Connections to ASME containers installed underground must be located within what type of structure?

Connections to ASME (American Society of Mechanical Engineers) containers installed underground must be located within a substantial dome structure to ensure safety and compliance with regulatory standards. Substantial dome structures are designed to provide protection from environmental factors, help manage gas pressure, and prevent unauthorized access. This type of structure also aids in the proper ventilation of any potential leaks, reducing the risk of explosion or fire associated with propane gas.

Utilizing a substantial dome ensures both the physical integrity of the container and the safety of the surrounding area, as it confines potential hazards and facilitates appropriate safety measures. Other structure types mentioned, such as open areas or residential zones, do not provide the necessary level of security or protection required for handling propane connections safely.