Why is the area above 15psig(103kPa) often marked with a red band on an acetylene regulator?

The area above 15 psig (103 kPa) on an acetylene regulator is marked with a red band to indicate that this pressure range is unsafe for acetylene use. Acetylene becomes unstable and poses a risk of explosion when pressurized above 15 psig, as it can decompose violently. The red band serves as a visual warning to prevent operators from exceeding this pressure limit, ensuring safe handling and operation.