Trailer for transporting liquids

The trailer (1) has a chassis (2) and a drawbar (4) connected to the chassis, where one of the chassis is supported by a tank (3) for receiving the liquid. The chassis has a longitudinal beam (9), which is arranged centrally, where the longitudinal beams are formed tubular. A longitudinal duct is arranged for the liquid in the tubular longitudinal beam and a pump (7) is inserted for the liquid in the longitudinal beam. The longitudinal beam is fastened to an axle assembly with a tire (6).