Pumps are the “right hands” for transporting crude oil, wastewater, mud and sewage. Today, global energy demand is soaring. The pumping field is looking forward to a “magic tool” that can improve productivity, ensure quality and reduce costs. When a centrifugal pump is working, there will be a loss of mechanical energy to liquid energy. It is mainly divided into three categories: mechanical, hydraulic, and volume.
However, there is another common problem with pumps – erosion. It damages the metal and causes a lot of problems. Next, South Pump will take you to understand pump corrosion, causes, types and effects on pumps.
What is Pump Corrosion?
Corrosion may occur when the fluid in a centrifugal pump reacts chemically with the metal surface. This can damage the metal shell. You may have to bear high maintenance costs and inefficient centrifugal pump performance. In severe cases, the standard centrifugal pumps will age prematurely. Parts such as wear rings and impellers are most vulnerable. Then the erosion and corrosion are more severe, and the metal loss is super fast.
How to identify pump erosion? Listen to the noise and feel the vibration. Or see if the seal bearing is faulty. You can also see the condition of the impeller. And whether the power consumption and operating speed are worse than usual.
Major types of Pump Corrosion
Pump Cavitation
When a durable centrifugal pump is running, it will be troublesome if cavitation occurs. Simply put, the fluid cannot fill the small space around the impeller. This may be because the inlet pipe is too thin. Or the pumped fluid has become sticky. In addition, the impeller rotates too fast and there is air leakage on the suction side.
Once cavitation occurs, the impeller and pump casing of the centrifugal pump will be in trouble. The steam bubbles toss back and forth in the water, generating vibrations. Over time, the impeller and pump casing will be damaged.
Uniform Corrosion
In centrifugal diesel pumps, the most common corrosion is “uniform corrosion”. It’s like the entire pump surface is slowly “peeling off”. Rust is one of them. Fortunately, it is the least destructive. It basically only occurs on the surface of the centrifugal electronic pump, which is also easy to judge.
Cast iron pumps are most prone to uniform corrosion. If you want to prevent it, choose a pump made of stainless steel or nickel-based high-temperature alloy. Keep the iron away from air and water, and the pump will rust less.
Galvanic Corrosion
Although galvanic corrosion is not as common as uniform corrosion, it is more destructive. When a pump is manufactured, if several base metals (common metals that are more active and prone to chemical reactions) are used. Then, during the operation of the pump, it encounters electrolytic media such as acids and alkalis, and it is easy to react.
When different bare metal surfaces come into contact, such as stainless steel next to copper. Add an electrolytic medium, and a battery-like environment is formed. Charges and materials are transferred back and forth, and corrosion occurs. Of course, using similar metals to make the pump can prevent it.
Pitting Corrosion
Pitting is also a common form of corrosion in electric-driven centrifugal pumps. It is like a hole in the “protective clothing” worn by the pump. The metal underneath is exposed and will rot over time. If pump cavitation occurs, it will be even worse. Even stainless steel cannot escape pitting. If it is soaked in chloride-containing liquid, it will be even more serious.
If you want to prevent pitting of the pump, use metal with a suitable coating to make the pump. Alloys with high nickel content are good. For example, the Fluoroplastic alloy centrifugal pump of Southern Pump.
What Causes Pump Corrosion?
The pump is easily corroded for the following reasons: the fluid is corrosive, like a “little devil” corroding the pump body. In addition, the flow rate and flow rate during transportation will also generate mechanical force. This will tear off the protective film on the metal surface. Then the metal underneath is directly exposed to the corrosive fluid and is constantly damaged.
Key parts such as the pipe inlet and pump impeller often become “severely affected areas”. If corrosion and erosion occur at the same time, degradation is very troublesome. Therefore, protecting the pump surface and preventing gas etching cannot be delayed.
Impacts of Erosion and Corrosion on Your Pumping System
As a key component for transporting raw water, wastewater, mud, etc., self-priming electric pumps are of great significance to various industries. At a time when global energy demand continues to grow, efficient and reliable pumping systems are highly anticipated. However, erosion and corrosion are like hidden “killers” that are extremely harmful to pumping systems.
On the one hand, they cause damage to moving parts such as bearings and glands of the classic centrifugal pumps. Then mechanical losses will occur.
On the other hand, corrosion will cause fluid leakage. It will cause volume loss. It will also increase the friction of the hydraulic channel and cause hydraulic loss. Ultimately, the lined-in magnetic driven pump efficiency will drop sharply. This will not only lead to a decline in production, but also soaring operating costs like an out-of-control kite. Seriously hindering the development of the industry.
However, you don’t have to worry too much about the pump’s clothing. Choosing the latest pump design and coating can greatly improve the performance of industrial pumps. Choosing the right materials, applying good protection, and regular maintenance can prevent centrifugal pumps from corrosion.
South Pump Industry has a professional team. Whether it’s choosing a pump or choosing a coating. Or understanding corrosion-resistant metals, feel free to contact us. Contact us now to start a worry-free pump experience.