Which refrigerant operates at a head pressure of 50 psig?

The refrigerant that operates at a head pressure of 50 psig is sulfur dioxide. This property makes it suitable for specific applications where a lower pressure is advantageous, such as in certain refrigeration cycles or industrial processes.

Sulfur dioxide has unique thermodynamic properties that allow it to function effectively at low pressures, which can be beneficial for specific cooling needs. Its relatively low operating pressure is one of the reasons it has been historically used in refrigeration systems before the widespread adoption of synthetic refrigerants.

Understanding the proper operating pressures for different refrigerants is critical for the design and maintenance of refrigeration systems, as it impacts system efficiency, safety, and environmental regulations related to refrigerant use.