Here is a little food for thought: Think of the penguins that go out and select the perfect pebble for their lifetime partners. The pebble has been shaped and changed over years of washing up against rocks and other stones. All this to make that perfect gift. It’s no wonder that if the ocean can shape and change such a solid piece over time, the water flowing through our pipes will do the same.
The water we send through our various systems has several chemicals in to balance it out, but over time, it will also break down the system it is coursing through. Being a critical element to the agricultural and industrial sectors, water pumps are subjected to harsh environments and nonstop work. Understanding what causes corrosion and how damaging it can be is imperative. We will explore the types of corrosion and how to minimize the damage.
Factors that will Affect the Water Pump You Buy
Let’s first look at what you need to know when you are selecting your water pump. The choice you make here depends on the usage it will endure. The type of water that will be flowing through the pump is also of great importance.
There could be water that contains corrosive solids or even bubbles that affect the pump. Below are some of the factors that will affect the type of water pump you need to purchase:
- The pH level of the water
- Duty type of the pump
- Flow Turbulence
- The temperature of the liquid
- Range of the liquid
- The pressure of the liquid flowing through
- Impurities in the water
- Air and Vapor trapped in the water
All of the above can cause significant damage to your water pump and connecting pipes.
Types of Corrosion
There are different types of corrosion damage that your water pump could be subjected to. We explore some of the main types of corrosion damage.
Cavitation Corrosion
When there is a rapid change in liquid, small cavities filled with vapor are formed. These bubbles will collapse when placed in high-pressure situations. This collapse will cause a shock wave that damages the impeller, piping, and other pump components.
Water pump cavitation can also remove the protective layers inside the mechanisms designed to protect them. The layers are made of components such as protective films of oxides and metallic substrate.
Pitting and Crevice Corrosion
Pitting corrosion occurs in materials with protective films. The surface is attacked, leaving localized holes on the surface of the metal. The pitting process is further enhanced when water contains substances like Chloride or Bromide.
Pitting occurs when the metal is exposed. When there is a lack of oxygen and small holes form, they are attacked and get bigger.
Crevice corrosion will occur in the gaps between seals or inside cracks. When these areas get exposed to a stagnant solution, corrosion occurs.
Microbiologically Influenced Corrosion
What does this mean? Well, this is when there is deterioration in the metal because of the activity of microorganisms. When a biofilm is attacked and has no oxygen in it, hydrogen peroxide will settle in.
This, in turn, will then react to metal making crevices in the pump or pipes.
Galvanic Corrosion
Galvanic Corrosion will occur when the two different kinds of metals are in electrical contact and an electrolyte is present. The noble metal will remain unaffected whereas the more active metal will corrode.
Erosive Corrosion
Erosive as a word speaks volumes. This type of corrosion occurs when solid contaminants are present in the water and cause damage.
Size, the rate and speed of impact, and the hardness of the surface all make a difference to the extent of the damage caused.
How to Prevent Corrosion
Below are some of the ways you can prevent water pump corrosion:
- Flow rates – While water is flowing at high speeds, it churns everything up, bringing solid particles up and throwing them around. At a lower flow rate, these solids will settle back down and won’t become dislodged.
- Ceramic Lining – When you are dealing with corrosive environments, ceramic-lined valves and pipelines are recommended. Ceramic is better suited to highly corrosive environments and temperatures.
- Polyurethane Coating – Due to its flexibility and strength, non-reinforced polyurethane coatings can be used for higher cavitation resistance. Non-reinforced Elastomers are coatings that work as a springboard when bombarded with gas bubbles.
- Teflon – PTFE coatings are used for water pumps that operate in the pharmaceutical industry. They are non-toxic and have a high resistance to heat.
- Thermal Sprays are used occasionally for coating as well. they are made from Stainless Steel, Zinc, and Aluminium.
Bear in mind that when you are coating a surface or impeller, you need to keep the original shape of the vanes to ensure longevity and functionality.
In Closing
The risk that corrosion runs for a manufacturing or agricultural plant can be immense if precautions are not taken.
Design and staging a system properly upfront are crucial aspects to success. This coupled with the nest coating options and materials, can make an impact negating that risk.
Having the right partner to design and set up all the pumps is just as crucial. It’s essential to have an efficient, well-maintained plant and partner in parts or installation.
Jordan Pumps offer one of the most comprehensive ranges in household and agricultural pumps. If you are looking for friendly advice or a lifetime partner, contact Jordan Pumps; they will have you covered. They also have an overnight delivery service backing up their friendly service.
