What type of protection should be provided for connections to underground ASME containers?

The correct choice involves providing a substantial dome or housing around connections to underground ASME (American Society of Mechanical Engineers) containers. This type of protective structure is crucial because it serves multiple safety functions, including safeguarding the integrity of the connections from physical damage, environmental factors, and potential corrosion that can arise from soil interaction or water exposure.

A substantial dome or housing is designed to withstand external pressures and impacts, ensuring that the piping and fittings connected to the underground container remain secure and functional. It not only protects the components physically but also aids in preventing accidental exposure to propane, which could lead to hazardous situations if a leak were to occur.

In contrast, other options, such as a simple cover or concrete slabs, may not provide adequate protection against the specific risks associated with underground installations. Plastic wrapping, while it can offer some level of moisture protection, does not provide the structural support needed to defend against potential damage from external forces. Thus, the substantial dome or housing is the recommended method for ensuring safety and reliability in these installations.