Majority of problems with cargo tanks are due to which components?

• A. Hatches and doors
• B. Pumps and gauges
• C. Valves and fittings
• D. Dome plugs and baffles

Answer: (C)

The main idea here is that the points where the tank is sealed and controlled—valves and fittings—tend to cause the most problems. These components are involved in every transfer, venting, and pressure-control operation, so they endure the most stress from cargo properties, pressure changes, temperature swings, vibration, and frequent use. A valve can fail to seal completely, an O-ring or gasket can degrade, a threaded connection can loosen, or a fitting can corrode, all of which create leaks or unsafe releases. Because these joints are continually cycled and exposed to hazardous contents, they are the most common source of issues on cargo tanks.

Maintenance and inspection focus on keeping these parts in good condition—checking seals for leaks, ensuring correct seating, confirming proper torque on connections, using compatible materials, and performing regular leak testing. While problems can occur with hatches, pumps, gauges, or dome plugs and baffles, the frequency and impact of leaks from valves and fittings make them the predominant source of cargo-tank problems.