Expansion Vessels
How Expansion Tanks Work: A Device to Protect Heating and Cooling Systems
Heating and cooling systems use liquid or gas to transfer heat from one place to another. When the temperature of the liquid or gas changes, its volume also changes. This change in volume can cause pressure problems in closed systems. For example, in a heating system that consists of a boiler and radiators, the water expands as it heats up and increases the pressure in the system. This pressure can damage or burst the system. To prevent this problem, an expansion tank is used.
An expansion tank is a device that balances the thermal expansion of liquid or gas. It works in connection with the system and keeps the system pressure constant. An expansion tank has two compartments that contain air and liquid. The air compartment is filled with nitrogen, which is a compressible gas. The liquid compartment is filled with the liquid in the system. The liquid compartment is separated from the air compartment by a diaphragm. The diaphragm is made of a flexible material and moves according to the liquid pressure.
When the liquid in the system heats up, it expands and increases the pressure in the liquid compartment. This pressure pushes the diaphragm towards the air compartment and compresses the air. This way, the expansion of the liquid is stored in the air compartment and the system pressure remains constant. When the liquid in the system cools down, it shrinks and decreases the pressure in the liquid compartment. This pressure pulls the diaphragm towards the liquid compartment and expands the air. This way, the shrinkage of the liquid is compensated by the air compartment and the system pressure remains constant.
An expansion tank is available in different types for different systems. Expansion tanks for drinking water systems have a special diaphragm material to maintain the water quality. They also have a size that matches the water volume of the system. Expansion tanks for heating and cooling systems have capacities ranging from 2 liters to 8,000 liters.
An expansion tank is an essential part of gas boilers and central heating systems. It helps to adjust the pressure and volume of the system and prevents possible failures. An expansion tank has a Schrader valve (bicycle tire type valve stem) to measure the system pressure and adjust the air pressure if needed.
An expansion tank is a device that improves the performance and lifespan of heating and cooling systems. A properly selected and installed expansion tank ensures the efficient and safe operation of the system.
