Closed-loop: Motor-return is related directly to the pump-inlet. To help keep up force to the reduced pressure facet, the circuits have a demand pump (a small gear pump) that provides cooled and filtered oil towards the minimal stress aspect. Closed-loop circuits are usually used for hydrostatic transmissions in cell purposes. https://wissenfakt.de/die-10-besten-rohrbiegemaschinen-des-jahres-2024-ein-umfassender-leitfaden/