paisuntasäiliö

A paisuntasäiliö, also known as an expansion tank or expansion vessel, is a crucial component in many closed-loop water heating systems, such as those found in residential central heating. Its primary function is to safely accommodate the expansion of water as it is heated. When water is heated, its volume increases. In a sealed system, this increase in volume would lead to a significant rise in pressure, potentially damaging system components like pipes, radiators, or the boiler itself.

The paisuntasäiliö is designed to absorb this excess volume. It typically consists of a sealed tank, part of which is filled with water from the heating system and the other part with a compressible gas, usually air or nitrogen, separated by a diaphragm or bladder. As the water expands, it pushes against the diaphragm, compressing the gas. This compression absorbs the increased water volume and keeps the system pressure within safe operating limits. Conversely, when the water cools and contracts, the gas pressure pushes the water back into the system, preventing a pressure drop that could lead to air ingress or pump cavitation.

Without a properly functioning paisuntasäiliö, a closed-loop heating system would be at risk of over-pressurization and subsequent component failure. Regular inspection and maintenance, including checking the gas pressure, are important to ensure its continued effectiveness. The size of the paisuntasäiliö is calculated based on the total volume of water in the heating system and the expected temperature range.