gummiring

A gummiring is a circular elastomer seal used to prevent leakage of liquids or gases between two mating surfaces. In many languages the term refers generically to a rubber ring; in English this type of seal is commonly called an O-ring. Gummirings are typically toroidal (donut-shaped) and are compressed in a groove to form a seal, both in static joints and in dynamic applications where a shaft passes through a housing.

Materials used for gummirings vary with the medium and operating conditions. Common elastomers include nitrile rubber (NBR), fluorocarbon (FKM, such as Viton), silicone (VMQ), EPDM, and polychloroprene (CR). Each material offers different resistance to temperature, chemicals, and wear. Temperature ranges can span from well below freezing to several hundred degrees Celsius depending on the compound and design. In addition to material, the cross-section and inner diameter determine fit and seal performance.

Applications of gummirings are widespread. They are standard in hydraulics and pneumatics, automotive systems, plumbing and consumer appliances, and many industrial machines. They can serve as static seals in joints or as dynamic seals around moving shafts, where proper groove design and lubrication are important to prevent extrusion or skiving.

Standards and sizing are important for compatibility and interchangeability. ISO 3601 and related standards cover O-rings and specify tolerances for inner diameter and cross-section. In North America, AS568 provides a widely used set of O-ring sizes. Installation practices, such as proper lubrication and avoiding twisting during assembly, help extend seal life.

See also: O-ring, gasket, elastomer, seal, hydraulic seal, dynamic seal.