Pressure vessels and tanks are used extensively in the petrochemical industry for process and storage purposes. In the areas of large openings, as in the case of cargo hatch opening, stress concentration is likely to occur at the corners of the openings because of the sudden change in the sectional area of the deck plate. To ensure the integrity of the pressure vessel, a plate of higher thickness, compared to the adjacent plates, is inserted at the corners and such plates are referred to as insert plates. This is done to enable the corner plates to withstand higher levels of stress because of inevitable stress concentrations. The paper presents a real-world instance of involving a part of design done for a very large refinery expansion project in India.

Pressure vessels can, in a way, be described as energy vessels due to the energy that is stored in the form of pressure inside. Thus, they carry inherent risks that need to be brought within tolerable limits. Most pressure vessels that are used in the process industries are designed and constructed in accordance with ASME Code (Code), which is divided into eleven sections.

The provision of nozzles in a pressure vessel creates a situation where material is removed and an opening created, thus weakening the pressure vessel. There are two ways to resolve this—use of reinforcement pad (reinf-pad) and use of insert plates.

Mechanical Engineering Journal, Structural analysis, Insert plate, Modeling, FEA, FEM, Pressure vessel.