🔍 Key Concepts

• function of a contaminated drain inspection tank in a fuel oil system • how fuel oil heaters and their coils/steam heating coils are arranged in relation to drains and tanks • difference between leakage of heating medium into oil vs normal drainage of clean oil or condensate

💭 Think About

• Think about what liquid is supposed to go to a contaminated drain inspection tank under normal conditions, and what abnormal condition would introduce oil there. • Which choice describes a condition where oil can pass from one side of a heating coil or tank boundary to the other side and end up in the drain system? • Eliminate any options that would mainly change temperature or pressure of oil, but would not provide a direct path for oil to enter a drain inspection tank.

✅ Before You Answer

• Identify which component, if it fails, creates a path for oil to leak into a drain line instead of staying in the fuel system. • Confirm which option involves internal leakage through a boundary (tube/coil) rather than just external drainage problems. • Check which choice best matches a known cause of oil showing up in contaminated drains in standard fuel oil/steam heating arrangements.