Installing bent tubes into a manufacturing system extends the time between repairs or replacements, compared to welded tube or other tube-joining methods. Axenics saves our clients time and money by utilizing tube bending processes since the process involves fewer fabrication hours and fewer materials than other tube-joining methods.
Using a CNC tube bending machine also means there’s less time and money spent on testing, as there are fewer components to test – just a single piece of bent tube.
The four attributes of tube bending that will make your systems last longer include the machine, material, tooling and lubrication used for the job.
We use a Horn Metric CNC Tube Bender, a dual stack hydraulic tube bender with roll forming capabilities, which produces bends ranging in a variety of diameters from ¼” to 2”. A CNC tube bending machine produces bent tubing without kinks. The CNC bender also significantly reduces time, materials and costs for customers who need to safely and consistently transport chemicals and gases.
We prefer using 300-series stainless steel for its long-lasting and strength attributes. A bending machine can also perform custom bends on copper, aluminum, Inconel, Titanium, bronze and other alloy metals. We recommend stainless steel tubing for its high corrosion-resistance properties and the ability to withstand long-term exposure to varying environments.
The basic components of the CNC bender are the mandrel, the bend die, clamping die and wiper die.
- Mandrel: The mandrel inserts into the tube for support during bending to avoid wrinkling, distortion, collapse, flattening, rippling or breakage during the process. Using a mandrel provides better control over the tube’s ovality or roundness. Mandrel tube bending elicits highly accurate, repeatable results for jobs with tight or large radius bends and multiple radii bends. The firmness of a mandrel is very important, depending on the firmness of the tube. For extremely durable tubing, a soft mandrel is used, and a hard mandrel is used on softer tubing. This prevents the mandrel from sticking to the inside of the tube, which can damage the tube.
- Bend Die: The radius of the bend die takes into account the durability of the tube to adjust for radial growth. Bending a harder material requires a bend die with a smaller radius.
- Clamping Die: The ideal length of a clamping die is three times the diameter of the tube. Clamping short, puts too much pressure on a short section of the tube, resulting in a damaged component.
- Wiper Die: The wiper die supports the tube on the inside of the bend to prevent wrinkles. Position the wiper die at a slight angle with its contact point extremely sharp at all times. Lubrication at the point of contact is important to avoid premature wear.
Proper lubrication is critical for top-quality bends. Lubrication lowers friction during bending for clean, smooth results. We prefer non-petroleum-based synthetic lubricants in a paste or gel. Durable metals often require more lubrication to prevent friction.
Types of production systems where tube bending is recommended include:
- Control systems: In chemical engineering production, it’s essential to have a seamless flow of gases or liquids. There are zero kinks in bent tubing systems to trap or slow materials flowing through the system.
- Delivery systems: CNC machine bent tubing creates liquid-tight and airtight seals for consistent movement of matter through the entirety of your system.
- Purification systems: Purifying processes often include the use of caustic chemicals, which can cause filler material on welded tubes to break down over time. Bent tubing has no filler material, but consists only of the base metal, leaving precise pathways for materials to flow.
- Storage systems: Manufacturers in the chemical production industry may use tube systems to deliver potentially hazardous materials into temporary or long-term storage. The interior of tubes used to transport that material must remain clean. Bent tubing has no sharp curves inside to trap materials, so the interior remains uncontaminated after materials flow through.
- Testing systems: Materials flowing through testing systems must retain their original properties. With bent tubing, there is a much lower risk of contamination as opposed to using a welded tube system or a system with multiple joints. The more components added to a system increases the opportunity for contamination.
There are other benefits related to tube bending services for a variety of projects that you can read about in this free download. This guide also offers industry statistics related to the use of a CNC bending machine and additional specifics regarding time and cost savings with tube bending.