Vibration measurement of pumps
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I would like to ask my colleagues in the industry: does your company measure the vibration of mechanical pumps on a regular basis? If testing is to be done, which position will be responsible for it? How often should it be measured?
The most important aspect of pump maintenance is “daily inspections”! This is also the key to identifying problems, and vibration is one of the very important indicators in the operation of pumps; therefore, it is necessary to measure vibration. The parameters of vibration include: frequency, velocity, and acceleration. We generally use mm/s to represent it. Testing is carried out once a day, with detailed inspection records kept.
Vibration needs to be measured when the pump is first started up for testing; it is generally not measured under normal conditions, and vibration is checked only if abnormal noises are detected during inspections
Measurement is taken during the first operation of a pump after maintenance or new installation; thereafter, technicians conduct measurements and analysis on pumps with high vibration levels during routine inspections.
Measurements are taken frequently, carried out by the equipment engineers on duty, with daily inspections as part of routine practice； However, a vibration meter is generally used for testing once a week on Fridays.
It seems that vibration measurements once a day are indeed a bit frequent, but the refinery has been doing this for over thirty years; it has become a tradition.
Now, foreign companies (following international standards) use vibration intensity in mm/s to express it, while our factory (a state-owned enterprise) generally uses amplitude for this purpose. For ordinary pumps, vibration is measured at the radial and axial positions of the bearings; operators also measure vibration and temperature. Our maintenance staff need to determine whether the pump is important, whether it has just been repaired, or whether it has just started operating, and they must go to the site to conduct an inspection. For power units, there are instrument readings available, so it’s sufficient to check those readings directly in the operator’s control room
Vibration must definitely be measured, but it needs to be measured in categories. 1. For example, key equipment, process workshops, the equipment department, maintenance workshops, etc., all need to be inspected, and records must be kept. 2. It is sufficient to pay attention to the regular equipment and process workshops as well as the maintenance workshops. 3. Vibration measurement includes parameters such as velocity, acceleration, frequency, and amplitude, with different specified values set by domestic and international standards.
We have dedicated status monitoring engineers here to conduct checks, twice a week.
The management of mechanical pumps involves, in addition to lubricating oil, the regular monitoring of these pumps. Existing monitoring methods are used to analyze their operating conditions; if measurements are taken only when the vibration level of the pump increases, by that time the pump has already suffered significant wear, and such management becomes passive. We now conduct measurements once a day, analyze the data collected, and when abnormal vibrations are detected, we carry out further detailed analysis to identify the issue with the equipment. After a period of testing, it has shown excellent results in preventing major failures of the equipment. It is recommended to continue vibration measurement over the long term