Check valve e.g. inlet and/or exhaust valve, diagnosing system for positive-displacement pump, has evaluation device evaluating impact sound signal for determining values of characteristic of sound signal received at valves

摘要

The system has a receiver (20) for diagnosing impact sound at check valves (8, 9) e.g. inlet and/or exhaust valves. An evaluation device (22) evaluates an impact sound signal for determining values of a characteristic of the impact sound signal received at the valves. The evaluation device determines which of the two values is the larger value, and outputs a signal for indicating an interference of the valves, if the larger value exceeds a predetermined reference value.