Monitoring pump health
Taking a more proactive approach to pump maintenance can play an important role in boosting uptime. So, it’s not surprising there’s increasing interest in condition monitoring. This involves regular measurement and analysis of key physical parameters such as vibration and temperature, and enables detection of pump system problems before they can result in unscheduled downtime, high repair or replacement costs, and lost productivity.
Basic instruments can assess and report on vibration, temperature and other parameters. More advanced tools include online surveillance systems and software that can deliver real-time data for review and foster more timely remedial action should this become necessary.
Many problems will manifest as vibration, which is widely considered the best operating parameter to judge pump-train condition. Vibration can detect problems such as imbalance, misalignment, bearing oil-film instabilities, rolling bearing degradation, mechanical looseness, structural resonance and a soft foundation.
Vibration measurements are quick and fairly non-intrusive because pump equipment remain undisturbed. In addition, established industry standards identify vibration levels for specific types of equipment.
A significant increase in “overall vibration” (the sum of all vibration within the frequency range of the instrument) compared to a baseline value will signal an impending problem, allowing it to be addressed before equipment failure occurs.
A wide range of technologies from hand-held vibration monitoring tools such as low-cost vibration pens and overall vibration meters to more sophisticated portable data collectors and related instruments combining compact size with data storage capabilities (Figure 2) can handle data collection.
Figure 2. This instrument provides a range of testing and analysis techniques as well as data recording.
Regular monitoring of temperature also can shed light on system conditions. It’s a useful indicator of mechanical condition or the load applied to a specific component such as a thrust bearing. For example, as a thrust bearing fails, friction causes its temperature to rise. Thermocouple sensors installed in the housing of a bearing and measuring temperature changes within the bearing or lubricant can send a signal about problems beginning to develop, enabling appropriate maintenance actions to be scheduled.
The technology toolbox for condition monitoring also includes online surveillance systems. These perform round-the-clock monitoring of pumps regardless of their location. Such technology can collect data continuously or at a predetermined frequency from permanently installed sensors and then send its findings to a host computer for subsequent analysis.
Involving the operator
Operators can play a pivotal part in proactive maintenance strategies and boosting pump uptime — by serving as the “eyes and ears” in a plant to detect equipment faults before problems can escalate.
Under Operator Driven Reliability (ODR), the operators perform basic maintenance activities above and beyond their classic duties (Figure 3). ODR enlists operators to observe and record the overall health of pumps by checking for leaks, listening for noises, monitoring temperature, lubrication and vibration, and taking responsibility to identify any abnormal equipment conditions — and, in some cases, to respond with the appropriate corrective actions. Hand-held technology allows operators to translate early detection of developing problems into prompt corrective action.