Abstract: A seal (10, 12) having a mating ring (100, 100?) mounted in a fixed axial and rotational relationship with respect to a shaft (14) and a primary ring (120, 120?) mounted in fixed rotational relationship but movable axially with respect to a housing assembly (16). Springs (136) are provided to urge the primary ring (120, 120?) axially into sealing engagement with the mating ring (100, 100?). The mating ring (100, 100?) are mounted with respect to the shaft (14) in abutment with a first radial face (44, 62). A circumferential surface of the mating ring (100, 100?) is spaced radially from a circumferential surface on the shaft (14) and an annular helical spring element (104) is located, under radial compression, between the circumferential surfaces. The annular helical spring element (104) is formed from wire of elongate section, the axial width of the section being greater than the radial thickness.

Abstract: A fermentation apparatus (10) with a fermentation vessel (12) having a low speed stirrer comprising a shaft (14) with at least one stirring element (18) mounted thereon. First and second seal assemblies (30, 50), spaced axially from one another to define a chamber (64) therebetween, are provided to seal a gap between the shaft and a vessel aperture. An inlet (66) opens into the chamber for connecting the chamber to a processing gas, the first seal assembly (30) is located between the fermentation vessel and the chamber comprising a seat (32) mounted on the shaft for rotation therewith and a mating ring mounted (36) in fixed rotational relationship but moveably axially of the housing. A sealing face (44) of the mating ring is resiliently biassed into engagement with a sealing face (42) of the seat, and the sealing face has grooves (18) which provide separation of the sealing faces upon rotation of the shaft.

Abstract: A composite seal face ring has an inner ring (60) made of material with good tribological properties, the inner ring (60) being pre-compressed by an outer ring (64) with a high tensile strength and a thermal coefficient of expansion substantially equal to that of the inner ring (60). The seal face ring is assembled by compressing the inner ring (60) and/or expanding the outer ring (64) by fluid under pressure, before inserting the inner ring (60) into the outer ring (64).

Abstract: A gas seal for providing a seal between a pair of relatively rotatable components is provided with a stand-still seal which will seal between the components when the components are stationary, the stand-still seal having a sealing element mounted in sealing relationship with respect to one of said components and being displaceable into sealing engagement with the other component when the components are stationary with respect to one another.

Abstract: A seal assembly (22) for sealing a pressurized gaseous product includes, a pair of seals (24,26) spaced axially to provide a chamber (28) therebetween, a gas seal (24) being disposed on the inboard side of the seal assembly (22) between the sealed gaseous product and the chamber (28), an inlet (38) opening to the side of the gas seal (24) exposed to the gaseous product, the inlet (38) being connected to a supply of clean gas, the chamber (38) defined between the seals (24,26) being connected to a reservoir (50), the reservoir (50) being connected back to inlet (38) via a pressure intensifier (70) and the reservoir (50) being connected to the supply of clean gas, so that additional clean gas may be supplied thereto, when pressure in the reservoir (50) falls below a predetermined minimum value.

Abstract: A seal between a pair of relatively axially movable coaxial components is provided by a spring energised plastic seal which is located axially with respect to the outer component to separate a high pressure fluid area from a low pressure fluid area, the spring energised plastic seal has a plastic ring, the plastic ring defining a body portion and a pair of sealing elements, the sealing elements extending coaxially to the high pressure side of the body portion and being spaced radially by spring means, into sealing engagement with opposed surfaces of the two components, a projection extending axially from the low pressure side of the body portion adjacent the external diameter thereof, said projection engaging an axial projection on the outer component so that engagement thereof will support the plastic ring radially.

Abstract: Mechanical face seal has a first sealing mounted in fixed axial and rotational relationship and sealed with respect to a housing and a second sealing ring mounted in fixed rotational relationship but movable axially with respect to a shaft. The second sealing ring being sealed with respect to the shaft by means of a bellows unit. One end of the bellows unit being engaged by a first drive band which applies a radial load to the end of the bellows unit forcing it into driving and sealing engagement with the shaft and the other end of the bellows unit being engaged by a second drive band which applies a radial load to the end of the bellows unit forcing it into driving and sealing engagement with the second sealing ring.

Abstract: A mechanical face seal has a first sealing ring mounted non-rotatably and sealed with respect to a shaft, a second sealing ring mounted non-rotatably and sealed with respect to a housing the second sealing ring being mounted in axial alignment and being resiliently urged into sealing engagement with the first sealing ring.

Abstract: A mechanical face seal includes a first sealing ring mounted non-rotatably and sealed with respect to a shaft and a second sealing ring mounted non-rotatably and sealed with respect to a housing, the second sealing ring being mounted in axial alignment with the first sealing ring and springs being provided to urge sealing faces of the first and second sealing rings into sealing engagement. The sealing face of the first sealing ring is provided with a plurality of grooved areas spaced angularly around its circumference, the grooved areas opening to one edge of the sealing face, a continuous annular dam formation being provided between the grooved areas and the other edge of the sealing face.

Abstract: A mechanical face seal has a first seal face member mounted in fixed rotational and axial relationship and sealed with respect to a housing, and a second seal face member mounted with respect to a shaft by means of an elastomeric bellows unit, the bellows unit being axially compressed so that it urges the second seal face member into sealing engagement with the first seal face member; the elastomeric bellows unit being formed from an elastomeric composition with reinforcing fibres embedded therein, the reinforcing fibres being orientated axially of the bellows unit.

Abstract: A mechanical face seal includes a first sealing ring mounted non-rotatably and sealed with respect to a shaft and a second sealing ring mounted non-rotatably and sealed with respect to a housing, the second sealing ring being mounted in axial alignment with the first sealing ring and springs being provided to urge sealing faces of the first and second sealing rings into sealing engagement. The sealing face of the first sealing ring is provided with a plurality of grooved areas spaced angularly around its circumference, the grooved areas opening to one edge of the sealing face, a continuous annular dam formation being provided between the grooved areas and the other edge of the sealing face.

Abstract: A seal includes a seal assembly associated with a housing, said seal assembly having an annular sealing element which is located both axially and radially between a retaining ring and a support ring, the sealing element sealingly engaging the retaining ring and having a first lip formation which is engageable, in response to fluid pressure being applied thereto, with a shaft to provide a fluid tight seal therewith, a seal being provided between the retaining ring and housing.

Abstract: A mechanical face seal includes a seal face member which is secured in fixed rotational relationship and sealed with respect to one component by means of a resilient bellows unit, said bellows unit being attached at one end to the associated component and at the other end to the seal face member, the seal face member being biased into sealing engagement with a second seal face member by compression of the bellows unit, the bellows unit defining a plurality of convolutions, a convolution in a portion of the bellows unit subject to higher stressing having a pitch which is greater than and/or a depth which is less than that of a convolution in a portion of the bellows unit subject to lower stressing, thereby evening out the stress distribution in the bellows unit when in operation.