Pressure Vessel Fatigue

Pressure Vessel Fatigue is a failure mechanism that involves cracking due to cyclic (or fluctuating) stress.  Fatigue is a progression that starts with small changes in material grain structure.  There are three main stages of fatigue:

  • Crack Initiation

  • Crack Propagation

  • Rupture

Cracking is typically caused by tensile mechanical stresses that are accompanied by another mechanism such as structural damage or corrosion.  As mentioned in numerous references, fatigue failures can happen at stresses below the yield strength of the material.   ASME VIII-2 (Division 2) defines fatigue as “Conditions leading to fracture under repeated or fluctuating stresses having a maximum value less than the tensile strength of the material.”

COMPRESS Pressure Vessel Fatigue Screening

ASME VIII-2 Fatigue in COMPRESS

COMPRESS includes ASME VIII-2 Fatigue Screening as a standard feature.  The ability to quickly model complete vessels and enter fatigue data makes performing VIII-2 or Appendix 46 Fatigue Assessments with COMPRESS simple.

ASME Division 2 Pressure Vessel Fatigue Screening 5.5.2.4 Method B

Professional Reports

COMPRESS provides professional pressure vessel fatigue reports that document the data entered and equations used.  A convenient summary lists the number of cycles allowed as well as the limiting pressure vessel component.

Pressure Vessel Fatigue Screening - Inputs Report
Fatigue Screening - Component Results
Pressure Vessel Fatigue Screening - Stress Amplitude Report
Pressure Vessel Fatigue Screening - Full Range Pressure Cycles Report

Increase Your Capabilities With COMPRESS

Nozzles Simplify the detailing of nozzle attachments with flexible and intuitive nozzle design capabilities. Finite Element Analysis Built-in FEA for Nozzles, Clips and TEMA Expansion Joints. API 650 Storage Tanks Modeling storage tanks is easy as COMPRESS guides you through an intuitive design wizard. Vacuum Rings Drag-and-drop vacuum rings and quickly see how the external pressure rating changes. Quick Design Speed up the process of pressure vessel modeling with Quick Design mode. Productivity Software packages like COMPRESS exist to increase productivity and save Engineering hours. Heat Exchanger Perform ASME UHX and TEMA calculations independently or leverage the bi-directional interface with HTRI. Division II As Division 1 increasingly references Division 2 provisions, many companies are transitioning to Division 2 rules to capitalize on material savings. MDMT Rules of UCS-66 The rules of UCS-66 guard against vessel failure by brittle fracture, a low probability, high consequence event. External Pressure Design Simplify the complexity of the
UG-28 rules for external pressure design and vacuum rating. Jacketed Vessels Design both conventional and half pipe jacketed vessels. Vessel Wizard The Vessel Wizard speeds pressure vessel design by creating complete pressure vessel models with minimal input. COSTER Import files from COMPRESS and create user customizable pressure vessel cost estimates in spreadsheet format. Flange Design Create optimized Appendix 2 flange designs with minimal time and effort and account for loadings on standard B16.5/16.47 flanges. Weld Seams Designers can visually confirm good practices such as staggered longitudinal seams. Lifting & Rigging Use an accurate weight, the correct center of gravity, and apply the actual section properties. Modeling + Drawings The Codeware Interface includes Drafter 3D, a feature that auto-generates 2D pressure vessel drawings. Related Codes COMPRESS implements a wide range of related engineering methods, codes and standards. Design Mode Save time by reducing the trial and error iterations that would otherwise be required when designing pressure vessels. Rating (Analysis) Mode The COMPRESS Rating Mode takes your design and determines the vessel’s MAWP, MAEP and MDMT. Hydrotest Performing hydrotest stress calculations in the design stage prevents equipment damage during hydrotesting. Hillside Nozzle COMPRESS saves time by calculating chord openings and governing planes of reinforcement automatically. ASME Editions Older ASME Codes are retained in all COMPRESS releases so you can always use the latest software. Automatic Liquid Levels COMPRESS eliminates the need to manually calculate each vessel component’s liquid static head. Global External Loads The Loads Menu allows designers to easily consider global external loads when sizing pressure vessel supports. Clips and Lugs Quickly add in various structural shapes to complete your design. Multi-Chamber Vessels Certain industrial processes require pressure vessels with multiple chambers operating under different design conditions. Appendix 46 Produce more economical Div 1 pressure vessel designs with increased accuracy from the Div 2 design by rule equations. Manufacturer's Data Reports Simplify the creation, submission and management of ASME Manufacturer’s Data Reports and NBIC Repair and Alteration Forms. Support Skirt Openings Specify piping connections to vertical vessels that require additional piping and openings cut out of the support skirt. Branch Connections Reduce pressure vessel welding and material costs by modeling tees in COMPRESS. Foundation Loads Summary Break down the loads for the specified vessel operating conditions including weight, wind, seismic, and vortex shedding. Shipping Saddles COMPRESS provides a shipping saddle option based on the industry standard Zick Analysis. UG-80 and UG-81 COMPRESS automatically provides out-of-roundness tolerances that must be maintained during pressure vessel fabrication. Nameplate Design Every pressure vessel is required by Code to have a nameplate. COMPRESS handles this by including a convenient nameplate option. Fatigue Screening Quickly enter fatigue data to determine if a fatigue assessment is required. WRC 537 Nozzle Loads Check stresses on nozzles using WRC 107 and WRC 537 stress analysis for spherical and cylindrical shells. COMPRESS Quick Design Mode Heat Exchanger designed in COMPRESS Division 2 option in COMPRESS MDMT Rules of UCS-66 Bill of Materials generated from COSTER Flange design in COMPRESS Weld seam wizard in COMPRESS Lifting mechanics in COMPRESS Drafter 3D from Codeware COMPRESS includes related engineering methods, codes, and standards Design mode in COMPRESS Rating mode in COMPRESS Hydrotesting in COMPRESS Hillside Nozzle design in COMPRESS 2023 ASME VIII Code Edition in COMPRESS Automatic Liquid Levels in COMPRESS External Loads in COMPRESS Pressure Vessel clip with pad in COMPRESS Multi chamber pressure vessels in COMPRESS Appendix 46 in COMPRESS ASME Manufacturer's data reports in COMPRESS Support Skirt Openings in COMPRESS Foundation Loads Summary in COMPRESS UG-80 and UG-81 design in COMPRESS Jacketed Vessel in COMPRESS Pressure vessel nozzles Shipping Saddles in COMPRESS Nameplate design in COMPRESS WRC 537 Nozzle Loads in COMPRESS Fatigue Screening in COMPRESS Vacuum Rings in COMPRESS FEA Nozzles in COMPRESS API 650 in COMPRESS Branch Connections in COMPRESS

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