What safety pressure limit is recommended for acetylene regulators during cutting?

• A. It damages hoses
• B. Acetylene is unstable above this pressure
• C. It reduces flame temperature
• D. It voids warranty

Answer: (B)

Acetylene is unstable when pressurized, so it must be delivered at a very low, controlled pressure. In cutting operations, the regulator for acetylene is kept at a small maximum to prevent decomposition or explosive release of energy. When pressure is allowed to rise above this limit, acetylene can become unstable and pose serious safety risks, such as flashback or hose/regulator failure. So the safest and most practical reason to set a low limit is to keep the gas stable and the flame controllable. The other ideas—damaging hoses, reducing flame temperature, or voiding warranty—aren’t the primary safety concern here.