Manway covers and exchanger heads may be covered with jacketing material by the combined use of an end cap with which seam?

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

Answer: (C)

The joint around a manway or exchanger head needs a strong, weather-tight closure that works well on curved shapes. The Pittsburg seam is a lock-type seam that interlocks and crimps the jacket edges, creating a tight, flush, and durable connection. When paired with an end cap, this seam provides a robust seal that resists moisture infiltration and cycling stresses, which is essential for a removable cover on open ends. Lap seams tend to overlap and can trap water; bead seams rely on the bead for sealing but aren’t as mechanically strong; hidden seams aren’t as easily inspected or maintained on end closures. So, using an end cap with a Pittsburg seam gives a reliable, long-lasting closure for manway covers and exchanger heads.