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What are the characteristics of square ring?

Update:2018-07-27

Square seals, like O-rings, are fixed seals that can be used for two-way sealing. The contact pressure is applied by the installation to produce initial sealing properties in the radial and axial directions. This contact pressure is correspondingly enhanced by the pressure of the hydraulic system

1. Slower aging

Unlike some rubber and some sealing materials, under the condition of stress, they will gradually age and reduce elasticity. Therefore, the seal has a certain service life and is closely related to the quality of the sealing material. The square ring has a relatively slow aging rate due to the small amount of pre-compression after installation.

2. Good stability

Due to the shape characteristics of the square ring, no distortion occurs after installation; the amount of deformation is small after pre-compression; and the shape is also small when the hydraulic pressure changes. The cross-sections collectively referred to as seals are stable.

3. Good sealing performance

When an O-ring seal is used as the end face seal, a "back suction effect" occurs when there is a large pressure pulse. In one effect, it is produced by the pressure between the low pressure side of the O-ring and the side of the groove in the groove. When a pressure shock occurs, the fluid is discharged as the O-ring moves. When the pressure drops, a slight leak of the “sweating” state shift occurs. When a square ring is used, it does not cause a similar sweating problem because it has its own geometric shape.

In terms of pressure performance, the rated pressure of the O-ring is 32 MPa, and the rated pressure of the square ring is 50 MPa.

4. Strong anti-extrusion ability

When an O-ring is used, a small amount of sealing material is sheared and extruded from the low-pressure side gap over a long period of time under frequent or long-term pressure shock. This phenomenon is known as "extrusion damage." Under the same conditions, such as the use of square ring, there will be no "extrusion damage".

5. High sealing pressure

The working pressure of O-ring is 32 MPa and the square ring is 50 MPa. When the O-ring is used for radial sealing and the pressure exceeds 10 MPa, it is necessary to add a back up ring on the pressure side to prevent extrusion damage. When using a square ring, needn’t set a back up ring.

6. Interchangeability

In the original groove of the O-ring, a square ring of the corresponding specification can be installed. So it has good interchangeability in O-ring seals.