Screen-wheel filtering apparatus for medium-to high-viscosity fluids, comprising a screen wheel which is rotatably mounted in a housing and which has at least one screen element through which flow is able to pass, wherein the housing comprises an inflow plate with at least one inflow channel, at least one intermediate plate (13, 14, 15), and an outflow plate with at least one outflow channel, wherein the plates (11, 12, 13, 14, 15) are screwed to one another via multiple threaded bolts extending through the set of mutually abutting plates (11,..., 15), and, for the threaded bolts, a pre-tension is selected such that, up to a maximum permissible operating pressure p max, all the plates (11, 12, 13, 14, 15) sealingly abut against one another by way of the contact and sealing surfaces (22, 23, 24) thereof, and a lubrication gap (25, 26) is formed in each case between an inner surface of the inflow plate and/or of the outflow plate and a sealing surface (22, 23, 24) of the screen wheel, characterized - in that, in the region of its sealing surfaces (22, 23, 24), the screen wheel has an identical height to the intermediate plate (13, 14, 15) between its contact surfaces; - in that the contact and sealing surfaces (22, 23, 24) are nitrided; - in that a gap-width-adaptation layer is inserted between the inflow plate and the at least one intermediate plate (13, 14, 15) and/or between the outflow plate and the at least one intermediate plate (13, 14, 15) and consists of a cold-rolled steel foil or steel strip, which is harder in comparison with the adjacent plates (11, 12, 13, 14, 15) and whose surface has a lower degree of roughness than the contact and sealing surfaces (22, 23, 24). wherein the plates (11, 12, 13, 14, 15) are screwed to one another via multiple threaded bolts extending through the set of mutually abutting plates (11,..., 15), and, for the threaded bolts, a pre-tension is selected such that, up to a maximum permissible operating pressure p max, all the plates (11, 12, 13, 14, 15) sealingly abut against one another by way of the contact and sealing surfaces (22, 23, 24) thereof, and a lubrication gap (25, 26) is formed in each case between an inner surface of the inflow plate and/or of the outflow plate and a sealing surface (22, 23, 24) of the screen wheel, characterized - in that, in the region of its sealing surfaces (22, 23, 24), the screen wheel has an identical height to the intermediate plate (13, 14, 15) between its contact surfaces; - in that the contact and sealing surfaces (22, 23, 24) are nitrided; - in that a gap-width-adaptation layer is inserted between the inflow plate and the at least one intermediate plate (13, 14, 15) and/or between the outflow plate and the at least one intermediate plate (13, 14, 15) and consists of a cold-rolled steel foil or steel strip, which is harder in comparison with the adjacent plates (11, 12, 13, 14, 15) and whose surface has a lower degree of roughness than the contact and sealing surfaces (22, 23, 24). - in that, in the region of its sealing surfaces (22, 23, 24), the screen wheel has an identical height to the intermediate plate (13, 14, 15) between its contact surfaces; - in that the contact and sealing surfaces (22, 23, 24) are nitrided; - in that a gap-width-adaptation layer is inserted between the inflow plate and the at least one intermediate plate (13, 14, 15) and/or between the outflow plate and the at least one intermediate plate (13, 14, 15) and consists of a cold-rolled steel foil or steel strip, which is harder in comparison with the adjacent plates (11, 12, 13, 14, 15) and whose surface has a lower degree of roughness than the contact and sealing surfaces (22, 23, 24).