In plasma cutting, the plasma arc cuts smoothly through any conductive metal and the process is much faster than any of the conventional cutting methods. And, although plasma cutting has been around for over 50 years. Smaller and portable cutting machines were introduced only in the mid-90s.
While plasma cutting is an efficient and a very easy process, it is not without any dangers like gas, electricity, UV light, etc. And, because the cutting process is fairly new, people are not too familiar with the proper safety procedures for plasma cutting. However, the safety practices are fairly simple and not difficult to learn.
During the process of plasma cutting, sparks and hot metal are produced by the plasma arc, especially when the metal is being pierced. The plasma torch and the workpiece get heated and can cause fire and burns. It is recommended that while cutting, you should wear approved safety glasses to protect your eyes and a helmet or a face shield along with the safety glasses can offer additional protection.
You should wear dry and flame-resistant gloves and clothing to protect your body from the flying hot metal and sparks. Denim, wool and leather clothing work well and you should button your cuffs, collars and pockets of your shirt to prevent them from catching the sparks. Avoid carrying any lighters or matches in your pockets while working with plasma cutters and avoid cuffed pants as the cuffs may catch fire. Leather boots or high-top shoes offer the best protection for your feet.
The pilot arc is very hot and can cause burns, so while pressing the trigger, you should keep away from the tip of the torch. Also, while you start the arc, keep the plasma torch pointed away from your body, towards the workpiece. Keep the cutting area clear of all flammable materials as they can catch fire and protect all flammable materials with fireproof covers.
Avoid cutting on pressurised or closed containers like drums or tanks and avoid cutting on containers that previously held toxic, combustive or reactive materials. Never cut with plasma near vapours, dust, liquids, flammable gases or in areas where there is a possibility of explosions.
The plasma arc needs high voltage i.e. 110-400 VDC to start the arc and maintain it. And you can get severe burns or fatal shocks if you touch the electrical parts of the torch. Any bare spots on the cable or poor connections increase the risk of electrical shock. So, you must inspect all these daily and replace any broken connections and worn out cables.
Avoid cutting with a plasma cutter in damp or wet areas. Insulate yourself properly by standing on a plywood sheet, a rubber mat or some other non-inflammable material. Ensure that the plasma torch is grounded properly as per the OSHA and the National Electrical Code (NFPA 70) standards. Inspect the ground connections properly and ensure that the workpiece is connected to a proper earth. Avoid using wire ropes, hoists, cranes, elevators and chains as grounding connectors.
Protect Yourself from the Light
Plasma arcs produce both visible, as well as invisible UV and infrared rays which can burn the skin and eyes. Not only should you wear proper protective clothing to shield your skin, you should protect your eyes by making use of safety glasses or a face shield with proper lens of appropriate shade.
Keep the Air Clean
Plasma cutting produces gases and fumes and breathing in these can cause health problems. Avoid breathing the fumes by holding your head to the side of the plasma torch and not directly above it. If you are working in a confined space, make sure that it is ventilated properly or wear a respirator with an air supply.
If you are cutting coated metals such as lead-plated, cadmium-plated or galvanised steel, try and remove the coating from the area that is being cut. The coatings can produce toxic fumes when being cut using a plasma torch. If you’re cutting coated materials, then it is recommended that the cutting area is ventilated properly and you should also make use of a suction system or an exhaust hood to keep the cutting area clear of any fumes and keep the breathing zone safe.
Usually, plasma cutters make use of shop air or they sometimes use compressed gases such as nitrogen. If you’re making use of gas cylinders, keep them upright, secured tightly to an upright support. Use the protector cap on the cylinder when moving or storing it to protect the valve from being damaged. If the regulator is damaged, remove it for repair.
Use only recommended clamps, ferrules, etc. to connect the hoses and avoid using wire or other fasteners. Keep the hose away from the ground and coil the excess hose to prevent any tangles or kinks. Check the hose regularly for any wear, loose connections or leaks and if the hose is worn or there is a leak replace it.
Plasma cutting is an excellent method of cutting metal; however, to prevent any accidents you must take proper precautions and follow the correct procedures. This will help you and the people around you stay safe and secure during the process of plasma cutting.