Patent ID: 8429951

Claim:
A diagnostic system for a valve which is actuatable by a drive and installed in a pipeline, comprising: a first sensor for detecting solid-borne sound; a second sensor for detecting a pressure in an inlet side of the pipeline; and an evaluation facility for evaluating a recorded measurement signal of the detected solid-borne sound, the evaluation facility being configured to, when the valve is closed, compare a pressure measured in the inlet side of the pipeline with a first pressure reference value, which is predetermined as at least a function of a valve size and a leakage class of the valve, determine a sound level of the solid-borne sound and compare the determined sound level with a second predetermined or predeterminable reference value, and to output a signal to indicate that a permissible leakage has been exceeded, if the sound level exceeds the second reference value and the pressure in the inlet side is lower than or equal to the first reference value.