The circulating pumps GHN, GHND-R with three rpm options are suitable for circulating hot or cold water in heating and ventilating systems requiring forced water circulation. The use of type GHND-R is recommended for ensuring absolute operational reliability provided by alternate operation of the two units in the pumping set. Flow max. to 70.2 m3/h, pressure max. to 11 m WC. Allowable operation temperature up to 110°C.