In oxyfuel welding, the secondary flame is the orange portion of the flame.

In oxyfuel welding, the secondary flame is the orange portion of the flame.

• A. The orange part of the flame
• B. The blue teeth on torch
• C. The green ring around the flame
• D. The white outer flame

Answer: (A)

In oxyfuel welding, the flame has two distinct zones. The blue inner cone is the main, or primary, flame where most of the controlled combustion and heat occur with the proper O2-Fuel mix. Surrounding it is the orange, luminous outer zone—the secondary flame—which forms when some gas mixes with ambient air after leaving the torch and burns in that air. The orange color comes from incandescent soot produced during this secondary combustion. So the orange portion is the secondary flame. In practice, a neutral flame has a small orange outer zone, while a larger orange area indicates more secondary combustion.

In oxyfuel welding, the flame has two distinct zones. The blue inner cone is the main, or primary, flame where most of the controlled combustion and heat occur with the proper O2-Fuel mix. Surrounding it is the orange, luminous outer zone—the secondary flame—which forms when some gas mixes with ambient air after leaving the torch and burns in that air. The orange color comes from incandescent soot produced during this secondary combustion. So the orange portion is the secondary flame. In practice, a neutral flame has a small orange outer zone, while a larger orange area indicates more secondary combustion.