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.
Cavitation decreases an application’s efficiency over time and puts repeated stress on critical pump parts, shortening their overall lifespan. Shockwaves can cause significant damage to the pump, which in turn leads to premature valve failure, decreased flow pressure, and, ultimately, breakage. If you’re experiencing any of these issues with your pumping application, our in-house pump experts can help.
Types of Pump Cavitation
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.
Common causes of suction cavitation include:
- Clogged filters
- Pipe blockage on the suction side
- Poor piping design
- Pump running too far right on the pump curve
- Conditions not meeting NPSH (net positive suction head) requirements
Discharge cavitation occurs when the pump’s discharge pressure is too high. Under these conditions, it’s difficult for the fluid to flow out of the pump. Instead, it continues moving at high velocities inside the working chamber, forming bubbles in the process.
Common causes of discharge cavitation include:
- Clogged filters
- Pipe blockage on the discharge side
- Poor piping design
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.
To discuss how we can assist with pump maintenance and part selection for your specific project, contact our in-house experts today.
