Richard S. Boswell, P.E.: About the Author
Stress Engineering Services, Inc.

A set of delayed coker drums were placed in service in 1968, and now have 27 years of service in what may be the most violent and severe cyclic loading conditions of any petrochemical vessel. As part of the continuous evaluation of their integrity, surface contour measurements were performed to document the growth of the bulges.

A set of delayed coker drums was placed in service in 1968, and now have 27 years of service in what may be the most violent and severe cyclic loading conditions of any petrochemical vessel. As part of the continuous evaluation of their integrity, surface contour measurements were performed to document the growth of the bulges.

A pair of delayed coker drums was placed in service in 1968, and now have 28 years of service in what may be the most severe cyclic loading conditions of any petrochemical vessels. They are a conventional ASME VIII/Div 1 pressure vessel design based on 60 psi and 836 degrees Fahrenheit at the top and 899 degrees Fahrenheit at the bottom. This design provides increasing thickness, from the bottom up, in seven rings constructed with clad plates, using longitudinal and circumferential weld seams.

Evaluations of aged and critical service vessels such as FCCU's and Delayed Cokers have been aided by the addition of two physical measurements referred to as structural characterizations. These are placed in perspective with the classic description provided by John Reynolds in his presentation of a multidisciplinary team effort in Fitness for Service (FFS) evaluations.