When operating the HFO purifiers in...

🔍 Key Concepts

• Understand the difference between parallel and series operation of fuel oil purifiers • Trace the HFO flow path from the settling tanks through each purifier and back to the day/mixing tank • Identify which numbered valves are cross‑connection / changeover valves versus normal inlet or outlet isolation valves

💭 Think About

• Follow the piping from the HFO settling tanks to the inlet of each HFO purifier: in true parallel operation, how should the inlet flow reach each unit? • Follow the outlet (clean oil) lines from each purifier: in parallel operation, should the discharge of one purifier feed into the suction of the other, or should they both return to the same clean oil manifold? • Looking at valves 2, 3, and 6, which ones, if opened, would cause the flow from one purifier to go through the other instead of operating them independently?

✅ Before You Answer

• Verify which valve(s) would create a series connection between the two HFO purifiers if left open • Confirm which valve(s) must stay open so that each purifier has its own inlet and outlet to the common manifolds • Before choosing, double‑check the symbols near each valve (upstream/downstream of each purifier) to see which are cross‑overs rather than normal line isolations

When operating the HFO purifiers in "parallel", as shown in the illustration __________. Illustration MO-0077

valve "2" would be closed

valve "3" would be closed

valve "6" would be closed

All of the above

🔍 Key Concepts

💭 Think About

✅ Before You Answer