Tube Mills is using to manufacture pipe and tubing by carefully taking a continuous length of raw material and repeatedly rolling it into a strip until the rolled strip meets together at a weld area. It is often referred to as “rolling tubing” or “rolling pipes.” The material to be rolled into the Strip is first placed inside the Case (the tube or pipe that will be formed) and then the material is fed through the Case and positioned in position. When the Case is heated, it forces the material into the actual weld area creating a neat and complete weld.
There are several different types of Tube Mills including pre-punching, direct pull, direct feed and drum milling. Pre-punching tube mills are used when the material is to be formed into smooth sheets. This equipment is known as a slow pig roller. The slower speeds of the roll forming equipment allow for more precise placement of individual sheets of metal. For most applications pre-punching is sufficient.
The next type of Tube Mills to discuss is the direct pull or drum milling system. This system is designed for heavy duty and long distance pipe and tubing. In a drum milling system the metal strip is fed into the Case, lined up with the Case walls and rolled around the inside of the case. The strips are fed into the pipe or drape in specific, predetermined shapes. These shapes and sizes are pre-punched into the machine. When the process is complete, you will see the punches on the outside of the case are visible to the operator.
Pipes and tubing can be produced and finished in a variety of unique forms utilizing various Tube Mills. A simple example of this is the pre-punching process mentioned above. Other examples include forming hollow metal tubes and the production of continuous strip meets.
A continuous roll forming machine is another application of these machines. In this application the tube mills can be configured in many different ways. For example, the machine can be positioned at the start of the wire where the wire will be fed into the machine for forming continuous rolls of wire. The same can be done at the end of a wire. Or the machine can be positioned at both the start and end of a wire. The machine can also be positioned at the end of a sheet that has been fed into the machine for forming hollow shapes.
In all cases where you will have your tubes and tubing pressed together there is a need for a welding machine to ensure the proper welding process takes place. For example, when you are forming long tubing the actual strip must be fed into the welding machine through a feed press. If the strip is supplied through an injection machine the filler rod will be fed into the feed press and then into the welded tubing to form the final shape. This is one application where the welded tube mills come into their own and where the operator will find the ability to control the sizes of both the strips and the welded strip ends.