Welding Digest

Oxyfuel torches are indispensable tools in varying applications. Like any equipment that involves combustible gases, it's essential to understand how to operate them safely. One potential hazard that operators should be aware of is a backfire, specifically, a sustained backfire. Follow our step-by-step instructors to learn how to identify a sustained backfire and the proper steps to shut down your oxyfuel system in case it occurs.

Identifying a Sustained Backfire:

When gas pressures are appropriately set, the torch tip should remain relatively cool during operation. However, if the volume of fuel gas is insufficient for the tip being used, it can lead to tip starvation. Tip starvation causes the tip to overheat, which can result in the gases igniting before they exit the tip. This is known as a sustained backfire, which is characterized by a hissing sound with little or no visible flame exiting from the torch tip.

Preventing and Shutting Down a Backfire:

To prevent a sustained backfire, always purge the system before use, inspect it for damage or leaks, and ensure cylinders have a minimum content of 20 psi. In the event of a sustained backfire, follow these immediate steps:

• Immediate Action: If you suspect or notice a sustained backfire, the first step is to act swiftly. Immediately turn off the oxygen and fuel gas valves to stop the flow of gases.
• Close Cylinder Valves: After extinguishing the flame, close the cylinder valves to isolate the gases.
• Bleed Oxygen: Open the torch valve and monitor the oxygen regulator gauges until both needles drop to zero. Close the torch oxygen valve.
• Fuel Gas Shutdown: Repeat the process for the fuel side. Close the torch’s fuel gas valve and adjust the fuel gas regulator to the “off” position. 

By following these safety procedures, you ensure that the oxyfuel system is properly shut down to minimize the risk of accidents and maintain a secure work environment.

Remember, safety should always be a top priority when working with oxyfuel torches. Understanding how to identify and respond to backfires is essential for anyone involved in gas welding and cutting operations.

-Sponsored by Miller-