Factors influencing performance of Gaskets

The purpose of a gasket is to create a positive seal between stationary parts and then maintain that seal over a length of time. Just like every item, gaskets also have a life period and when that life is over, a gasket should be easily removable in order to be replaced. So, what are the factors that influence the performance of a gasket.

Surface condition of sealing surface

Soft gaskets are kind of insensitive to the surface condition because of its easy deformation, while hard ones are greatly affected by the surface condition. Smooth surface is beneficial to sealing.

Properties of the fluid

Higher the viscosity of the fluid, easier it is to seal because of its poor fluidity. Liquid is easier to seal than the gas due to its higher viscosity. Saturated vapor is easier to seal than superheated vapor since it condensates droplets and blocks the passage between the sealing surfaces.

Contact width of sealing surface

Larger the contact width between sealing surface and gasket cuases longer path of fluid leakage, hence greater loss of flow resistance, thus conducive to sealing. But under the same compression force, larger contact width would mean lower sealing pressure. So, appropriate contact width should be sought according to the material quality of the seals.

Temperature of the fluid

Temperature affects the viscosity of the liquid, thereby affecting the sealing performance. A rise in temperature causes viscosity of the liquid to decrease and viscosity of the gas to increase. 

Material of gaskets and fillers

The corrosion resistance, heat resistance, compactness and hydrophilicity of sealing materials surely affect the sealing. Soft materials are prone to elastic or plastic deformation under preloading force, thus blocking the passage of fluid leakage, thus conducive to sealing; but soft materials generally can not withstand the role of high-pressure fluid. 

Influence of external conditions

Conditions like vibration of pipeline system, deformation of connecting components, offset of installation position produce additional force on the seal, thus causing adverse effects on the seal. Hence, the above factors must be carefully considered.

Storage of gaskets also needs some considerations to save them for getting useless. Read here how - How to store the gaskets to maintain their shelf life.