A double seal includes two sliding seals. The seals can be non-pusher secondary seals (NPSS). In one embodiment, by employing an NPSS as the chamber side seal can handle large pressure reversals where the inner diameter pressure (pressure in the chamber) spikes and exceeds the outer diameter pressure that is provided between the two seals forming the double seal.

Low-torque sliding components have sliding surfaces rotated relative to each other with an annular mating ring and an annular seal ring facing each other. The sliding surface of at least one of the mating ring and the seal ring has therein a plurality of multi-stepped recess portions formed in a circumferential direction. Relative rotation and sliding of the mating ring and the seal ring causes the multi-stepped recess portions to generate a dynamic pressure, and the multi-stepped recess portion is formed in a stepwise shape in a cross-sectional view by a dynamic pressure recess portion and a static pressure recess portion with the dynamic pressure recess portion surrounding the static pressure recess portion deeper than the dynamic pressure recess portion.

Low-torque sliding components have sliding surfaces rotated relative to each other with an annular mating ring and an annular seal ring facing each other. The sliding surface of at least one of the mating ring and the seal ring has therein a plurality of multi-stepped recess portions formed in a circumferential direction. Relative rotation and sliding of the mating ring and the seal ring causes the multi-stepped recess portions to generate a dynamic pressure, and the multi-stepped recess portion is formed in a stepwise shape in a cross-sectional view by a dynamic pressure recess portion and a static pressure recess portion with the dynamic pressure recess portion surrounding the static pressure recess portion deeper than the dynamic pressure recess portion.

A rotary machine system includes: a rotary machine including a gas seal portion; a gas seal device connected to the rotary machine and that supplies a seal gas to the gas seal portion; and a connecting pipe that connects the gas seal portion and the gas seal device. The rotary machine includes a casing through which a working fluid flows; a rotatable rotary shaft; and the gas seal portion that seals the working fluid by the seal gas having a pressure higher than a pressure of the working fluid in the casing. The gas seal device includes: a seal gas supply pipe through which the seal gas delivered to the connecting pipe flows; a pressure regulating valve provided in the seal gas supply pipe and that adjusts the pressure of the seal gas supplied to the gas seal portion; and a control part.

A positive pressure generating mechanism comprising a positive pressure generating groove is provided to a high-pressure side of one of two sliding surfaces that slide relative to each other in a pair of sliding components, and a negative pressure generating mechanism comprising a negative pressure generating groove is provided to a low-pressure side. The positive pressure generating groove and negative pressure generating groove are communicated with a high-pressure fluid side and separated from a low-pressure fluid side by a seal surface.

A positive pressure generating mechanism comprising a positive pressure generating groove is provided to a high-pressure side of one of two sliding surfaces that slide relative to each other in a pair of sliding components, and a negative pressure generating mechanism comprising a negative pressure generating groove is provided to a low-pressure side. The positive pressure generating groove and negative pressure generating groove are communicated with a high-pressure fluid side and separated from a low-pressure fluid side by a seal surface.

A mechanical seal assembly includes a gland assembly having a chamber formed in an inner surface for seating a fluid insert element. The fluid insert element promotes movement of particles present in a slurry process fluid away from a seal interface formed by the sealing surfaces of rotary and stationary seal rings.

A mechanical seal assembly includes a gland assembly having a chamber formed in an inner surface for seating a fluid insert element. The fluid insert element promotes movement of particles present in a slurry process fluid away from a seal interface formed by the sealing surfaces of rotary and stationary seal rings.

A circumferential seal assembly suitable for forming a thin film between a rotatable runner and a sealing ring is presented. The assembly includes an annular seal housing, a rotatable runner, an annular seal ring, and a plurality of groove structures. Each groove structure includes a groove and an optional feed groove. The groove includes at least two adjoining steps defined by base walls arranged to decrease depthwise. Two adjoining base walls are disposed about a base shoulder. Each base shoulder locally redirects a longitudinal flow to form an outward radial flow in the direction of the annular seal ring. The base walls are bounded by and intersect a pair of side walls. A side wall includes side shoulders which narrows the groove widthwise and locally redirects the longitudinal flow to form a lateral flow in the direction of the other side wall. Outward and lateral flows separately or in combination enhance stiffness of a thin-film layer between the annular seal ring and the rotatable runner.

A circumferential seal assembly suitable for forming a thin film between a rotatable runner and a sealing ring is presented. The assembly includes an annular seal housing, a rotatable runner, an annular seal ring, and a plurality of groove structures. Each groove structure includes a groove and an optional feed groove. The groove includes at least two adjoining steps defined by base walls arranged to decrease depthwise. Two adjoining base walls are disposed about a base shoulder. Each base shoulder locally redirects a longitudinal flow to form an outward radial flow in the direction of the annular seal ring. The base walls are bounded by and intersect a pair of side walls. A side wall includes side shoulders which narrows the groove widthwise and locally redirects the longitudinal flow to form a lateral flow in the direction of the other side wall. Outward and lateral flows separately or in combination enhance stiffness of a thin-film layer between the annular seal ring and the rotatable runner.