If your pump has been making some funny noises such as popping sounds and loud bangs, you may have an issue with cavitation. This issue is very common within centrifugal pump systems, and left untreated you will notice a sharp loss in efficiency combined with excessive noise and potentially serious damage to the motor and inner workings of your system.
To help you diagnose and repair the issue, we’ve prepared a brief blog post to fill you on everything you need to know. As always, feel free to contact us if you have any further questions or would like some assistance.
What is pump cavitation?
To put it simply, cavitation occurs when bubbles begin to form within the liquid being pumped. The problem usually occurs in areas which are prone to low pressure, such as around the impeller. Pumping is an intensive process, and as the bubbles start to break down and collapse, they can cause severe shockwaves within the pump. Eventually, this can lead to severe pump housing and impeller damage, if not complete product failure.
In the short term, you will begin to notice a sharp decline in flow rate and pressure, along with excessive power drain and loud vibrations.
Pump cavitation can occur in many different forms:
Vaporisation
This is the most commonly observed form of cavitation, and it occurs at the eye of the impeller when pump pressures are too low and/or temperatures are too high.
Turbulence
Sometimes you may not have the right equipment for the job. Pumps are highly technical, and it’s always a good idea to seek advice from a professional before choosing a system. If the pipes, filters, valves or elbows in your system are not up to the task for the type of liquid you are pumping, you will begin to notice turbulence and pressure fluctuations.
Vane Syndrome
If your impeller is too large in diameter there will be insufficient space within the housing. As a consequence, liquid has a much higher velocity and lower pressures are observed. This results in liquid temps that are too high, causing cavitation bubbles.
Internal Recirculation
Pumps need to be able to discharge efficiently, and when this cannot occur the liquid gets stuck in a cycle revolving around the impeller. It travels through various pressure zones which add heat and velocity, causing vaporised bubbles.
Air Aspiration Cavitation
It is important to check your valves and joint rings on a regular basis. These replaceable parts are prone to failure, and as they start to degrade, they allow air inside your system. This creates large bubbles which enter the impeller and make loud popping sounds.
Preventing Cavitation
So now you know the warning signs, how do you go about preventing it? Essentially it boils down to the following:
• Regularly Check Your Pump – look for signs of wear and tear on your filters and strainers. Any clogs should be cleared immediately.
• Check Your Pump Curve – Grab a pressure gauge or flow meter and carry out a few quick checks to see where your pump stands on the centrifugal pump curve. Is it running at the optimal efficiency point?
• Ask an Expert – In some cases your problems may be due to poor pipe design or pump selection. It might be a good idea to consult an expert in pump design who can advise on all aspects including optimal pump size.
Need help diagnosing? Contact TRUFLO Today
If you’ve been hearing strange noises in your pumps or are concerned about a drop in efficiency, it’s important to get down to the root of the problem so that it can be fixed ASAP. Commercial grade pumps are designed to provide many years of reliable and efficient service, but this is only true if you look after them properly.
Contact us today and we’ll help to diagnose your issues and get your pump operating at its best.