Abstract: A seal that can be used alone or as a containment seal for another seal includes a primary ring (36) and a mating ring (30), the primary ring being axially shiftable relative to a rotating shaft (12) and the mating ring being axially fixable relative to the rotating shaft, a biasing mechanism (500) that urges the primary ring toward the mating ring, and an annular flexible sealing membrane (100). The membrane includes a flange portion (102) disposed at least partially between the biasing mechanism and the primary ring, a coaxial portion (104) that is axially fixable relative to the shaft, and a flexible connection portion (106) positioned within a radially inward extent of the flange portion and connecting the flange portion to the coaxial portion.

Abstract: A mechanical seal assembly adapted for arrangement around a rotating shaft of a pump has first and second seals. Both include primary and mating rings, biasing mechanisms and annular flexible sealing membranes. The two seals can have different seal balances or different biasing forces (or both) to allow the second seal to run dry for extended periods.

Abstract: A mechanical seal assembly adapted for arrangement around a rotating shaft of a pump has first and second seals. Both include primary and mating rings, biasing mechanisms and annular flexible sealing membranes. The two seals can have different seal balances or different biasing forces (or both) to allow the second seal to run dry for extended periods.

Abstract: A non-collapsible flexible sealing membrane (or bellows) for incorporation in a mechanical seal assembly and use in rotary shaft equipment. The sealing membrane includes a substantially radially outward extending first flange portion, which can be urged into an axially shiftable ring by a biasing mechanism. The sealing membrane further includes a substantially axially outboard extending second coaxial portion, substantially radially inward of the balance diameter of the seal. The horizontal portion is advantageously held fixed to a stub sleeve by an annular band. The angle between the vertical portion and the horizontal portion of sealing membrane enables directional control of the forces acting on stub sleeve and primary ring.

Abstract: A non-collapsible flexible sealing membrane (or bellows) for incorporation in a mechanical seal assembly and use in rotary shaft equipment. The sealing membrane includes a substantially radially outward extending first flange portion, which can be urged into an axially shiftable ring by a biasing mechanism. The sealing membrane further includes a substantially axially outboard extending second coaxial portion, substantially radially inward of the balance diameter of the seal. The horizontal portion is advantageously held fixed to a stub sleeve by an annular band. The angle between the vertical portion and the horizontal portion of sealing membrane enables directional control of the forces acting on stub sleeve and primary ring.

Abstract: A seal that can be used alone or as a containment seal for another seal includes a primary ring (36) and a mating ring (30), the primary ring being axially shiftable relative to a rotating shaft (12) and the mating ring being axially fixable relative to the rotating shaft, a biasing mechanism (500) that urges the primary ring toward the mating ring, and an annular flexible sealing membrane (100). The membrane includes a flange portion (102) disposed at least partially between the biasing mechanism and the primary ring, a coaxial portion (104) that is axially fixable relative to the shaft, and a flexible connection portion (106) positioned within a radially inward extent of the flange portion and connecting the flange portion to the coaxial portion.

Abstract: A non-collapsible flexible sealing membrane (or bellows) for incorporation in a mechanical seal assembly and use in rotary shaft equipment. The sealing membrane includes a substantially radially outward extending first flange portion, which can be urged into an axially shiftable ring by a biasing mechanism. The sealing membrane further includes a substantially axially outboard extending second coaxial portion, substantially radially inward of the balance diameter of the seal. The horizontal portion is advantageously held fixed to a stub sleeve by an annular band. The angle between the vertical portion and the horizontal portion of sealing membrane enables directional control of the forces acting on stub sleeve and primary ring.

Abstract: A non-collapsible flexible sealing membrane (or bellows) for incorporation in a mechanical seal assembly and use in rotary shaft equipment. The sealing membrane includes a substantially radially outward extending first flange portion, which can be urged into an axially shiftable ring by a biasing mechanism. The sealing membrane further includes a substantially axially outboard extending second coaxial portion, substantially radially inward of the balance diameter of the seal. The horizontal portion is advantageously held fixed to a stub sleeve by an annular band. The angle between the vertical portion and the horizontal portion of sealing membrane enables directional control of the forces acting on stub sleeve and primary ring.

Abstract: A contacting mechanical end face seal for use in applications having slow shaft rotational speeds, such as mixers, agitators and reactors, includes at least one seal ring having a face with spiral grooves. Both hydrostatic and hydrodynamic lift characteristics in the seal are utilized to generate and maintain a seal gap having sufficient stiffness to prevent contact of the seal ring faces during operation. Specific characteristics, or combinations of them, include a land to groove ratio between 0.2-0.9, tapered groove surfaces which are inclined from the O.D. toward the dam, groove area to land area ratios greater than 1.5, a stepped groove having a greater depth at the O.D. relative to the depth adjacent the dam, alternating deep and shallow grooves, and groove area to dam area ratio in the interface greater than 1.2.

Abstract: A mechanical end face seal of the non-contacting type includes a primary seal ring having a back section, a seal face section and a middle section between the seal face and the back sections, each primary ring section having a radial dimension, defined as the difference between the outermost radius and the innermost radius of said respective section, the radial dimension of the back section being in a ratio relative to said middle section of between about 1.5 to about 3.1, and more preferably of between about 1.9 to about 2.5, and most preferably about 2.0 to about 2.3. Additionally, the mating seal ring includes grooves extending from one seal ring circumference toward the other and terminating adjacent a dam at a radius R.sub.g, it is beneficial to have the boundary between the grooves and the dam have a radius R.sub.g slightly larger or smaller, within about 10%, than the outer radius of the middle section.

Abstract: A double, back to back oriented mechanical end face seal arrangement for use in sealing pumps or other devices used in fluid transfer of toxic or corrosive fluid has an intermediate buffer fluid chamber into which a relatively inert gas, such as nitrogen, is provided for use as a buffer fluid, and is maintained at a pressure which exceeds the process fluid pressure by at least 10 p.s.i. Each seal has a primary ring and a mating ring with gap maintaining means, such as spiral pumping grooves, formed in one of the rings which are shaped and dimensioned to pump the buffer gas through the first seal from the intermediate chamber into the process fluid chamber against the process fluid pressure and through the second seal from the intermediate chamber into the environment external to the housing and sealing area, thus avoiding the escape of the process fluid into the intermediate buffer chamber and thereby to the atmosphere.

Abstract: A mechanical end face seal of the non-contacting type includes a primary seal ring having a back section, a seal face section and a middle section between the seal face and the back sections, each primary ring section having a radial dimension, defined as the difference between the outermost radius and the innermost radius of said respective section, the radial dimension of the back section being in a ratio relative to said middle section of between about 1.8 to about 2.8, and more preferably of between about 1.9 to about 2.5, and most preferably about 2.0 to about 2.3. Additionally, the mating seal ring includes grooves extending from one seal ring circumference toward the other and terminating adjacent a dam at a radius R.sub.g, it is beneficial to have the boundary between the grooves and the dam have a radius R.sub.g slightly larger or smaller, within about 10%, than the outer radius of the middle section.

Abstract: A mechanical end face seal with a mating ring having a beveled inner diameter extending frusto-conically to the back face. Atmosphere or other fluids located outside of the housing can enter through the frusto-conical opening between the primary ring and the shaft to cool the seal rings during shaft rotation. In a preferred embodiment, a drive collar disposed adjacent the primary ring and attached to the shaft includes a series of cantilever projection portions which rotate in the atmosphere outside the housing to circulate the atmosphere into the frusto-conical space between the beveled inner diameter of the stationary mating ring to provide a fan blade effect.

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.