INTRODUCTION

At the time of transportation, the pressure vessels need to be lifted. For lifting, a lug arrangement is provided on the vessel. At the time of lifting, due to the self-weight of structure & various angles of inclination, some stresses got induced in the vessel geometry. This stresses sometimes leads to permanent sets in a pressure vessel. Analytical calculations do not provide the actual stress pattern & hence FEA is an important tool in such cases.

Process equipment manufacturer from India & Abroad approached ANALYZER to seek assistance in evaluating the design of their newly developed vessels for lifting conditions & provide the solution in case of any observed failure.

FEA WORKFLOW

• Design parameters & material properties extraction for complete pressure vessel
• Preparing FEA Model for a pressure vessel with complete structured Hexahedral Mesh.
• Solving the FEA Model & Result extraction
• Preparing an easy to understand report for the performed FEA.

CHALLENGES

• Preparing complete structural hexahedral mesh.
• Applying correct boundary conditions in order to simulate actual lifting conditions

THE SOLUTION

The pressure vessel was analyzed using the Finite Element Method to determine the induced stresses at the time of lifting for a different angle of inclinations. The vessel is evaluated for the stress & deformation pattern. The results showed that the induced stresses were well within the allowable stress limits. Hence, the structure’s design was predicted to behave safely during lifting without inducing any permanent set.

BENEFITS

• Better insights on structural behavior which is not possible by usual analytical methods
• Helpful in studying the stress & deformation pattern at the time of vessel lifting.