Abstract: A screen basket for filtering an aqueous fiber suspension includes a cylindrical foraminous filter element, anchoring collars surrounding and fixed to opposite ends of the filter element, at least two support rings surrounding the filter element, and support rods for adjusting the support rings between axially contracted positions disengaged from the anchoring collars, and axially expanded positions engaging the anchoring collars and axially tensioning the filter element. In a first embodiment, the anchoring collars are relatively flexible. This allows the anchoring collars to be deformed for insertion of the cylindrical foraminous filter element within the support rings. Alternatively, the upper and lower support rings are divided into segments that are easily disassembled and reassembled to facilitate removal of a defective cylindrical foraminous filter element and installation of a new filter element.