Pump Cavitation and What Causes It?
Pump cavitation is one of the leading causes of malfunction in industrial water pumps. This specific problem formulates by creating bubbles or vapor cavities in a particular liquid due to quick pressure changes. They mostly form in low-pressure zones and have the capacity to burst when exposed to high pressures, emitting powerful shockwaves throughout the pumping application. Cavitation provides many risks, especially for petroleum, food, and chemical processing industry manufacturers. This is why when they design machinery; they consider these risks first to avoid certain complications in the future.
Pump cavitation always decreases a pump application’s efficiency. It brings stress to its relevant parts, and it reduces their lifespan. By causing continuous damage to the pump, these shockwaves will eventually lead to premature failure of the valves. It will also decrease its flow pressure, and eventually, your pumps will break.
Causes of Pump Cavitation
There are specific reasons why pump cavitation suddenly occurs inside these applications. If you are not sure how to fix it, another option besides calling a professional is by checking these probable causes. This way, you could have a more comprehensive look inside your pump’s system.
- Pressure Drop Inside the Suction Nozzle – If the vapor pressure of the liquid inside the pump suction is not sufficient enough for operating conditions, it will vaporize. This will result in the formation of gas bubbles, which will most likely lead to cavitation.
- Flow Reduction Inside the Pump Suction – Centrifugal pumps require a specific flow rate to avoid running dry as much as possible. If this drops down even lower, it will develop the vapor, and the possibility of pump cavitation increases.
- Temperature Increase from Pumped Liquid – If the liquid’s temperature increases at the pump suction, it also increases its vapor pressure. This will produce more bubbles and lead to cavitation.
- Obstructed Flow Conditions Due to Irrelevant Objects and Sharp Elbows in the Suction Piping – Frictional pressure decrease in the pump suction is caused by sharp elbows, valves, and other obstructions and fittings. This will increase the possibility of lowering the pressure, resulting in cavitation.
- Incorrect Selection of the Pumps – Each centrifugal pump has a specific net positive suction head requirement or NPSHr. If you fail to select the right pumps properly, the net positive suction head available or NPSHa has the chance to fall below the NPSHr limit. This will most likely cause cavitation in the long run.
- Fluid Velocity Increase at the Pump Suction – Higher flow rates cause an increase in fluid velocity inside the pump suction compared to the design case. If we are going to take a more in-depth look at Bernoulli’s principle, this means that higher liquid velocity leads to higher speed and lowered head of pressure. Pressure drop caused by friction inside the pump suction also rises with the flow rate, producing low pressures and cavitation within it.
Seoca Pump’s High-Quality Industrial Pumps
Here in Seoca Pump, we provide every pump you need. We can help you determine all of your application’s problems, and we are always ready to help. If you need our services, you may call us at 0086-020-83565381. Check out our pumps only at Seoca-Pump.com!