There are a several drums in service that have used the CB&I vertical plate technology. The thinking was that the circ welds in a normal plate arrangement were contributing to the cracking of the drums as the circ welds were slightly different metallurgically than the base metal. These drums have been in service less than 20 years and depending on the cycle time have roughly 5000 cycles (some more and some less), so it is likely too soon to tell if this design provides a difference in overall drum life.
Some of the drums with this design have had bulges and cracks, similar to drums with the conventional design. The stresses imposed on the coke drum during the water quench phase may be high enough that the orientation of the plate and the number of circ welds does not influence the fatigue damage. The drum wall thickness is a factor in the fatigue damage. The type of coke produced, the length of the fill cycle and how well the drum was warmed up prior to switching feed back into the drum all impact the fatigue damage on the drum.
