🔍 Key Concepts

• Nominal pipe size vs. actual dimensions (outside and inside diameter) • How schedule (wall thickness) changes inside diameter while outside diameter often stays the same for a given nominal size • Using the given 3-inch pipe data to compare with the unknown pipe

💭 Think About

• Start by finding the wall thickness of the known 3-inch standard pipe from its given outside and inside diameters. How does that compare to the wall thickness of the unknown pipe? • Ask yourself: for the same nominal size, what usually stays constant—outside diameter or inside diameter? What changes when you go to heavier schedules? • Look at the choices: some are larger nominal sizes, others are different schedules of the same nominal size. Which type of change best matches the dimensional differences you calculate?

✅ Before You Answer

• Carefully compute wall thickness = (OD − ID) / 2 for BOTH pipes, using inches • Verify whether the outside diameters match closely enough to be considered the same nominal size • Confirm that a heavier schedule means a thicker wall and smaller inside diameter for the same outside diameter