The three basic steps to bend steel tubing and pipes are: support the pipe interior using a mandrel or a “sand mandrel”; mount the pipe onto the bending machine; and bend the pipe using a rotary bender, ram bender or roll bender.
You can bend steel tubing using a number of ways. Some of the equipment you can use in the process of bending steel tubes and pipes is a ram bender, an angle roll or a rotary bender. Here are 3 steps you can follow.
Step 1: Support the pipe interior using a mandrel or a “sand mandrel”
You need to provide support from the interior of the pipe in order to keep it from collapsing or breaking during the bending process. You may slide the pipe onto a mandrel or make one if none is available. Mandrels typically follow the shape of the pipe with the tip specially formed in such a way that it supports the pipe when it bends. You might need a mechanized extractor to remove the mandrel from the pipe afterward because it is difficult to extract the mandrel manually. You can also make your own “sand mandrel” if you do not have a mandrel on hand. Attach duct tape in several crisscrossing layers at the end of the pipe. The number of layers you need to use will depend on the pipe’s size. Taping the pipe’s end will help it withstand pressure. Pour water into the pipe and add sand into the pipe to displace water. Tap the pipe with a hammer while pouring the sand to prevent air bubbles from forming. Fill the pipe with more wet sand and dry off the top before attaching more duct tape.
Step 2: Mount onto the bending machine
After you have prepared the pipe’s interior, mount it onto a bending machine. Open the machine so it can accommodate the entire pipe. You can do this by applying pressure or pulling the handles apart. Ensure that the pipe is set properly into the three contact points of the machine grooves.
Step 3: Bend the pipe by using a rotary bender, ram bender or a roll bender
You can bend the steel tubing by choosing one of 3 different methods. With the rotary bender method, you have to mount the tube into the rotary bender first. The rotary bender has points near its handles which are used to grip the pipe in place. There is a flat side running on the edge of one of handles, and this flat side must face the bench and typically screwed in place. The handles are then used like a pair of pliers by squeezing the pipe against the bending arch. Ram benders commonly have a bending arch or a bending die which is used to press upon the pipe and force it between its contact points which bends the pipe. Apply force to the pipe and release it after bending. As for roll benders, you have to clamp the pipe in between the three “rolls” or wheels on the machine. One of the wheels is typically found across the two. When pressure is applied and gradually increased, the wheel at the middle is forced between the two others and, consequently, bends the pipe. The pressure applied on the pipe will change and depend on the bending radius.
Bending pipes and steel tubing are made much more accurate and convenient with the use of bending equipment such as rotary benders, angle rolls and ram benders.