Question 46 1AE01 - First Assistant Engineer

The Correct Answer is C **Explanation for C (Correct Option):** Option C, "prevent separated oil from mixing with the incoming bilge water," accurately describes the function of item "7" in a typical illustration of an Oily Water Separator (OWS), such as GS-0153. Item "7" typically points to a **weir** or an **oil retention baffle** within the separation chamber. * In the first stage of an OWS (gravitational separation), oil, being lighter, floats to the top of the tank. * The function of the baffle (7) is to create a barrier and retain this separated layer of oil in the upper section of the tank. * This barrier ensures that the incoming oily water mixture (which enters lower down) does not agitate the settled oil layer and prevents the clean, separated water (which flows out from the bottom) from re-mixing with the surface oil. The primary role is containment and prevention of re-emulsification. **Explanation for Incorrect Options:** **A) allow the oil accumulated to exit the device, while remaining separated from the liquid:** This is incorrect. The oil weir/baffle (7) retains the oil; the exit or discharge valve/port for the accumulated oil is a separate component (often located near the top, above the baffle). **B) direct the flow of the oily-water mixture against the coalescer bed:** This is incorrect. While baffles sometimes direct flow, the *primary* purpose of the oil retention baffle (7) is vertical separation and containment of the surface oil layer. Flow against the coalescer bed is usually directed by inlet piping and possibly distribution plates, not this specific oil containment weir. **D) support the tank access panel:** This is incorrect. The oil retention baffle/weir is an internal structural component designed for fluid separation and flow control. Tank access panels are supported by the main tank structure or dedicated external brackets/frames.