You are on a vessel designed to carry...

🔍 Key Concepts

• 46 CFR requirements for compressed flammable gases in bulk (especially special requirements for butadiene) • Materials compatibility of valves and fittings with specific cargoes (metals that may cause hazardous reactions or polymerization) • Difference between general documentation rules and special cargo-specific rules for dangerous gases

💭 Think About

• Which of these choices looks like a cargo-specific safety restriction that would appear word‑for‑word in a regulation for butadiene, rather than a general practice? • Think about why some metals might be prohibited in contact with certain gases. Which metals are known to promote polymerization or dangerous reactions with butadiene? • For the options about sampling, documentation, and ullage padding: do current rules usually require exact quantities, sampling only at one time, or the use of compressed air on a flammable gas cargo?

✅ Before You Answer

• Look in 46 CFR Part 151 (or the section on special requirements for specific cargoes) for the entry on Butadiene and read the exact conditions listed. • Verify whether any rule allows padding the tank with compressed air for a highly flammable gas like butadiene, or if an inert gas is normally required instead. • Check if the regulation mentions prohibited metals (such as silver, copper, or high‑copper alloys) in parts of valves and fittings that are in contact with butadiene. This is a key safety clue.

You are on a vessel designed to carry compressed gasses in bulk with a cargo of butadiene. Which statement is TRUE?

The cargo tank may be sampled only when the tank is being filled.

Silver and copper are prohibited in the parts of valves and fittings in contact with the cargo.

The shipping document must specify the exact quantity of butadiene being carried.

The ullage must be padded with compressed air at a minimum pressure of 2 psig.

🔍 Key Concepts

💭 Think About

✅ Before You Answer