Y-type sealing rings are widely used in hydraulic systems, such as piston sealing in automotive hydraulic systems, other hydraulic devices, and hydraulic cylinders. The product quality of sealing rings directly affects equipment performance. Depending on the sealed medium, Y-type sealing rings are often made of two materials: NBR (Nitrile Butadiene Rubber) and EPDM (Ethylene Propylene Diene Monomer). Structurally, Y-type sealing rings belong to the category of lip-type seals, with distinctions between low-lip and high-lip designs. Traditional production processes for sealing rings mainly use compression molding, while the currently more advanced technology employs turning equipment, featuring a simple process flow and high yield rate. This is the most advanced method to date, capable of producing highly precise Y-shaped sealing rings.

Advantages and Disadvantages of Various Specifications of Y-Type Sealing Rings Compared to Other Types of Sealing Devices

1.Advantages:

• Reliable sealing performance.

• Low frictional resistance and smooth movement.

• Good pressure resistance and a wide operating pressure range.

• Simple structure and low cost.

• Easy installation.

2.Disadvantages:

• Can only function unidirectionally. For bidirectional sealing of pistons, a pair of Y-type sealing rings is required, increasing axial dimensions.

• The cross-sectional size of ordinary Y-type sealing rings is larger than that of O-type sealing rings, resulting in larger installation groove dimensions. Split grooves are sometimes needed for easy installation.

• Many countries have developed Y-type rings with smaller cross-sectional sizes, gradually improving size and installation issues.

  
  

Role of Y-Type Sealing Rings

Y-type sealing rings are primarily used for sealing piston rods or pistons in hydraulic cylinders. Their sealing function can be divided into two pressure scenarios:

• Without medium pressure: Sealing is achieved solely by the pre-compression of the lip to adhere to the sealing surface.

• With medium pressure: The medium fills the groove between the inner and outer lips, applying pressure to both lips to expand them and closely fit the sliding parts. Therefore, during installation, the cavity of the Y-type sealing ring must face the medium.

Notes from senior sealing ring engineers:

• Y-type rings can withstand a maximum working pressure of approximately 20 MPa. When pressure exceeds this value, support rings can be used as auxiliary components to increase pressure resistance.

• Y-type rings also have a certain self-compensating ability to address gradual wear during use.

Application Scenarios

Y-type sealing rings are suitable for sealing medium and low-pressure reciprocating movements, such as between pistons and cylinder barrels, or between piston rods and piston covers. They mainly rely on the lips to adhere tightly to the sealed surface for sealing. Therefore, the dimensions of the lip tips—including the outer diameter, inner diameter, pre-compression amount, and clearance—are critical during surveying, mapping, and design, as the lip tips are prone to wear, heat generation, and deformation.