Why is it preferable to connect fuel units as a one-pipe system?

Connecting fuel units as a one-pipe system is preferable primarily because it simplifies the installation process. A one-pipe system requires fewer connections and components, which not only streamlines the overall installation but also reduces the potential points of failure.

In contrast, a two-pipe system, while offering certain advantages such as the ability to recover oil from the return line, does complicate the setup and can introduce more opportunities for leaks or errors during installation. Additionally, the statement regarding filtering oil several times in a two-pipe system may not accurately reflect the mechanism or function of the systems involved.

Ultimately, the simplicity and efficiency of a one-pipe system contribute significantly to both ease of installation and reliability during operation.