1. PIPING STRESS ANALYSIS BY CAESAR-II SOFTWARE
CAESAR MODELING ANALYSIS REPORT
FDC PIPING

2. WHAT MAKES PIPING CRITICAL?
Temperature
Pressure
Occasional loads (Seismic & Wind)
Dynamics of the flowing fluid
FDC PIPING

3. WHAT CAUSES STRESS IN THE PIPE?
Live and Dead load (Piping component, Insulation, Flowing medium etc.).
Line pressure
Restraining of pipe expansion or Temperature gradient
Discharge reaction (E.g. Relief valves)
Seismic / Wind load
Dynamics of flowing fluid.
Cont….
FDC PIPING

4. WHY STRESS ANALYSIS IS TO BE DONE?
To ensure that all stresses in the piping system are within allowable limits.
To limit the loads on the equipment nozzle.
To limit the thermal displacement and sagging
To limit the loads on the supporting structures & flanged joints.
To avoid excessive piping vibration
FDC PIPING

5. WORK FLOW DIAGRAM FOR STRESS GROUP

6. INPUT FOR STRESS ANALYSIS
Stress Isometrics
LDT / P&ID
Equipment G.A.Drawing
Instrument(e.g.PSV/control valve) data sheet
FDC PIPING

7. SOFTWARE USED Piping Stress Analysis Software
CAESAR II 4.5
In-house software (Tracking system)
SATS
SSTS
CAESAR CONVERT
FDC PIPING

8. MODELLING Piping Components Piping Equipments Restraints Cont….
FDC PIPING

9. NODE SKETCH
Cont….
FDC PIPING

10. STRESS ISO MARKUP

11. CAESAR INPUT SPREADSHEET
Start Run
Batch Run
Allowable Stress At Cold Condition
Geometry
Allowable Stress At Hot Condition
Caesar Modelling
Material Selection

12. RESTRAINT MODELLING

13. SPRING MODELLING

14. CONSTANT SPRING

15. INPUT SPREADSHEET

16. FORCE MODELLING

17. BEND MODELLING

18. SEISMIC FORCE INPUT

19. PROCEDURE FOR PUMP LINE ANALYSIS

20. PROCEDURE FOR PUMP LINE ANALYSIS
2. Top suction – Top discharge & 3. Side suction – Side discharge
Referring to Fig.2 & 3, node marking 1-2 shows nozzle flange with given flange rating as “rigid” element. Node 2-3 shows nozzle standby with pipe element (Dia equal to pump impeller dia and thickness equal to pipe wall thickness) as rigid element with zero weight from flange welding joint to pump impeller center line. Node 3-4 shows rigid element with zero weight up to center line of the pump.
Restraints –
1) The pipe flange to be get anchored as C- Node with pump flange to get nozzle load due to piping reaction. This load value should be less than allowable values.
2) Rigid element at pump C/L to be get anchored i.e. anchor at node4.

21. PROCEDURE FOR PUMP LINE ANALYSIS

22. ANALYSIS
STATIC ANALYSIS
DYNAMIC ANALYSIS
FDC PIPING

23. TYPES OF STRESSES
PRIMARY
SECONDARY
FDC PIPING

24. TYPES OF LOAD Sustain Load Occasional Load Thermal Load
Hydro Test Load
FDC PIPING

25. LOAD CASE DEFINATION L1 WW + HP (HYD) L2 W + T1 + P1 + H (OPE)
L4 W + P1 + H (SUS)
L5 L2 – L4 (EXP)
L6 L3 – L4 (EXP)
FDC PIPING

26. LOAD CASE DEFINATION L1 W + T1 + P1 + H (OPE) L2 W + P1 + H (SUS)
L3 U1 (OCC)
L4 U2 (OCC)
L5 L2 + L3 (OCC)
L6 L2 + L4 (OCC)
FDC PIPING

27. CAESAR LOAD CASES
DESIGN TEMP. LOAD CASE
OPERATING TEMP. LOAD CASE

28. PROCEDURE FOR PUMP LINE ANALYSIS
LOAD CASES FOR PUMP LINE STRESS ANALYSIS Load cases for the pump connected lines are discussed below. 1. Hot Cold Load case:
♦ Both pump operating.
When two or more pumps are used in a system then from stress analysis point of view the different load cases are made. Like,
♦ One pump operating & one stand by.
(This point to be get discussed with process, what will be the requirement, whether “at any moment only one pump will operate, for more than two pump case”)
♦ Hot Cold analysis to be done at design and operating temperature.
♦ For the pump, which is not operating, ambient temperature should be considered from Tee point
► When two pumps are present in the system hot cold cases can be made as below (Refer Fig. 4).

29. PROCEDURE FOR PUMP LINE ANALYSIS
Case 1: When both pumps are in operating condition, provide design and operating temperature for node A & B
Case 2: When pump “A” is operating and pump “B” is cold, provide design and operating temperature for node A and ambient temperature for B.
Case 3: When pump “B” is operating and pump “A” is cold, provide design and operating temperature for node B and ambient temperature for A.
► When three pumps are present in the system hot cold cases can be made as below (Refer Fig. 5).

30. PROCEDURE FOR PUMP LINE ANALYSIS
CASE6: W+P1+T5 (OPE) ………Pump “A” at operating temp and Pump “B” standby.
CASE7: W+P1+T6 (OPE) ………Pump “B” at operating temp and Pump “A” standby.
CASE8: W+P1 (SUS)
CASE9: WNC (SUS)
CASE10: L2-L8 (EXP)
CASE11: L3-L8 (EXP)
CASE12: L4-L8 (EXP)
CASE13: L5-L8 (EXP)
CASE14: L6-L8 (EXP)
CASE15: L7-L8 (EXP)
♦ For load case no 2, 3, 4, 5, 6,7and 8 pump nozzle load is checked and it should be within acceptable limit as specified by vendor or API 610.
♦ For load case no 1, 8, 10, 11,12,13,14 and 15 stress value is checked and it should be less than allowable stress as specified by relevant code.
♦ For load case no 9 (WNC case) deflection is checked at pipe flange for cold alignment case as discussed in earlier topic of WNC load case.
B. Load Cases for Static Analysis (Three Pumps A, B & C)
CASE1: WW+HP (HYD)
CASE2: W+P1+T1 (OPE) …Three pumps at design temperature.
CASE3: W+P1+T2 (OPE) …Three pumps at operating temperature.
CASE4: W+P1+T3 (OPE) ….Pump “B&C” at design temp and Pump “A” standby.
CASE5: W+P1+T4 (OPE) …..Pump “A&C” at design temp and Pump “B” standby.
CASE6: W+P1+T5 (OPE) …..Pump “A&B” at design temp and Pump “C” standby.
CASE7: W+P1+T6 (OPE) …..Pump “B&C” at operating temp and Pump “A” standby.
CASE8: W+P1+T7 (OPE) …..Pump “A&C” at operating temp and Pump “B” standby.
CASE9: W+P1+T8 (OPE) …..Pump “A&B” at operating temp and Pump “C” standby.
CASE10: W+P1 (SUS)
CASE11: WNC (SUS) CASE12: L2-L10 (EXP) CASE13: L3-L10 (EXP) CASE14: L4-L10 (EXP)

31. PROCEDURE FOR PUMP LINE
Case 1: When three pumps are in operating condition, provide design and operating temperature for whole system.
Case 2: When pump “A” is cold and pump “B & C” are operating, provide design and operating temperature to node B & C and ambient temperature for A.
Case 3: When pump “B” is cold and pump “A & C” are operating, provide design and operating temperature to node A & C and ambient temperature for B
Case 4: When pump “C” is cold and pump “A & B” are operating, provide design and operating temperature to node A & B and ambient temperature for C.
2. WNC (Weight No Content) Load case:
The basic philosophy for “WNC” is by what magnitude the piping flange displaced at the mating point while cold alignment. For “WNC” case, make the pump flange anchor node free and replace the spring support to rigid support. Go in load case spread sheet, drag the “WNC” from side menu to load case row and select “Sustain case”. Run the case and get the displacement at the pump nozzles, this displacement should be less than 1mm (or consult mechanical department to get allowable deflection).
3. Load Cases in CAESAR-II for two pump connected system
Load cases for stress analysis of two pump connected piping system are discussed below. Same philosophy is applicable for more than two pump connected system.
Abbreviation: W = Weight; T= Temperature; HP = Hydro Pressure; WW = Water Filled Weight; WNC = Weight No Contents; P = Design Pressure. U1 = Uniform load (NS Seismic); U2 = Uniform load (EW Seismic);
A. Load Cases for Static Analysis (Two Pumps A & B)
CASE1: WW+HP (HYD)
CASE2: W+P1+T1 (OPE) ………Both pumps at design temperature.
CASE3: W+P1+T2 (OPE) ………Both pumps at operating temperature.
CASE4: W+P1+T3 (OPE) ………Pump “A” at design temp and Pump “B” standby.
CASE5: W+P1+T4 (OPE) ………Pump “B” at design temp and Pump “A” standby.

32. CAESAR OUT PUT

33. REPORT INTERPRETATION
Displacement
Restraints
Restraints Summary
Global Element Forces
Local Element Forces
Stresses
Sorted Stress
Code Compliance
FDC PIPING

34. REPORT INTERPRETATION
Hanger Table
Hanger Table W/Text
Input Echo
Miscellaneous Data
Load Case Report
Warnings
FDC PIPING

35. OUTPUT SHEET

36. REPORTING Stress Analysis Query Front Sheet Caesar Title Sheet
Stress Isometrics with markup
Load summary sheet
Spring / Bellow data sheet
SPS drawing
Caesar Load summary sheet
FDC PIPING

37. SAQ SHEET

38. CAESAR DUMP

39. RESTRAINT OUTPUT

40. SPRING DATASHEET

41. SPS DRAWING

42. BELLOW DATASHEET

43. LOAD SUMMARY SHEET

44. COMPLETED STRESS ISO
FDC PIPING

45. PRACTICAL SESSION
DEMONSTRATION OF CAESAR

46. THANK YOU!!