At what pressure is R717 discussed in terms of gauge pressure?

The term "gauge pressure" specifically refers to pressure measured relative to atmospheric pressure. In the context of refrigeration, R717 (ammonia) is often discussed in terms of pressure and temperature readings that are crucial for effective system operation and monitoring.

When pressure is expressed in psig (pounds per square inch gauge), it indicates that the measurement excludes atmospheric pressure, providing a reading that reflects only the pressure exerted by the refrigerant itself above atmospheric levels. This is a standard convention in many industrial applications, including those involving refrigerants, as it provides a more relevant understanding of the internal pressures within a refrigeration system.

Understanding that R717 is commonly referenced using psig allows operators to make necessary calculations and safety assessments in refrigeration systems, enabling them to maintain efficient and safe operational conditions. It is standard industry practice to report the pressures of refrigerants in gauge pressure, which is why this option is correctly associated with R717.