O-Ring Characteristics: The simple geometry is the main characteristic of an 0-Ring which, in conjunction with proper elastomer selection results in a low cost, easy-to-use, efficient sealing system.
Elastomeric materials, when compressed, react like a high viscosity fluid which transmits applied stress in every direction; therefore, the 0-Ring serves as a barrier, blocking the leak paths between the sealing surfaces.
DIN Standards define technical sealing as follows:
A) "Static Seal" - The sealing action created between two mating surfaces with no leakage of liquid or minimal diffusion of gas.
B) "Dynamic Seal" - The mating surfaces have relative movement with minimal leakage of liquid (useful to protect the sealing efficiency, acting as lubricant).
0-Rings offer several advantages over other sealing systems: simplicity of construction, standardized seal dimensions, wide selection of materials, suitability for both static and dynamic applications, standard dimensioning of glands, low cost due to high volume manufacturing.
Sealing is always achieved through a positive compression or squeezing action, resulting in a deformation of the 0-Ring cross-section.
The most important sealing characteristic of an 0-Ring is its resistance to compression set or residual deformation.