Durametallic Corporation

Flowserve Management Company

William V Adams

Christopher D McCowey

Joseph C Parker

Duane A Avard

Leroy A Waling

Antonio F Artiles

A brush seal arrangement for sealing cooperation between a shaft and a surrounding member which is relatively rotatable with respect to the shaft. The brush seal includes an annular rotor disposed in surrounding relationship to the shaft and sealed with respect to the housing, and the rotor mounts thereon first and second annular bush members which are disposed in axially spaced relation and which have annular edge portions which create a frictional and sealing engagement with the shaft to nonrotatably and sealingly couple the rotor to the shaft. A passage extends through the rotor for communication with an annular region defined between the annular brushes in surrounding relationship to the shaft, and a pressurized buffer gas is supplied through the passage into the annular region.

Brush seal

An improved gas seal having inboard and outboard seal units each defined by a pair of opposed and relatively rotatable seal faces, one face of each pair having appropriate grooves which communicate with a pressurized barrier gas, preferably an inert gas such as nitrogen. The inboard seal unit, at its other seal periphery, communicates with a process fluid being handled by a rotating equipment, namely a pump. Each seal unit has one of the seal rings, the nonrotating ring in the preferred embodiment, urged axially toward its opposed ring by a compact bellows which axially cooperates between the respective seal ring and a backing member. The bellows is positioned to create an isolation between the barrier and process fluids and to provide an effective diameter to provide desirable balance of pressures as imposed on the axially moving seal ring to optimize seal performance. The bellows is preferably a single convolution which is free of fixed securement to the moving seal ring.

Double gas seal having an improved bellows arrangement

An improved gas seal having inboard and outboard seal units each defined by a pair of opposed and relatively rotatable seal faces, one face of each pair having appropriate grooves which communicate with a pressurized barrier gas, preferably an inert gas such as nitrogen. The inboard seal unit, at its other seal periphery, communicates with a process fluid being handled by a rotating equipment, namely a pump. Each seal unit has one of the seal rings, the nonrotating ring in the preferred embodiment, urged axially toward its opposed ring by a compact bellows which axially cooperates between the respective seal ring and a backing member. The bellows is positioned to create an isolation between the barrier and process fluids and to provide an effective diameter to provide desirable balance of pressures as imposed on the axially moving seal ring to optimize seal performance. The bellows at one end is connected to a support ring which is urged toward the adjacent seal ring with an annular gasket maintaining a soft sealed contact therebetween. The other end of the bellows is connected to a pressure piston which seats against a stationary gland. The process fluid urges the pressure piston into contact with the support ring to increase the sealing pressure at the gasket in the event of an improper balance between the pressures of the barrier and process fluids.

Double gas seal with bellows supported by backing and support rings

A magnetic-type end face seal assembly for creating an airtight seal between a housing and a rotatable shaft which projects outwardly through a housing bore. An insert ring of magnetically attractable material surrounds the shaft within the bore, and has a seating ring of hard synthetic material externally fixed thereto and sealingly engaged with the wall of the housing bore. The insert ring defines a first annular seal face on the outer axial end thereof. A rotating ring arrangement encircles and is nonrotatably coupled to the shaft axially adjacent the insert ring. This rotating ring arrangement includes a ring-shaped magnet which is disposed closely axially adjacent but slightly spaced from the insert ring, and this magnet mounts thereon a face ring which defines a second annular seal face which is maintained in engagement with the first seal face due to the magnetic attraction between the magnet and the insert ring.

Magnetic seal assembly

A mechanical seal construction of the double or tandem-type, wherein a stationary ring, preferably the gland ring, is provided with a circulation inducing dam positioned within an annular chamber defined between the inner and outer seals. The dam extends from the downstream side of an outlet to the upstream side of an inlet, whereby rotation of the shaft effectively induces coolant to flow into the chamber through the inlet and then around the chamber to the outlet. The dam has end walls which effectively act as deflectors at both the inlet and outlet to assist the cooling fluid in its entry into and departure from the chamber.

Mechanical seal assembly with coolant circulation structure

A double or tandem mechanical seal construction having as an integral part thereof a pumping structure for effecting circulation of buffer fluid. The shaft sleeve is provided with surface irregularities thereon, such as a series of circumferentially spaced slots, so that the shaft sleeve functions as a pumping rotor. The surrounding seal stator has supply and discharge ports extending radially therethrough, which ports extend substantially tangentially with respect to the shaft sleeve so that the latter, due to its rotation, will effectively pump and hence circulate the cooling or buffer fluid through the buffer chamber.

Mechanical seal assembly with integral pumping device

A bypass flush system for cooling and lubricating a mechanical seal assembly as used in association with a fluid handling apparatus, such as a centrifugal pump. A bypass line connects the mechanical seal assembly and the discharge side of the pump for permitting recirculation of a limited quantity of the fluid being pumped. To control the flow of bypass fluid, a flow control device is disposed between the seal assembly and the pumping chamber. The flow control device comprises a thermal bushing which permits the bypass system to operate with a minimum flow rate, while at the same time allowing accurate control of the small flow rate without the device becoming plugged with deposits and the like. Use of the thermal bushing for flow control also enables the bypass system to employ an air-cooled heat exchanger for cooling the fluid flowing through the bypass line. In a preferred embodiment, the thermal bushing has a thermal expansion rate slightly less than the thermal expansion rate of the shaft which it surrounds whereby the clearance between the shaft and the thermal bushing gradually and progressively decreases in response to temperature increases so as to maintain a substantially constant flow rate past the bushing.

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Scotts, MI, United States of America

William V Adams