Pump monitoring

Pumps are rotating machines in which we can establish their protection, monitoring and predictive diagnosis by means of vibration measurement systems.

Failure modes

Vibration analysis provides valuable information for the predictive diagnosis of pumps. The most common types of faults diagnosed in industrial pumps are:

• Imbalance
• Coupling misalignment
• Bank failures, resonance
• Bearing failures
• Cavitation
• Drive related failures

Monitoring systems

The recommended monitoring systems for this type of machine are:

Offline vibration

Monitoring of failure mode parameters by means of periodic vibration paths with portable vibration collectors.

Vibration and temperature online

Here we make a distinction between pumps with their shafts supported on plain bearings and pumps with bearings. We indicate what would be a basic monitoring, as each vibration parameter can be analyzed and decomposed into several more precise monitoring parameters when advanced predictive diagnostic systems are used.

Pumps with plain bearings

                                                            Image courtesy of API670 5th Ed.

Pumps with shafts supported on plain bearings are continuously monitored:

• Radial vibration on each bearing. Two displacement probes placed at 90º on each bearing (peak-to-peak microns).
• Axial positioning of the axis. Two redundant displacement probes (peak-to-peak microns).
• Bearing temperature. Two probes per bearing
• Active axial bearing temperature. Two probes per bearing
• Passive axial bearing temperature. Two probes per bearing

Pumps with bearings

Image courtesy of API670 5th Ed.

In pumps that support their shafts on bearings, it is continuously monitored:

• Radial vibration on each bearing. One accelerometer sensor per bearing or set of bearings in the same housing (mm/s rms).
• High frequency parameter to monitor bearing condition, e.g. Acceleration Envelope, Spike Energy... This parameter is obtained from the same accelerometer sensor that is applied to measure vibration.
• Temperature of each bearing housing. It is recommended to use accelerometer sensors that include temperature measurement.

Functions of the online condition monitoring systems

Continuous monitoring systems provide interesting functionality for the protection, supervision and predictive diagnostics of machinery such as:

• Integration of failure mode monitoring data to Distributed Control System (DCS, SCADA, PI...)
• Automatic triggering when dangerous vibration levels for the machine are reached.
• Alerts for maintenance needs, e.g. balancing, relubrication, cavitation, bearing replacement...
• Automatic measurement and presentation of data in diagnostic graphs.
• Remote access to data, which facilitates diagnostics from a remote monitoring center.

Recommended equipment and systems for pumps

Continuous monitoring:

• Pumps with bearings: Vibrovision and vibration transmitters.
• Plain bearing pumps: SETPOINT and Dynamix 1444

Portable collectors for machinery vibration monitoring: Falcon, PRE5140, PRE5050M and Dynamix 2500

Laser Alignment: Fixturlaser Aligners

Contact our sales department at info@preditec.com to request a proposal for monitoring your machinery.