A labyrinth barrier is disclosed and comprises two or more members each defining respective vertical axes. One or more of the members are constructed at least in part of a shape memory material having a first energy state and a second energy state. The members are oriented relative to one another by their respective vertical axes in an original state to create a flow pathway that restricts fluid flow in a direction transverse to the respective vertical axes. The members are urged towards one another to further restrict the flow pathway when the shape memory material transitions from the first energy state to the second energy state.

A mechanical seal assembly has two axially-spaced apart seals and including a rotary component that includes rotational members of each axially-spaced apart seal and a stationary component that includes stationary sealing members of each seal. A sleeve is located radially inwards of the rotational sealing members. An element, such as fluid ports, directs barrier or buffer fluid towards the sleeve and between the two axially-spaced apart seals. The sleeve is provided on its outer surface with means, such as recesses or protuberances, which displace barrier/buffer fluid axially towards both axially-spaced apart seals.

A main pump shaft seal water injection system of a nuclear power plant includes a jet pump, a high pressure cooler, a hydrocyclone, valves and a main connection pipeline outside of a main pump, and an auxiliary pump and an internal flow path inside the main pump. Inner and outer flow paths of the main pump are connected with a shaft seal water injection hole and a high temperature water drainage hole. The main connection pipeline is connected between an upper filling water pipeline and a shaft seal water injection hole. A bypass pipeline connected with the jet pump, the high pressure cooler and the hydrocyclone, the main connection pipeline is provided with a normally open main pipeline isolating valve. The bypass pipeline allows low temperature upper filling water in the RCV system to enter the shaft seal water injection hole of the main flange directly.

In an embodiment, in a slide component, a negative pressure generation mechanism 12 that generates negative pressure by relative rotational sliding of a stationary-side seal ring 5 and a rotating-side seal ring 3 is provided on a sealing face of one of the stationary-side seal ring 5 and the rotating-side seal ring 3, and at least the surface of the negative pressure generation mechanism 12 is covered by an adhesion-resistant material film 15. With the configuration, deposition of precipitates on a negative pressure portion of a sealing face can be inhibited.

A seal includes a carbon seal that is disposed about an axis and extends between a first axial end and a second axial end. The second axial end includes a seal surface and a radially outer edge of the seal surface is axially spaced from a radially inner edge of the seal surface along the axis.

A seal system includes a ceramic component that has a non-core-gaspath surface region that defines a first surface roughness and a core gaspath surface region. A metallic component is situated adjacent the non-core-gaspath surface region. A coating system is disposed on the ceramic component. The coating system includes a silicon-containing layer on the non-core-gaspath surface region and a barrier layer that has a first section on the silicon-containing layer and a second section on the core-gaspath region and that is connected to the first section. The surface of the barrier layer has a second surface roughness that is less than the first surface roughness. The first section is in contact with the metallic component and the second section serves as an environmental barrier on the core-gaspath region.

A seal system includes a ceramic component that has a non-core-gaspath surface region that defines a first surface roughness and a core gaspath surface region. A metallic component is situated adjacent the non-core-gaspath surface region. A coating system is disposed on the ceramic component. The coating system includes a silicon-containing layer on the non-core-gaspath surface region and a barrier layer that has a first section on the silicon-containing layer and a second section on the core-gaspath region and that is connected to the first section. The surface of the barrier layer has a second surface roughness that is less than the first surface roughness. The first section is in contact with the metallic component and the second section serves as an environmental barrier on the core-gaspath region.

An embodiment includes a gate valve comprising: a valve body including a cavity coupled to a channel having proximal and distal portions; a gate to seal and unseal the channel; proximal and distal seats adjacent the gate; wherein (a) the proximal seat traverses towards the gate and stops at a first position when the gate is closing and the proximal channel portion is more highly pressurized than the cavity, and (b) the distal seat slides away from the gate and stops at a second position when the gate is closing and the cavity is more heavily pressurized than the distal channel portion. Other embodiments are described herein.

A cycle residual boost and two release cavities are provided on a cylinder wall. Wankel cycle air pump is provided with additional cavities which allow the pressure output higher than its fixed compression ratio and further increase compression efficiency. An apex seal active tracking mechanism is also provided. Wankel cycle air pump rotor plates passage makes apex seals keep firmly contact against a cylinder.

An apparatus for sealing such a gap may be a plunger seal which may include a flap arm comprising resilient sheets and a wall arm comprising resilient sheets. A proximal end portion of the flap arm may include a closeout seal coupled to the flap. A proximal end portion of the wall arm may include a plunger having a geometry corresponding to that of the closeout seal so the plunger may be matingly received by the closeout seal. When positioned in a gap, the plunger seal may exert a force to urge the flap arm towards the flap and to urge the wall arm and resilient sheet towards the structure to seal the gap.