Poor packing leads to flattening the pipe Bends, so the sand to condense, obstukivaya tube from top to bottom. After filling with sand the other end of the pipe need to hammer a wooden stopper, in which must be perforated to release gases when heated. Sometimes the as a filler is used water that freezes in the pipe. For each tube, depending on its diameter and the material must be set the minimum allowable bend radius. The radius of curvature in flexible pipe-ke taken at least three pipe diameters, and length of the heated part depends on the angle of bending and pipe diameter.
If the pipe bent at an angle of 90 , then heated area, equal to four pipe diameters, and if an angle of 45 – three diameters, and so d.Pri bending the outer side pipe is pulled, and the interior is compressed. Welded pipes with a longitudinal seam is necessary to have in bending so that the seam side and outside, or it may separate. Thin-walled tubes of diameter 30 mm or more with a small radius of curvature bend only when heated with fillers. This operation is performed on prefabricated shaped inserts 14 of various sizes and profiles (174 lb). Pipe a bend with a heating, since the reheating affects the quality of the metal. When heated, you should pay attention to warm sand. We can not allow excessive overheating of individual sections, from the heated part of the tube is enough rebounds scale, in the event of overheating the tube is cooled by water. After heating the tube bends to the template are copied or manually.
At the end of flexible tube beaten out or burn out and pour the sand. Poor, loose fill pipe inadequate or uneven heating of the front flexible leads to the formation of folds or tears. Bending of copper and brass pipes.