Embodiments include an apparatus and techniques for operating an electromagnetic cartridge seal. Embodiments include operating a cartridge seal in one of a plurality of modes, and receiving a signal at a force applying mechanism of the cartridge seal, the force applying mechanism being coupled to a primary sealing component of the cartridge seal. Embodiments also include controlling the force applying mechanism based at least in part on the received signal.

A method and system for actively controlling an axial separation between a seal face of a stationary ring and a seal face of a rotating ring of a gas seal is disclosed. At least one property is sensed indicative of a condition of at least one of the seal faces. With at least one sensing device, a characteristic of the axial separation between the seal faces is sensed. A net magnetic force of at least one magnetic device is adjusted based on the property and/or the characteristic. Adjusting the net magnetic force adjusts the axial separation between the seal faces. Without using a buffer gas between the seal faces, flow of gas or other fluid is controlled between the seal faces by adjusting the axial separation.

A mechanical seal assembly with an electronically controllable carrier load. The assembly includes a magnetic ring affixed to the carrier and driven by a solenoid. The solenoid can apply an axial force to the carrier. The carrier load can be controlled to prevent or reduce friction between the primary ring and mating ring in slow-roll running conditions by partially or completely compensating a spring force provided by a biasing mechanism. The carrier load can further be controlled to inhibit seal hang-up. In embodiments, desired the carrier load can be determined by rotational speed. In embodiments, carrier load can be determined based on sensor signals.

Disclosed is a device for regulating the compression force of a spring-spacer assembly provided in a mechanical shaft seal in a system including a motor and a pump or compressor. The device includes a spacer made from shape memory alloy, a spring in line with the spacer, and a heater proximate the spacer. When heated, the spacer contracts in length, resulting in a decrease in compression force. Also disclosed are systems and methods utilizing the device. The device is particularly useful when starting a pump or compressor to reduce friction in the mechanical seal. Existing mechanical seals can be easily retrofitted with the device.

A representative seal system (such as a seal system for a turbopump of a rocket engine) automatically adjusts a balance ratio of a seal. The system can include a ring element encircling an axis. A front side of the ring element contacts a revolving surface to form a seal with the revolving surface. The front side can include a stepped surface having two or more steps. Each step includes a sealing surface configured to contact the revolving surface to form a sealing area that is different from a sealing area of each other sealing surface. Each step is positioned and configured to wear away during operation of the machine to expose an underlying surface to the revolving surface, to change the sealing area and the balance ratio of the seal. A representative method of operating a turbomachinery system includes changing the balance ratio of a seal while rotating a rotor.

A seal connector device (1) for achieving a temporary fluid-tight connection between a rotating shaft (17) rotatably connectable to a structure and said structure, wherein the seal connector device (1) comprises said rotating shaft (17) which defines a rotational axis (S-S); a sealing disc (19) extending radially from said rotating shaft (17); at least one first cylinder-piston assembly (100) comprising a cylinder (9) and a piston (21) slidable into said cylinder (9), said piston (21) having a sealing surface (22) facing the sealing disc (19), and the sealing disc (19) having a sealing counter-surface (34) facing the sealing surface (2), said sealing surface (22) being suitable for abutting against said sealing disc (19); said piston (21) being configured to be selectively operated between: a sealing position in which the sealing surface (22) of the piston (21) is at a minimum distance or in contact with the seal ing counter-surface (34) of the disc (19), in order to achieve a temporary fluid-tight connection between the rotating shaft (17) and the structure, preventing a fluid to flow between the sealing surface (22) of the piston (21) and the sealing counter-surface of the disc (19); and a non-sealing position, in which the sealing surface (22) is moved away from the sealing counter-surface (34) of the disc (19) whereby a fluidic seal is absent between the rotating shaft (17) and the structure.

Face seals of the rotors of main circulation pump units for separation of media or pressure drop used in nuclear power plants. A multistage face seal design is proposed, which comprises mounted in series work stages and end stage, each of which includes a rotor element located on the shaft and a spring-assisted axially movable stator element contacting it, sealed relatively to the casing with an O-ring, at the same time the cavities of high and low pressure of work stages are connected in series with restricted openings made in the stator element, which is designed to fulfill the functions of an axially movable step-like piston sealed relatively to the casing.

The second lip has an annular protrusion formed at one end portion in a thickness direction of a lip tip portion configured to be in sliding contact with the slinger and protruding in the thickness direction, and a thickness of the lip tip portion is formed thicker than a thickness of a lip part except for the protrusion. The protrusion is formed to be reduced in width toward the tip-side in the thickness direction and configures a sliding contact part configured to be in linearly sliding contact with the slinger. The circular plate part of the slinger is formed tilted toward the seal member in the axial direction, and the slinger has an annular flange part integrally formed therewith by bending a tip of the circular plate part so as to axially cover an area above the sliding contact part of the seal member.

A method and system for actively controlling an axial separation between a seal face of a stationary ring and a seal face of a rotating ring of a gas seal is disclosed. At least one property is sensed indicative of a condition of at least one of the seal faces. With at least one sensing device, a characteristic of the axial separation between the seal faces is sensed. A net magnetic force of at least one magnetic device is adjusted based on the property and/or the characteristic. Adjusting the net magnetic force adjusts the axial separation between the seal faces. Without using a buffer gas between the seal faces, flow of gas or other fluid is controlled between the seal faces by adjusting the axial separation.

A shaft seal assembly for sealing a moving shaft of a fluid consumer includes a seal case movable relative to a mating surface of the shaft, a biasing force that biases the seal case towards the mating surface, and a seal at least partially disposed in the seal case. In a dynamic condition, when fluid pressure against the seal case is equal to or greater than a threshold pressure, the seal case sealingly separates from the mating surface, and the seal is forced into sealing engagement against the mating surface of the shaft to form a dynamic seal. In a static condition, when fluid pressure exerted against the seal case is less than the threshold pressure, the seal is sealingly engaged against the mating surface to form a static seal, and the seal case is sealingly engaged against the mating surface of the shaft to form an additional static seal.