🔍 Key Concepts

• Bilge overboard discharge arrangement in GS-0042 • Difference in symbol/shape between a gate valve and a check valve (swing or stop-check) on piping diagrams • Purpose of remote operation from above the bulkhead deck for overboard discharges

💭 Think About

• Look closely at the valve symbols on the overboard discharge line: do they show a one‑way (check) feature or a simple open/close gate? • Trace where the operating mechanisms or reach rods go: do they extend up to the bulkhead deck or are they local only? • Ask yourself which type of valve is normally required on bilge overboard lines to prevent backflow into the ship

✅ Before You Answer

• Confirm whether the symbol shows a hinged disk/arrow (check feature) or a plain gate symbol • Verify if there are dotted/solid lines or reach rods leading from the valve up to a higher deck in the illustration • Make sure your choice matches both the valve type and how it is operated, as described in the answer options