How to Avoid Zero Anchor Loads from Piping? - What is Piping

How to Avoid Zero Anchor Loads from Piping?

For example, we have symmetric system with two U-shape loops.

The load along the pipe in intermediate anchor (node 11) will be zero


In reality the piping heating up can be uneven, the friction forces can be different on the left and right part of piping, piping design can’t be ideal. Therefore, the real load on the anchor will not be zero.

To avoid such situation the Anchor Factor “k” is used in piping stress engineering practice. Following method can be manually used in any pipe stress analysis software. In PASS/START-PROF piping stress analysis software this is built-in function. Learn more

  • If loads from pipes to the left and right of the support  (N1 and N2) are in the same direction, they are combined as  N1+N2
  • If loads  N1 and N2 are in different directions, the lower values is multiplied by k and then combined as  N1+N2*k (|N2|<|N1|)
  • If the support is on an end node, factor  k is not used

Factor k applied only for loads in the horizontal plane: axial force, lateral force, horizontal moment.

The common value, that is recommended by some piping stress analysis codes is k=0.8. If we use 0.8 value the result will be following:

You can try to model this situation in a free demo of PASS/START-PROF software: demo.passuite.com

Training video shows how to create this model. It takes 2 minutes

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2 thoughts on “How to Avoid Zero Anchor Loads from Piping?”

    1. No information in EN. Factor k=0.8 is specified in codes SNiP 2.05.06-85 and SP 36.13330.2012. Also k=0.8 is offered in many Russian piping design and stress analysis handbooks. It is common design practice since 1950

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