How far should the propane valve be opened when adjusting the torch?

The correct adjustment for opening the propane valve when setting up a torch is generally measured to ensure optimal fuel flow while maintaining safety and performance. A 3/4 turn opening is usually recommended because it allows enough propane to flow for efficient combustion while ensuring that the flame can be properly adjusted for the specific application.

Opening the valve too much—up to a full turn—can introduce excess propane, leading to a less controllable flame and potential safety hazards, such as backfiring or flashbacks. Conversely, opening it only 1/4 or 1/2 turn might not provide sufficient fuel, resulting in an insufficient flame for effective welding. Thus, the 3/4 turn strikes a balance between safety and functionality, providing a strong enough flame while minimizing risks associated with gas buildup.