How to Avoid Zero Anchor Loads from Piping

By Alex Matveev

Table of Contents

Why Software may show Zero Anchor Loads?

While stress analysis and supporting considerations it is always a better engineering practice to provide line stops or axial stops or anchors at the neutral point of the straight portion of the piping. It is believed that at the neutral point, thermal movement is zero and frictional resistance equalizes from both sides of the piping system. In such a scenario, the frictional forces cancel out as forces are positive at one side and negative at the other. Also as there is no thermal movement, there will be zero axial loads due to temperature effect. So, the software will show zero anchor loads in such locations.

Example of Zero Anchor Loads

For example, In the following symmetric system with two U-shape loops as shown in Fig. 1, The leg length on both sides of the intermediate anchor is equal. Thus the intermediate anchor node 11 becomes a neutral point.

**Fig. 1: Symmetrical piping system with Intermediate Anchor**

As can be seen in Fig. 2, The load along the pipe in an 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.