🔍 Key Concepts

• Cargo tank safety/relief valves on tank vessels and their normal method of remaining closed until needed • Operational restrictions on testing or "popping" safety valves, especially in port due to vapors and pollution/fire risk • Difference between a valve that opens directly by tank pressure vs one that can be pilot-operated

💭 Think About

• Think about how a typical spring-loaded safety/relief valve stays closed under normal conditions. What keeps it shut until the set pressure is reached? • Consider why ports and terminals might have strict rules about intentionally lifting or "popping" cargo tank relief valves. • Ask yourself whether cargo tank safety valves on modern tankers can be designed to use pilot valves, and how that affects whether they can be opened.

✅ Before You Answer

• Check whether safety valves are normally held closed by tank pressure or by some mechanical means (like a spring). • Consider whether regulations and safe practice allow intentionally lifting/popping cargo tank safety valves in port. • Verify if cargo tank safety valves may be pilot-operated and how that relates to each of the listed statements.