Which plan shows plumbing supply and water lines, fixtures, and valves?

• A. Floor plans
• B. Plumbing plan
• C. Fire protection plan
• D. Mechanical plan

Answer: (B)

Understanding how water systems are documented in drawings is tested here. The plumbing plan is the drawing that specifically shows the water supply and distribution piping, where fixtures connect, and the location of shutoff valves. This plan is used to lay out supply lines, drainage connections, fixtures (sinks, toilets, urinals, showers), and the valves or backflow devices that control flow.

A floor plan shows room layout and features, not the piping details. A fire protection plan illustrates fire sprinkler and other suppression piping. A mechanical plan focuses on HVAC equipment and ductwork, and may touch piping in some cases but does not concentrate on plumbing fixtures and water lines.