Field experiments were conducted to record acoustic noise on the surface of an above-ground pipeline (existing heating main). Research was carried out on sections of the pipeline with various types of fastening—rigid (pipes welded to the support) and non-rigid (heat-insulating tube freely lies on the support rack). Experiments have shown that noise waves can create certain frequencies and shapes of bending waves that occur in spans of a pipeline. Depending on how rigid and reliable the fasteners are, they can be used to diagnose sections of the pipeline by acoustic noise. In computer simulation by the finite element method, the frequencies of bending waves were obtained, which are close to some experimental ones. The interaction between the nodes and beams of bending waves passing along the spans of pipes with different types of fastening to quality is consistent with laboratory experiments conducted earlier.