Ellipsoidal Vessel Heads Research Articles

Stresses in ellipsoidal pressure vessel heads with noncentral nozzle

The objective of this paper is further investigation of the shell intersection problem. The shell theory and finite element method are used for stress analysis of nozzle connections in ellipsoidal heads of the pressure vessels. Ellipsoidal heads having attached nozzles considerably displaced from the head axis are mainly considered. The features of the numerical procedure, structural modeling of nozzle-head shell intersections and SAIS special-purpose computer program are discussed. The results of stress analysis and parametric study of an ellipsoidal vessel head with a noncentral nozzle under internal pressure loading are presented.

Stress analysis of ellipsoidal vessel head with large-diameter flush radial nozzle and comparison of reinforcement types

The membrane solution and the asymptotic solution of the edge problem of thin shells of revolution were employed to solve analytically the stress analysis for an ellipsoidal vessel head with a large-diameter flush radial nozzle and its reinforcement structures under internal pressure.A comparison of several reinforcement types is given. Results are presented for the stress distributions and stress concentration factors.

On the estimation of stress concentration and flexibility at nozzles in ellipsoidal vessel heads

The US Welding Research Council Bulletin Number 107 (WRC-107) is currently being used by many designers in the estimation of stress concentrations at nozzle-vessel junctures. The validity of the application of this design document to the case of nozzles in ellipsoidal vessel heads is studied in this paper. A number of comparisons of the stress intensity and flexibility at the nozzles between approximate approaches and the exact situation were made and discussed.

Stress concentration and flexibility factor of nozzles in ellipsoidal pressure vessel heads subject to external moment

Ellipsoidal heads are commonly used as end closures for cylindrical pressure vessels in chemical and process industries. In the design of nozzles in pressure vessels, stress and flexibility of the nozzle-vessel structure are important factors to be considered. In this paper, a parametric study of radial nozzles in ellipsoidal vessel heads, when the nozzles are subjected to overturning moments, is presented. The computer program KSHEL, which is based on elastic thin shell theory, was utilized. Stress concentration factors and flexibility factors were determined and are presented as graphs of dimensionless nozzle-vessel parameters.

Stress analysis of ellipsoidal shell with radial nozzle

The thin shell equations of equilibrium in Love-Meissner form for an internally pressurized ellipsoidal vessel head with intersecting radial nozzle (flush or protruding) are solved numerically to obtain the stress distribution in both the ellipsoidal head and the nozzle. The results are presented graphically using appropriate non-dimensional parameters, as stress concentration factors at the point of intersection.