Non-Pusher Mechanical Seals: A Comprehensive Guide

Mechanical seals are essential components in pumps and other rotating equipment. They prevent the leakage of fluids and gases between the rotating shaft and the stationary housing, ensuring safe and efficient operation. There are different types of mechanical seals available, and non-pusher seals are among the most popular.

Non-Pusher Mechanical Seals: A Comprehensive Guide

What are Non-Pusher Mechanical Seals?

Non-pusher mechanical seals, also known as stationary seals, are designed to maintain a constant contact force between the sealing faces. Unlike pusher seals, which rely on springs or bellows to apply pressure to the sealing faces, non-pusher seals use a set screw or similar mechanism to maintain a fixed contact force. This design allows for a simpler and more compact seal configuration.

Benefits of Non-Pusher Mechanical Seals

Non-pusher mechanical seals offer several benefits over pusher seals. For one, they have a simpler and more robust design, which makes them easier to install and maintain. They are also less prone to wear and tear, which can extend their lifespan and reduce maintenance costs.

Another advantage of non-pusher seals is their ability to handle higher pressure differentials. Because they rely on a set screw or similar mechanism to maintain a fixed contact force, they can accommodate larger variations in pressure without compromising their sealing performance.

Applications of Non-Pusher Mechanical Seals

Non-pusher mechanical seals are used in a wide range of applications, including pumps, mixers, agitators, and other rotating equipment. They are particularly well-suited for applications that involve high pressures or high temperatures, as they can withstand these conditions without compromising their sealing performance.

Non-pusher seals are also commonly used in applications that require a high degree of reliability, such as in the chemical and petrochemical industries. They are often used in applications that involve hazardous or corrosive fluids, as they can prevent leakage and minimize the risk of environmental damage or personal injury.

How Non-Pusher Mechanical Seals Differ from Pusher Seals

While non-pusher and pusher mechanical seals both serve the same purpose, there are several key differences between the two types. As mentioned earlier, non-pusher seals use a set screw or similar mechanism to maintain a fixed contact force, while pusher seals rely on springs or bellows to apply pressure to the sealing faces.

Pusher seals tend to be more complex and require more maintenance than non-pusher seals. They are also more prone to wear and tear, as the springs or bellows can lose their elasticity over time. However, pusher seals offer greater flexibility and can accommodate larger axial movement between the shaft and the housing.

Conclusion

Non-pusher mechanical seals are an excellent choice for a wide range of applications that require high pressure or high temperatures. They offer several advantages over pusher seals, including a simpler and more robust design, a longer lifespan, and the ability to handle larger pressure differentials. Whether you're an engineer or a maintenance professional, non-pusher seals are worth considering for your next sealing application.