The identification feature described as a single manhole assembly protected by a flash box and roll-over protection corresponds to which designation?

The identification feature described as a single manhole assembly protected by a flash box and roll-over protection corresponds to which designation?

• A. MC 306/DOT 406
• B. MC 307/DOT 407
• C. MC 312/DOT 412
• D. MC 331

Answer: (B)

A single manhole on top that is protected by a flash box and surrounded by roll-over protection identifies a low‑pressure liquid cargo tank. This combination is a hallmark of the MC 307/DOT 407 designation. The flash box serves to shield the opening and help prevent ignition of flammable vapors, while the roll-over protection around the manhole guards the fitting in the event of a tip or impact, helping keep the opening secure. Other tank types use different top fittings and safety features, so they don’t match this exact arrangement. This distinctive top assembly is why the correct designation is MC 307/DOT 407.

A single manhole on top that is protected by a flash box and surrounded by roll-over protection identifies a low‑pressure liquid cargo tank. This combination is a hallmark of the MC 307/DOT 407 designation. The flash box serves to shield the opening and help prevent ignition of flammable vapors, while the roll-over protection around the manhole guards the fitting in the event of a tip or impact, helping keep the opening secure.

Other tank types use different top fittings and safety features, so they don’t match this exact arrangement. This distinctive top assembly is why the correct designation is MC 307/DOT 407.