Question 13 TK01 - Tank Vessel Assistant - Dangerous Liquids

The Correct Answer is D. **Why Option D ("150 psi") is Correct:** Regulations governing cargo transfer systems on tank vessels, specifically those dealing with petroleum products or hazardous chemicals, mandate that the cargo hose must be robustly constructed and certified to handle the operational pressures and potential surges. According to U.S. Coast Guard regulations (specifically found in 33 CFR 156.170, which outlines hose requirements for transfer operations), hoses used during liquid cargo transfers must be designed and constructed to withstand a minimum burst pressure of at least four times the maximum working pressure, and must be certified or distinctly marked to indicate a minimum **working pressure of 150 psi** (pounds per square inch). This minimum standard ensures safety margins are met during high-volume pumping operations. **Why the Other Options are Incorrect:** * **A) 75 psi:** This pressure is significantly too low for the safe handling of liquid bulk cargoes on modern tank vessels. While some older or smaller hoses might have lower ratings, 75 psi does not meet the minimum regulatory requirements for standard cargo transfer operations. * **B) 100 psi:** While 100 psi is higher than 75 psi, it still falls short of the mandatory minimum working pressure requirement (150 psi) set by regulatory bodies for cargo hoses used on regulated tank vessels. * **C) 120 psi:** This pressure is closer to the required standard but is still below the minimum acceptable working pressure of 150 psi required by regulations for certified cargo hoses used in transfer operations.