Expansion vessels play an important role in heating & cooling, solar and ACS circuits. They allow to absorb the increases of volume caused by the increase of temperature of the system, as well as to maintain the pressure of the circuit within acceptable limits, avoiding the appearance of phenomena like cavitation, evaporation and vacuum.

Bladder or diaphragm expansion vessels without mass transfer have a fixed air load. Its operating principle is based on the compression of the air chamber inside the expansion vessel when a volumetric change in the heating circuit fluid occurs due to the variation of the system temperature, maintaining system pressure within permissible limits.

Depending on the application,