🔍 Key Concepts
• Study the flow paths in all four figures (A–D) to see what happens to the stream that passes through valve V‑4.
• Use the legend: solid arrows are oil flow, open arrows are water flow. Match V‑4’s line to the correct fluid and direction.
• Identify the pump symbol and note which valve is on the suction side, and which lines go to overboard/holding, and which go to drains.
đź’ Think About
• In each figure, if you follow the line that contains V‑4, where does that line come from and where does it go? Does it lead to the pump, the separator inlet, the clean‑water outlet, or to a sludge/oil drain?
• Compare V‑4 with valves V‑1, V‑2/V‑2A, V‑3, and V‑14. Which of those clearly handle overboard discharge, system suction, or automatic oil drain? That helps eliminate some answer choices.
• Look at the operating condition where the unit is actually processing oily water (not stopped or dumping). In that condition, what function must a valve in V‑4’s position provide for the system to work correctly?
âś… Before You Answer
• Be sure you have positively identified the pump and confirmed which side is suction vs. discharge.
• Verify whether the line with V‑4 is marked by oil arrows or water arrows in the legend; this rules out some options.
• Confirm whether the V‑4 line connects to the inlet to the separator, the processed water outlet, or a drain/sump connection before choosing.