Circulator pump

Circulator pumps are centrifugal pumps, which maintain a forced circulation of the heated fluid handled in hot-water heating systems whose geodetic head is insufficient for ensuring an appropriate natural circulation velocity based on density differences (thermosyphon effect).

Forced circulation means that smaller pipe diameters can be used, keeping system costs down compared to natural circulation systems (e.g. gravity heating).

Small circulator pumps up to approximately 2.5 kW are driven by canned motors (see Canned motor pump) This ensures absolute tightness in the area of the circulator pump. See Fig. 1 Circulator pump

Large circulator pumps are designed as in-line pumps with mechanical seals. See Fig. 2 Circulator pump

If a stand-by pump is required for reasons of reliability or comfort, twin pumps can also be employed as circulator pumps. See Fig. 3 Circulator pump