The storage calorifier (U-tube bundle) is an indirect heating system that produces hot water through thermal storage. It is commonly used together with boilers and other high-temperature heat sources. The storage water heater uses a removable U-tube bundle with flange connections for convenient installation, maintenance, and cleaning. It is suitable for large-scale domestic hot water systems and central heating systems that require continuous hot water supply under demanding operating conditions.

High-temperature heating media enters the U-tube bundle inside the calorifier and transfers heat to the cold water surrounding the tube bundle. The heated water is stored inside the large-capacity tank, which is equipped with a 50 mm high-performance insulation layer to reduce heat loss. During peak water demand periods, the stored hot water is supplied directly to the system to maintain stable temperature output. Unused return water from the circulation system mixes with incoming cold water and returns to the heating section for reheating. This circulation process maintains thermal storage and supports continuous hot water supply for large-scale systems.