Fristam has expanded its range of hygienic centrifugal and positive displacement pumps by adding pumping units with double-screw technology. Fristam’s engineers have placed emphasis on simple, robust, low maintenance design in developing the FDS pump models. The pump casing comes in three parts, consisting of an intermediate flange, the screw casing and the pump cover. This enables individual adaptation of the connections to any conceivable production system requirement, Fristam says. Central positioning of the gearwheels inside the bearing support area means the entire pump is compact. Its shaft has reinforcements in the area of critical diameters to ensure maximum rigidity. Further stability, the company adds, is achieved through a combination of large bearings and an increased bearing distance, resulting in smooth running with minimal wear. An improved lubrication system for the bearings prolongs the pump’s service life, according to Fristam, as they are immersed in oil flowing along a specifically designed circulation path. Maintenance work on the gears is facilitated by direct access to the drive system without removal of the pump. Up to nine different screws are available for each pump size to cover the entire bandwidth of possible applications, which include dairy plants. The pump is also able to transport large amounts of any low-viscosity medium such as water or liquid detergents. This dispenses with the need for an additional pump for cleaning processes. Fristam says the axial displacement principle results in extremely low pulsation even at the highest pressure ranges. The pump is easy to clean, since the mechanical seals of the FDS are positioned in fully flushed areas with constant pressure conditions, it adds.