Different Types of Mechanical Seals

Mechanical sealing technology is the key to ensuring the stable operation of rotating equipment such as pumps. It involves different types of mechanical seals to meet various application needs. The following is a detailed introduction to several main types of mechanical seals:

Pusher Mechanical Seals and Non-Pusher Mechanical Seals

Pusher mechanical seals, such as spring-loaded mechanical seals, use mechanical pushing to compensate for the wear of the sealing surface.

Non-pusher mechanical seals, such as bellows mechanical seals, fix the auxiliary sealing element on the shaft and utilize the elasticity of the bellows to achieve sealing.

Single-Spring Mechanical Seals and Multi-Spring Mechanical Seals

Single-spring mechanical seals have a simple structure, and the spring can also serve as the driving element. However, the specific pressure on the face is uneven, making them unsuitable for high-speed operation.

Multi-spring mechanical seals have a relatively complex structure, but they offer even specific pressure on the face, making them more suitable for high-speed operation. Thus, they are usually recommended as the first choice.

Balanced Mechanical Seals and Unbalanced Mechanical Seals

Balanced mechanical seals (load coefficient K<1) can balance the effect of the liquid on the face, reducing the specific pressure on the face as the fluid pressure increases.

Unbalanced mechanical seals (load coefficient K>1) cannot balance the effect of the liquid on the face, and the specific pressure on the face increases with the fluid pressure.

Inside Mounted Mechanical Seals and Outside Mounted Mechanical Seals

Inside-mounted mechanical seals are installed inside the sealing chamber, directly facing the medium.

Outside-mounted mechanical seals are installed outside the sealing chamber, making them easier to maintain and replace.

Pressurized Dual Mechanical Seals and Non-Pressurized Dual Mechanical Seals

Pressurized dual mechanical seals (double mechanical seals) have a complex structure and require an external sealing liquid system. They use isolation liquid with pressure higher than the medium pressure for sealing and lubrication.

Non-pressurized dual seals (tandem seals) also have two pairs of frictional elements, but the buffer liquid inside the sealing chamber is not pressurized. The process medium directly lubricates the inner seal.

Rotary Mechanical Seals and Stationary Mechanical Seals

The compensating component of rotary mechanical seals rotates with the shaft, making them suitable for various rotating equipment.

The compensating component of stationary mechanical seals does not rotate with the shaft and is used in specific applications.

In summary, different types of mechanical seals each have their characteristics and applicable scenarios. When selecting a mechanical seal, it is necessary to comprehensively consider factors such as the working conditions of the equipment, the properties of the medium, and the speed requirements to ensure the selection of different types of mechanical seals that can meet actual needs and ensure the stable operation of the equipment.