Choosing Between Metallic and Plastic-Lined Chemical Pumps

When handling corrosive chemicals, selecting the right pump is essential for safe and efficient operation. Two common options are metallic chemical pumps and plastic-lined pumps. Both offer advantages, but the most suitable choice depends on several factors, including material strength, product temperature and chemical compatibility. This article explores the key considerations when choosing between them.

Material Strength and Durability

One important consideration when selecting a chemical pump is the strength of its construction materials. Metallic chemical pumps are typically manufactured from stainless steel, cast iron, or other alloys, providing excellent strength and durability and making them well suited to applications that involve high pressure and high temperatures.

Their robust construction can also make them a suitable choice for demanding applications involving abrasive or erosive fluids, where resistance to wear is important. They offer superior resistance against wear and tear, ensuring long pump life and minimising maintenance requirements. Where the pumped fluid contains solid particles or the application involves high system pressures, a metallic chemical pump is often the preferred choice.

Product Temperature

The temperature of the pumped fluid is another important factor when selecting a chemical pump. Metallic pumps can be suitable for a wide range of operating temperatures, including both low and high extremes. The inherent thermal conductivity of metals helps to dissipate heat, which can reduce the risk of overheating and support consistent pump performance.

Plastic-lined pumps, meanwhile, combine a metallic outer casing with a chemically resistant lining, such as PTFE (polytetrafluoroethylene). This provides exceptional resistance to a broad range of corrosive chemicals, but the lining material has specific operating temperature limits that must be taken into account. Plastic-lined pumps are specifically designed for applications operating at moderate temperatures.

Selecting a pump that is compatible with both the chemical being handled and its operating temperature is essential for reliable performance and service life.

Chemical Resistance

Chemical compatibility is one of the most important considerations when selecting a pump for handling corrosive substances.

Metallic chemical pumps can offer good resistance to a range of chemicals, depending on the material of construction. Stainless steel, for example, can provide exceptional resistance to many corrosive fluids, including acids, alkalis, and solvents, but its suitability varies according to the specific chemical being handled and the grade of stainless steel. Selecting the appropriate alloy for the chemical being pumped is therefore essential to minimise the risk of corrosion.

Plastic-lined pumps can be a highly effective alternative when handling highly corrosive fluids that are incompatible with metallic materials. The lining acts as a barrier between the pumped fluid and the metallic components, helping to protect against chemical attack and preventing corrosion-related issues. PTFE, for example, offers excellent resistance to a broad range of aggressive chemicals, including many strong acids, caustics and organic solvents.

In both cases, compatibility should be assessed against the specific chemical and operating conditions to ensure safe handling.

Making the Right Choice

Choosing between a metallic chemical pump and a plastic-lined pump depends on the specific demands of your application. Both options can provide safe, reliable and efficient solutions for corrosive fluid handling and ensure the longevity of your equipment.

Understanding the properties of the pumped fluid and the operating conditions will help you identify the most suitable option for safe, reliable and efficient operation.

By evaluating the specific requirements of your application and considering the compatibility of the pumped media, you can make an informed decision between a metallic chemical pump and a plastic-lined pump. Both options provide reliable and efficient solutions for corrosive fluid handling, ensuring the longevity of your equipment and the safety of your operations.

If you need advice on selecting a pump for handling corrosive chemicals, our engineers are here to help. To discuss your application and find a solution that meets your requirements, contact the CDR Pumps team on 01933 674777 or at sales@cdrpumps.co.uk

Read more about plastic chemical pumps for corrosive and aggressive fluids