Wear in pumping system
Wear in pumping systems is a significant problem that can lead to both reduced pump performance and early failure. In this article, we take a closer look at wear and tear, how it occurs and what you can do to reduce the risk of wear and tear.
In pumping systems, wear and erosion can occur due to fluid and particles in the pump, valves or pipework. This occurs especially when the fluid changes direction or speed, which can lead to component deterioration, reduced efficiency and ultimately system failure.
How does wear occur in pumping systems?
Wear in pumping systems, valves and pipes is mostly caused by solid particles suspended in the fluid (cavitation wear is a separate chapter, cavitation causes burst damage to the material). These particles may be naturally occurring, such as sand, crystals or other particulate process fluids, or they may be the result of system contamination. As the liquid and particles pass through the pump, they can wear the impeller, casing and other components.
In addition to the amount of particles, the size and hardness of the particles also affect the degree of wear. The liquid speed also affects wear, as higher speeds can increase the impact force of the particles on the pump surfaces. Therefore, to avoid wear, you should choose a pump where the motor can run at lower speeds. In piping systems, it is mainly in bends and valves that turbulent flows occur and here larger dimensions for lower flow rates can be a solution. Ceramic valves, pipes or hoses can be another way of tackling the problem.
How to prevent wear in pumping systems?
The white parts and the impeller are made of wear-resistant UHMW-PE (Ultra-high molecular weight - Polyethylene). An excellent pump when pumping e.g. hot sulphuric acid with particles.
One way to prevent wear in pumping systems is to use a filter that can remove larger particles from the liquid before it enters the pump. Another way is to choose a material with high resistance to wear. Exclusive materials such as SMO, titanium and ceramics often have excellent wear properties. Even soft materials that can flex wear less, such as rubberised metal impellers and high-density polyethylene (UHMW-PE).
In addition, if you have chemicals in your medium, you need to be extra careful when choosing materials. Ceramics and UHMW-PE have the best combined wear and chemical properties.
UHMW-PE - a durable material
UHMW-PE is a type of polyethylene that exhibits exceptional wear resistance due to its high molecular weight and unique molecular structure. It has a low coefficient of friction, which helps to reduce abrasion of particles on pump surfaces. UHMW-PE also has excellent impact resistance, making it less susceptible to damage from particles. Its self-lubricating properties contribute to additional wear resistance as it reduces friction and heat generation. These properties make UHMW-PE a popular choice for pump components exposed to abrasive fluids or particles. A disadvantage of UHMW-PE is that the maximum temperature for pumps is approximately 90°C.
Ceramic - excellent for corrosive liquids
Ceramics are also known for their exceptional hardness and resistance to wear. Ceramic materials, such as aluminium oxide or silicon carbide, are extremely hard, making them highly resistant to abrasive wear. Ceramics have excellent chemical properties, making them suitable for handling corrosive liquids. One drawback, however, is that ceramics are brittle and cannot withstand mechanical shocks or large rapid temperature changes. The investment cost of ceramic pumps is often high, but in return the life cycle cost is very low.
CP's Model ET ceramic pump for extreme abrasive chemical applications.
Why do I need to understand the onset of wear?
Wear and erosion in pumping systems is a significant problem that can lead to both reduced pump performance and early failure. Understanding the factors that influence wear such as particle size, hardness and fluid velocity is important in order to implement appropriate preventive measures that mitigate the problems and extend the life of the pumping system.
Lyma can help you
At Lyma Kemiteknik, we have more than 40 years of experience working with chemically aggressive and abrasive fluids and can help you make the right application and material choices. In our large range you will find pumps, valves, pipes and tanks that can handle the industry's toughest applications. Welcome to contact us at Lyma!