What is the term for a pipe that connects a potable water source to a building's water distribution system?

The term that accurately describes a pipe connecting a potable water source to a building's water distribution system is "water service." This terminology is widely employed in plumbing and building codes to denote the system that brings safe, drinkable water from a municipal supply or a private well directly to a structure. The water service pipe is critical for ensuring that the building receives an adequate supply of clean water for consumption, sanitation, and other domestic uses.

In contrast, the other terms refer to different aspects of plumbing systems. A drainage pipe is involved in the removal of wastewater from a building and is not used for supplying potable water. A vent pipe is part of the plumbing system that allows air to enter the drainage system, preventing vacuum formation and ensuring smooth wastewater flow. A faucet line generally refers to the specific piping leading directly to a faucet, not the primary connection from the water source to the building's overall water distribution network.