So, what is the Process of Induction Bending or Pipe Bending?
BendTec built its first induction bending machine in 1972 and has bent curved or bent pipe since 1973. Today, BendTec is one of the leading pipes bending and fabrication companies in the Western Hemisphere.
But what exactly is induction or pipe bending? What does it consist of?
The Induction bending process is as much a heat-treating process as it is a bending process.
This is how induction bending works: Our experts place a piece of pipe, tube or structural shape through an electric induction heating coil that has an alternating current inside of it, while simultaneously applying a bending force to the heated narrow band. This heats a narrow band around it to a temperature of about 1,800 degrees Fahrenheit.
That process creates a magnetic field. If the workpiece conducts electricity and produces sufficient electrical resistance to the magnetic field, it will generate heat. We can control that heat in small, localized areas.
This means your piece of steel has minimized thinning and ovality. It also has predictable material deformation, and its mechanical properties are consistent, based on controllable temperature profiles in the section that is being heated. Another benefit is that multiple radii can be used without the need for a die or mandrel.
We set the radius of bending prior to the bending, itself. We do this by placing the pivot at the end of the swinging arm, where the distance from the member that we are bending equals the desired radius.
The material is heated as it moves through the coil and it is then cooled by water or forced air, which keeps the heated zone narrow. This allows the cold material on both sides of the band to restrict the heated area from forming wrinkles or becoming oval. The cold material on the downstream side of the coil acts as an extension of the arm. This imparts the bending moment back into the heated zone. The member being bent should be moved continuously at a constant velocity to ensure the material properties are the same throughout the arc of the bend.
Induction bending is extremely helpful, especially in the construction of bridges, arches, and other structural projects. We guarantee extremely accurate bends and mechanical properties — which is why our team meets stringent ASME standards.
We test our bending procedure in just as stringent fashion as we test our fabrication and welding procedures. The properties of all areas of the bends need to be tested to ensure the members will perform as expected. We test our bending process on a short section of the same pipe that we use for the production bends. The section is bent to the same parameters that we’ll use for the production bends. We remove pieces from four quadrants of the bend, prepare and test those pieces.
If we see satisfactory results, we make the bends using the same parameters.
If not, we adjust the bending parameters, make, and test a new bend. We will continue this process until acceptable properties are achieved!
Our bending process can partner with you to bring success to your project, big or small. We trust our guaranteed process and stringent standards, not to mention our years of success! Reach out to us with any questions today.