What is the minimum distance a conduit must extend beyond the end of a building for an underground gas line?

The minimum distance a conduit must extend beyond the end of a building for an underground gas line is related to safety and accessibility requirements. Extending the conduit at least 4 inches beyond the building ensures that the gas line is adequately protected as it transitions from the underground environment to an above-ground environment. This distance helps to mitigate risks such as physical damage or interference from the building structure, ensuring that maintenance and inspection are easier and safer.

Maintaining this distance also aligns with national and local code requirements aimed at preventing leaks and other hazards associated with gas lines. In addition, this distance facilitates proper drainage and minimizes the potential for water intrusion into the conduit, which could lead to both physical damage and hazardous conditions.

Other options represent distances that are either insufficient to maintain safety and accessibility or exceed what is generally deemed necessary for the protection of the gas line. Thus, extending the conduit a minimum of 4 inches is deemed a standard practice to promote safety and compliance with regulatory requirements in the installation of gas lines.