Key Learnings from Large-Bore Compressor Piping Design of a Carbon Capture System
J. Fernando, L. Chan, H. Kwok, S. Yuen, S. Roberts
Thermo-mechanical loading and nominal pipe size are two critical considerations in the design/engineering of large-bore piping configurations. Here is a study that outlines several important design features that should be considered when designing systems that require large-bore piping, using the successful retrofit of a carbon capture and storage (CCS) facility as a case study.
Optimizing Coke Drum Keyhole Dimensions using Statistical Modeling
J. Fernando, H. Kwok, L. Chan, J. Penso
Keyholes have become an important consideration in coke drum skirt design. Here is a study that investigates keyhole designs for two commonly used skirt designs to identify functional trends between keyhole parameters and stress, and proposes a simple linear regression model to quickly assess the fatigue performance of a keyhole design.
Local Post Weld Heat Treatment of a Pressure Vessel: A Postmortem Evaluation
S. Yuen, A.B. Mackay, D. McArthur, H. Kwok, J. Fernando, L. Wong
There are currently established industry guidelines on the placement of heating coils and insulation, but no standard analytical technique, engineering protocol or acceptance criteria. Here is a study that is a postmortem evaluation of a process tower that suffered significant distortion after a local post weld heat treatment (PWHT). Additional analytical techniques are also tested using Finite Element Analysis (FEA) to determine which method best predicts the deformation experienced by the pressure vessel in question.
On the Effect of Rising Liquid on Coke Drum Skirt Fatigue Life
J. Fernando, H. Kwok, L. Chan, M. Iverson, F. Ju, S. Yuen
Accurate modeling of the heat transfer from the fluid to the vessel is of critical important in the analysis of coke drums. Here is a study that focuses on comparing two temperature methodologies with different degrees of complexity by estimating fatigue life at the skirt-to-vessel attachment weld for two common skirt designs.
Reliability Improvement Concept on Welded Lip-Seal Heat Exchanger Flange Joints
S. Yuen, J. Fernando, J. Penso, H. Kwok, D. Serate
Lip-seal flange joints are commonly used in high-pressure heat exchanger design when there exists a significant temperature differential along the circumference of the heat exchanger flanges. Here is a study that investigates several special joint design features that aim to improve the reliability of such joints, particularly looking at stress distributions at critical locations of the joint to compare designs.
On the Effect of Hot-Box Size on Coke Drum Skirt Fatigue Life
J. Fernando, L. Wong, H. Kwok, L. Chan
Fatigue failure is commonly observed at the skirt-to-shell attachment weld, due to thermal gradients that develop during heating and cooling cycles. To reduce temperature differences between the coke drum shell and skirt near the attachment weld, “hot-boxes” are often implemented in skirt designs. Here is a study that investigates the effect of hot-box emissivity and height on the fatigue life of the attachment weld for skirt designs with and without keyholes.
Coke Drum Keyhole Optimization with Alloy Weld Overlay
J. Fernando, E. Falo, H. Kwok, M. Iverson, L. Wong, S. Yuen, L. Chan
To increase fatigue life of attachment welds, vertical slots and keyholes are often machined in a circumferential pattern near the top of the skirt to increase local flexibility near the weld. Here is a study that investigates a new keyhole design consisting of N06625 overlay at the keyhole locations and also conducts a sensitivity study to determine the effect of fillet size on fatigue life.
Integral Mean of Yield Concept Applied to Thermal Hotspots – Validation of a Level 2 Damage Assessment Method
H. Kwok, S. Yuen, J. Penso
A Level 2 assessment methodology is developed, which invokes the concept of integral mean of yield and a refence volume to determine the reduction of load capacity caused by hot spot damage. Here is a study that investigates the accuracy of this assessment by comparing the results of the Level 2 assessment with a Level 3 assessment (inelastic finite element analysis).