Local pressure stresses on lateral pipe-nozzle with various angles of intersection

This paper reports the variations of local pressure stress factors (local p ressure stress/internal pressure) at the juncture of a pipe-nozzle when the angle of the pipe-nozzle intersection varies from the standard 90 degrees to the 30 degrees lateral. These stress factors in both the circumferential and longitudinal directions at four symmetric points around the pipe-nozzl e juncture are plotted as functions of the angle. The ALGOR finite element software was employed to model the true pipe-nozzle geometry. The numerical stress results come from a pipe-nozzle with geometric parameters, beta, be ta, (nozzle mean radius/pipe mean radius) of 0.5, and gamma, gamma, (pipe t hickness/pipe mean radius) of 50.0. This study shows that the 90 degrees in tersection, a standard pipe-nozzle, exhibits relatively less severe local s tresses. These stresses are increasing as the angle of intersection is decr easing from 90 degrees and become more severe when the angle of intersectio n is further decreasing from 45 degrees. The circumferential stress at the inside crotch point exhibits the worst stress value. The stress factor resu lts in pipe circumferential direction at the inside crotch points are in go od agreement with the stress factor equation from the ASME boiler and press ure vessel code. (C) 2000 Published by Elsevier Science S.A. All rights res erved.