How to Repair Welded Roll Form Systems
Tube Mills and Piping Makers make pipes and tubes of different configurations. They serve chiefly to deliver a circulating product uncompromised at both endpoints. Their basic structure and materials offer inherent flexibility to the application, which means that they are perfect for delivering hard-edged, high-pressure compressed media (e.g., gas, water) through difficult environments without the risk of internal contamination. In other words, they work well as drying agents, separators, and de-mineralizing agents.
In general, a tube mill serves to improve the productivity and efficiency of the assembly line. One of its most significant contributions is in the area of electrode material handling. The type of material used and the length of the electrode wire run to determine the electrode life and the physical condition of the workpiece.
Electrode material plays a vital role in the overall success of the welding process. The ability of the welder to cut through non-metal parts with ease is dependent primarily on the quality of the electrode material. The higher the quality of the material, the better the weld and the more consistent the welds will be. With high quality electrodes, the tube mill manufacturer can provide a reliable and consistent welding process, which in turn means a longer pipe life.
There are several different types of electrode material used in tube mill operations. Two primary types are solid indium plating and semi-precious gemstone abrasive. The former is typically used when the pipe or rod to be welded is round or curved, while the latter is used when the pipe or rod is flat. Solid indium plating is usually a single bond process where a single indium (colored) plate is deposited on the internal surface of the pipe or rod, while semi-precious gemstone is a multi-crystalline disulfide where a multiple disulfide bond is formed between the crystals. Depending on the welding situation and the diameter range of the product to be welded, the wire gauge will need to be adjusted to match the diameter range of the part being welded. Since most tube mill machines use a round product, it is important to ensure the appropriate wire gauge is used.
After the welding has been completed, the work piece is normally exposed to atmospheric pressure and compressed air. This forces the weld quality to deteriorate over time. Any cracks or weld damage that occur after the tube mill weld has been applied significantly degrades the weld quality. Most welders place a special metal insert into the chuck to keep this from happening. A quality tube mill welder should have specially designed extractors to remove excess weld fluid for the sole reason of restoring weld quality quickly.
The weld quality of these welded roll form systems can degrade over time as a result of a decrease in the diameter range of the work piece. Although the tube mills come with a variety of welding gauges to allow for varying product diameters, it is not uncommon for them to fall below the desired diameter range during some repetitive welds. This process of ‘slippage’ will eventually diminish the weld quality of the entire system. For this reason, it is crucial to maintain the correct welding tolerances. The welded roll form system may have a higher tolerance than the diameter of the product, but if the weld is allowed to slide, the product can become weakened and the tube mill may fail. This is why it is important to always use the proper weld tolerances when welding rolls and tubes using tube mills.