Abstract: A double, back to back oriented mechanical end face seal for use in sealing toxic or corrosive fluids having an intermediate buffer fluid chamber into which a relatively inert gas, such as nitrogen, is provided for use as a buffer fluid. The nitrogen gas is maintained at a pressure which exceeds the process fluid pressure by at least 10 p.s.i. and, in a preferred embodiment, spiral pumping grooves in the mating rings of each of the seals are shaped and dimensioned to pump the nitrogen buffer gas through the first seal from the intermediate chamber into the process fluid chamber and through the second seal from the intermediate chamber into the environment external to the housing and sealing area, thereby avoiding the escape of the process fluid into the intermediate buffer chamber and to the atmosphere. Contamination of the process fluid by the buffer gas may be tolerated.

Abstract: This invention relates to barrier seal systems for sealing the annular space between a housing and a rotating shaft which extends through a bore in the housing. The seal system has inboard and outboard mechanical end face seals. The inboard seal faces have spiral grooves for pumping a buffer fluid from a buffer chamber between the two seals toward the high pressure side of the inboard seal. The primary ring of the inboard seal may be double balanced. For high pressure applications, the buffer fluid may be pressurized and a pumping ring may be included in the outboard seal to circulate buffer fluid. High pressure applications also require two hard seal rings and optimum dam and face widths. Buffer fluid can be supplied to the seal system by a reservoir connected by a gravity feed line. A buffer fluid containment device may be attached to the high pressure side of the seal to prevent process fluid from contaminating the seal faces or secondary seals.

Abstract: A seal system for sealing a housing and rotatable shaft against leakage of a gas under high pressure; hydrogen is an example. The system, using multiple seals in tandem, provides a stepped reduction of high pressure gas at full height pressure to a low pressure across the individual seal modules.The seal system has plural, axially spaced spiral-grooved end face seal modules mounted between the shaft and housing, the axial spaces between the seals defining a chamber. Each seal module has a primary seal ring affixed to the housing and a mating ring affixed for rotation with the shaft, the two rings having opposed, radially extending faces; each mating ring has a plurality of radial spiral grooves extending radially inward from the outer diameter or circumference.

Abstract: A mechanical face seal for a high speed, rotary fluid pressure device comprising rotating and stationary seal rings disposed in a housing and having confronting radial seal faces normally biased into engagement with one another. Oppositely inclined sets of spiral grooves are formed in the seal face of one ring, one set functioning to pump fluid from the reservoir downstream between the seal faces, and the other set functioning to pump fluid between the faces upstream back toward the reservoir. Each downstream pumping groove preferably intersects only one upstream pumping groove. Fluid pressure between the faces forms a gap therebetween, and the reversely inclined groove construction minimizes fluid loss or leakage.

Abstract: A totally split mechanical face seal being installable and replaceable without necessitating breakdown of the shaft and/or housing. The inventive split seal is well suited for replacement of packing or stuffing in heavy duty or inaccessible locations. The inventive seals include a sealing element that seals the primary ring against the shaft and rigidly positions the primary ring in the axial, circumferential and radial directions, and also includes a sealing element which seals the mating ring against the housing and non-rigidly positions the mating ring in the axial direction while simultaneously providing an axial biasing force on the mating ring to provide mating contact of the two rings.

Abstract: A mechanical seal for use between a housing and a rotatable shaft supported by the housing having adjacent annular primary and mating sealing rings, each ring having a generally radial sealing face and means for sealing and nonrotatably retaining the first sealing ring relative to the housing, and means sealing and nonrotatably retaining the second sealing ring so that it rotates with the shaft. One sealing ring is movable axially of the shaft, and biasing means urge this one ring toward the other sealing ring, which is axially fixed relative to the shaft. The axially movable sealing ring is centered coaxially with respect to the axis of the axially fixed sealing ring through engagement of a centering element which is centered relative to the shaft and which engages the axially movable sealing ring to center it relative to the shaft. The centering element engages the axially movable sealing ring and includes an integral pinless retainer.

Abstract: A secondary seal for use in a high temperature environment, including only non-elastomeric elements, includes split high temperature carbon graphite secondary seal rings axially biased by a first set of springs and radially biased by a second set of springs.

Abstract: A totally split mechanical face seal being installable and replaceable without necessitating breakdown of the shaft and/or housing. The inventive split seal is well suited for replacement of packing or stuffing in heavy duty or inaccessible locations. The inventive seals include a sealing element that seals the primary ring against the shaft and rigidly positions the primary ring in the axial, circumferential and radial directions, and also includes a sealing element which seals the mating ring against the housing and non-rigidly positions the mating ring in the axial diection while simultaneously providing an axial biasing force on the mating ring to provide mating contact of the two rings.

Abstract: A seal face of a ring used in a non-contacting, gap-type seal having an annular groove area with microdams, each having a preferable width of about 0.025 inches, between a plurality of groove surface areas. The microdams provide a boundary to the groove surface areas whereby the recess of each groove surface area bounded by the microdams acts as a unitary pressure zone and the pressure in the separate zones decreases in a series of steps as measured from one circumference of the ring to the other circumference.

Abstract: A seal system is disclosed for sealing a housing and rotatable shaft against leakage of high vapor-pressure liquids such as natural gas. The method of sealing comtemplates 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 have a pattern which upon shaft rotation creates shear heating of the liquefied hydrocarbon fluid.

Abstract: A multi-layer radial lip seal assembly adapted to be retained to the housing of an automotive air conditioning compressor and to be disposed about a rotatable shaft extending through a chamber provided in the housing. The lip seal assembly includes a first seal member or disc of virgin FEP adjacent to a second seal member or disc of graphite-filled PTFE. A retainer is provided to support the first and second seal members and an elastomer is molded to the retainer and seals the seal members to the retainer. The first seal member acts to protect the second seal member during installation and quickly wears away, so that the second seal member becomes the primary seal member.

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: An impeller pump including a housing defining a seal cavity having a shaft rotatably mounted therein, and an expeller to pump fluid from the seal cavity. A dynamic seal provides a fluid tight seal between the housing and the shaft. The seal comprises an axially movable primary seal ring which rotates with the shaft and a mating stationary seal ring, both rings disposed annularly of the shaft and each defining a generally radial sealing face adapted to seal against the other. A biasing device urges the primary seal ring into sealing engagement with the mating seal ring. The radial face of the mating seal ring defines a plurality of spiral grooves and a sealing dam area which is at the periphery of the ring exposed to high pressure. When the pump is not operating, the seal ring faces contact one another and the dam provides a seal against the opposing face.

Abstract: An impeller pump including a housing defining a seal cavity having a shaft rotatably mounted therein, and an expeller to pump fluid from the seal cavity. A dynamic seal provides a fluid tight seal between the housing and the shaft. The seal comprises an axially movable primary seal ring which rotates with the shaft and a mating stationary seal ring, both rings disposed annularly of the shaft and each defining a generally radial sealing face adapted to seal against the other. A biasing device urges the primary seal ring into sealing engagement with the mating seal ring. The radial face of the mating seal ring defines a plurality of spiral grooves and a sealing dam area which is at the periphery of the ring exposed to high pressure. When the pump is not operating, the seal ring faces contact one another and the dam provides a seal against the opposing face.