laajenemissäiliötä

Laajenemissäiliö, known in English as an expansion tank or expansion vessel, is a crucial component in many closed-loop heating and cooling systems. Its primary function is to accommodate the natural expansion and contraction of the fluid (typically water) within the system as its temperature changes. When the fluid heats up, it expands, increasing the pressure. Without an expansion tank, this pressure rise could damage system components like pipes, boilers, or radiators. The expansion tank provides a space for this excess volume, preventing dangerous pressure surges.

Conversely, when the fluid cools and contracts, the pressure within the system drops. The expansion tank helps maintain a minimum system pressure by releasing some of its stored fluid back into the loop, ensuring the pump can continue to circulate the fluid effectively and preventing issues like cavitation.

Expansion tanks are typically found in hydronic heating systems, solar thermal systems, and refrigeration circuits. They consist of a sturdy tank, often made of steel, which is divided into two compartments by a flexible diaphragm or bladder. One side of the diaphragm is connected to the heating/cooling system, while the other side contains a pre-charged air or nitrogen cushion. This air cushion acts as a spring, absorbing the pressure fluctuations caused by the fluid's volume changes. Proper pre-charge pressure and regular checks are essential for the efficient and safe operation of the expansion tank and the entire system.