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What does CAESAR II do?

What does CAESAR II do?. 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.

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What does CAESAR II do?

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  1. What does CAESAR II do?

  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. Intergraph CADWorx & Analysis Solutions

  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 Intergraph CADWorx & Analysis Solutions

  4. So what’s 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. 100 feet @ 170F Intergraph CADWorx & Analysis Solutions

  5. Designer “handoff” to engineering • 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 • 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) 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 Intergraph CADWorx & Analysis Solutions

  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 Intergraph CADWorx & Analysis Solutions

  7. Creating a CAESAR II Model (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) 90 110 80 100 20 120 50 10 Intergraph CADWorx & Analysis Solutions

  8. Analog to digital Analog Digital representation Intergraph CADWorx & Analysis Solutions

  9. CAESAR II Results • Hanger selection, restraint load • Pipe sag, horizontal deflection • Equipment check • Stress check • A few examples will illustrate… Intergraph CADWorx & Analysis Solutions

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

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

  12. Evaluate Equipment Load Is this compressor overloaded? Compressor Thermal Growth Anchor Intergraph CADWorx & Analysis Solutions

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

  14. Analyze and review TURBO Intergraph CADWorx & Analysis Solutions

  15. Document Results Intergraph CADWorx & Analysis Solutions

  16. Conclusion Intergraph CADWorx & Analysis Solutions

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