🔍 Key Concepts

• Trace the sea water flow path carefully, especially when the distiller is placed in service (on line). • Identify which side of the lube oil cooler (item 4) is lube oil and which is sea water; only one of these is affected by the distiller. • Think about series vs. parallel flow: when another heat exchanger (the distiller) is added in series with the cooler, what happens to the sea water’s temperature and pressure before it reaches item 4?

💭 Think About

• Follow the piping: does the sea water go to the lube oil cooler first and then to the distiller, or to the distiller first and then to the lube oil cooler? How would each arrangement change the temperature of the sea water entering item 4? • If the same pump is supplying sea water, and you add the distiller into the circuit, does that logically increase the pressure at the cooler, or does it mainly change temperature and flow resistance? • Would putting the distiller on line have any direct effect on the lube oil side (pressure or temperature entering the cooler), or is its influence limited to the cooling medium (sea water) side?

✅ Before You Answer

• Verify which lines are sea water to and from the lube oil cooler and which are lube oil to and from the cooler. • Check whether the distiller sea water connections are in series with, or in parallel to, the cooler’s sea water side; this determines what happens to temperature and pressure at item 4. • Eliminate any choices that describe changes on the lube oil side that are not connected by piping or control valves to the distiller in the diagram.