What is defined as "DOT jurisdictional piping" for inside meters?

The definition of "DOT jurisdictional piping" in the context of interior gas systems specifically pertains to the piping that runs from the building wall to the outlet fitting of the gas meter. This portion of piping is critical because it is included under the regulations set forth by the Department of Transportation (DOT), which govern the transportation and safety of gas. This piping segment represents the transition between the utility's gas supply and the gas system within the building. It is important for ensuring the integrity of gas delivery and is subject to stringent safety standards to prevent leaks and ensure proper function.

In contrast, the other choices represent different components of a gas piping system but do not fall under DOT jurisdiction. The piping leading to appliances, while important for distribution, does not fall within the regulated boundary defined by DOT, as it pertains instead to the internal gas system within the building. Underground conduits for gas distribution are typically regulated differently based on their configuration and use. Similarly, surface lines connecting appliances address overall gas distribution in a building but do not represent the boundary that DOT regulations typically define for jurisdictional piping.