Abstract: A ferrofluidic seal is fitted with a centering ring having an inner edge adapted for engagement with a rotating shaft for centering the seal about the rotating shaft. The centering ring automatically engages the shaft and centers the seal when the seal is fitted onto the shaft. The centering ring is affixed to the housing, and/or magnet and pole module. In one embodiment, the centering ring may be removed after it performs its centering function. In another embodiment, the centering ring is non-removable and remains within the seal permanently. According to this latter embodiment, the centering ring serves the additional purpose of retaining ferrofluid, expelled from the seal during "bursting", within magnetic reach of the seal so as to be re-drawn into the seal, thus extending seal life. Additionally, a ferrofluid retaining ring absent a centering function may be employed.

Abstract: A secondary mechanical seal assembly is used on a shaft that is rotatable within a housing to seal both gaseous and liquid medium. The assembly includes a stationary seal face element that is fixed relative to the housing and a rotating seal face element that is fixed relative to the shaft. One of the seal face element back surfaces includes at least one slot configured to produce a wave on the front surface of the seal face element when the shaft is rotated. The wave creates an opening force that is sufficient to control wear and prolong seal life when the secondary seal assembly is exposed to a gaseous medium. When exposed to a pressurized liquid medium, the hydrodynamic loading from the liquid medium alters the seal face element waviness, and increases the closing force due to the action of the pressurized liquid on the back surface of the seal face elements, such that excessive leakage is prevented.

Abstract: A mechanical seal assembly for use in a pump seal chamber, through which a pump shaft rotates and in which a process fluid is contained by a stationary seal and a rotating seal, converts the velocity head of the circulating process fluid in the seal chamber back to a positive static pressure at the stationary seal and rotating seal faces and ensures a steady film of the process fluid at the seal faces. The mechanical seal assembly converts the velocity head to a positive static pressure through one or more velocity recovery tubes that project outwardly from the pump housing into the sealed chamber, or that project outwardly from the rotating seal into the seal chamber, and communicate with respective passages through the seals and channel the process fluid to the seal faces.

Abstract: An improved mechanical seal using hard non-weldable seal rings in which the seal ring is supported by a seal ring flange and in which a GRAFOIL gasket is positioned in an annular recess between the seal ring and the flange; the seal ring being held in the flange by means of a retainer ring welded to the flange, thereby avoiding the use of interference fits and/or lap fits between the flange and the seal ring.

Abstract: An improved lubricating system for mechanical seal assemblies in which baffle means are positioned closely adjacent to the seal faces forming restricted passages for the flow of lubricating fluid under pressure to the opposing seal faces especially when the pressure of the product fluid is relatively low.