Download presentation

Presentation is loading. Please wait.

Published byAmir Jen Modified over 2 years ago

1
What does CAESAR II do? 9/15/2010

2
Session overview Taking the task from piping design to piping engineering. What questions does CAESAR II answer? A brief CAESAR II design sequence. Should conclude within the hour. Please use the Webinar dialog box to post your questions. 9/15/2010 Intergraph CADWorx & Analysis Solutions 2

3
Piping designer responsibilities Designer locates equipment and then routes pipe between these positions using an established pipe specification –The piping system is a unique pressure containment. Givens: –Pipe size is based on pressure drop, flow rate –Pipe specification (e.g. wall thickness) is based on design pressure & temperature –Material based on service requirements Designer has established rules for basic layout –Hydraulic issues –Spans between supports (deadweight sag) –System stability –Access / clearance 9/15/20103 Intergraph CADWorx & Analysis Solutions

4
So whats left for the piping engineer? Many systems require analysis to evaluate strain –Sources of thermal growth Pipe Equipment connections (vessels and equipment) –Other sources of strain Support settlement Support movement in marine piping Strain Load Stress –Evaluate pipe load as stress due to this strain –Evaluate load on equipment directly Except for simple layouts, the system response due to this strain is difficult to estimate Analysis yields a better estimate of pipe deflection, loads on pipe supports and equipment connections, and stress in the piping; and not only for strain. 9/15/20104 Intergraph CADWorx & Analysis Solutions F

5
Designer handoff to engineering 9/15/2010 A sample Critical Line List from PROCESS PIPING: The Complete Guide to ASME B31.3, by Charles Becht IV, ASME PRESS, New York, 2002 ======================================== In the case of general piping systems; according to the following line size/flexibility temperature criteria: All DN 50 (NPS 2) and larger lines with a design differential temperature over 260°C (500°F) All DN 100 (NPS 4) and larger lines with a design differential temperature exceeding 205°C (400°F) All DN 200 (NPS 8) and larger lines with a design differential temperature exceeding 150°C (300°F) All DN 300 (NPS 12) and larger lines with a design differential temperature exceeding 90°C (200°F) All DN 500 (NPS 20) and larger lines at any temperature All DN 75 (NPS 3) and larger lines connected to rotating equipment All DN 100 (NPS 4) and larger lines connected to air fin heat exchangers All DN 150 (NPS 6) and larger lines connected to tankage Double-wall piping with a design temperature differential between the inner and the outer pipe greater than 20°C (40°F) A sample Critical Line List from PROCESS PIPING: The Complete Guide to ASME B31.3, by Charles Becht IV, ASME PRESS, New York, 2002 ======================================== In the case of general piping systems; according to the following line size/flexibility temperature criteria: All DN 50 (NPS 2) and larger lines with a design differential temperature over 260°C (500°F) All DN 100 (NPS 4) and larger lines with a design differential temperature exceeding 205°C (400°F) All DN 200 (NPS 8) and larger lines with a design differential temperature exceeding 150°C (300°F) All DN 300 (NPS 12) and larger lines with a design differential temperature exceeding 90°C (200°F) All DN 500 (NPS 20) and larger lines at any temperature All DN 75 (NPS 3) and larger lines connected to rotating equipment All DN 100 (NPS 4) and larger lines connected to air fin heat exchangers All DN 150 (NPS 6) and larger lines connected to tankage Double-wall piping with a design temperature differential between the inner and the outer pipe greater than 20°C (40°F) 5 Intergraph CADWorx & Analysis Solutions Design by Rule vs. Design by Analysis: Design by Rule: Minimum pressure thickness = (PD)/(2(SEW+PY)) Design by Analysis: Maximum stress due to pressure = Sh = (2/3)(yield stress) Stress due to pressure = PD/2t Is PD/2t < Sh ? Yes: OK No: Redesign required Design by Rule vs. Design by Analysis: Design by Rule: Minimum pressure thickness = (PD)/(2(SEW+PY)) Design by Analysis: Maximum stress due to pressure = Sh = (2/3)(yield stress) Stress due to pressure = PD/2t Is PD/2t < Sh ? Yes: OK No: Redesign required Many shops develop a critical line list to determine which piping layouts require additional engineering evaluation So, a move is made from Design by Rule to Design by Analysis This is where CAESAR II enters the picture

6
Four typical interests in pipe stress analysis Selecting and sizing supports Checking pipe deflection under load Verifying loads on connected equipment Evaluating pipe stress And not only for those strain-based loads… –Deadweight –Pressure –Wind & wave –Earthquake –Hydraulic transients –Vibration 9/15/20106 Intergraph CADWorx & Analysis Solutions

7
Creating a CAESAR II Model 9/15/20107 Intergraph CADWorx & Analysis Solutions (the analog) Start with a stress isometric or similar concept Mark up the drawing for analysis Create the piping input model (a digital representation of that analog)

8
Analog to digital 9/15/2010 Intergraph CADWorx & Analysis Solutions 8 AnalogDigital representation

9
CAESAR II Results 1.Hanger selection, restraint load 2.Pipe sag, horizontal deflection 3.Equipment check 4.Stress check –A few examples will illustrate… 9/15/20109 Intergraph CADWorx & Analysis Solutions

10
1.Size Support Size this spring… …to minimize this pump load What is the load on this steel? 9/15/ Intergraph CADWorx & Analysis Solutions

11
2.Check Deflection How much does this elbow move when the system heats up? 9/15/ Intergraph CADWorx & Analysis Solutions

12
3.Evaluate Equipment Load Is this compressor overloaded? 9/15/2010 Compressor Thermal Growth Anchor 12 Intergraph CADWorx & Analysis Solutions

13
4.Evaluate Pipe Stress 9/15/ Intergraph CADWorx & Analysis Solutions This stub in connection is overstressed and will fail by fatigue over time.

14
Analyze and review TURBO 9/15/ Intergraph CADWorx & Analysis Solutions

15
Document Results 9/15/ Intergraph CADWorx & Analysis Solutions

16
Conclusion 9/15/2010 Intergraph CADWorx & Analysis Solutions 16

Similar presentations

© 2017 SlidePlayer.com Inc.

All rights reserved.

Ads by Google