Abstract: The invention shows pipe cleaning apparatuses for oil and gas pipelines in which a shield with a cleaning apparatus is moved forward by a liquid flow in the pipeline. The shield forms one or more apertures in the pipeline for a passing liquid flow in order to build up a predetermined pressure and is provided at its rear end with a braking apparatus which prevents undesirably large speeds of advance in that at least one clamping element adheres momentarily to the pipe wall and moves relative to the braking apparatus. This movement is kinematically transmitted to a hydraulic displacer which produces a secondary liquid flow that is braked via at least one throttle point and thus determines the speed between the shield and the pipe wall.