Insertion loss of pipe clamps: Quantity for prediction or manufacturer's advertising?

The noise emitted by water conveying pipes as part of sanitary installations is, in most cases, dominated by structure-borne sound transmission. The water flowing through the pipe causes a vibration of the pipe system that is transmitted to the installation wall through pipe clamps. A common mitigation measure is an elastic inlay inside the pipe clamps. Some manufacturers of these clamps advertise the insertion losses determined by non-standardized tests. Recent studies show a high dependency of the insertion loss on the mounting conditions, e.g. how tight are pipes fastened in the clamp. This contribution aims to answer the question of whether and how the mounting condition affects the insertion loss of the pipe clamps and thus how representative the specified values can be for the building situation. The investigations are carried out in-situ on the reception plate and in a building like test stand with an excitation by flowing water as well as with impact hammer excitation. This study is part of a research project with the overall aim to provide source data for the prediction of the sound transmission in buildings using EN 12354-5.