Which statement is true about acetylene safety and welding parameters?

Which statement is true about acetylene safety and welding parameters?

• A. The fusible plug melts at 100 C.
• B. The fusible plug melts at 50 C.
• C. The critical point is 15 psi @ 21 C.
• D. Neutral flame is used only for TIG welding.

Answer: (A)

Acetylene cylinders include a fusible plug as a safety feature. This plug is designed to melt if the cylinder overheats, around 100°C, which vents gas and helps prevent a dangerous rupture. That temperature threshold is chosen to stay below typical fire temperatures but high enough to avoid accidental venting under normal handling. So, stating that the fusible plug melts at about 100°C correctly describes the safety mechanism. The other statements don’t reflect how acetylene cylinders are designed. A fusible plug melting at 50°C would vent too easily under normal conditions. The idea of a “critical point” at 15 psi @ 21°C isn’t how this safety feature is described or used. And neutral flame is not exclusive to TIG welding; it’s the balanced flame used in oxy-fuel welding (and brazing) as well, not a property limited to TIG.

Acetylene cylinders include a fusible plug as a safety feature. This plug is designed to melt if the cylinder overheats, around 100°C, which vents gas and helps prevent a dangerous rupture. That temperature threshold is chosen to stay below typical fire temperatures but high enough to avoid accidental venting under normal handling. So, stating that the fusible plug melts at about 100°C correctly describes the safety mechanism.

The other statements don’t reflect how acetylene cylinders are designed. A fusible plug melting at 50°C would vent too easily under normal conditions. The idea of a “critical point” at 15 psi @ 21°C isn’t how this safety feature is described or used. And neutral flame is not exclusive to TIG welding; it’s the balanced flame used in oxy-fuel welding (and brazing) as well, not a property limited to TIG.