1. Chris Wowk MANE 6970 Master’s Project

2. Bolted, flat faced flanges are typical for fluid power applications when disassembly of the joint is required for maintenance or access to the internals of the system. The design of these flanges is typically governed by requirements outlined in the ASME Boiler and Pressure Vessel Code. For flange designs that come into contact with one another outside of the bolt circle, additional analysis is required to account for the interactions that occur due to the flexibility of each flange. Separation of this joint leads to leakage and higher than predicted bolt prying loads Fluid Pressure Prying Load Outside Bolt Circle

3.  Design and analysis of these bolted joints are covered by Appendix Y or ASME Boiler and Pressure Vessel Code (BPVC) ◦ Plate bending approximated as flexure of discrete beams  An alternate method of analysis using Plate Theory was proposed by Galai for identical flange pairs  Finite Element Analysis using ABAQUS provides deeper analysis into the behavior of the joint The primary goal of this project is to determine the agreement between the three methods selected to analyze bolted flange joints with contact outside the bolt circle. Shortcomings and strengths of each analysis method will be discussed.

4.  Design equations exist in Appendix Y of ASME BPVC to determine joint separation and flange stresses  Plate method proposed by Galai for identical flange pairs will be adapted for a flange-cover joint  Symmetry will be exploited for FEA analysis Fluid Pressure 1/8 (45° Segment) ABAQUS Model (8 bolts) Cylindrical Symmetry Boundary Conditions Contact Defined to Govern Joint Behavior

5.  Configuration Variables: ◦ Pipe Size (4 & 16 NPS) ◦ Thickness of cover plate (t=minimum thickness required by ASME B16.5) ◦ Bolt Preload (0, Equal to Pressure Load, & 80%YS)  Results to be Investigated ◦ Separation of flange-cover joint due to pressure ◦ Additional loading of fasteners due to prying effects ◦ Location of cover/flange contact Nominal Pipe Size Cover ThicknessPreload 40.5t0 4 Equal 40.5t80%YS 41t0 4 Equal 41t80%YS 42t0 4 Equal 42t80%YS 160.5t0 160.5tEqual 160.5t80%YS 161t0 161tEqual 161t80%YS 162t0 162tEqual 162t80%YS

6.  ASME Boiler and Pressure Vessel Code  Galai, Hichem, and Bouzid, A.H, Analytical Modeling of Flat Face Flanges with Metal to Metal Contact Beyond the Bolt Circle, Journal of Pressure Vessel Technology, ASME, Vol 132. December 2010  Schneider, R. W, and Waters, E. O, The Background of ASME Code Case 1828: A Simplifying Model of Analyzing Part B Flanges, Journal of Pressure Vessel Technology, ASME, Vol. 100, No. 2, May 1978