Piping Vibration Mitigation Comparison Using Snubbers and Struts

Abstract

One of the typical characteristics of high temperature piping systems is that they are more flexible. This is due primarily to expansion stress limits which cause the piping designer to add additional elbows and to minimize axial or lateral stops. The resulting higher flexibility and lower frequency piping system is vulnerable to vibration loading which may result in excessive displacements, and hence, excessive stresses. Two options for reducing vibration displacements are adding snubbers or adding struts to the piping system. Both snubbers and struts will act as rigid components when subjected to vibration loading. The snubber has the advantage over the strut of being able to displace in all directions when the piping system is heated, thus allowing the expansion stresses to be minimized. Also, snubbers that are better suited for mitigating operational vibrations also have the advantage of being effective in all three orthogonal directions. The strut has the advantage over the snubber in that the installation cost is less. Two identical piping systems were both experiencing high vibration loading requiring the addition of vibration mitigation supports. One piping system was remediated with snubbers, and the other was remediated with struts. The resulting cost differences and the vibration response of these two piping systems will be discussed. Additionally, the challenges of making these two approaches most effective will be discussed.