paisuntasäiliöön

Paisuntasäiliö, often translated as expansion tank or surge tank, is a vital component in closed-loop hydronic heating and cooling systems. Its primary function is to accommodate the natural expansion and contraction of water as it changes temperature. When water is heated, it increases in volume. Without a mechanism to absorb this excess volume, the pressure within the system would rise dramatically, potentially leading to damage of pipes, fittings, or even the boiler or chiller itself. Conversely, as the water cools, it contracts, and the paisuntasäiliö helps maintain adequate system pressure, preventing air from entering the system.

A typical paisuntasäiliö consists of a sealed tank, usually made of steel or stainless steel, divided into two chambers by a flexible diaphragm or bladder. One chamber is connected to the heating or cooling system and contains the system water. The other chamber is pre-charged with air or an inert gas at a specific pressure, acting as a pneumatic cushion. As the system water expands, it pushes against the diaphragm, compressing the gas. When the water cools and contracts, the compressed gas expands, pushing the water back into the system and maintaining stable pressure. The correct sizing and pre-charge pressure of the paisuntasäiliö are crucial for its effective operation and are determined by factors such as system volume, temperature range, and maximum operating pressure.