Rubber sealing gaskets have properties such as oil resistance, acid and alkali resistance, cold and heat resistance, and aging resistance, and are widely used in industries such as automobiles, electronics, chemicals, anti-static, flame retardant, and food. So how to choose the size of the rubber sealing gasket?

1. Choose thin rubber sealing gaskets as much as possible

The required thickness of rubber sealing gasket is related to its form, material, diameter, processing condition of sealing surface, and sealing medium. For example, for most non-metallic plate-shaped rubber sealing gaskets, their ability to resist stress relaxation increases as the thickness of the rubber sealing gasket decreases. Thin rubber sealing gaskets have less area exposed to the sealing medium around them, so leakage along the rubber sealing gasket body also decreases. However, the rubber sealing gasket must fill the unevenness and unevenness of the flange sealing surface. Therefore, the minimum thickness of the rubber sealing gasket depends on factors such as the surface smoothness of the flange, the compressibility of the rubber sealing gasket, the stress at the gasket, and the degree of flange deflection. The thickness of the metal wound rubber sealing gasket is usually 4.5mm, but other thicknesses can also be selected based on the diameter of the equipment or pipeline.

2. Choose narrower rubber sealing gaskets as much as possible

Under the same bolt loading hormone, the narrower the width of the rubber sealing gasket, the higher the stress on the rubber sealing gasket, and the greater the sealing pressure. However, the rubber sealing gasket is not prone to fracturing or crushing, and it also needs to have the necessary radial sealing channel length and sufficient blowing resistance. The general plate shaped rubber sealing gasket can usually be selected based on the nominal diameter and nominal pressure, and appropriately modified according to the actual flange and usage situation. For example, if the flange sealing surface smoothness is low or the sealing medium viscosity is low, the width can be increased.

3. Do not let the inner diameter of the rubber sealing gasket extend into the pipeline, and do not excessively increase the outer diameter of the rubber sealing gasket

The former will cause the fluid medium inside the pipe to wash away the rubber sealing gasket, not only contaminating the medium and increasing flow resistance, but also damaging the compressed rubber sealing gasket due to the expansion of the rubber sealing gasket material by the medium; The latter will also damage the rubber sealing gasket due to environmental corrosion. For cases where the sealing surface is a raised face or full face flange, when the rubber sealing gasket is located within the center circle of the bolt hole, usually for installation positioning purposes, the length of the diameter of the bolt hole center circle is taken as the outer diameter of the rubber sealing gasket (or outer ring outer diameter).