Estimating the insertion losses of simple pipe laggings

A procedure for estimating the insertion losses produced by simple pipe laggings formed of either a porous jacket alone or a porous jacket covered by an impervious jacket is presented. The procedure is based on a model involving an infinitely long pipe, which is supporting various types of structural waves. It is pointed out why the bending type of structural wave is often of particular importance. Data that enables the insertion loss produced by laggings for the bending type of structural wave in the lagged pipe is given in a dimensionless form. An example of how this data can be used to predict the insertion loss produced by a typical lagging applied to a typical pipe is given.