O psig is equal to:

The correct answer indicates that 0 psig (pounds per square inch gauge) is equal to 14.7 psia (pounds per square inch absolute). This relationship arises from the definitions of gauge pressure and absolute pressure.

Gauge pressure measures pressure relative to atmospheric pressure. Therefore, when a gauge reads 0 psig, it means that the pressure inside the system is equal to the atmospheric pressure acting on the gauge, which is considered as a reference point. At sea level, atmospheric pressure is approximately 14.7 psi.

Consequently, when you translate 0 psig to absolute pressure, you add the atmospheric pressure to the gauge measurement. Thus, 0 psig corresponds to 14.7 psia, accurately reflecting the actual pressure in an absolute sense.

Understanding this relationship is crucial for those working in refrigeration and other related fields, as it helps in making accurate pressure calculations, ensuring system safety, and effectively troubleshooting issues.