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The main factors affecting gasket and packing seals are as follows: 1. Surface condition of the sealing surfaces: The shape and surface roughness of the sealing surfaces have an impact on the sealing performance; a smooth surface facilitates sealing. Soft gaskets are not sensitive to surface conditions due to their ease of deformation, whereas for hard gaskets, surface conditions have a significant impact. 2. Contact width of the sealing surface: The greater the contact width between the sealing surface and the gasket or filler, the longer the path that the fluid must travel to leak, and the greater the flow resistance loss; this therefore contributes to better sealing. However, under the same compressive force, the greater the contact width, the lower the sealing specific pressure will be. Therefore, the appropriate contact width must be determined based on the material of the seal. 3. Properties of the fluid: The viscosity of a liquid has a significant impact on the sealing performance of gaskets and seals; fluids with high viscosity are easier to seal due to their poor flowability. The viscosity of liquids is much greater than that of gases, so liquids are easier to seal than gases. Saturated steam is easier to seal than superheated steam, as it condenses into liquid droplets that block the leakage paths between the sealing surfaces. The larger the molecular volume of a fluid, the easier it is for it to be blocked by narrow sealing gaps, thereby facilitating sealing. The wettability of the liquid to the seal material also has an impact on the sealing performance. Liquids that are easily saturated can easily experience seepage leaks due to the capillary action in the micropores within gaskets and fillers. 4. Fluid temperature: The level of temperature affects the viscosity of the liquid, which in turn influences the sealing performance. As the temperature rises, the viscosity of liquids decreases, while the viscosity of gases increases. On the other hand, changes in temperature often cause the sealing components to deform, which can easily lead to leaks. 5. Material of gaskets and fillers: Soft materials are advantageous for sealing, as they tend to undergo elastic or plastic deformation under preloading forces, thereby blocking the pathways through which fluid can leak ； However, soft materials generally cannot withstand high-pressure fluids. The corrosion resistance, heat resistance, density, hydrophilicity, and other properties of the sealing material all have an impact on the seal. 6. Sealing surface specific pressure: The normal force per unit contact area between the sealing surfaces is referred to as the sealing specific pressure. The value of this specific pressure is an important factor that affects the sealing performance of gaskets or packing. Typically, a preload is applied to create a certain specific pressure on the sealing surface, causing the seal to deform in order to reduce or eliminate the gap between the sealing surfaces and thereby prevent fluid from passing through, achieving the purpose of sealing. It should be noted that the effect of fluid pressure causes changes in the specific pressure on the sealing surfaces. Although an increase in the specific pressure on the sealing surface is beneficial for sealing, it is limited by the compressive strength of the sealing material ； For dynamic seals, an increase in the specific pressure on the sealing surfaces also leads to a corresponding increase in frictional resistance. 7. Influence of external conditions: Vibrations in the piping system, deformation of connection components, and deviations in the installation location can all exert additional forces on the seals, thereby having an adverse effect on their sealing performance. In particular, vibration causes periodic changes in the compression force between the sealing surfaces, leading to the loosening of the connecting bolts and thus resulting in seal failure. The cause of vibration can be external, or it may be due to fluid movement within the system. To ensure reliable sealing, the aforementioned factors must be carefully considered, and the manufacturing and selection of gaskets and packing are of paramount importance.