Question 29 TK01 - Tank Vessel Assistant - Dangerous Liquids

The Correct Answer is B **Explanation for Option B (Correct):** Closing a valve completely, then opening it slightly (one or two turns), and then re-closing it is a standard and essential procedure, particularly in tanker operations. This technique ensures that the valve seat is properly sealed and that the valve is fully shut. Valves, especially gate valves frequently used in cargo systems, can sometimes appear closed when they are not fully seated, leading to leakage (known as "weeping"). Performing this double-closing procedure confirms a positive shutoff, which is crucial for safety and preventing accidental mixing of cargo or spills during loading and segregating tanks. **Explanation for Other Options (Incorrect):** * **A) keep the seamen on watch on standby in the messroom:** This is incorrect. Personnel on watch during critical operations like loading must be readily available at their stations (e.g., manifold, pump room, control room, on deck monitoring tanks) to respond immediately to any changes, alarms, or emergencies. Keeping them in the messroom compromises reaction time and safety. * **C) keep a strain on the loading hoses:** This is incorrect. Hoses and arms should be rigged or supported such that they are not subjected to undue strain (tension, compression, or bending). Excessive strain can lead to premature failure, leakage at the couplings, or rupture, causing a catastrophic spill. The connection should be secure but stress-free. * **D) load only one tank at a time:** This is generally incorrect and highly impractical for large commercial tankers. While initial loading rates or specialized operations might involve filling one tank, standard tanker loading procedures often involve topping off several tanks simultaneously or loading multiple tanks at varying rates to manage stability, trim, and stress on the hull girder efficiently. Safety is maintained through careful monitoring and controlled rates, not by strictly limiting flow to a single tank.