How much should acetylene valves be opened?

Acetylene valves should be opened one and a half turns to ensure optimal gas flow while maintaining safety. This level of opening is designed to provide adequate control over the flow of the gas, preventing issues that can arise from either insufficient pressure or excessive back pressure. By opening the valve one and a half turns, users gain a balance between the need for sufficient gas delivery for various torch operations while minimizing the risk of creating an unsafe environment, as too much gas can lead to hazardous conditions.

It's also worth noting that different gas cylinders and brands may have specific recommendations, so it's essential to understand the operating manuals for the equipment being used. The goal is to strike a careful balance in valve operation that facilitates efficiency while adhering to safety protocols, making this approach the best practice in torch operations.