Session: HT-01-01 Design, Analysis and Life Prediction of High-Pressure Vessels and Equipment

Paper Number: 154707

154707 - Enhancing Thread Load Distribution Methodology 

Abstract: 

The thread load distribution methodology outlined in ASME Section VIII, Division 3, E-220, "Thread Load Distribution," provides guidance for determining the load distribution in threaded connections. However, it lacks explicit direction on how to incorporate the thread angle when applying loads in Finite Element Analysis (FEA). This omission can lead to inaccuracies in the calculation of both horizontal and vertical force components within threaded joints, potentially resulting in misrepresentations of load distribution and, ultimately, the performance of pressure vessels and other equipment under load.

This paper proposes an enhancement to the existing methodology by integrating the thread angle into the load distribution calculation. By explicitly considering the angular orientation of the threads, the proposed approach improves the accuracy of force balance, both vertically and horizontally, within threaded connections. This refinement ensures a more realistic simulation of load behavior, capturing the full impact of thread geometry on load transfer.

The paper explores the theoretical foundation of this enhanced methodology and demonstrates its practical application through numerical examples involving a variety of common thread geometries. These examples highlight how the revised approach provides a more precise representation of force distribution across threads, offering engineers a more reliable tool for designing and evaluating threaded joints in pressure vessels and other critical applications.

Presenting Author: Erick Ritter Structural Integrity Associates, Inc.

Presenting Author Biography: Erick Ritter is a Professional Engineer and Consultant at Structural Integrity Associates. His work predominantly includes the design, assessment, and lifetime management of critical, high-pressure assets. His responsibilities and expertise include but are not limited to finite element analysis (FEA), fatigue and fracture analysis, structural analysis, computer-aided design (CAD), fitness-for-service (FFS), and finite element model (FEM) iteration/validation.

Authors:

Erick R. Ritter Structural Integrity Associates, Inc.
Thomas R. Draper Structural Integrity Associates, Inc.