Everything You Need to Know About Cartridge Seals

Cartridge seals are one of the most critical components of modern machines that require sealing around rotating shafts. They are ideal for preventing leaks of fluids and gases in various industrial applications, such as water treatment, chemical processing, pharmaceuticals, and food processing.

If you are unfamiliar with this type of seal, this article will tell you everything you need to know about cartridge seals, including its working principle, components, types, and applications.

What are Cartridge Seals?

Cartridge seals are a type of high-performance mechanical seal that comes in a pre-assembled cartridge form that dynamically seals the leakage around rotating shafts in pumps or mixers. They frequently come with a built-in gland plate, which is a seal chamber designed to hold the sealing elements, such as the rotating faces, stationary seats, and elastomers, and help protect them from external contaminants.

How do Cartridge Seals work?

The primary function of cartridge seals is to maintain a clean, sealed environment between the pump and the atmosphere while controlling the leakage with zero to minimal emissions. They work by using a set of mechanical components that interact with each other, such as:

Rotating seal face: This is a hard ring that rotates with the shaft and makes contact with the stationary seal face.

Stationary seal face: This is a softer ring that remains stationary and is clamped between the gland plate and the pump body.

Elastomers: These are O-rings or gaskets that seal the interface between the gland plate and the pump body.

Spring: This component provides the force necessary to keep the two faces in contact with each other, increasing the seal's effectiveness.

Types of Cartridge Seals

There are several types of cartridge seals, each designed for specific applications and operating environments. Here are some of the most common types:

Single Cartridge Seal: This is the most basic type and is ideal for non-critical applications. It comprises a single seal face and is suited for low to medium pressure and temperature limits.

Double Cartridge Seal: This type is ideal for critical applications and comprises two sets of seal faces that are lubricated and cooled via a barrier fluid. It also comes with a leakage detection system to detect seal failure.

Split Cartridge Seal: This type is designed to fit into existing equipment with limited space for the installation of new seals. It is split into two halves, making installation and maintenance easier.

Gas Seal Cartridge: This type is ideal for sealing high-pressure gas in compressors or turbines, and it does not require external flush or cooling. It comprises a set of gas-tight seal rings and a stationary seat.

Applications of Cartridge Seals

Cartridge seals have a wide range of industrial applications, including:

Pumps: Cartridge seals are commonly used in centrifugal pumps, positive displacement pumps, and axial-flow pumps to prevent leakage of fluids, such as water, chemicals, or petroleum products.

Mixers: In the chemical and food processing industries, cartridge seals are used to prevent contamination of products and improve process control.

Compressors: Cartridge seals are ideal for sealing the high-pressure gas in compressors and turbines, ensuring reliability, efficiency, and leak-free performance.

Agitators: In the pharmaceutical industry, cartridge seals are used to seal mixers, agitators, and reactors, ensuring product safety, quality, and regulatory compliance.

Conclusion

Cartridge seals are a critical component of many rotating machinery, providing reliable and efficient sealing solutions for various industrial applications. By understanding their working principles, components, types, and applications, you can make informed decisions about selecting the right cartridge seal for your specific needs.