The first patent for hollow disc rotary pumps was registered in 1918. The hollow disc is set eccentrically on the pump shaft and guided by the diaphragm separating the suction from the delivery chambers. When the shaft rotates, the disc oscillates remaining tangent in any position to the two diametrically opposite walls of the casing, thus forming two mobile fluid-tight joints. In every position the disc is radially and axially balanced . There are no radial components which could detach the disc or press it against the casing, therefore the liquid does not tend to escape. The resultant pressure force is the same in any position so that the absorbed power amount is always uniform. The elastic device acts like a spring by keeping the disc in grazing contact with the cylindrical walls of casing, thus creating an elastic coupling between the central bearing of the disc and the shaft.


- low operating speed as best guarantee for long service life,
- adaptable for any kind of liquid, from the most fluid to the most viscous,
-  self priming operating conditions, NPSH required less than 3 meters, no foot valve is needed,
- reversible flow by operating the pump in the opposite direction,
- all mechanical seals as per API Standards could be installed to meet any process requirement.
> models: G - L - RS    pdf
> models: U   pdf