SDF Rotary Filters are semi-automatic filters: back-flush cleaning is maintained simply by opening the drain valve and rotating the filter's body a couple of times around its center-tube.
There is no need to dismantle the filter or to replace any cartridge. This advanced design provides an infinite number of self-cleaning cycles, each made by a reverse flow of clean water ("back-flush").
The SDF Rotary Filter is a permanent self-cleaning filter. No need for cartridge replacement.
A fragmentary illustration of the Rotary Filter is shown below. Dirty water flows in via the center-tube, it is circulated to the exterior of the filtration disks stack and infiltrated to the inner chamber, then the clean water flows out via the left end side of the center-tube. The rotating body is designed with internal longitudinal ribs which make twelve peripheral cells, eleven are used for filtering and one for back-flush. When the drain valve is opened a reverse flow is initiated and the dirt is washed through the back-flush cell, and then out of the drain valve. Rotation of the body sweeps the back-flush flow around all the disks, till after a couple of turns the filter is completely cleaned. The disks remain tightened at all times and the back-flush pressure is attained from the on going filtration through the eleven cells.
The SDF Rotary Filter is currently available in two sizes: