🔍 Key Concepts

• Purpose of preheating lube oil before turning (rolling) a steam turbine • How a lube oil purifier works and its effect on oil temperature and circulation • Normal function of the gland sealing steam, gravity tank, and multiple lube oil pumps

💭 Think About

• Which option actually causes controlled circulation of oil through a heater or warm system path before the turbine is rolled? • Which options would have little or no effect on lube oil temperature, or might even create unsafe/abnormal conditions for the lube oil system? • Think about normal operating procedures: what equipment is specifically designed to clean and warm oil in a sump?

✅ Before You Answer

• Identify which choice is directly connected to the main lube oil sump and can run with the turbine secured • Confirm which systems (gland sealing steam, gravity tank, extra pumps) are not intended primarily to preheat oil • Ask: in real shipboard practice, what is the usual way engineers warm lube oil in a large sump before starting a main turbine?