Session: DA-01-01 Design and Analysis of Pressure Vessels and Components-1

Paper Number: 122693

122693 - Evaluation of Stresses in Saddle (Q-Lip) Type Nozzles With Weaker Material Strength Compared to the Pressure Vessel Shell 

ASME BPVC Section VIII Division 1 and 2 provide various design configurations for reinforcing nozzle openings in pressure vessels.  One of these configurations is integrally reinforced saddle (Q-Lip) type nozzle forgings, which are utilized when the nozzle to shell junction is required be radiographically examined.  These types of nozzles provide smoother geometrical transition at the nozzle to vessel junction, which results in reduced stress concentrations.  In addition, these nozzles do not require a corner fillet weld, enhancing their performance if they are subject to cyclic (fatigue) loads.  When the strength of the pressure vessel shell and the nozzle is similar, the nozzle to shell junction does not require any special consideration in the design.
However, when the nozzle has a weaker material compared to the shell, connection between the two requires a refined design to address the local stresses.  This paper aims to provide an insight to the stress distribution and potential design implications for such nozzle types and material combinations.  Accordingly, various nozzle and pressure vessel geometries are designed using ASME Section VIII Code. Stresses are calculated using Finite Element Method at the vicinity of the nozzle to shell junction including the nozzle saddle transition and at the shell. 
 

Presenting Author: Koray Kuscu Chicago Bridge & Iron Company

Presenting Author Biography: Dr. Koray Kuscu received his BS, MS and Ph.D. degrees in Mechanical Engineering. He started his career as a process engineer after receiving his bachelor's degree and worked in various industrial natural gas - LPG conversion station and industrial process system designs. During his graduate studies, his interests shifted towards plate and shell theory, structural dynamics and developing constitutive finite element theory for composite plates with smart materials. After his graduate studies, he started working as an FEA analyst in the oil & gas industry focusing on cryogenic LNG tanks and pressure vessels. Later, he resumed roles of design engineer, project engineer, design manager and senior principal engineer. He is a licensed professional engineer in six US states. He actively participates in ASME BPV Code Committee work.

Authors:

Koray Kuscu Chicago Bridge & Iron Company
Mandeep Singh Chicago Bridge & Iron