Top 5 failures in pumps and how to detect them

One of the biggest problems facing maintenance and reliability teams today is the ever-growing skills gap. Every year there are fewer people with the expertise to diagnose and repair the major faults that plague pumps. And that can lead to catastrophe. From paper mills to water treatment plants, even one failed pump can shut down production.

It’s crucial to keep pumps healthy, but to do that you need to answer one important question: why do pumps fail? These 5 things account for over 60% of pump failures, according to Grundfos:

1. Mechanical seal leakage

Most leakages usually take place at the interface between the two seal faces, but there are occasions when leakages also come from the secondary sealing area. There are a variety of reasons for mechanical seal leakage, such as dry running, thermal distortion and misalignment of seal rings, to name a few.

2. Process issues

These types of failures happen as a result of an improperly selected pump for the specific process, industrial application or operating conditions. So it’s crucial to fit the right pump for your specific application.

3. Bearing issues

According to the technical report by the RKB Bearing Industries Group, by far the most common reason for bearing failure is improper lubrication (80%), causing it to overheat. Other causes include improper bearing selection, overload, fatigue and many more.

4. Impeller wear and tear

As with other failures, there are multiple reasons for impeller wear and tear. One of the most common is erosion, but it can also result from an improperly sized pump, which can lead to an imbalance of pressure.

5. Coupling-related issues

Most frequently encountered coupling failures happen for the following reasons: misalignment, overload, uncommon environmental causes, torsional vibration and improper lubrication.

The fastest fix is to just replace the failed component. But that doesn’t address the underlying cause, and as we see from the examples above, there are always several causes that can lead to a specific type of damage. For example, if the pump isn’t properly grounded, current can leak into a bearing and damage it. Another example is cavitation, which over the long term will damage seals, bearings and impellers. In both cases, replacing the damaged part will fix the pump for now, but if you don’t fix the root cause—the grounding issue, or the cavitation—the part will simply keep failing, over and over again. So how can you catch these root-cause problems before they start to manifest physically, endangering operations and possibly leading to major revenue losses? One way is to use a condition monitoring technology.

How does a condition monitoring system track down potential failures in pumps before they happen?

A condition monitoring system tracks the pump’s operation using a signal such as vibrations, temperature, noise, etc. The key is what we call “fingerprints of failure”: every developing fault changes the usual pattern in a distinct way, which the condition monitoring system can track and identify. Each condition monitoring technique is better at detecting certain issues sooner than others.

To craft the best condition monitoring strategy for your pumping system, you will have to weigh different factors, including the fault types you want to monitor, the pump’s environment, and the process it’s operating in. To help you get started, we’ve put together a free condition monitoring comparison guide that examines five common technologies: acoustic emissions analysis, infrared thermography, electrical signature analysis, oil analysis and vibration analysis. The guide explores the strengths and weaknesses of each technology, plus example performance on common pump failures.

Learn how current, voltage, oil, sound, vibration and heat can give you early insight into developing centrifugal pump failures—and which techniques work best in which situations to keep critical centrifugal pumps 100% up and running.

This e-book covers:

• the anatomy of a centrifugal pump
• condition monitoring methods in centrifugal pumps
• examples of when different techniques will detect different pump failures
• pump energy and performance insights

Fill in the form to download the e-book.