Which of the following would not be considered an "appurtenance"?

In the context of RV systems, appurtenances refer to equipment or components that attach to a primary system and are considered essential but not integral to the system's primary function. These components typically include gauges, valves, and safety devices that enhance the operation or safety of the primary system.

A fixed liquid level gauge is a clear example of an appurtenance because it provides vital information about fluid levels and assists in monitoring but is not necessary for the system itself to operate. Similarly, a pressure relief valve serves a safety purpose by preventing overpressure conditions, thereby making it an appurtenance crucial for safety but not directly involved in the primary function.

A service valve, often used to shut off flow for maintenance or repairs, is essential for operational control and is thus classified as an appurtenance too.

In contrast, an excess flow valve is not considered an appurtenance because it is primarily a safety device that regulates and controls flow in response to changes in system pressure or flow rates. It is designed to shut off the flow if it exceeds a preset limit, directly impacting the system's operation rather than merely adding to the existing functionality or monitoring. Therefore, the identification of it as an appurtenance is incorrect as it