0
DESIGN INNOVATION PAPERS

Proposed Design Criterion for Vessel Lifting Lugs in Lieu of ASME B30.20

[+] Author and Article Information
Dennis K. Williams

 Sharoden Engineering Consultants, P.A. P.O. Box 1336, 1153 Willow Oaks Trail, Matthews, NC 28106-1336DennisKW@sharoden.com

J. Pressure Vessel Technol. 129(2), 326-333 (Sep 07, 2006) (8 pages) doi:10.1115/1.2716439 History: Received January 23, 2006; Revised September 07, 2006

This paper describes a method for evaluating the structural adequacy of various lifting lugs utilized in the erection and up righting of large pressure vessels. In addition, the analysis techniques are described in detail and design guidelines for vessel lifting are tendered. The statutory and provincial regulations in both the United States and the province of Alberta, Canada are also reviewed and discussed with respect to the too often utilized phrase “factor of safety” (FOS). The implied implications derived from the chosen FOS are also outlined. A discussion is presented as to the applicability of the ASME safety standard B30.20 entitled, “Below the Hook Lifting Devices” (1999, ASME, New York) and as to the severe shortcomings of the safety standard in its attempt to delve into the design of lifting devices, especially when applied to lifting lugs on large and heavy-weight pressure vessels. Exemplar lugs on vessels are defined and the finite element analyses and closed form Hertzian contact problem solutions are presented and interpreted in accordance with the proposed design criteria. These results are compared against the very limited design information contained within ASME B30.20. Suggestions for the revision and applicability of the safety standard are presented and discussed in light of the examples and technical justification presented in the following paragraphs. In addition, the silence of this safety standard on the very large contact stresses that are well known to exist between a lifting pin and clevis type geometry is also discussed. Because of the limited number of repetitive loading cycles that vessel lifting lugs actually experience during the service life of a vessel, a recommendation is made to either clearly exclude vessel lifting lugs from the scope of ASME B30.20 or to specifically include a separate design and analysis section within this standard to properly address the mechanical and structural design issues applicable to pressure vessel lifting lugs.

FIGURES IN THIS ARTICLE
<>
Copyright © 2007 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Figure 1

Lifting-lug geometry

Grahic Jump Location
Figure 2

Lifting-lug finite element mesh

Grahic Jump Location
Figure 3

Stress-intensity contour

Grahic Jump Location
Figure 4

Von Mises stress Contour

Grahic Jump Location
Figure 5

Max principal Stress Contour

Grahic Jump Location
Figure 6

Min. Principal Stress Contour

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In