A seal ring is made of resin, applied to a valve body that changes an opening degree of a fluid passage through which a fluid passes, and that seals, when the valve body fully closes the fluid passage, between an inner peripheral surface defining the fluid passage and an outer peripheral edge of the valve body. The seal ring includes a ring main body fitted in an outer peripheral groove formed on the outer peripheral edge.

The invention relates to an internally clamping rectangular seal (40) for sealing a shaft (20) with respect to a housing (10), wherein the rectangular seal can be inserted into a groove (13) disposed circumferentially on a shaft bore (12), wherein the rectangular seal is interrupted along its circumferential direction at a joint (42) and two ring-end sections (43, 44) are formed, and wherein the rectangular seal has an outer surface (40.4) facing radially outwards, an inner clamping surface (40.1) facing radially inwards and opposing flank surfaces (40.3) facing in the axial direction. Therefore, provision is made that at least one contact ramp (45.1, 45.2, 45.3) is disposed at at least one ring-end section, that the at least one contact ramp is oriented obliquely with respect to the circumferential direction and obliquely with respect to the radial direction of the rectangular seal, and that the at least one contact ramp, starting from a non-stressed state of the rectangular seal, forms a first mechanical contact, pointing in the circumferential direction, between the opposing ring-end sections when the radius of the rectangular seal is reduced by prestressing the rectangular seal.

The rectangular seal permits low leakage rates and can be installed non-directionally.

The invention relates to an internally clamping rectangular seal (40) for sealing a shaft (20) with respect to a housing (10), wherein the rectangular seal can be inserted into a groove (13) disposed circumferentially on a shaft bore (12), wherein the rectangular seal is interrupted along its circumferential direction at a joint (42) and two ring-end sections (43, 44) are formed, and wherein the rectangular seal has an outer surface (40.4) facing radially outwards, an inner clamping surface (40.1) facing radially inwards and opposing flank surfaces (40.3) facing in the axial direction. Therefore, provision is made that at least one contact ramp (45.1, 45.2, 45.3) is disposed at at least one ring-end section, that the at least one contact ramp is oriented obliquely with respect to the circumferential direction and obliquely with respect to the radial direction of the rectangular seal, and that the at least one contact ramp, starting from a non-stressed state of the rectangular seal, forms a first mechanical contact, pointing in the circumferential direction, between the opposing ring-end sections when the radius of the rectangular seal is reduced by prestressing the rectangular seal.

The rectangular seal permits low leakage rates and can be installed non-directionally.

A seal ring is made of resin, applied to a valve body that changes an opening degree of a fluid passage through which a fluid passes, and that seals, when the valve body fully closes the fluid passage, between an inner peripheral surface defining the fluid passage and an outer peripheral edge of the valve body. The seal ring includes a ring main body fitted in an outer peripheral groove formed on the outer peripheral edge.

To provide a seal ring capable of suppressing wear of a mating housing and preventing protrusion from an annular groove and thereby being superior in low leak performance, which is an original object of the seal ring. A seal ring 1 formed of resin is attached to an annular groove 12 formed on an outer periphery of a butterfly valve 11 having a substantially disc shape so as to seal an annular gap 14 between the butterfly valve 11 and a housing 13 in which the valve is housed. A part of the seal ring 1 is protruded from the annular groove 12, so that the seal ring 1 adheres to the housing 13 to seal the annular gap 14 due to pressure from sealed fluid. A radial direction thickness t of the ring is set in a range of 7-11% of a ring outer diameter in a free state. A ring inner diameter in a state in which the diameter is enlarged due to pressure from the sealed fluid when the valve is opened, is smaller than an outer diameter r of the valve.

A recessed part formed on a side surface includes a dynamic pressure part extending in the circumferential direction to converge on the side surface, and an introduction part extending from the dynamic pressure to open the dynamic pressure part toward the inner periphery side. One or two inner peripheral wall parts are provided for each of the recessed parts. The inner peripheral wall part is a portion defined on the inner periphery side of the corresponding recessed part by the dynamic pressure part and the introduction part. The inner peripheral wall part includes an inner peripheral wall surface. The inner peripheral wall surface extends toward the introduction part in the circumferential direction with inclining with respect to the side surface such that the inner peripheral wall surface is depressed from the side surface.

A sealing unit for a drive shaft driving a working fluid; the sealing unit comprising a sleeve attached to the drive shaft and a gland attached to the housing, a static seal ring attached to the gland and in close proximity to the sleeve, and a stuffing box about the static seal ring, fibrous packing seal blocking the distal and proximal ends of the stuffing box and a first sealant comprising a viscous, non-Newtonian fluid that is injected into the stuffing box under a first pressure exceeding the pressure of the working fluid; the sealing unit further comprising an inner fluid seal of a Newtonian fluid between the first sealant and the drive shaft upstream of the first sealant, such that the Newtonian fluid seal is kept at a pressure slightly higher than the pressure of the working fluid and prevents the working fluid from reaching the first sealant.

A sealing unit for a drive shaft driving a working fluid; the sealing unit comprising a sleeve attached to the drive shaft and a gland attached to the housing, a static seal ring attached to the gland and in close proximity to the sleeve, and a stuffing box about the static seal ring, fibrous packing seal blocking the distal and proximal ends of the stuffing box and a first sealant comprising a viscous, non-Newtonian fluid that is injected into the stuffing box under a first pressure exceeding the pressure of the working fluid; the sealing unit further comprising an inner fluid seal of a Newtonian fluid between the first sealant and the drive shaft upstream of the first sealant, such that the Newtonian fluid seal is kept at a pressure slightly higher than the pressure of the working fluid and prevents the working fluid from reaching the first sealant.

An inflatable seal includes an annular body made of elastic material. The inflatable seal includes a chamber disposed in the annular body. The inflatable seal includes a fixing end and a movable end opposite to the fixing end in a cross section. The inflatable seal further includes first and second sides interconnected between the fixing end and the movable end and opposite to each other. The fixing end includes an annular lining disposed in the annular body. The sealing ability of the inflatable seal is improved in the axial direction and the radial direction.

A seal ring has, on an outer peripheral surface side thereof, a pair of recessed parts 140 extending in a circumferential direction on both sides in a width direction thereof to form a projection part 120 between the pair of recessed parts 140, and has a plurality of ribs 130 connected to the projection part 120 and extending to lateral surfaces of the seal ring at intervals in the circumferential direction inside the pair of recessed parts 140, and a plurality of ribs 130 arranged on a sealed region side among the plurality of ribs 130 have lateral-wall surfaces on an upstream side in a relative rotation direction of a housing with respect to a shaft, each of the lateral-wall surfaces having inclined surfaces inclined from the upstream side to a downstream side in the relative rotation direction of the housing from the projection part 120 toward the lateral surfaces of the seal ring.