Global Pumps provide the latest remote condition monitoring technology available in Australia. Tags: Maintenance. Peristaltic Hose Pumps. Air Operated Diaphragm Pumps. Slurry Pumps. Magnetic Drive Pumps. Drum Pumps. Follow Us. Copyright Global Group of Companies. All Rights Reserved. Part of the Intrax Group. Privacy and terms of use. Privacy and terms of use Sitemap Related Articles. What is Pump Cavitation? Types of Cavitation There are five different types of cavitation.
One or a combination of the following symptoms can be a result of cavitation: Decreased Flow or Pressure: If your pump is not producing the amount of flow as stated by the manufacturer, this could mean that cavitation is occurring. Unexpected Vibrations: Cavitation can cause unusual vibrations not accounted for by both the equipment used and the liquid being pumped. Impeller Erosion: Pieces of impeller within the system, or eroded parts are a sure fire sign of cavitation. Erratic Power Consumption: If bubbles are forming around the impeller, or the impeller itself has already started to fail, you may notice that your pump requires more power than usual to transport its media.
You may also notice fluctuations of power use as suction rises and falls depending on how the impeller is performing. When the bubbles implode they can make a series of bubbling, cracking, sounds. Alternatively, it might sound like tiny marbles or ball bearings rattling around inside the impeller housing. How to Prevent Cavitation Now that you know what to look for, and understand the different types of cavitation you might encounter, you can formulate a plan to prevent cavitation, saving large amounts in maintenance and replacement parts.
Note: Slowing the pump down will reduce flow rate and head pressure. Install an impeller inducer Incorporate a booster pump into your pump system. This will take some of the stress off of your primary pump. Increase liquid level around the suction area. If possible, try to increase the diameter of the eye at the centre of your impeller. Turbulence Cavitation Preventative steps: Evaluate all components to ensure that they can take the strain of the flow rate, volume, and properties of your transported fluid.
Replace components as needed. Consequently, it is important to build in a safety margin about 0. Positive displacement pumps require an inlet pressure to be a certain differential greater than the vapour pressure of the fluid to avoid cavitation during the suction phase. Manufacturers may quote NPIP-R as the recommended inlet pressure and provide charts showing how it varies with pump speed. Cavitation is a potentially damaging effect that occurs when the pressure of a liquid drops below its saturated vapour pressure.
Under these conditions it forms bubbles of vapour within the fluid. If the pressure is increased again, the bubbles implode, releasing damaging shockwaves. This can cause severe erosion of components.
A common example of cavitation is when a centrifugal pump is starved of feed: vapour bubbles form in the eye of the impeller as it imparts velocity on the liquid and collapse again on the discharge side of the vanes as the fluid pressure increases.
Cavitation can also occur in positive displacement pumps such as gear pumps and plunger pumps. Contact us. Thank you. One of the team will be in touch soon. Please make sure you have completed all the required fields. Useful information on pump cavitation What is cavitation? What are the symptoms of cavitation? How does cavitation cause damage? What is Vane Passing Syndrome? What is Suction Recirculation? What is Air Aspiration Cavitation? What is NPSH? Summary Cavitation is a potentially damaging effect that occurs when the pressure of a liquid drops below its saturated vapour pressure.
There are a number of measures that can be taken to reduce the risk of cavitation: Choose pumps carefully by consulting pump manufacturers and suppliers, discussing your application in detail. Author: Sam Kelton. Frequently occurring in pumping applications, cavitation creates bubbles or vapor cavities in a liquid as a result of rapid changes in pressure.
These liquid-free voids typically form in low-pressure zones and can burst when subjected to high pressures, sending powerful shockwaves throughout the entire application. Manufacturers in the chemical processing , food processing , and petroleum industries must consider the risk of cavitation when designing machinery in order to avoid unwanted noise, vibration, and component damage.
Shockwaves can cause significant damage to the pump, which in turn leads to premature valve failure, decreased flow pressure , and, ultimately, breakage. There are two types of cavitation that may occur in reciprocating positive displacement applications: suction and discharge. Suction cavitation occurs ahead of the suction stroke, when the pump is starved of flow, either from being in a high-vacuum or low-pressure environment.
The opening of the valve is delayed by inertia, causing a lower flow rate on the suction side and resulting in expansion, pressure decrease, and the formation of bubbles close to the plunger. Instead, it continues moving at high velocities inside the working chamber, forming bubbles in the process. When working with pumping applications in a processing industry, cavitation should always be kept in mind; being able to recognize the warning signs and identify the root causes of cavitation in your machinery can significantly reduce the risk of long-term damages, saving both time and money.
Triangle Pump has nearly a century of experience assisting clients with pump issues such as cavitation. Our pump components are designed to preserve expensive parts such as crankshafts and power frames by transferring the majority of wear to less expensive, more expendable parts such valves, plungers, and packing.
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