Larger diameter tubes require the outer surface to be sanded to remove scale, remove surface defects and to improve the appearance of the tubes. The pipe is loaded into the machine on driven radial rollers that are placed in a catch basin. A mobile grinding unit equipped with grinding belts is ready in the parking position next to the pipe. After start-up, the grinding unit cycles along the rotating tube and grinds the material with a constant supply of coolant. The machined material is rinsed into the tub and conveyed out of the tub by a worm shaft. Water with abraded material is filtered in three stages. Magnetic filter, fabric filter and mechanical separator. The solid residues are stored in an attached pallet and the filtered water is reused for grinding.