Today, plasma cutting has become an extremely popular method of cutting used in large industries, as well as by small fabricators. And, maintaining your plasma cutting system can help to save a lot of money in terms of the operating expenses and several hours of downtime. Here are a few mistakes that are seen commonly in the case of plasma cutters and if avoided, can help in the efficient functioning of the system.
Overusing the Consumables
Often, it is seen that operators overuse the consumables and the use of severely worn consumables not only ruins a good workpiece but can result in the failure of the plasma torch and process downtime. It is a good idea to inspect the consumables regularly, especially when you notice that the quality of the cut is deteriorating. Keep track of the average life of the parts and on basis of the type of material, thickness and amperage, you can decide when the consumables must be replaced to prevent failure of the plasma torch.
Changing Consumables Often
Instead of changing the consumables when they are showing wear, often, operators change them after a certain number of hours. Consumables should be changed only if the orifice is out of round, the inside and outside of the nozzle has gouges, if the electrode has been consumed and if the swirl rings are cracked, burned or show excessive wear. The shield should also be replaced only if they show signs of physical damage.
Using Wrong Parts and Parameters
The selection of the consumables essentially depends on the type and thickness of the material being cut, the plasma gas, the amperage and other cutting parameters. The consumables should be selected according to the operator’s manual, as using the wrong consumables can lead to reduced consumable life and diminished cut quality. The parts must also be run at the correct amperage. Too low an amperage will cause the cut to be poor, while if it is too high, the nozzle life will be shortened.
Incorrect Torch Assembly
The torch should be assembled properly to ensure that all parts are fit snugly. This ensures that the coolant and gas flow properly and the electrical contact is proper. The area should be kept clean while assembling the torch and the O-ring lubricant should be used in the right quantity, as too much lubrication will cause metal dust contamination causing the torch to get clogged, resulting in uncontrolled arcing and finally failure of the torch.
Improper Gas and Coolant Flow
The consumables in the torch will not be cooled properly if the gas and coolant flow is not right and this will reduce the part life. Insufficient water flow can lead to system failure. The gas pressure must be constant to maintain the plasma arc. While excess pressure causes hard starting which results in the failure of the arc to start and too much of gas results in the failure of the electrodes. The gas supply must also be clean to prevent short torch and consumable life.
The distance maintained between the torch tip and the workpiece is important to the consumable life and the cut quality and maintaining the height of the torch is also extremely important. If the pierce is too low, then the molten metal will spatter on the shield and nozzle and it may also cause arc snuffing which affects the torch and consumable parts.
The cutting speed is also very important to the cut quality. If the cutting speed is too slow, there will be an accumulation of low-speed dross, too much of spatter on the top and a wide kerf, whereas if the cutting speed is very fast, it will result in a narrow kerf, bevelled edge and dross at the bottom of the workpiece. Cutting at the right speed results in a clean edge and minimum dross.
With proper maintenance and upkeep, you can ensure the long life of your plasma torch. By avoiding the above mistakes, you can ensure that your plasma torch works efficiently. And, a well-maintained plasma cutting system can help to increase productivity, cost savings and increase the profits of your cutting operations.