PUMPS DO NOT WORK! AND OTHER CENTRIFUGAL PUMP FOUNDATIONS
Is the centrifugal pump giving you any problems? Here are a few guidelines given below that might help or at least help to minimise many of the usual problems associated with a centrifugal pump:
The foundation of a centrifugal pump should be able to observe the torque and force extended by the pump without any shift in its position. In some cases, it must also resist the forces extended by the piping and associated drive connected to the pump.
The strength of the foundation, together with the vibration behaviour, is crucial to ensure that the pump functions reliably.
On a concrete foundation, a combined base plate along with the drive for the pump must be placed.
Table foundations composed of steel and concrete that rest on special anti-vibrating elements for vibration insulation against the environment are necessary. The individual components are fitted on the table using a base or individual frames.
A special pump foundation may not be required if the base plate is composed of concrete, steel or iron. However, the entire setup has to be rigid enough to prevent distortion so that small and medium-sized pump sets with medium load from the piping can be installed even without a foundation.
If you are using a centrifugal pump, then it is important for you to understand why such pumps may frequently fail and what methods are available to deflect before things come to a standstill.
One of the biggest problems that reliability and maintenance teams face today is the growing skill gap. Few individuals available have the required expertise to diagnose and repair frequent and major faults that haunt these pumps. Pump failures do not just cause inconvenience but can lead to catastrophe as well. From a paper mill to a water treatment plant, a non-functional pump can directly impact production. Therefore these pumps must remain healthy and running at all times. For that, it is important to understand why these forms failed.
In more than 50 per cent of pump failures, five broad factors are taken into consideration:
In centrifugal water pump, most leakages happen at the interface between the two seal faces. However, there are instances when leakages may happen in the secondary sealing area. There can be numerous reasons for mechanical seal leakage. These include non-alignment of the seal ring, thermal distortion and dry running.
Such failure happens when the pump is selected improperly for an industrial application, operating condition, or a specific purpose. Therefore it is essential to match the right pump depending on the nature of the specific application.
According to various technical reports, the most common reason for bearing issues is improper lubrication, causing it to overheat. It happens in almost 80 per cent of the cases. The other causes include fatigue, overload, and improper bearing selection, among others.
Just like with the other failures, there can be several reasons for the wear and tear of the impeller. One of the most common reasons happens to be erosion. However, it can also result from an improper size pump leading to an imbalance in pressure.
The most common coupling failure happens due to the reasons such as improper lubrication, torsional vibration, unexpected environmental issues, overload and misalignment.
The easiest fix is to replace the faulty component. However, such a move sometimes does not cover the actual cause since there can be several reasons for damage. For example, if the pump is not properly grounded, it can leak current into the bearing and damage it. Another factor could be cavitation, which can damage impellers, bearings and seals over time. In both instances, simply replacing the damaged part resolves the issue. However, if the root cause, like grounding or cavitation, is left unattended, the issue will be repeated. So what is the way to detect the root cross problem before it manifests physically, thereby hampering operation and leading to revenue loss. One of the ways is to go for condition monitoring technology.
Condition monitoring technology is capable of keeping track of the pump operation using a signal. The signals could be noise, temperature, vibration and so on. The main thing here is the ‘footprints of failure’. Whenever a fault develops, it changes the normal pattern uniquely. The condition monitoring system is capable of tracking and identifying these changes. In fact, the system can even detect a few issues much sooner than any other approach.
To come up with the best condition monitoring strategy for the pumping system, various factors need to be considered, including the fault type that needs to be monitored, the pump environment and the process of its operation. A condition monitoring system usually consists of essential technologies like vibration analysis, oil analysis, electrical signature analysis, infra-red thermography and acrostic emission analysis.
By keeping track of the current, oil, voltage, vibration, sound and heat, it is possible to have an early insight into the failures of a centrifugal pump. It can also help to understand what technique or approach would work best and in what condition to keep a critical centrifugal pump up and running all the time.