Abstract: An assembly with hydrocyclones comprising: multiple hydrocyclones having a inlet chamber with two side openings positioned on opposite sides of the inlet chamber and a overflow chamber having two side openings positioned on opposite sides of the overflow chamber. The hydrocyclones are arranged at a support structure, comprising a support bar for support of the hydrocyclones. The hydrocyclones being arranged side by side with their side openings adjacent each other thus forming an inlet pipe by means of the inlet chambers and an overflow pipe by means of the overflow chambers. The inlet chambers and the overflow chambers being adapted to be pressed against each other respectively. The hydrocyclones being arranged in pairs with one of the two hydrocyclones arranged on one side of the support bar and the other on the opposite sides thereof.