SEALING SYSTEM WITH ANNULAR SEAL MEMBER AND EXPANDING RING FOR BI-DIRECTIONAL SEALING, FLUID VALVE WITH SEALING SYSTEM, AND SEALING METHOD

The present invention relates to a sealing system (1; 100) for an annular seal mount (40). It comprises an annular seal member (10) with two sealing lip portions (12, 14) connected by a connecting portion (11) and a spring-elastic spreader (17) secured within an annular groove of the seal member (10) and forms a channel (18) opening towards a first side in an axial direction (L). For providing bi-directional sealing in an inexpensive but reliable manner within small installation space, the sealing system (1; 100) has an expanding ring (20; 120) for abutting on the seal mount (40) at the first side. An engagement portion (23, 24; 122) of the expanding ring (20; 120) protrudes in the axial direction (L) towards a second side and is received within the channel (18). When the seal member (10) is pressed along the axial direction (L) against the expanding ring (23, 24; 122), the latter directly abuts the spreader (17) at a first radial position (R1; R1') and a second radial position (R2; R2'), thereby inducing spreading force for forcing the end sections of the sealing lip portions (12, 14) apart from each other via the spreader (17). The present invention further relates to a fluid valve (50) with a sealing system (1; 100) and to a sealing method.