The hydraulic screen changers are characterized by simple design, ergonomics and rationality which they were designed. Thanks to a uniform and efficient heating system, are suitable for the processing of highly sensitive polymers. The operation in combination with a quick-change hydraulic power unit allows the replacement of the filtering media while the extruder is running. The units are equipped with a cable channel in the bottom that conveys the power cables and thermocouples in a junction box located next to the hydraulic cylinder. This prevents dangerous overheating of the electrical system, ensures maximum reliability. The many possible configurations allow a wide use of these models where perfect flow continuity during screen replacement.