In a commercial refrigeration system, where should a sight glass be installed?

The sight glass in a commercial refrigeration system is installed between the filter-drier and the metering device because this location is crucial for assessing the refrigerant's condition before it enters the expansion valve or metering device. Placing the sight glass here allows technicians to observe whether there is the correct amount of refrigerant flow, ensuring that the system operates efficiently.

If the sight glass shows bubbles, it indicates that the refrigerant is low, and if it's clear, it suggests proper refrigerant flow. This crucial information helps in identifying and troubleshooting potential issues in the refrigeration cycle, allowing for timely adjustments and maintenance.