What is the maximum safe pressure for acetylene gas when not in use?

The maximum safe pressure for acetylene gas when not in use is 15 psi or less. This limitation is crucial because acetylene is a highly unstable gas under pressure, and exceeding this threshold can lead to dangerous situations, including the risk of explosions.

The stability of acetylene decreases significantly as pressure increases beyond this point. At higher pressures, acetylene can undergo decomposition, which can result in violent reactions. Therefore, maintaining the storage pressure at or below 15 psi ensures safety when the gas is not actively being utilized in a welding or cutting process.

Adhering to this maximum pressure is a standard safety practice within the industry to mitigate risks associated with acetylene gas.