How are bolt holes in the base plate of a vertical vessel laid out?

How are bolt holes in the base plate of a vertical vessel laid out?

• A. Straddle the center lines of the vessel
• B. Aligned along the outer circumference
• C. In a square grid
• D. In a min-max pattern

Answer: (A)

Bolt holes in a vertical vessel’s base plate are arranged to transfer loads evenly and keep the vessel stable. Placing the holes so they straddle the vessel’s centerlines creates a pattern that is symmetric about both axes. This symmetry minimizes eccentricity in the load path, helps prevent rotation or tipping under vertical and lateral forces, and aligns well with the vessel’s saddles and foundation footing. It also makes leveling and grouting easier and ensures differential settlement is shared more evenly among the bolts. Patterns that align holes only along the outer edge or in irregular grids don’t provide the same balanced load transfer and can lead to uneven stresses and instability.

Bolt holes in a vertical vessel’s base plate are arranged to transfer loads evenly and keep the vessel stable. Placing the holes so they straddle the vessel’s centerlines creates a pattern that is symmetric about both axes. This symmetry minimizes eccentricity in the load path, helps prevent rotation or tipping under vertical and lateral forces, and aligns well with the vessel’s saddles and foundation footing. It also makes leveling and grouting easier and ensures differential settlement is shared more evenly among the bolts. Patterns that align holes only along the outer edge or in irregular grids don’t provide the same balanced load transfer and can lead to uneven stresses and instability.