This document discusses pipeline stress analysis using CAESAR II. It summarizes that pipeline and piping stress analysis differ in modeling approaches due to underground versus aboveground conditions. Key aspects of pipeline modeling covered include buried element modeling, use of anchor blocks at transitions from underground to aboveground, and consideration of load case combinations for stress analysis. Example results from a CAESAR II stress report are presented.

1. PIPELINE STRESS ANALYSIS WITHPIPELINE STRESS ANALYSIS WITH
CAESAR IICAESAR II
by
Andrey Puruhita

2. PIPELINE STRESS ANALYSISPIPELINE STRESS ANALYSIS
WITH CAESAR IIWITH CAESAR II
 What the different with piping stress ?What the different with piping stress ?
 Pipeline burried modelingPipeline burried modeling
 Anchor block restrainAnchor block restrain
 Load case combination & resultLoad case combination & result

3. The difference of piping & pipeline
stress analysis
Piping modeling
• Code requirement shall use
ASME B31.3
• Aboveground
• Many support or restrain
needed
Pipeline modeling
• Code requirement use
ASME B31.4 for liquid &
B31.8 for gas transmission
• Usually Underground
• Shall use anchor block as a
restrain from aboveground-
underground conversely

4. Burried Pipe
• Buried pipe deforms laterally in areas
immediately adjacent to changes in directions
• In areas far removed from bends and tees the
deformation is primarily axial

5. PIPELINE BURRIED MODELING
• The Buried Pipe Modeler is started by selecting an existing
job, and then choosing menu option Input-Underground from
the CAESAR II Main Menu
• Enter the soil data using Buried Pipe - Soil Models
• Describe the sections of the piping system that are buried,
and define any required fine mesh areas using the buried
element data spreadsheet
• Convert the original model into the buried model by the
activation of option Buried Pipe - Convert Input

6. Input soil models

8. The buried element description spreadsheet serves
several functions
• It allows the user to define which part of the piping system is
buried.
• It allows the user to define mesh spacing at specific element
ends.
• It allows the input of user defined soil stiffnesses

9. Burried pipe example

10. Anchor Block Restrain
• Pipeline with a long distance needs block
valve, there were a change direction from
underground to aboveground
• In this situation pipeline must be installed
with anchor block before and after
aboveground pipe

11. Why we need anchor block ?
• To prevent stress failed on block valve due to
axial deformation of a long pipeline

12. Example of block valve modeling
Anchor block
Anchor block

13. Load Case Combination
• To check stress analysis on pipeline shall use
several load case combination as folow :

14. • Sustain Load ( W + P)
• Thermal Load (T)
• Combination Load ( W + T + P)

15. Caesar Stress Result
• CAESAR II STRESS REPORT FILE:FOR TUTORIAL
• CASE 3 (OPE) W+T2+P1 DATE:OCT 1,2009
• --Stress(lb./sq.in.)--- --(lb./sq.in.)--
• ELEMENT BENDING TORSION SIF'S ALLOWABLE
• NODES STRESS STRESS IN/OUT PLANE STRESS STRESS %
• HIGHEST STRESSES: (lb./sq.in.)
• OPE STRESS %: 21.06 @NODE 90
• STRESS: 12636.4 ALLOWABLE: 60000.0
• BENDING STRESS: 3254.8 @NODE 90
• TORSIONAL STRESS: 0.0 @NODE 49
• AXIAL STRESS: 9455.2 @NODE 130
• 3D MAX INTENSITY: 30120.4 @NODE 20
• 60 1357. 0. 1.000 / 1.000 10739. 60000. 18.
• 70 919. 0. 1.000 / 1.000 10300. 60000. 17.
• 80 1461. 0. 1.000 / 1.000 10842. 60000. 18.
• 90 3255. 0. 1.000 / 1.000 12636. 60000. 21.
• 90 3255. 0. 1.000 / 1.000 12636. 60000. 21.
• 95 2703. 0. 1.000 / 1.000 12085. 60000. 20.

16. THANK YOU