What is the single pipe called on a reversing valve?

The part referred to as the "single pipe" on a reversing valve is known as the permanent discharge line. This line plays a crucial role in the operation of heat pumps and air conditioning systems that utilize a reversing valve to switch between heating and cooling modes.

In the context of the reversing valve, the permanent discharge line is crucial because it is responsible for directing the refrigerant flow to the appropriate coil, depending on whether the system is in heating or cooling mode. This makes it essential for the system's efficient operation, as it helps manage the refrigerant after it has been compressed.

Understanding the role of the permanent discharge line is important for anyone working in HVAC, as it influences the overall performance and effectiveness of the heating and cooling systems. Correct identification and knowledge of this component are vital for troubleshooting and maintaining HVAC systems.