The Safest Approach

By design, manufacturers build safe equipment. Millions of people work accident-free every year. However, welding and cutting do pose a potential danger from flames, sparks and intense heat. To help reduce risks at your operation, we’ve compiled some safety tips that are easy to understand and follow.

Tip 1: The fire triangle

The concept of the “triangle of combustion” (or fire triangle) comes from the fact that starting a fire requires three things: fuel, heat and oxygen. Controlling those elements is within everyone’s power, and it starts with good housekeeping. Before welding or cutting, remove oily rags, paper, flammable liquids (e.g., petroleum-based products, solvents), trash cans and debris from the work area. Keep a fire extinguisher handy and know how to use it.

Proper PPE includes safety glasses, flame-retardant jackets, gloves, boots and jeans that fit over the boots. Note the cylinders are chained to the cart and cylinder caps are on when moving the cylinders.

Tip 2: Clothing and PPE

Wear appropriate clothing made from natural fibers. Cotton duck, denim and leather won’t melt like polyester fleece. Wear good work boots and make sure your pants go over the tops of your boots, so they don’t catch a spark.

Wear PPE to shield yourself from UV rays, sparks, heat and molten metal. This includes long sleeves, long pants, gloves and a welding helmet. For cutting, safety googles or glasses with a minimum of a shade 4 or 5 lens may work as well as an automatic welding helmet in “grind mode,” as grind mode is typically shade 4.

Tip 3: Gas flow monitoring

For high-volume gas users (typically more than 50 arcs or users of automated welding and cutting systems, including lasers), the cost of gas leaks and excess flow rates adds up quickly. The cost of manually monitoring such a high number of systems is prohibitive, so there are often long periods between inspections.

ESAB’s FloCloud dashboard provides complete gas consumption usage from manifold to torch to track, analyze and report any over- or under-consumption events to prevent potential dangerous gas leaks.

As an alternative, consider installing a combination pressure and flow sensor system, such as ESAB’s FloCloud, that can digitally track and transmit data related to gas pressure, flow and temperature at critical points as the gas flows from the manifold to the arc. Critically, the system allows users to set upper and lower limits for gas consumption; when values deviate, the system sends an alert.

Tip 4: Safe torch design

A potential hazard in oxyfuel cutting is flashback, which is when the flame burns back inside the torch and potentially up into gas hoses, regulators and gas supply. In 1982, Victor introduced two safety features to mitigate this hazard. The first was reverse flow check valves, designed to stop the reverse flow of gases past the torch handle. The second was flashback arrestors, designed to prevent the flame from traveling beyond the arrestor.

Tip 5: Protection from fumes and gases

A good ventilation system is essential when welding or cutting. You can also use a portable fume extraction machine or wear a respiratory system. Companies like ESAB have developed lightweight, portable fume extractors like the CarryVac3 and Origo Vac Cart W3 as well as combination welding helmet/respiratory systems like the Savage A40 with PAPR that filters out 99.9 percent of fine particles from the air.

Tip 6: Minimize potential electrocution

Electric shock is a serious risk. To avoid electrocution, inspect the electrode holder for damage before starting a weld. Make sure your gloves are dry and in good condition, keep a dry insulation between your body and the ground or metal being welded, and never touch the metal parts of an electrode holder with your skin or wet clothing.

Tip 7: Proper cylinder care

First, confirm a cylinder’s contents using its label, not the color of the regulator that may be attached. Some commonly used compressed gas cylinders for welding and cutting are nitrogen, argon, LPG, air and oxygen. Most cylinders are pressurized at high ranges, up to 300 bar. If these compressed gas cylinders aren’t handled properly, they can leak or explode. A few general suggestions include:

Many professional-grade torches incorporate built-in safety features such as reverse flow check valves to prevent the flow of gases past the torch handle and flashback arrestors.

Store cylinders upright and out of sunlight in a cool, dry, ventilated environment.
Check caps, nozzles, regulators and valves for damage.
Before moving a cylinder, remove the regulator and install the cylinder cap. Use a cart designed to transport cylinders.
Move cylinders in an upright position, don’t lift by a regulator or nozzle, and avoid hitting or dropping cylinders as they can crack.
Always secure cylinders to prevent tipping or falling. If a cylinder falls with the regulator attached, Victor Edge 2.0 regulators can prevent catastrophic failure with two design features. First, the critical components stay within the cylinder wall, using the cylinder to shield the regulator. Second, SLAM technology – a patented shock limitation absorbing mechanism – disburses the impact like the crumple zone of a car, which can prevent a catastrophic failure. With standard regulators, the stem is prone to snapping and could turn the cylinder into a compressed gas rocket.

Tip 8: Acetylene safety

Acetylene is the gas used in oxyfuel cutting. Unlike the basic structure of most cylinders, an acetylene cylinder contains a porous mass that is saturated with liquid acetone. Acetylene gas is pumped into the cylinder and absorbed by the liquid acetone. As the gas is used, more is released from the acetone. Because of this, there are three important safety considerations specific to acetylene:

Never use acetylene above 15 psi (indicated by the red zone on the regulator gauge), and always follow the pressure and flow settings on the manufacturer’s tip chart.

The withdraw rate of an acetylene cylinder is one-seventh the capacity of the cylinder per hour. Exceeding this withdraw rate may cause an unsafe condition by pulling acetone from the cylinder.
Never use acetylene above 15 lbs. per sq. in. The gas becomes unstable and it could lead to an explosion (which is why acetylene regulators are marked with a red zone above 15 psi).
Store cylinders upright to prevent the liquid acetone from getting into the regulator.
If a cylinder must be stored on its side, move that cylinder to an upright position and allow it to stand there for at least twice as long as it was on its side, or overnight to be safest.

Tip 9: Oxygen safety

Pure oxygen can reduce the kindling temperature of petroleum-based lubricants to room temperature, leading to violent combustion. Remember these key rules:

Never lubricate a regulator, torch or other part of an oxyfuel system.
Dust, lint and metal particles can also combust in the presence of pure oxygen. Inspect all fittings prior to assembly and crack the cylinder oxygen valve before attaching the regulator to blow out any dust.
Edge 2.0 regulators add an extra layer of confidence because they feature a patented particle trap that can rob these particles of their explosive energy.
Never use oxygen in place of compressed air. Common mistakes include using oxygen to run pneumatic tools or for ventilation. Also, don’t open a torch’s oxygen valve to blow off a table as that can be incredibly dangerous.

Tip 10: Fuel gas-specific components

Because of different pressure and flow requirements between acetylene and alternate fuels such as propane, propylene and natural gas – regulators, cutting tips and multi-flame attachments are fuel-specific.

A diagram of a Victor Edge 2.0 oxygen regulator shows the design differences from a conventional regulator, including a crumple zone built into the knob and a particle trap that robs particles of their energy.

Only use these components with their intended fuel gas. For easy regulator identification, Victor color-codes and labels its regulators. With cutting tips, note that acetylene tips are one piece and tips for alternate fuels require a two-piece design. Multi-flame heating tips are also fuel-specific and, like cutting tips, are marked to indicate gas type. Welding tips are only for acetylene because it’s the only fuel gas that generates CO2 during combustion to shield the weld puddle.

Torches with a “spiral” or “equal pressure” mixer design are calibrated to work with both lower pressure fuels (e.g., propane) and higher pressure fuels (e.g., acetylene). These torches keep the gas pressurized and mix them via turbulence between the handle and the torch head. As for hoses, use a T Grade hose, which is compatible with all fuels (most oxyfuel outfits come with a T Grade hose).

Tip 11: Properly Attach a regulator

Ensure all inlet and outlet valves, threads and seats are free from oil, grease and dirt. Then inspect them for dents and dings. If the inlet GCA fitting on the regulator doesn’t mate up with the gas cylinder, it means you have the wrong regulator.

After inspection, ensure the regulator is in the closed position by turning the adjusting mechanism counterclockwise until it’s fully backed out. Put the cylinder valve between you and the regulator for safety and briefly crack the valve to blow out any dust. Attach the regulator and then tighten the nut with a wrench.

While this combination torch can be used with all fuels, other components are fuel-specific. Notice the color coding (red for acetylene, orange for propylene).

Now crack the valve and allow pressure to stabilize. Next, open the oxygen valves all the way as they seal in the fully open or fully closed position. With acetylene, open the cylinder valve about three quarters of a turn, and never more than one turn. This will enable quick shut-off in the event of an emergency. With alternate fuels, open the valve all the way.

Tip 12: Perform leak tests

In addition to using digital gas monitoring hardware and software to detect leaks, check gas connections using an approved leak solution. This is preferable to soapy water because you can be assured the solution has no petroleum components. To check for a leak between the regulator and the flame or arc, use the following method:

Back out the regular adjusting mechanisms to the fully “off” position.
Open the cylinder valves slowly until the high-pressure gauge reading stabilizes, then shut off the cylinder valves.
Monitor the gauge for any pressure drop, which would indicate a leak on the high-pressure side of the system. If no leak is evident, open the cylinder valve and adjust the oxygen regulator to deliver 20 psi.
Repeat the process with the fuel gas valve and regulator but adjust the fuel gas regulator to deliver only 10 psi.

Observe the gauges for a few minutes. If the readings don’t change, then the system is leak-free. If the readings change, check the connections, tighten as needed and inspect the gas hose. If the hose is damaged, discard it and get a new one.

Tip 13: Purge the system

Before lighting a torch, purge the oxygen and acetylene lines by opening the torch valves for 5 to 10 sec. This helps remove contaminates that might have come from the manufacturing environment. Close the valves, double check regulator pressure and adjust if necessary.

Tip 14: Proper shutdown

With all oxyfuel cutting, close the oxygen preheat valve first and then the fuel valve. If there is a small flame still present, you may have a leaking fuel valve. If you hear a popping sound, either you reversed the shut-off order or you have a leaking oxygen control valve.

Even from a distance, the gauges clearly show that this system is under pressure. If there was a gas leak, leaving the torch unattended could allow fumes to rise in the bottom of the scrap bin, creating a hazardous situation.

Never leave oxyfuel systems pressurized while unattended, even for a lunch break. A classic mistake is to drape the torch over a cutting table, scrap bin or barrel. Because acetylene is heavier than air, a leak from the torch can pool in the barrel and lead to a catastrophic situation in the event of a spark.

Even if you’re only setting the torch aside for a short time, always follow this shutdown procedure:

Follow the shut-off procedure.
Close valves on the gas supply.
Open the fuel gas valve on the torch, bleed pressure from the system and close the fuel gas valve.
Follow the same procedure with the preheat oxygen valve. Never have both valves open at the same time, as it may cause a reverse flow.
Release tension on the adjusting knobs.
Wait a few minutes and check the inlet gauge to ensure no pressure remains in the system.

Welding and cutting safety is everyone’s responsibility. If you see a coworker acting in an uninformed manner, provide guidance. If they know better and still act carelessly, speak to a safety manager or supervisor. For more support, ask your ESAB/Victor representative about performing a safety audit for your facility and safety training for your people.

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