The "better" argument is essentially an economic one over the long term. While fabricating a chair adds shop labor compared to a simple flat plate, the elimination of base plate reinforcement and the prevention of future maintenance shutdowns makes the AISE design superior.
A standard chair detailed in Part VII typically consists of: aisi e 1 volume ii part vii anchor bolt chairs better
: Small tubular columns (under 4 feet in diameter) may bypass chairs if the base plate is thick enough to resist bending. However, for most other shells, chairs are "always needed" to prevent structural deformation. The "better" argument is essentially an economic one
: Instead of isolated chairs, a continuous ring is welded at the top of the vertical plates. This ring acts as a single structural unit that distributes the anchor bolt load more uniformly around the entire circumference of the shell. However, for most other shells, chairs are "always