Patent attributes
In accordance with the present application, a fluid seal 30 and fluid sealing element 32, which are tolerant of fluid F direction reversals are provided. A sealing element 32 has at least two brush stages 50 to restrict leakage of the fluid F through a gap 38 between a component and a sealing surface. Each brush stage 50 includes a bristle arrangement 44 sandwiched between a back plate 48 and a common mid plate 46. A value allows 70 the fluid F to bypass a bristle arrangement 44 if the fluid pressure P1 or P2 varies between the chambers. Permanent damage to the sealing element 32 is avoided by allowing the higher pressure fluid F to bypass the upstream bristle arrangement 44 and a properly load the downstream bristle arrangement against a back plate 48.