What position should the four ball valves on the clean air separator be in?

The correct configuration for the four ball valves on the clean air separator is for the top valve to be open while all others remain closed. This setup is crucial because it allows for the proper management of air and vapor separation processes in the system. By having the top valve open, air can escape or be vented effectively, which helps to prevent pressure buildup or potential issues with backflow or blockage in the system.

With all other valves closed, the system maintains its intended focus on separating clean air from vapors without allowing unnecessary pathways for vapor escape that can affect recovery efficiency. This specific configuration is designed to optimize the function of the clean air separator while maintaining the system's integrity and effectiveness in vapor recovery.

In various operational situations, ensuring that only the top valve is open can significantly impact the recovery system's performance, making it vital to adhere to this arrangement for proper functioning.