Longitudinal laps on jacketing are typically placed at which clock position?

• A. 9 o'clock to 10 o'clock
• B. 12 o'clock to 1 o'clock
• C. 3 o'clock to 4 o'clock
• D. 6 o'clock to 7 o'clock

Answer: (C)

Longitudinal laps are placed to protect the seam from moisture, weather, and mechanical damage while keeping the seal reliable along the length of the jacket. Positioning the seam on the side of the pipe circumference—not on the top or bottom—puts it in a less exposed spot. Water from rain or spray is less likely to run directly into the seam, and the seal (tape or adhesive) can be applied with a full, uninterrupted surface for a more durable bond. A side seam is also less prone to being damaged by handling, supports, or equipment that contact the top or bottom of the pipe. For these reasons, the side location is the preferred practice for longitudinal laps.