SEPARPRESS hydraulic system for prep chromatographic columns. Used to compress the piston inside the column and to compact the sorbent. Supplied as a kit that includes a hydraulic double-action cylinder (D) or with a spring (S), connecting hoses, oil pump - manual (M) or driven by motor (E), with a control device mechanical manometer (M) or an electronic system with a pressure gauge (E). Small single-action cylinders are not able to pull a column piston out of the tube, so liquid pressure has to be used instead. Bigger cylinders (D30 +) are delivered only with an electric oil pump since a high oil-flow rate is necessary. All EE systems can be modified to be used in hazardous environments.