🔍 Key Concepts

• Fuel oil strainers remove solids before the burners • A dirty or clogged strainer creates more resistance to flow • Effect of restricted flow on pressure drop across the strainer and pressure at the burner manifold

💭 Think About

• What happens to the flow of oil when the strainer becomes partially blocked? Does resistance increase or decrease? • If resistance through the strainer increases, how does that affect pressure before the strainer, after the strainer, and at the burner manifold? • Which of the listed conditions is a direct and immediate indication at the strainer itself, and which are more indirect, downstream effects?

✅ Before You Answer

• Compare pressure before and after the strainer: does a dirty strainer make the pressure drop larger or smaller? • Ask whether fuel temperature is directly related to strainer cleanliness or mainly to heaters and controls • Decide which options show a symptom at the burner versus a measurement across the strainer itself