Question 35 UFIV01 - Chief Engineer - UFIV

The Correct Answer is B **Explanation for Option B (Daily):** Starting air receivers must be drained frequently to remove moisture (condensate) and oil carryover. This is crucial for several reasons: 1. **Preventing Corrosion:** Water in the receiver promotes internal rusting, weakening the structure and potentially causing failure. 2. **Maintaining Air Quality:** Excess moisture can be carried into the engine air lines, damaging air-starting motors (especially vane types, where water can wash away lubrication and cause corrosion/seizing) and potentially causing hydraulic lock in the engine cylinders if the air admission valves leak. 3. **Ensuring Capacity:** Accumulated water reduces the effective volume and pressure capacity of the receiver, which is critical for reliably starting the main engines. While best practice often dictates draining at least once per watch (every 4 hours) or multiple times daily, industry minimum standards and good engineering practice mandate draining receivers at least **daily** while the vessel is underway and the compressor system is actively in use, especially in the absence of automatic drain systems. **Why the Other Options are Incorrect:** * **A) Hourly:** While draining hourly (or every four hours) is ideal or best practice in humid conditions or for very high-use systems, it is generally considered an excessive minimum requirement for standard operational procedures on an underway vessel. A daily check is the accepted minimum standard for safe operation. * **C) Weekly:** Draining only weekly is insufficient. Moisture accumulation is rapid, especially in tropical waters or humid environments. Allowing water to sit for a full week significantly increases the risk of corrosion, reduces starting capacity, and increases the chance of water carryover into the engine starting system. * **D) Monthly:** Draining monthly is dangerously inadequate. By the time a month has passed, the air receiver could contain a substantial amount of water, severely compromising the safety and reliability of the vessel's primary starting mechanism.