What’s that racket? 

It’s been a stressful couple of months on-site, full of early mornings, hard work in planning and installation, countless phone calls and dozens of deliveries. But at last… your project’s HVAC system is done and ready to go. 

But hang on a minute – what on earth is that sound? 

Pumpset noise can be caused by a variety of culprits – namely mechanical, hydraulic and electrical sources. More confusing still, is the fact that each of these sources can be brought on by different issues, meaning that not all mechanical noise has the same solution. 

Luckily, Masterflow is here to help. By the end of this article, you will be familiar with the most common causes of mechanical, hydraulic and electrical motor noise, and more importantly, you’ll be familiar with the associated risks and most effective solutions for putting a stop to unpleasant pumpset noise and the potential consequences associated with it.

Mechanical Noise 

Mechanical noise refers to noise generated by the machinery itself. While there are a variety of components that this noise can be created by, the most common causes are bearing issues, misalignment of pump and motor shafts, and incorrect spacing of coupling hubs.

Signs

If the noise seems to be coming from the motor itself, the issue is likely related to the bearings. The most common cause of bearing issues is improper lubrication. 

Misalignment of pump/motor coupling and inadequately supported pipework will create undue strain on the bearings. If your motor seems to be vibrating more than it should, it’s worth investigating the alignment of your pump and motor, as well as checking that your pipework and valves are self-supported. A clear indication of insufficiently supported pipework is the rubber eliminators not sitting parallel to the pump’s suction and discharge flanges.

Consequences 

Premature bearing failure is a costly outcome of both improperly greased bearings, and misaligned pump/motor connections. Bearing failure can lead to further complications in your motor, leading to increased downtime and high maintenance costs. It is always advisable to address these concerns as soon as you notice high noise levels, preventing further damages. 

Solutions 

When inadequately lubricated bearings are to blame for your motor noise, greasing the bearings in your motor with the grease quantity dictated on the motor’s nameplate will remedy the noise and improve the efficiency of your system operation. 

Of course, when misalignment of the pump and motor are to blame for your noise, the solution is to have an alignment performed. Masterflow uses extremely precise laser alignment equipment and can be booked to perform one on your site here. Not only will the perfect alignment achieve quieter operation, but it will improve efficiency and performance, putting money back in your pocket with every energy bill. 

Similarly, misalignment of pipework is obviously solved by a realignment. Masterflow is equipped with the experience and expertise to inspect and correct any pipework alignment issues that plague your system. 

Hydraulic Noise 

Noise in a hydraulic system is typically generated by fluid pulsations. While a low level of noise generated by water flowing through the pipework is inevitable, undersized pipework and air entering the system can cause heightened noise levels, warning you of potential inefficiencies and strains.

Signs

Next to Cavitation noise (more of this later), undersized pipework and air in the system are the two most common causes of hydraulic noise. While air is a hydraulic system’s worst nightmare and any presence of it can cause issues, the hiccups caused by undersized pipework will depend on how poor the gap between ideal and actual sizing is in your individual case. Undersized pipe means increased velocity and this will result in higher noise level in the pipe. 

Cavitation

The hydraulic noise of cavitation is easy to identify as it sounds like there is gravel rustling through the pump casing. It is in reality the implosion of water entering the eye of the impeller. If left unchecked, devastating damage will occur to the internals of the pump. To verify whether your pump is cavitating, partially close the discharge valve to half closed. If the noise changes or disappears, this is a sure sign of cavitation. If this is the case, then leave the valve partially closed and engage a pump company.  Refer to this video for a better understanding of cavitation. 

Consequences

Undersized pipework puts additional strain on the pump. In modest cases, this will cause inefficiencies as the pump has to work slightly harder than it should. If the pipework is severely undersized, this results in premature damage to the motor, including premature bearing failure as the load handled by the bearings is significantly increased. 

The consequences of cavitation include increased vibrations, poor pump performance and premature failure of pump parts. The consequences of air in your system will be reduced performance and higher than normal level of noise.  

Vibration, corrosion of pipework and not achieving desired flow rate are just some of the other potential consequences of undersized pipework for your system. If you notice noise coming from the hydraulic components in your system, it is strongly recommended to heed this as a serious warning and remedy the cause as soon as possible. 

How’s your system going? Is there noticeable changes like this situation?
Contact us for a quote to perform tests on your site to ensure the longevity and reliability of your motor-driven equipment.