Why is the pressure that acetylene is used at so important?

The importance of the pressure at which acetylene is used is closely related to its stability. Acetylene is a hydrocarbon compound that can become unstable if exposed to high pressures, particularly above 103 kPa (about 15 psi). When acetylene is subjected to high pressures, it poses a risk of decomposition, which can lead to a potentially explosive situation. This instability is a critical safety concern in industrial and welding applications where acetylene is commonly used.

Understanding that acetylene must be handled at specific pressure levels ensures safe practices in its storage and application. By maintaining pressure below the critical threshold, it prevents unsafe conditions that could lead to accidents or equipment failure, making safety and proper handling of the gas paramount in its usage.