When the system stops automatically or manually, it is necessary to wash with water for surface sweeping purposes in order to prevent the ions in the water remaining in the membrane sheaths from precipitating on the membrane surface and causing blockages. In addition, depending on the raw water content of the membranes, chemical washing should be carried out at certain intervals when the production flow rate starts to decrease. Chemical washing is carried out to prevent clogging of the membranes and to extend their service life. Membrane washing unit is used for these purposes. CIP tank and pump are calculated depending on the system capacity.