Pipe Bending 101

Pipes serve an array of important purposes in the agricultural, petrochemical, automotive, shipbuilding and aerospace industries. There are many projects where fabricated straight pipes often need to be bent to conform to fit specific configurations or to be redirected to specific obstacles. The general name for this process is pipe bending. It can be done manually using a bending clamp or with specially designed machines calibrated to produce specific shapes. Here’s an overview of four common pipe bending techniques.

1. Ram bending
The oldest, simplest and cheapest way to bend pipes is ram bending. This method uses fixed rollers and a ramming cylinder to bend a pipe attached to two fixed points. Although widely used for electrical conduit tubing and exhaust pipes, it’s a poor choice for situations with limited radii or tight tolerances since it doesn’t allow for a high degree of precision and often results in deformation.

2. Rotary draw bending
Rotary draw bending is more precise than ram bending and uses a set of dies, including a fixed radius die and counter die. The pipe is first inserted through the fixed die and then pushed against the counter die to produce sufficient bending force. This is the bending process of choice to ensure precise and uniform bends in several pieces.

3. Roll bending
This method is particularly effective for bending pipes with large circumferences. Roll bending uses three rollers: one upper and two lower, which also can be configured horizontally which is preferred for large diameter pipe. The top roller produces the required downward pressure to bend the pipe against the bottom rollers. This method is particularly effective at producing large rings used in many appliances, drum rolls and truss pipes. It’s also commonly used to produce spiral bends.

4. Mandrel bending
This is a specific type of rotary draw bending that allows for great precision without significant deformation. A mandrel is a cylindrical rod that fits inside the pipe, providing support while holding it securely in the bend transition. It also helps prevent the pipe from springing back to its original shape while minimizing ovality and ripples during bending. Mandrel bending is useful for bending light wall pipe with tight radii, that require maximum circulation with minimal deformation.

Pipe bending professionals

Advanced Bending Technologies is known as an industry leader throughout North America with the ability to bend pipe from 1”-48” diameter We have the expertise required to manage you bending whether it be small or large. Contact us today for more information on how we can help you meet your pipe bending needs.