What is the term for the vertical pipes connecting the system main line(s) with the branch lines on different levels in a facility?

The term for the vertical pipes that connect the system main lines with the branch lines on different levels in a facility is "risers." Risers play a crucial role in the distribution of medical gases or other utilities throughout a building, facilitating the upward and downward movement of these supplies through vertical shafts.

In a medical gas system, risers help maintain pressure and flow rates as gases are transported from the main supply lines to various floors and branch outlets where they are needed. Understanding the function of risers is essential for compliance with safety standards and ensuring proper installation and maintenance of medical gas systems.

The other terms provided do not accurately describe this system component: columns typically refer to structural supports within a building, elevators are vertical transport systems for moving people or goods, and conductors typically refer to channels through which electric current or fluids flow, rather than specifically indicating vertical piping in a medical gas context.