Stress of a Flat End Plate with a Manhole

Abstract

A flat end plate with a manhole is preferable for a pressure vessel such as a steam receiver of high pressure boiler, when the ratio between diameters of the man-hole and the end plate is larger than 50%. A new approximate caluculating formula was induced taking the boundary conditions at a joint part of the end plate and cylindrical part into consideration, assuming that manhole to be a circular hole having a diameter equal to the lengeh of major axis of an elliptical manhole, that the radius of the end plate to be equal to the distance from its centre line to the outer edge, and that the radius of corner fillet at a joint part to be negligible. The results of the model test and other methods of investigation prove that the calculated stress value agrees with that from experimentation. From the test were also obtained calibration curves of stress from the effects of the radius of corner fillet at the joint part and a roundness radius at the outer edge of the end ptate. Then following simplifled formula by which the thickness of the end plate with a manhole is conveniently calculated was induced.[numerical formu]