CHEMCO Exit Exam • Set 1 Question 19 of 30

What device is installed on chemical tank venting systems to prevent over-pressure or vacuum?

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Direct Answer

Option B: High-velocity Pressure/Vacuum (P/V) valve

High-velocity Pressure/Vacuum (P/V) valves are installed on chemical tank venting systems. These devices are crucial for preventing over-pressure or vacuum conditions within the tanks during loading, unloading, and thermal expansion/contraction, as specified by the IBC Code.

All Options

Check valve

High-velocity Pressure/Vacuum (P/V) valve (Correct Answer)

Globe valve

Needle valve

Detailed Explanation & Context

Relevant Framework: STCW 2010 Manila Amendments • DG Shipping E-Learning & Exit Exam Standards • Advanced Training for Chemical Tanker Cargo Operations (CHEMCO).

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More Questions in CHEMCO Set 1

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Q1 Which IMO Code regulates the carriage of dangerous chemicals in bulk on chemical tankers? Q2 Under MARPOL Annex II, which pollution category presents the major hazard to human health or marine resources? Q3 What test is performed on tank bulkhead surfaces to detect microscopic hydrocarbon residues before loading sensitive chemical cargoes? Q4 What type of chemical tanker skin/tank construction is required for carrying high-hazard cargoes like Isocyanates? Q5 What material is widely used for cargo tanks carrying aggressive acids such as Nitric or Phosphoric acid? Q6 What is the key limitation of Zinc Silicate tank coatings in chemical tankers? Q7 What document must be maintained on board detailing all chemical cargo loading, discharging, tank washing, and slop handling? Q8 What is self-polymerization in chemical cargoes? Q9 What mandatory document provides chemical property, health hazard, reactivity, and emergency response data for a chemical cargo? Q10 What system is used to purge chemical lines and maintain an inert nitrogen cushion over moisture-sensitive cargoes?