Pii: 0308-0161(94)00169-3

The present version of the Pressure Vessel Standard, BS 5500’ restricts the design of the local load type situations to certain vessel and attachment geometries. This paper identifies the main underlying reasons for these restrictions; which are a limitation of the deflection and rotations by the use of small displacement analysis, and a neglect of the rigidity of the attachment. This paper addresses the influence of the attachment rigidity by considering a number of attachment thicknesses. The companion paper’ considers the large displacement phenomenon and brings the two effects together in a design approach for these components. The method proposed provides a series of stress and displacement correction factors whereby the existing British Standard design method can be modified to cover the entire range of geometries up to (C,/R) = 0.25 for all values of (R/T) up to 250.