Which seam is used when combining an end cap with jacket material to cover manway covers and exchanger heads?

• A. Pittsburgh seam
• B. Lap seam
• C. Bead seam
• D. Hidden seam

Answer: (C)

Bead seam is used because it creates a raised edge along the joint that can be sealed tightly around irregular shapes like manways and exchanger heads. This bead provides a durable, weather-tight finish and a neat seal where the end cap meets the jacket, allowing caulking or sealing material to grip and stay put as the assembly contracts and expands with temperature changes. The bead seam is specifically suited to securing and finishing around protrusions, giving a clean exterior and reliable moisture protection around the end cap area. Other seams tend to rely on overlaps or flat joints that are harder to seal cleanly and maintain around such shapes, or are intended for different applications (straight runs or concealed joints) rather than the curved, complex geometry of end caps and heads.