Support calculator: Calculation of maximum recommended pipe length between supports


A simple support will increase the mechanical stiffness of the pipelines and make it more robust against vibration. This tool is intended to be used as an aid for operational personnel at a process facility for doing a rough estimate of recommended maximum distances between supports.

The calculator is not meant to be a replacement for a thorough stress calculations done during the design of a modified or new facility, but can be used in situations where vibration occurs and needs to be handled rapidly or verification that the current supports are sufficient.

Please note that often it is more important to verify the function of existing supports than to add more supports. By inspecting existing supports you will find places where the support is not sufficiently well fastned to the pipeline or that the pipe with the support have moved due to thermal or mechanical changes.
Another common mistake is that the supports are not well aligned in the direction of high vibration. The supports should then be modified to accomodate such vibration.


How to use this tool from the Vibration Toolbox?

  1. Use ISO drawings or measure the outer diameter of the bare piping to find the Nominal Pipe Size (NPS) diameter.
  2. Select the NPS from the drop down list and press the Calculate button.
  3. The tool will show recommendations for lengths between two supports for a straight pipe span.

Nominal Pipe Size (NPS):

The results of the calculations are based on assessment of main line flexibility from Guidelines for the avoidance of vibration induced fatigue failure in process pipework. Beware that the calculations are only rules of thumb and will not work for larger diameters.