Protect Your Pumps From Corrosion in Just 5 Ways!

Pumps are the fundamental component for moving crude water, wastewater, mud, and sewage water through distinctive forms. With expanding worldwide necessity for energy, the industry has been looking forward to pumping frameworks that maximize productivity, unwavering quality, and cost-effectiveness. 

Centrifugal pumps experience different types of losses while converting mechanical energy into liquid energy. The losses experienced in centrifugal pumps can be divided into 3 types: Mechanical loss, Hydraulic loss, and Volume loss. 

The mechanical losses occur due to the moving components present in the pump such as impellers. The volume losses occur due to the leakage error which can be further divided as internal leakage or external leakage. The hydraulic loss also termed energy loss that occurs when there is a sudden change in flow rate and pressure. 

What is Pump Corrosion?

Corrosion occurs from chemical reactions between the pumped fluid and exposed metal surfaces that lead to metal loss. Due to corrosion, the customer has to experience high maintenance costs, low performance, and a decrease in efficiency. In extreme cases, corrosion can cause premature failure of equipment. The most affected parts are wear rings, shaft sleeves, packing, mechanical seal faces, lip seals, pump casting, and the impeller.

What Causes Pump Corrosion? 

The rate of metal loss is accelerated when the mechanical action of a fluid’s flow or velocity and the fluid’s corrosive activity are combined. In the initial stage, protective layers are mechanically removed, and after that, a flowing corrosive starts to corrode the bare metal. Processes are circular unless a component tear occurs. Inlet ends of tubes, pump impellers, and areas near tube blockages are frequently reported to have corrosion-erosion. The degradation of the mechanism can become quite complex and is dependent on the substrate and fluid chemistry when both corrosion and erosion are present in the operating circumstances. Corrosion on a substrate with limited adhesion that is prone to erosion produces oxide layers. Erosion can harm the passive layers, which activates the surface and speeds up corrosion. The primary answer in this kind of situation is protection on surfaces.

 What Causes Pump Cavitation?

A pressure difference can cause cavitation on the pump impeller. When there is a rapid pressure decrease in the fluid, it causes the liquid to flash for vaporizing when the local pressure drops below the saturation level of the fluid being pumped. The vapor bubbles created by the pressure drop are swept along the impeller vanes as the fluid moves. When the vapor bubbles come into contact with an area where the local pressure is higher than the saturation pressure, they quickly collapse. This shockwave can eventually significantly harm the impeller and/or pump housing. It is crucial to avoid cavitation rather than just reduce the impact on the pumping machinery. 

How to Recognize Pump Cavitation?

  • Noise and vibrations.
  • Seal/bearing failure. 
  • Impeller corrosion or erosion. 
  • Higher power consumption than usual. 
  • Slow operation speed than usual.

5 Ways to Prevent Your Pumps From Cavitation.

1. Pump Selection 

Selecting the right pump according to the application demand is the best way to prevent cavitation. An increase in capacity or pump head falls increases the cavitation. The positive margin of NPSHa (Net Positive Suction Head) above NPSHr (Net Positive Suction Head Required) is the best first move to assure that the pump selected is correct according to the demand of the application. 

Additional Read: How to Choose the perfect submersible pump for you?

2. Pump Installation 

Proper installation of the pump can also reduce the possible chance of cavitation. 

3. Pump Maintenance 

To increase pump life routine maintenance is very important. 

4. Choose the Correct Material for the Pump 

Your pump’s material should be chosen to minimize issues brought on by corrosion and erosion. If you buy cast iron or carbon steel pumps to lower your overall cost, the corrosion rate and maintenance cost will increase. You could buy carbon steel or cast iron if you could manage the maintenance costs after accounting for the corrosion rate. Another significant factor in the erosion and corrosion of stainless steel pumps is the existence of stagnant circumstances. Similarly, a stainless steel pump may corrode if the displaced fluid has a high chlorine content.

5. Protective Coating

The overall performance of your water pump may be stepped forward with the aid of using coating techniques. To lessen the impact of corrosion and erosion, coating inclusive of Fusion Bonded Epoxy which is a polymeric coating may be implemented to pump components. It additionally improves the hydraulic overall performance of the pumping process. Other corrosion-resistant coatings are carbide coatings which might be tungsten in conjunction with nickel, cobalt, and chrome. Such custom-designed coatings can meet the precise necessities of your applications.

Wrapping up!

This blog covers points on what causes corrosion and ways to prevent corrosion.

To know more about stainless steel fabricated submersible pumps, do

To know more about impellers and diffusers, do and