How can flush properly in refrigerant pipes?

To properly flush refrigerant pipes, first, ensure the system is deactivated and safely evacuated of refrigerant according to regulations. Use a suitable flushing agent recommended by the manufacturer to remove contaminants, and connect it to the system's service ports. Run the flushing agent through the pipes, allowing it to circulate and clean the interior surfaces, then collect and dispose of the used agent responsibly. Finally, verify the cleanliness of the pipes, and recharge the system with refrigerant as per the manufacturer's specifications.