Abstract: Apparatus for the treatment of fluids are disclosed including a cylindrical housing closed at both ends by end caps, one of which includes an inlet for a fluid and the other includes an outlet for the fluid, a plurality of hollow fibers are arranged longitudinally within the housing between a pair of end walls, and one of the end caps includes an outlet for a second fluid which can thus be withdrawn from the outer surface of the hollow fibers between the end walls, and the apparatus includes a ring mounted between the hollow fibers at one of the end caps in order to create a fluid channel for the second fluid between the ring and the inner wall surface of the housing. This apparatus can be used, for example, for hemofiltration, hemodiafiltration or hemodialysis, but it may also be generally used for dialysis or filtration and purification of sewage, and for heat transfer, or as an oxygenator.

Abstract: Resilient sealing rings are disclosed including an annular ring of resilient material having a cross-sectional configuration so that when not compressed the cross section of the sealing ring extends substantially longitudinally and when compressed between two parallel sealing surfaces the sealing ring bends so that the longitudinal ends approach each other. This provides acceptable compression force between the parallel sealing surfaces over an extended range of deformation particularly as compared to conventional O-rings.