In addition to selecting the proper pump type and size, consider the construction materials, such as pump casings, impellers, mechanical seals, and other critical components. These key pieces are manufactured with unique metals and coatings, so that each application and its liquids have appropriate parts. The proper casing helps protect equipment from premature failure while extending the overall pump system lifespan.
Common Pump Materials
Cast iron, bronze, and low-carbon steel are among the most common—and least expensive—materials used for pump casings. These materials are readily available and easier to replace if there is an eventual failure. However, costs may significantly add up if repeated failures within the pump system, costing you time and money with each shut down for maintenance or repairs. This begs whether it’s worth upgrading your pump casing materials from the start to prevent these headaches.
Factors to Consider
Several factors must be considered with selecting materials for the pump casing and other wetted pump parts:
• Operating Lifespan
• Pump Performance
• Liquid Viscosity
• Abrasion and Corrosion
• Ease of Maintenance/Repair
• Environmental Impact
These last two factors are worth extra attention. Of course, if you are pumping hazardous or toxic liquids, you have to be very careful to prevent pump leaks. Leaks may be deadly and costly if your casing, impeller, seals, bearings, or other parts fail because of amplified wear and tear on weaker construction materials. Cavitation is another significant concern for pump operators. Any imperfections within the pump system can lead to entrapped air bubbles that implode and cause even more damage to the wetted parts.
Corrosion & Abrasion Resistance
Selecting pump materials that will withstand the corrosive and abrasive properties of the process fluids is a base-level recommendation. Cast iron is common because it is cheaper, but how well will the housing stand up if your liquids are continually eating away at it? First, you start to experience hindered pump system performance and eventually could fail altogether. The result is increased replacement parts and repair costs than the material upgrade would have cost you in the first place.
The following pump materials are rated based on standard wear-resistance measures, listed from the lowest abrasion-resistance to the highest for average processing applications:
- Cast Iron
- Manganese Bronze
- Nickel-Aluminum Bronze
- Cast Steel
- 300-Series Stainless Steel
- 400-Series Stainless Steel
Keep in mind that different fluid applications and pump systems may demand specific casing and impeller materials for optimum performance. Simple cast iron or bronze may be all you need when dealing with liquids that aren’t corrosive or abrasive. However, other applications will benefit from stronger, more durable, and more abrasion-resistant materials such as stainless steel.
Helping You Make the Right Pump Decisions
Pump casing material is just one of many pump selection and configuration factors with which the DXP Pacific team can assist you. We take the time to understand your operation and application(s) to match you with the ideal pump type, size, components, and design. Our goal is to help you achieve exceptional pump performance and extended equipment lifespan. We also offer professional maintenance, repair, and upgrade services if you need help keeping your existing system running its best. Contact us today to learn more.