Abstract: A static pressure test fixture for use with centrifugal compressor non-contacting seals, also called dry gas seals, typically assembled and applied in cartridge form. Subject fixture consists of only three major components of simple shape for easy fabrication and easy assembly with the dry gas seal cartridge. This is done on site near the centrifugal compressor so that dry gas seal cartridges can be pressure-tested just prior to installation in the compressor or on removal from the compressor to verify their static sealing function as well as measure static leakage at different pressures. Subject fixture is also designed to rectify some high leakage conditions.

Abstract: A Non-contacting face type pressure sealing assembly for shafts rotating at high speeds, such as for example those of centrifugal compressors, such assembly having at least two mating sealing rings. One of the subject sealing rings is fixed to the rotating shaft. The other is non-rotating but typically biased by coil springs and allowed to slide within the seal housing in the axial direction. Non-rotating sealing ring is sealed at the housing by an arrangement of two elastomeric elements, one a sealing O-ring the other a compliant force transmitter. Compliant force transmitter can also be an O-ring or it can be an element triangular in cross-section. Angular contact between the two elements maintains transmission of the axial coil spring load towards the non-rotating ring, but also derives a radial load needed for low friction contact at the sealing O-ring.

Abstract: Non-contacting spiral groove face seal for shafts rotating at high pressures and high speeds with combination of two groove patterns on one of the two sealing faces of mating sealing rings; one pattern relatively deep, the other relatively shallow. The relatively deep spiral-shaped groove pattern is optimized for hydrodynamic operation and on shaft rotation pumps the sealed fluid in-between sealing faces to set the running clearance. The relatively shallow pattern is designed to prevent a friction lock of the sealing faces hydrostatically at starts and stops of shaft rotation by admitting controlled amount of the sealed fluid between the sealing faces when the shaft is at or near to a stationary condition.

Abstract: A non-contacting grooved face seal for a shaft rotating at a high pressure and high speed with a combination of two groove patterns on one of the two sealing faces of mating sealing rings; one pattern being relatively deep angled grooves, and the other pattern begin a relatively shallow annular groove. The relatively deep groove pattern is optimized for hydrodynamic operation and on shaft rotation pumps the sealed fluid between the sealing faces to set the running clearance. The relatively shallow pattern is designed to hydrostatically prevent a friction lock of the sealing faces at starting and stopping of shaft rotation by admitting controlled amount of sealed fluid between the sealing faces when the shaft is at or near to a stationary condition.

Abstract: A non-contacting face seal assembly for a shaft rotating at high speed with an improved secondary seal for low axial drag force. The secondary seal comprises an O-ring with a compliant spring element at its outer circumference. The compliant spring provides a controlled radial force, which keeps the secondary seal in a more reliable sealing contact with the seal ring and the seal housing surface but avoids excessive radial forces so that low axial drag forces due to secondary seal displacements are generated to prevent sealing face hang-up.

Abstract: A mechanical seal assembly for creating a sealing relationship between a housing and a shaft which is rotatable relative thereto. The seal assembly includes first and second seal rings having axially adjacent and opposed flat seal faces for creating an annular sealing region therebetween. A driving member is nonrotatably secured to the shaft and positioned in close proximity to the second seal ring, and a plurality of resilient drive connectors cooperate between the drive member and the second seal ring in angularly spaced relation therearound for effecting synchronous driving rotation of the second seal ring in response to rotation of the shaft.

Abstract: A non-contacting grooved face seal for a shaft rotating at a high pressure and high speed with a combination of two groove patterns on one of the two sealing faces of mating sealing rings; one pattern being relatively deep angled grooves, and the other pattern begin a relatively shallow annular groove. The relatively deep groove pattern is optimized for hydrodynamic operation and on shaft rotation pumps the sealed fluid between the sealing faces to set the running clearance. The relatively shallow pattern is designed to hydrostatically prevent a friction lock of the sealing faces at starting and stopping of shaft rotation by admitting controlled amount of sealed fluid between the sealing faces when the shaft is at or near to a stationary condition.

Abstract: Non-contacting seal for shafts rotating at high speeds with improved centering means for low unbalance of seal rotating parts. Centering means comprise a shallow circumferential groove with slanted sides and an elastic centering strip of ladder-like form between two cylindrical surfaces to be held concentric. Since slanted sides of the groove overlap sides of the centering strip it cannot be displaced out of its groove during assembly, or during operation. Displaced centering strip could cause unbalance, vibrations, damage to the seal or to the surrounding equipment.

Abstract: A fluid seal of the type employing a groove pattern on one of the opposed seal faces, which groove pattern includes a series of angled grooves formed in and positioned circumferentially around one of the seal faces, with the configuration of the grooves and of the flat face lands defined between adjacent grooves being configured to improve the squeeze film effect over the lands and between the opposed faces. The angled grooves are formed such that the sides of adjacent grooves extend generally in parallelism with one another so that the intermediate land area between adjacent grooves maintains a substantially constant width, even adjacent the radially inner ends of the grooves.

Abstract: Fluid film seal for shafts rotating at high speeds with improved centering means for low unbalance of the rotating seal ring. Centering and drive means are combined and interspaced at the center portion of the outer diameter of the symmetrical rotatable seal ring. The drive and centering at the outer ring diameter direct drive and centering forces inward, lowering tensile stresses due to centrifugal forces. Symmetry of the rotatable seal ring cross-section makes also centrifugal stresses symmetrical with no resulting torsion around the ring cross section to cause face distortions and yields an alternate seal surface at the back side of subject seal ring.

Abstract: A non-contacting face seal for shafts rotating at high speeds with improved secondary sealing means for low axial drag forces. Secondary sealing means comprise an O-ring with a compliant spring element at its outer circumference.Compliant spring provides a controlled radial force, which keeps the secondary seal in a more reliable sealing contact with the seal ring and the seal housing balance surface but avoids excessive radial forces, typical for secondary seal located between two machined cylindrical surfaces. Low axial drag forces due to secondary seal displacements are important for prevention of sealing face hang-up and consequent high leakage condition.

Abstract: Indexing rotary vacuum valve in which second stage vacuum at torr p.sub.i is applied through aligned ports of one valve member juxtaposed to another, originating a force tending to bring the two tightly together, but wet lubrication is not needed since gas under supra atmospheric pressure is admitted to an interface chamber in the lower valve member lifting the upper one to establish a slight clearance, sealed against ingress of atmospheric pressure. First stage vacuum at torr p.sub.o greater than p.sub.i is applied at the interface around the vacuum ports, to prevent leakage of the second stage vacuum.

Abstract: A seal system is disclosed for sealing a housing and rotatable shaft against leakage of high vapor-pressure liquids. The method of sealing contemplates phase change of the liquefied hydrocarbon fluid across a first module. The gas so formed is contained by a second seal module which operates as a dry running gas seal. The seal system has plural, axially spaced spiral-groove seal modules mounted between the shaft and housing. Each seal module has a primary ring affixed to the housing and a mating ring affixed for rotation with the shaft and the modules define an intermediate cavity. The rings have opposed, radially extending faces, one of which has a plurality of downstream pumping spiral grooves extending from one circumference. The grooves of the grooved ring of the upstream module are of a depth not to exceed about 100 micro-inches. In a preferred form, the depth of the grooves of the upstream module do not exceed 50 micro-inches.

Abstract: This specification discloses a dual seal combination for sealing the space between a housing and a shaft which passes through the housing. The combination is formed of an inboard seal and an outboard seal which are axially spaced from one another to define a buffer zone containing a buffer fluid. The inboard seal has radial faces provided with pumping grooves for sealing high pressure and for pumping buffer fluid from the buffer zone towards the upstream or high pressure side of the seal to lubricate the seal faces and to insure against leakage of fluid.

Abstract: This invention is directed to a low energy tandem seal which includes an end face seal cooperatively interconnected to a dynamic seal for sealing the circumferential space between a housing and a shaft. Under static non-operating conditions, the end face seal precludes fluid loss from the housing. Upon rotation of the shaft, the low energy dynamic seal provides fluid pressure which opposes loss of fluid from the housing and which disengages the end face seal to avoid a loss of energy and to reduce wear.

Abstract: A self aligning, spiral groove, gas seal having a primary sealing ring and a mating sealing ring with opposed radially extending sealing faces, one of said rings having:(a) Spiral grooves extending inwardly from the outside diameter of the face of one of said rings, said grooves having a depth of between approximately 0.0001 and 0.0003 inches, said grooves extending across the face of said ring to provide a dam width ratio of between approximately 0.5 and 0.8 according to the formula ##EQU1## where GD is the diameter of a circle defined by the boundary of the grooved area and the ungrooved area in said face, ID is the internal diameter and OD is the outside diameter; and(b) Said ring has a balance of between 0.8 and 0.9 according to the formula ##EQU2## where OD is the outside diameter of the sealing interface, ID is the internal diameter and BD is the balance diameter.