Under what circumstance is refrigerant loss through a pressure relief valve (PRV) permitted?

Refrigerant loss through a pressure relief valve (PRV) is permitted primarily in the context of safety. When a fault with the condenser fans leads to dangerously high pressure within the refrigeration system, the PRV serves as a crucial safety mechanism. It is designed to release excess pressure to prevent the risk of catastrophic failure or an explosion, which can occur if the pressure becomes excessively high. This situation recognizes the importance of protecting both the equipment and people working in or around it.

In contrast, the other scenarios do not justify the loss of refrigerant through a PRV. Servicing or routine maintenance usually involves managing refrigerant in ways that minimize loss, and charging a system with additional refrigerant should typically not require venting it through a PRV. Each of these processes is expected to be conducted in a controlled manner that abides by regulations and best practice guidelines aimed at minimizing refrigerant emissions.