Factors to consider when selecting silicone rubber O-ring seals

Factors to consider when selecting silicone rubber O-ring seals:

1. Working medium and working environment conditions
In the specific selection of O-ring seal product materials, first consider whether the sealing medium is compatible during operation. The pressure, temperature, working time, operating cycle and other working conditions at the seal shall be comprehensively considered. If it is used in rotary seals, temperature rise reaction caused by friction heat shall be considered. The physical properties and chemical changes of materials used in different seal products are different.

2. Sealing form
Silicon rubber O-ring can be divided into static seal and dynamic seal according to load type; According to the sealing purpose, it can be divided into three kinds of seal products, namely, hole seal, shaft seal and rotary shaft seal; According to the installation form, it can be divided into radial installation and axial installation. During radial installation, for shaft seals, the deviation between the inner diameter of O-ring products and the sealed diameter d2 should be as small as possible; For hole seals, the inner diameter of the O-ring should be equal to or slightly less than the diameter d1 of the groove.

When installing axially, consider the pressure direction. Under the internal pressure, the outer diameter of the O-ring should be about 1-2% larger than the outer diameter d3 of the groove; Under external pressure, the inner diameter of O-ring should be about 1-3% smaller than the inner diameter d4 of the ditch.