How to Select a Corrosion Resistant Chemical Pump

How to Select a Corrosion Resistant Chemical Pump

Corrosion resistant chemical pumps are vital for many industrial applications that require the safe handling of corrosive fluids.corrosion resistant chemical pump Handling these chemicals without the proper equipment will result in equipment damage, downtime, and dangerous conditions at best, and can cause disasters and injury at worst. This is why the selection of the right pump for a given application is so important, and it’s critical to understand what makes a corrosion resistant chemical pump and how to select the best one for your operation.

A chemical resistant pump is designed to handle a broad range of chemical media that would rapidly deteriorate standard metal pumps. These media can include strong inorganic acids, caustic alkalis, slurries, volatile solvents and reactive gases. Each of these media has its own specific corrosive properties that demand unique material and design choices.

Aggressive chemical media can erode metal pump components at the molecular level. This can result in pitting, cracks and leakage. These problems are compounded by other factors, including thermal stress, mechanical fatigue and the accumulation of debris in confined spaces. In addition, metallic corrosion can induce bacterial corrosion and other forms of contamination.

A pump’s ability to withstand aggressive chemicals is based on the materials used in its construction and the quality of those materials. For example, nickel-based superalloys have a higher resistance to corrosion than stainless steel. Typically, these are used in the casing and impellers of chemical-resistant pumps.

In addition to metals, pumps are also made from plastic and other materials that have a high corrosion resistance. Chemically resistant pumps are often lined with fluoroplastics, such as PTFE or PVDF. These have a much better resistance to aggressive chemicals than most thermoplastics. Chemically resistant plastics can withstand a wide range of temperatures, so they’re ideal for use in chemical processing.

Typical applications for chemical resistant pumps include reverse osmosis (desalination), brine pumping and cleaning, waste-water injection, industrial degreasing, and spraying and humidification. These types of pumps are often used for the transfer of high-viscosity liquids at low power loads, and they offer a consistent flow rate that mitigates erosion corrosion.

When selecting a chemical-resistant pump, it’s essential to check compatibility charts for the chemical and its concentration, temperature, viscosity, pH, and other properties. This will help ensure that all wetted parts of the pump are suitable for the fluid to be pumped. Failure to do so can result in excessive maintenance, costly repairs or downtime, and even product contamination. This is because some metals have a fixed corrosion rate in any fluid, while others can be damaged by a variety of factors. These include stress corrosion cracking, inter-granular and crevice corrosion, and microbiologically influenced corrosion (MIC). Choosing the proper pump construction for your application will avoid these issues. A good rule of thumb is to opt for a chemically resistant pump that includes stainless steel in all wetted surfaces. These can be coated with special alloys to further enhance their resistance to corrosion.

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