Case study: Customer experience with PROGNOST®-Wireless for monitoring plunger pumps

In the PROGNOST®-NT VISU, the trend showed that the Crest-factor MP Y-2 was significantly conspicuous.

A long-standing customer uses PROGNOST®-NT to monitor its reciprocating compressors. Due to its good experience with the system and the associated service from PROGNOST, the customer decided to expand its PROGNOST®-NT with PROGNOST®-Wireless on its plunger pumps. Two sensors were installed on the main bearings of each pump.

Shortly after the installation of PROGNOST®-Wireless, strong external noises occurred on a plunger pump. These noises did not yet allow any conclusions to be drawn as to what the cause was or which component might be affected.

The measured low-frequency vibration velocities showed no recognizable change compared to the machine start.

During the analysis, the acceleration values, crest factor and kurtosis value were examined. This revealed that A sudden increase in the measured values was followed by a further permanent increase in the values

The graph of the PROGNOST®-NT VISU shows clear changes: While the outlet pressure remained constant (red), the speed of the pump increased (green), the temperature on the suction side dropped (light green) and the suction pressure (blue) fell slightly and then showed a high dynamic.

Although a change in vibration was detected on the pump, the process data was analyzed in combination with the vibration values in order to obtain more precise information about the reason for the increased vibration. The results showed a drop in suction pressure and a subsequent strong fluttering in the suction line.

This fluttering in the suction line led to the assumption that there was a fault in the suction line.

Result

The initial suspicion that it was probably a leaking suction valve was confirmed by inspecting the valves!

A damaged suction ball valve with intensive signs of wear was discovered and replaced during the repair.

A damaged suction ball valve with intensive signs of wear was discovered and replaced during the repair.

Only by combining the values of the PROGNOST®-Wireless with the process data was it possible to analyze the cause of the fault in more detail. This revealed a defective ball in the suction valve.