PIPELINE STRESS ANALYSIS WITH PIPELINE STRESS ANALYSIS WITH CAESAR IICAESAR II

by

Andrey Puruhita

PIPELINE STRESS ANALYSIS PIPELINE 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

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

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

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

Input soil models

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

Burried pipe example

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

Why we need anchor block ?

• To prevent stress failed on block valve due to axial deformation of a long pipeline

Example of block valve modeling

Anchor block

Anchor block

Load Case Combination

• To check stress analysis on pipeline shall use several load case combination as folow :

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

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.

THANK YOU