Recommended Load Cases - CAESAR II - Help

CAESAR II Users Guide (2019 Service Pack 1)

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English
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CAESAR II
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CAESAR II Version
11.0 (2019)

When you initially open the Static Analysis - Load Case Editor dialog box, the software recommends three types of load cases, based on the loads defined in the model: Operating, Sustained, and Expansion. The software does not recommend Occasional load cases.

Operating load cases represent the loads acting on the pipe during hot operation. These load cases include primary loadings (weight pressure, and force), secondary loadings (displacements and thermal expansions). Operating cases are used to find hot displacements for interference checking, and to find hot restraint and equipment loads. CAESAR II combines weight, pressure case, and hanger loads with each of the thermal load cases when recommending operating load cases. For example, the software combines the first displacement set with the first thermal set, the second displacement set with the second thermal set, and so on. Then, the software combines any cold spring loads.

Sustained load cases represent the primary force-driven loadings acting on the pipe. This case is weight and pressure alone. This usually coincides with the cold as-installed load case. Sustained load cases are used to satisfy the code sustained stress requirements, as well as to calculate as-installed restraint and equipment loads. Sustained load cases are generally built by combining weight with each of the pressure and force sets, and then with any hanger loads.

Expansion load cases represent the range between the displacement extremes usually between the operating and sustained cases. Expansion load cases are used to meet expansion stress requirements. Generally, when you specify only one temperature and one pressure, the recommended cases look like:

Case 1

W+D1+T1+P1+H (OPE)

Operating

Case 2

W+P1+H (SUS)

Sustained load case

Case 3

L1-L2 (EXP)

Expansion load case

Review any load recommendations made by CAESAR II.

CAESAR II does not recommend any occasional load cases. Definition of these is your responsibility.

If the recommended load cases do not satisfy the analysis requirements, you can delete or modify them. Conversely, you can reset the load cases at any time to the software recommended set.

If you have an operating temperature below ambient in addition to one above ambient you should add another expansion load case as follows:

Case 1

W+D1+T1+P1+H (OPE)

Operating

Case 2

W+D2+T2+P1+H (OPE)

Operating

Case 3

W+P1+H (SUS)

Sustained load case

Case 4

L1-L3 (EXP)

Expansion load case

Case 5

L2-L3 (EXP)

Expansion load case

Case 6

L2-L1 (EXP)

Expansion load case