Friction Scale Factor

I am new to use AutoPipe. Currently I am modeling a 48" steam line with DP: 70 psi, and DT: 377F. Could you let me know what is the proper friction scale factor in this case.

Thanks,

  • Hello DF Huang,

    Due to liability lawsuits, Bentley technical support cannot provide explicit setting or values that you should use in your modeling with AutoPIPE. The only suggestion I can give you is to research this topic.  

    As mentioned in the AutoPIPE help:

    Friction coefficients for two materials in contact are rarely known precisely. In addition, vibration can relieve friction. Therefore, in order to determine the importance of friction effects on a system model, analyses may need to be performed with smaller, or larger friction coefficients at each support. This factor has been provided to facilitate the modification of defined friction coefficients at all supports at the same time. Each friction coefficient is multiplied by this scale factor, allowing friction parameter studies without changing the properties of each support individually.

    From an internet search you'll find that the typical setting is 0.3. However some codes like CSA-Z662  have a minimum requirement of 0.4 (section 4.8.6).

    In conclusion, you must select the factor for your model based on good engineering practices. 

    Regards,

    Mike Dattilio
    Bentley Product Advantage Group Analyst

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