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The following section will cover general questions about AutoPIPE's results based on Loads and Load Sets that are NOT answered by Piping Code calculations
Question: noticed that results for all thermal analysis are the same, no mater what temperature setting is entered:Answer:Thermal expansion coefficient at ambient temperature is entered in the pipe properties screen or grid ONLY. Units for that coefficient "alpha" is 1.0E-6 in/in/degF or 1.0E-6mm/mm/degC
The expansion rate for each operating case is entered on the OPerating Pressure & Temperature data screen or Press/Temp/PipID tab of the input grid as shown below:The expansion rate is defined as:
Expansion = MeanAlpha*DeltaT = MeanAlpha*(OperatingTemperature - AmbientTemperature)
In this equation MeanAlpha is the average alpha between Ambient and Operating temperature
The units for this is in/100ft or mm/m (no temperature units since temperature is already multiplied).
If you enter a standard material like CS or a SPEC material like A106-A on the pipe properties dialog, the expansion data will be filled up automatically based on temperature (note: check box in from of data is enabled, checked ON). Only when you enter NS (Non-Standard) as the material, expansion data will not be computed and needs to be manually entered (note: check box in front of data is disabled, checked OFF). AutoPIPE expansion data is based on code expansion data table (in/100 ft) and not on alpha table. The alpha table might give slightly different results.
You can override calculated expansion and enter your own values if you wish by disabling (check OFF) the check box in front of the data, then enter your own value (note the value units when entering data).
In addition, various material libraries are now provided with AutoPIPE where the material library can be edited and compiled to add or modify expansion data.
In this case above, the model had T2, T3, and T4 where the expansion values are all the same. Therefore the thermal displacement would be all the same regardless of temperature settings because Auto check box was found disabled (checked OFF). Solution, manually update the data with the correct values, OR enable (check ON) Auto box in front of the expansion values, OR change the pipe properties material to a listed values other than NS.
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