What is the critical pressure of C2H2?

The critical pressure of a substance is the pressure above which a substance cannot exist in the liquid state, regardless of temperature. For acetylene (C2H2), the critical pressure is approximately 29.8 psi, often rounded to 28 psi. It is essential for users working with acetylene to understand this property, especially in welding applications, as it defines the limits within which acetylene can be effectively stored and utilized. When operating at pressures lower than the critical pressure, acetylene can exist as a liquid. Understanding the critical pressure is important for safety, storage, and efficient utilization of welding gases.

Other values presented, such as 10 psi, 20 psi, and 35 psi, do not represent the critical pressure for acetylene and would not provide the necessary operational criteria for safe practices in welding environments.