Answers to Your Most Pressing Pump Vibration Questions

In this post, we answer some of the most common questions that we receive from our customers regarding pump vibrations. We have collected these answers from our knowledgeable pump specialists, here at Sintech. We hope these answers will help you solve the challenges you’re experiencing while operating your industrial pumps. Have a question that is not listed here? You can always contact our technical experts. Let’s get started.

1. Why is my pump vibrating? Is something wrong with it?

A certain amount of vibration is typical in all pumps. If your pump is vibrating as usual and there are no reductions in the pump efficiency, then you don’t have to be worried about the vibrations.

2. When I operate my pump, it sounds like it is pumping gravel. What is the reason for it?

If your pump sounds like gravel is tossed inside, the most likely reason for it is cavitation. Cavitation occurs when air bubbles (or cavities) form inside the liquid that is being pumped. Some of the common symptoms to watch out for cavitation include: Excessive noise and vibration – like gravel being tossed inside the pump Loss of efficiency, pressure, and capacity Cavitation, when left unchecked, can cause severe damage to your pump. Click here to read more about cavitation and ways to rectify it.

3. What are the causes of excessive pump vibrations?

Excessive pump vibration can occur due to several reasons. They can be divided into:

Mechanical Causes of Vibration

Excessive vibration due to mechanical causes are a result of one or more of the following phenomenon: Worn or loose bearings Parts that rub against each other Damaged/loose parts Bent or warped shaft Damaged impellers Unbalanced rotating components Loosely held down bolts Pump base too small Pipe strain either due to design or as a result of thermal growth, especially in shafts Driver misalignment

Hydraulic Causes of Vibration

Vibration due to hydraulic causes are: Internal recirculation Water hammer Pump operating away from the BEP (Best Efficiency Point) Air getting into the system due to cavitation Turbulence in the system The vaporisation of the transported fluid Impeller vane running too close to the cutwater Other Causes of Excessive Pump Vibration Operating the pump at critical speed – this is a common occurrence in pumps that use VFDs (Variable Frequency Drives) and pulley-driven pumps. Harmonic vibration from other equipment nearby Slip-stick at seal faces occurs when you’re pumping a non-lubricating fluid, like a dry solid or gas.

4. How can I determine if the excessive vibration problem is mechanical or hydraulic?

You can determine the root cause of excessive vibration by analysing the symptoms. It’s a hydraulic issue if you notice any of the following symptoms: Intermittent flow No liquid delivered Insufficient pressure Insufficient flow It’s a mechanical issue if you notice any of the following symptoms: Hot bearings or frequent bearing failures Short packing life The pump consumes excessive energy Higher than normal vibration levels Frequent failures of mechanical seals Excessive wear and tear

5. What are the possible damages caused by excessive vibration?

When the vibration levels in your pump exceed usual standards, they can lead to several damages and affect your pump’s performance. At least six primary components of your pump get affected due to excessive vibration: Life of the mechanical seals gets impacted – if left unchecked, vibration causes excessive wear and tear of mechanical seals, leading to frequent repairs. Wear rings, impellers, bushes all get affected by excessive vibration. It leads to a drop in the pump’s efficiency, leading to unplanned downtime and frequent repairs.

6. How can I distinguish if the vibration is due to cavitation, air-entrapment, or recirculation?

Identifying the root cause of excessive vibration is quite challenging. Let’s give you a simple way to determine whether the vibration is due to cavitation, air-entrapment, or recirculation. Slowly throttle, the discharge valve closed. Watch out for what happens. If the vibration and noise reduce – then the issue is mostly cavitation. If the vibration and noise stay the same – then the issue is mostly air entrapment. If the vibration and noise increase – then the issue is mostly due to recirculation. However, if the vibration issues still exist, then it’s either a design or operational problem.

7. How to put an end to pump vibration issues?

The best way to eliminate excessive vibrations is by preventing them from happening in the first place. For this, you need the right hardware. Invest in high-quality pumps that are customised to your specific requirements. Sintech supplies the best industrial pumps for various sectors like food processing, paper manufacturing, wastewater, etc. Get in touch with our sales team to start discussing your requirements. Once you have installed the right-sized pumps, the next step is to ensure proper maintenance. By adopting the right maintenance techniques like predictive maintenance, you can spot any vibration issues before it becomes a significant challenge. Have additional questions about vibration troubles going on in your pumping system? Shoot us your questions! Our team of pump experts will gladly provide you with the right technical assistance.