Horizontal, single-stage volute casing pumps with the dimensions and nominal ratings to EN 22858 in back pull out design, with uncooled balanced mechanical seal. The series ZDN has especially been designed for the trouble free handling of hot water up to 207 °C. The back pull out design permits the removal of the complete bearing unit towards the drive side without removing the pump casing from the pipe work. If a spacer coupling is installed it is also unnecessary to disconnect the motor. Applications: The volute pumps of the series ZDN are part of the overall programme heat transfer and circutation pumps. They are primarily used for circulation of hot water in closed pipe and vessel systems. Therefore their fields of application are the energy production, the heat transport industry and here mainly in systems where hot water as heat carrier is given preference, despite its high system pressure, over oil as heat carrier. Technical Data: Flow rate: up to 600 m³/h Head: up to 90 m Speed: max. 3,600 rpm Temperature: max. 207 °C Casing pressure: up to 25 bar Shaft seal: mechanical seal Material: nodular iron