What type of cargo tank is classified as an "MC 331"?

The classification of an "MC 331" refers specifically to pressure cargo tanks designed for transporting liquefied gases. These tanks are built to withstand high pressures and are typically used for materials that are gaseous at normal atmospheric temperatures but can be transported in liquid form when subjected to pressure.

Pressure cargo tanks are generally cylindrical in shape with a specified operating pressure, and they often have associated safety features, including pressure relief valves, to manage the high-pressure conditions. This classification is crucial for understanding the design and operational parameters of the tank, as it reflects the specific needs of transporting materials that require containment under pressure.

The other options do not relate to the characteristics of the MC 331 designation. Low pressure cargo tanks are designed for different pressure specifications, intermediate bulk containers are portable and suitable for handling bulk materials but do not conform to the MC 331 design standards, and hazardous waste tanks have a separate classification that pertains primarily to the containment of hazardous substances rather than the design standards associated with cargo tanks.