FIVE KEY CHARACTERISTICS OF A GOOD MECHANICAL SEAL DESIGN

The mechanical sealing performance is very important. The mechanical seal is an important part to ensure the normal operation of the machine. What factors will affect the mechanical sealing performance? Below we mainly introduce the five key features that a good mechanical seal should have to help you choose a better mechanical seal.

Five key characteristics of a good mechanical seal

Fixed design

Each rotating mechanical seal has a spring mechanism in the rotating part. When there is misalignment, even slight misalignment, when the seal rotates at high speed, adjustment will become difficult. In a stationary seal, the springs remain stationary, they do not rotate with the shaft. Therefore, it is not necessary to perform correction or adjustment every rotation.

Single sealing surface

It is possible to use an integral sealing surface or an inserted sealing surface for mechanical sealing. The inserted face design is not suitable due to various restrictions. In this design, the thermal expansion and coefficient of the panel material and the bracket material are different. Due to this difference, the net interference force varies between the two parts. Due to facial friction, they are exposed to heat. Therefore, if a plug-in sealing surface design is used, the deformation of the sealing surface is very common. The integral sealing surface overcomes all these limitations.

Protected spring

If the spring is immersed in an unclean liquid, dust will accumulate and affect the use effect. It weakens the mechanical seal's ability to respond to movement. The sealing surface will not remain closed. Eventually, the spring will permanently fail. In a good design, the spring can remain protected from fluid exposure.

Balanced design

In the seal design, the compressive force is generated in the following way: spring pressure / hydraulic pressure / liquid pressure in the seal, which forces keep the surface of the seal closed. In a properly balanced seal design, the seal ring area can be minimized. It reduces the net closing force and provides better lubrication, and you will get high quality seals with higher rated pressure.

Non-friction design

The auxiliary seal moves with the spring and keeps the sealing surface closed. The spring adjusts with each rotation, thereby minimizing misalignment. The dynamic secondary seal ring moves back and forth with each rotation. It does not allow the protective layer to form. It will corrode unprotected areas. Non-micro-moving designs do not have this limitation.

The requirements of mechanical seals on sealing materials

The sealing material should meet the requirements of the sealing function. Due to the different media being sealed and the different working conditions of the equipment, different adaptability of the sealing material is required. The requirements for sealing materials are generally:

1. The material is dense and not easy to leak media.

2. It has proper mechanical strength and hardness.

3. Good compressibility and resilience, and small permanent deformation.

4. No softening and decomposition at high temperature, no hardening and brittle cracking at low temperature.

5. Good corrosion resistance, it can work for a long time in acid, alkali, oil and other media, its volume and hardness change is small, and it does not adhere to the metal surface.

Spring seals, elastomer bellow seals, pump seals, elastomer bellow seals, mechanical seals and other seals have different characteristics and requirements.