system.
An expansion tank or expansion vessel is a small tank used to protect closed (not open to atmospheric pressure) water heating systems and domestic hot water systems from excessive pressure.
The tank is partially filled with air, whose compressibility cushions shock caused by water hammer and absorbs excess water pressure caused by thermal expansion.
The rubber diaphragm in modern expansion tanks prevents this undesired transfer of air, and helps maintain low levels of oxygen, reducing corrosion in the system.
The rubber diaphragm in modern expansion tanks prevents this undesired transfer of air, and helps maintain low levels of oxygen, reducing corrosion in the system.
