Bending of thick-walled pipes
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Outer diameter 159mm, wall thickness 12mm, bending radius 1000mm. What are some good methods for bending thick-walled pipes of this type?
Our company’s approach is to compact the interior with sand, weld the ends shut, then heat the section that needs to be bent; after that, a pipe or cylinder of appropriate diameter is placed against it and bent.
Due to the large bending radius, only simple operations are required. If there is no pipe bending equipment, the pipe can be bent by filling it with sand; the purpose of using sand is to prevent the pipe from flattening out. If a manual pipe bender is available, the pipe can be bent directly
For such large thick-walled pipes, the sand filling hot bending method is generally used.
The special elbow for Line XII, made of X80 grade steel with a diameter of 1219 millimeters and a wall thickness of 22 millimeters, can be bent using an intermediate-frequency bending machine. All our factory’s thick-walled pipe fittings are processed using such equipment. The previous sand-filling pushing equipment was too cumbersome (our factory usually used alum for filling), and its quality was not as good as that of the medium-frequency type. Medium-frequency bending is recommended.
The bending radius for a φ159×12 steel pipe is 1000, so the processing is not very difficult. The original poster didn’t specify whether it was to complete a full circle or just a 90° turn. For something as simple as a 90° bend or a ring with modest requirements, the method of heating with sand can be used ； For rings with higher requirements, it is better to bend them on an intermediate-frequency heating bending machine.
For a small quantity, heating with sand without special equipment is sufficient; for larger quantities, professional bending equipment is needed.