Oxy-Fuel Practice — Select the Typical Oxygen Pressure at the Torch For general gas welding, what oxygen pressure range is commonly set at the welding torch (delivery side) for stable flame control?

Introduction / Context:
Correct regulator settings are vital for safe, controllable oxy-fuel welding. Oxygen delivery pressure must match tip size and material thickness to ensure a stable neutral or slightly adjusted flame without excessive noise or backfire tendencies.

Given Data / Assumptions:

• Standard oxy-acetylene welding (not heavy cutting).
• Typical torch and tips used for mild steel fabrication.
• Focus is on oxygen pressure at the torch side, not cylinder pressure.

Concept / Approach:
In common practice, acetylene delivery pressures are relatively low, whereas oxygen pressures are higher to maintain correct flame characteristics and flow. A frequently cited torch-side range for oxygen in welding is about 280 to 560 kN/m², balancing flow with safety and flame stability.

Step-by-Step Solution:
Identify typical welding (not cutting) operation.Recall that oxygen pressure is higher than acetylene in welding setups.Select the range 280–560 kN/m² as the practical torch setting for many welding jobs.

Verification / Alternative check:
Workshop charts list oxygen pressures in this band for common tip sizes; adjust within the range for thickness and tip bore.

Why Other Options Are Wrong:
7–103 and 70–280 kN/m² are too low for oxygen in most welding tips.560–840 kN/m² and above are more typical for certain cutting setups or special applications, not general welding.

Common Pitfalls:
Setting oxygen much higher than needed can cause a roaring, oxidizing flame and rapid tip wear.

Final Answer:
280 to 560 kN/m²