Pipe bending is the process of modifying pipes for them to achieve a specific angle or direction. This process is done as it allows systems to cut pressure changes while still directing materials through intricate piping systems.
Most pipes do not alter the ends of the piping, which makes tube bending easy to put in place within a processing system. You can do it at home with the right tools, depending on the pipe size and desired angle. It isn’t easy, especially without the knowledge and appropriate equipment. That is why it is entrusted to companies that offer professional pipe bending services.
What is the different pipe bending methods?
There are many methods available, but most fall into one of these two categories:
1. Cold Bending
2. Hot Bending
Cold bending methods often rely on pure physical force to help bend the pipe to its final shape. In contrast, hot bending methods use careful heating to reduce the pressure required. Each technique will determine to what extent bending is possible and the final shape of the pipe.
Cold Bending Methods
1. Mandrel Bending
To prevent defects in the pipe’s bend, such as flattening, rippling, or collapse, they place a mandrel inside the tube or pipe, especially those with thinner wall materials. This method gives you better control over the pipe’s roundness.
This is useful for difficult jobs requiring tight, large radius bends, high accuracy, and repeatability with minimal deformation.
2. Rotary Draw Bending
The pipe is bent using a combination of dies and other components working in a rotary action. This action pulls the pipe or tube forward, making the desired bend. Rotary draw bending can also use mandrels.
It is commonly used to form small radius bends in the smaller-size round, square and rectangular metals. Specific tooling for the machine is required for size, shape, and bend radius, so this method is best for projects requiring many identical curves.
3. Roll Bending
This method places a piece of pipe or tube through a series of two or three rollers to achieve the desired curve. It is usually done when pipes need to be curved into cylindrical shapes or shapes with a smooth radius.
Hot Bending or Induction Bending Method
Hot metal bending is when heat softens pipes to allow their shape to be altered with pressure to make the intended bend. It needs less physical force than cold bending methods, mostly done by machines. It can produce curves of similar quality with no filler materials, mandrils, or other additions used to avoid deformations.
Although it minimizes diameter cutbacks at the bend site, induction bending causes changes in a pipe’s thickness. Typically, the inner section will become thicker, while the outer area of the curve will become thinner. The method is often used in massive diameter tubing, piping, and long radius bends.
How to bend a pipe?
A pipe bender is an equipment used to bend pipes of different materials, like copper and stainless steel, to form varied curves and angles. There are four main classifications of pipe benders: manual, electric, mechanical and hydraulic.
1. Ram Bending
This is one of the oldest and most cheap methods used today. In this process, a pipe is secured at two external points while a bending ram presses into the workpiece’s central axis. Power is moved through a vertical ramming cylinder. The ram thrusts the tube against a pair of fixed rollers, causing it to curve around the die.
Ram bending is commonly used to fabricate automobile exhaust pipes and form electrical conduits. It suits applications in which a round cross-section is not required. This method lacks a mandrel and internal supports that can cause deformation, causing an oval-shaped cross-section.
2. Mechanical Pipe Bender
These are a popular choice for locations where access to electrical power is unavailable or limited or in sites where mobility is needed. Manual pipe benders can be purchased on your hardware and are usually handy. These are also offered in different types to cater to various sizes and angles.
3. Electric Pipe Bender
These pipe benders are machines that bend the pipes or tubes to achieve the required curves of the final product. These are powered by electricity and reduce the working time and increase the efficiency of the work.
4. Hydraulic Pipe Bender
These mechanisms use hydraulic pressure to bend various sizes of metal pipe and electrical conduit to specific angles. They operate with a hydraulic piston that rises to exert high pressure on the tube between the bending dies.
They can do many bends constantly with less time and effort than manual benders. Models are usually available for shaping aluminium, steel, and brass pipes in various applications, from automotive repair to bar bending for landscape and concrete work.
The Different Types of Bends
1. Back-to-back Bend
It is a bend built from an initial stub-up bend and looks like an elongated ‘U’ shape. This bend is used when you need to fit a pipe between two parallel surfaces, and such as between two walls, when you need the ends of the tube to remain tight to the surface.
2.90-degree stub up Bend
It is a bend made by bending a piece of piping into 90 degrees or an ‘L’ shape. It is the st typical bend used by plumbers and electricians, and this bend is often used to run conduit into electrical boxes and pipe into walls through floors and ceilings.
3. Offset Bend
This bend has two equal-degree bends in opposite directions. It moves the pipe around an object or staggers it up steps or slopes. The angle of an offset bend can differ depending on where it is and how steep the path changes need to be. The most common use for an offset bend is to create a staggered joint and an elevation change.
4. Three-point saddle Bend
The three-point saddle bend moves the pipe around obstacles like the offset bend. However, this bend returns to its original path once it has passed the barrier. They call it the three-point saddle bend because it has three separate bends.