A sealing system includes: a first seal including at least one first seal lip sealing against a first surface and a second surface and having a first cavity filled with a first energizer forcing the at least one first seal lip against the first surface and the second surface, the first cavity facing a first pressure region; and a second seal spaced from the first seal and having at least one second seal lip sealing against the first surface and the second surface, the second seal including a second cavity filled with a second energizer forcing the at least one second seal lip against the first surface and the second surface to separate a second pressure region from a third pressure region. The at least one second seal lip is configured to deform such that fluid pressures in the first, second, and third pressure regions equalize.

A progressive sealing system for a reciprocating machine includes a pressure breaker having a first seal, and one or more additional seals between the pressure breaker and an end plate. One or more seal housings hold the seals between the first seal and the end plate. The end plate couples the progressive sealing system to a housing of a cylinder of the reciprocating machine such that a surface of the first seal faces a chamber of the cylinder. A housing for the second one of the seals includes a bore having an inner surface. The inner surface of the bore of the second seal housing and an outer surface of a rod of the reciprocating machine define an annular space when the rod is received in the bore. The packing case includes an expansion chamber adjoining the annular space.

Provided is a sealing apparatus capable of linear and rotational motion including a housing; a hollow first shaft penetrating and coupled to the housing; a first sealing member provided between the housing and the first shaft to seal therebetween; a second shaft of which at least a part is inserted into the first shaft; a second sealing member provided between the first shaft and the second shaft to seal therebetween; and a third sealing member provided on either an inner circumferential surface of the first shaft or an outer circumferential surface of the second shaft.

A hydraulic machine has a first assembly and a second assembly movable in rotation relative to each other along an axis of rotation. The hydraulic machine has a crankcase defining an internal volume, in which an interface between the fixed assembly and the movable assembly has a housing provided with a first sealing element ensuring the sealing of the internal volume relative to the external environment. A second sealing element is positioned between the internal volume and the housing. The second sealing element is adapted to allow a passage of fluid from the internal volume to the housing when the pressure deviation between the internal volume and the housing is less than or equal to a threshold value, and to isolate the housing from the internal volume when the pressure deviation is greater than the threshold value.

The invention relates to a shaft seal arrangement, comprising a first seal, a second seal and a third seal which are arranged in series between a product side to be sealed and an atmosphere side, wherein the second seal is arranged between the first seal and the third seal, wherein a first pressure is present in a space adjacent to the second seal in the direction towards the product side, and a second pressure is present in a space adjacent to the second seal in the direction towards the atmosphere side, wherein the space that is adjacent to the atmosphere side is connected to a pressure supply line via which a pressure medium can be supplied into the space, and wherein the first pressure is equal or substantially equal to the second pressure, so that the second seal can be operated with a pressure difference of zero between the first pressure and the second pressure.

A sealing system is between two components, which are translatorily movable relative to each other along a motional axis for sealing off a high-pressure side from a low-pressure side. The sealing system includes pressure relief elements. The use of such a sealing system produces an intermediate-space pressure cascade.

A downhole rotary seal assembly is provided that includes a primary rotary seal, a barrier seal, and a seal carrier. The seal carrier includes an inner surface, an outer surface, and a first groove dimensioned to receive the primary rotary seal at the inner surface. The seal carrier also includes a second groove dimensioned to receive the barrier seal at the inner surface. An aperture is defined on the inner surface between the first groove and the second groove. A relief port is positioned between the first groove and the second groove, the relief port being positioned to fluidly couple the aperture and the outer surface. A valve provided in the relief port. The valve includes a check valve having a predefined crack pressure.

Piston ring having an endless base ring and sealing ring have a radially outwardly directed base ring face side. The sealing ring has a radially inwardly directed, circularly running sealing ring inner side with three tangential cuts separating three sealing ring segments are arranged in a circumferential direction (U). The base and sealing rings are arranged in succession in a longitudinal direction (L). A top ring is arranged to adjoin the sealing ring having a top ring has a radially outwardly directed top ring outer side and a radially inwardly directed top ring inner side. The top ring has, on the side opposite the sealing ring, a radially running return flow channel extending radially, the sealing face side protrudes in a radial direction beyond the top ring outer side and the base ring face side. The base and the top rings have a greater tensile strength than the sealing ring.

The invention relates to a ring seal which comprises a main body capable of implementing a seal by static contact relative to a first cylindrical element, and a first circumferential lip capable of engaging by friction with a cylindrical surface of a second cylindrical element, said cylindrical elements being substantially coaxial and mounted so as to pivot relative to one another. The main body comprises a front surface configured to be in axial contact with a front surface of the first cylindrical element, the main body comprising a second circumferential lip radially opposite the first circumferential lip and capable of being in radial contact with a cylindrical surface of the first cylindrical element.

The piston ring unit includes a plurality of piston rings and an inner contact ring. A plurality of piston rings are disposed adjacent to each other in an axial direction of the piston such that joints of plurality of the piston rings do not overlap with each other in the axial direction. An inner contact ring is interposed between an outer circumferential surface of the piston and an inner circumferential surface of the piston ring in a state where the inner contact ring extends over all of the plurality of piston rings in the axial direction, and is disposed such that an opening of the inner contact ring does not overlap with the joint of the at least one piston ring as viewed in a radial direction of the piston.