressure and signaling the system to resume water intake.

Some pressurized tanks, known as constant pressure tanks, maintain stable pressure regardless of water demand. Traditional hydropneumatic tanks can lose pressure if too much water is drawn simultaneously, while constant pressure tanks use electronic sensors to maintain consistent water pressure.

Atmospheric Tanks

Atmospheric tanks do not use air chambers or diaphragms. Instead, they store water at ambient pressure, which is the natural pressure of their surroundings. Since they lack pressurization, a booster pump is often required to distribute water throughout a home or business. These tanks are widely used for agricultural irrigation, rainwater collection, fire suppression, and chemical storage.

Atmospheric tanks are typically larger than pressurized tanks and are designed to withstand outdoor conditions. Some are equipped with UV-resistant materials to prevent algae growth and contamination. Additionally, they can be used for storing various liquids, including chemicals and fuels.

Why Are Water Storage Tanks Elevated?

Atmospheric water storage tanks are often elevated to naturally generate water pressure. Gravity causes water to gain pressure as it flows downward. Municipal water towers function on this principle. Water is pumped into the tower, and its height allows it to deliver high-pressure water to homes and businesses. A similar effect can be achieved by placing an atmospheric tank at a higher elevation near your home.

What Are Underground Water Storage Tanks?

Underground water storage tanks, commonly known as cisterns, safely store potable water, rainwater, or wastewater below ground. These tanks are typically made of ribbed plastic resin to withstand soil pressure. It is essential not to completely drain a cistern, as the water inside helps balance external soil pressure, preventing deformation.

Rainwater collection systems can be integrated with cisterns, channeling rainwater from rooftops into underground storage. This is a practical solution for regions with poor groundwater quality or limited municipal water supply. In some mining towns, rainwater harvesting is a preferred alternative due to groundwater contamination.

Uses of Water Storage Tanks

Water storage tanks serve a variety of applications:

• Residential Use: Drinking water storage, pressurized water supply

• Commercial Use: Restaurants, cafes, food processing facilities

• Agricultural Use: Irrigation systems, livestock water supply

• Industrial & Fire Safety: Manufacturing plants, fire suppression systems

Selecting the right tank depends on water consumption, intended use, and water source. Choosing the appropriate storage capacity ensures a reliable and efficient water supply tailored to your needs.