When a service valve is back seated, which port is closed?

When a service valve is back seated, the service port is closed. This specific configuration is commonly used during maintenance activities to isolate the refrigerant flow, allowing technicians to safely service or replace components without risking refrigerant release. Essentially, back seating a valve means that the valve stem is pushed back, which effectively closes off the service port while keeping the other ports (inlet and outlet) open for operation. This is crucial for retaining pressure in the system while ensuring that the technician can perform necessary checks or repairs safely. By closing the service port, the refrigerant can be contained in the system, minimizing exposure to the technician and the environment.