A sealing arrangement having inboard and outboard dynamic seals in a housing separated by a barrier fluid and having a sealed relationship with a relatively movable bearing-guided shaft. A bearing chamber having bearing lubricant exposed to the inboard dynamic seal. The inboard dynamic seal is a hydrodynamic seal having a hydrodynamic pumping action in response to relative rotation between the shaft and the inboard dynamic seal. The hydrodynamic pumping action forcing a film of the bearing lubricant between the inboard dynamic seal and the shaft. The hydrodynamic pumping-related leakage of the inboard dynamic seal being returned to the bearing chamber in which the shaft guidance bearings are located.

A sealing device includes an annular seal portion formed of an elastic material. On an inner peripheral surface of the seal portion, a main lip is formed so as to be in slidable contact with an outer peripheral surface of a rotary shaft, and a vacuum space side inclined surface is formed so as to gradually enlarge in diameter from the main lip toward a vacuum space side. On the vacuum space side inclined surface, a plurality of annular projections are formed along an axial direction so as to be in slidable contact with the outer peripheral surface of the rotary shaft in a state where the main lip is in slidable contact with the outer peripheral surface of the rotary shaft.

In order to provide a piston device that is of simple construction and provides optimised sealing, it is proposed that the piston device should include the following: a housing that includes a piston receptacle; a piston that is arranged to be linearly displaceable in the piston receptacle; a main gasket element that separates a first medium space from a second medium space, and a supplementary gasket element, different from the main gasket element, for sealing in a region between the piston and the piston receptacle.

A method of monitoring degradation of seals of a packing case includes receiving signals from a first temperature sensor installed in a first location in a housing of the packing case; receiving signals from a second temperature sensor installed in a second location in the housing of the packing case; computing, from the signals, a temperature differential between the first temperature sensor and the second temperature sensor at two or more times; and determining, at least in part from the temperature differential at the two or more times, a degradation indicator for at least one of the seals of the packing case.

The invention relates to a mechanical seal arrangement, in particular a retarder-mechanical seal arrangement, comprising a first mechanical seal (2) with a first rotating slide ring (3) and a first stationary slide ring (4) which define a first sealing gap (5) in between them, an additional seal (6), a cooling medium space (7) which is filled with a cooling medium and extends all the way to the sealing gap of the first mechanical seal (2), wherein the first mechanical seal (2) seals the cooling medium space against an environment, a cooling medium access (8) into the cooling medium space (7) for supplying cooling medium, and a cooling medium exit (9) from the cooling medium space (7) for draining cooling medium, wherein the additional seal (6) is arranged in the cooling medium access (8), and wherein the additional seal (6) is configured to open when a pressure inside the cooling medium access (8) rises above a first pressure (P1) inside the cooling medium space (7), and to close at a second pressure (P0) inside the cooling medium access (8) that is lower than the first pressure (P1) inside the cooling medium space.

Sealing device for a propeller shaft of a marine vehicle propulsion unit including a plurality of sealing lips axially offset relative to each other, with a receiving space for a hydraulic fluid delimited by two adjacent sealing lips, at least one buffer space axially offset with respect to the receiving space and delimited by two adjacent sealing lips, whereby the sealing device includes suitable feeding means for supplying the buffer space with a buffer fluid. The device includes a sampling circuit able to sample fluid included in the buffer space and a monitoring device able to check parameters of the fluid sampled by the sampling circuit.

A seal packing assembly for a hydraulic pump includes a plurality of annular dynamic seals disposed within annular grooves circumferentially defined in the annular bore, a packing gland circumferentially housing a section of the plunger, and a plurality of seal manifolds distributed and defined within the packing gland, each seal manifold defining a port at one end exposed to the pumping fluid and further defining a clean lubrication fluid inlet proximate to a second end, the fluid inlet coupled to a lube pump via a check valve, where the clean lubrication fluid housed in the seal manifolds is maintained at a constant pressure. Each seal manifold includes a piston disposed within the seal manifold having a first end configured with a first surface area to interface with the pumping fluid and a second end configured with a second surface area to interface with the clean lubrication fluid, and a fluid port configured to provide fluid communication between the seal manifold and the annular grooves of the annular dynamic seals.

The dry-running piston rod packing for sealing a piston rod supported in such a way that the piston rod can be moved in a longitudinal direction (L) having at least one chamber ring, a sealing chamber, and a sealing ring arranged in the sealing chamber, wherein the piston rod packing has a high-pressure side and a low-pressure side, wherein a lift-off device is designed and arranged in such a way that the lift-off device can lift and lower the sealing ring in the longitudinal direction (L).

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 seal assembly for a dual-flow compressor is provided. The seal assembly may include an annular body disposed about a rotary shaft between a first compression assembly and a second compression assembly of the dual-flow compressor. An inner radial surface of the annular body and an outer radial surface of the rotary shaft may at least partially define a radial clearance therebetween. The annular body may have a first seal section and a second seal section at a first axial end portion and a second axial end portion thereof, respectively. The first and second seal sections may at least partially define a cavity therebetween. The seal assembly may also include a reference line communicably coupling the cavity with an inlet of the first compression assembly and configured to at least partially generate a pressure differential between the cavity and an outlet of the first compression assembly.