What position should the service valve be in during normal operation?

The service valve should be in the back seated position during normal operation because this setting ensures that the valve allows for the proper flow of refrigerant while also preventing leaks. In the back seated position, the valve is designed to be fully open, allowing the system to operate efficiently.

This position is especially important as it minimizes the risk of refrigerant escaping from the system, which is crucial for maintaining both the operational integrity of the cooling system and compliance with environmental regulations concerning refrigerant leaks. Additionally, having the valve back seated helps in certain maintenance tasks by isolating sections of the system while keeping other areas pressurized and operational.

In contrast, being fully closed would completely stop the flow of refrigerant, which is not appropriate for normal operation. A partially opened valve might restrict the flow, leading to inefficiencies in the system. A fully opened valve does allow for operation, but the terminology of 'back seated' clarifies that the valve is also designed to prevent leaks and maintain system integrity effectively.