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2022

Installation Precautions for Large Size Seal

The installation quality of large size seal has an important influence on its sealing performance and service life. Leakage problems are usually caused by improper installation. The large-size seal shall not be scratched, installed in incorrect position or twisted during installation. The sealing groove and sealing mating surface must be strictly cleaned before assembly, and the large-size sealing surface should be coated with grease during assembly.

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　　Large size sealThe quality of the installation has an important impact on its sealing and service life. Leakage problems are usually caused by improper installation. The large-size seal shall not be scratched, installed in incorrect position or twisted during installation. The sealing groove and sealing mating surface must be strictly cleaned before assembly, and the large-size sealing surface should be coated with grease during assembly.

In order to prevent large-size seals from being cut or scratched by sharp corners, threads and other sharp edges during installation, more than 15-30 lead-in angles should be set aside at the shaft end and hole end during installation. When the large-size seal needs to pass through the external thread, a special thin-walled metal guide sleeve should be used to cover the external thread; if the large-size seal passes through the hole, the hole should be inverted into the corresponding bevel shape to prevent the large-size seal from being scratched. The bevel angle of the groove is generally 120-140 degrees.

The sealing effect of the large-size seal is obtained by the elastic deformation of its radial diameter d2 in a reasonably designed groove. This means that the circular cross-section is compressed into an oval, thereby closing the gap between the sealing or contact surface and the bottom of the groove. The resulting surface compression is key to achieving the desired sealing effect. The deformation degree of large size seal wire diameter mainly depends on the groove depth t. There are many types of sealing rings, and the applicable scenarios and parameter performance corresponding to different types will be different. We can only rely on the previous understanding and analysis to determine the appropriate type, to further ensure the superior experience of the later. Therefore, the knowledge that is popularized to everyone today is the specifications and specific examples of the sealing ring, as well as the specifications and models of the sealing ring and the detailed information of the sealing principle system. Interested friends can refer to filter out suitable and reasonable content.

The Y-shaped sealing ring is connected to the coupling surface of the sealing pair by its open edge. When there is no internal pressure, only a small contact pressure is generated due to the deformation of the lip tip. In the case of sealing, every point in contact with the sealing medium has a normal pressure equal to the medium pressure, so the bottom of the lip ring will be axially compressed, the lip will be circumferentially compressed, and the contact with the seal The sealing surface will widen, and the contact stress will increase. When the internal pressure rises again, the distribution form and size of the contact pressure are further changed, and the lip and the sealing surface are more closely matched, so the sealing performance is better, which is the "self-sealing effect". Due to this self-sealing effect, a Y-ring can effectively seal a high pressure of 32MPa.

The effective sealing pressure of a pressure energized seal is equal to the sum of the pre-pressure and the fluid pressure. The seal effectively acts on the fluid pressure on the seal through the action of the lip, and its pre-pressure can be reduced to a small value, and the higher the fluid pressure, the smaller the effect of the pre-pressure. In high-pressure applications, the effect of preloading is negligible. In this case, it is advantageous to reduce the seal friction because the seal friction is proportional to the seal contact pressure. Therefore, the friction force of the seal is less than that of the squeeze seal while ensuring the seal.

The sealing ring is mainly used for reciprocating sealing. From its working principle, it can be seen that when the sealing ring is installed, the lip must face the high pressure side to play a role, so the sealing ring can only work in one direction.

Key words:

Large size seal