What junction requirement is mandated for vertical and horizontal junctions?

• A. At least 10% of junctions
• B. At least 25% at vertical and horizontal junctions
• C. All junctions must be inspected
• D. No requirement for junctions

Answer: (B)

The requirement for junctions in the construction of welded tanks, as outlined in API 650, stipulates that at least 25% of the junctions must be inspected for both vertical and horizontal connections. This inspection requirement is crucial because junctions are critical points where structural integrity is essential, especially considering the stresses placed on tanks due to liquid contents, temperature changes, and environmental factors. By mandating that a significant portion of these junctions undergo thorough inspection, the standard aims to ensure quality control and safety in tank construction, thereby reducing the risk of failures which could lead to leaks or catastrophic incidents. This focus on a substantial percentage of inspection helps ensure that potential defects are identified and remedied early in the construction process.