A device carrying a wash-down hose and a process positioning and process control unit for process control of a wash-down hose with flushing nozzle for cleaning waste-water pipes wherein the wash-down hose is mounted on a cylindrical wash-down hose drum which wash-down drum hose has an axial length, wherein the wash-down hose has a roll out length indicated by the position of the flushing nozzle, the wash-down hose drum has a rotational position defined by the total net number of rotations plus the rotated angle of the wash-down hose drum in relation to a basis position of the wash-down hose drum, wherein the process positioning and process control unit includes a pulse emitter, a rotating direction indicator and a memory unit and: - the wash-down hose drum is equipped with the pulse emitter which pulse emitter is designed for emitting a fixed number of electrical pulses per rotation of the wash-down hose drum, - the rotating direction indicator is designed for determining a rotation direction of the wash-down hose drum, and - the memory unit is designed with an address for storing data related to the electrical pulses from the pulse emitter and for storing data from the rotating direction indicator about the rotation direction of the wash-down hose drum for determining the rotational position of the wash-down hose drum and wherein the storage of data is maintained independently from power supply to the memory unit (6,) the memory unit also includes an address for storage of data related to the dimension of the wash-down hose drum, and the dimension of the wash-down hose wherein the roll-out length of the wash down hose is determined by an algorithm that compares the rotational position of the wash-down hose drum, the dimension of the wash-down hose drum and the dimension of the wash-down hose, where the unit includes a hose guide which is designed to include at least one guide roll for positioning of the wash down hose in the wash-down hose drum's axial length, in which the at least one guide roll is movable in axial direction characterized in that the axial movement of the guide roll is carried out hydraulic by use of a hydraulic cylinder whereby the unit is adapted to control the hose guide for positioning the wash-down hose in the wash-down hose drum's axial length on the basis of the data stored in the memory unit, such that there is continuously correspondence between the axial position of the at least one guide roll and the rotational position of the wash-down hose drum. - the wash-down hose drum is equipped with the pulse emitter which pulse emitter is designed for emitting a fixed number of electrical pulses per rotation of the wash-down hose drum, - the rotating direction indicator is designed for determining a rotation direction of the wash-down hose drum, and - the memory unit is designed with an address for storing data related to the electrical pulses from the pulse emitter and for storing data from the rotating direction indicator about the rotation direction of the wash-down hose drum for determining the rotational position of the wash-down hose drum and wherein the storage of data is maintained independently from power supply to the memory unit (6,) the memory unit also includes an address for storage of data related to the dimension of the wash-down hose drum, and the dimension of the wash-down hose wherein the roll-out length of the wash down hose is determined by an algorithm that compares the rotational position of the wash-down hose drum, the dimension of the wash-down hose drum and the dimension of the wash-down hose, where the unit includes a hose guide which is designed to include at least one guide roll for positioning of the wash down hose in the wash-down hose drum's axial length, in which the at least one guide roll is movable in axial direction characterized in that the axial movement of the guide roll is carried out hydraulic by use of a hydraulic cylinder whereby the unit is adapted to control the hose guide for positioning the wash-down hose in the wash-down hose drum's axial length on the basis of the data stored in the memory unit, such that there is continuously correspondence between the axial position of the at least one guide roll and the rotational position of the wash-down hose drum.