What could happen if the discharge service valve is closed while the compressor is running?

If the discharge service valve is closed while the compressor is running, the compressor could experience damage due to a lack of adequate flow of refrigerant. When the valve is closed, the refrigerant cannot exit the compressor as it normally would. This creates a situation where the compressor is essentially "starved" of refrigerant, leading to several potential issues.

Without proper refrigerant flow, the compressor can overheat since refrigerant is crucial for absorbing heat and lubricating the compressor's moving parts. Excessive heat can lead to thermal breakdown of internal components and may even result in the compressor seizing or failing completely. Additionally, increased pressure within the compressor due to the blockage can cause mechanical failure.

Understanding this principle is key for technician safety and system integrity, emphasizing the importance of monitoring valve positions during system operation.