Extreme temperature, high pressure balanced, rising stem gate valve with super preloaded, stacked, solid lubricated, metal-to-metal seal

A sealing system for a high pressure valve including a valve body having inlet and outlet conduits and upper and lower apertures with a chamber therebetween, a bonnet closing the upper aperture, a cap closing the lower aperture, an upper stem and a lower stem mounted within the valve body and having a gate disposed therebetween, a gate seat disposed within the chamber and housing the gate, the upper stem extending into the bonnet, the lower stem extending into the cap, and the valve having an open position where the gate permits flow through the conduits and a closed position where the gate blocks flow through the conduits, the improvements comprising:

• first dual seal means providing at least two separate means for providing metal-to-metal sealing engagement between the upper stem and the bonnet, one of said separate means of said first dual seal means including at least one dished metal ring gasket deformed at its peripheral edges into such metal-to-metal sealing engagement with both the upper stem and bonnet;
• second dual means providing at least two separate means for providing metal-to-metal sealing engagement between the lower stem and the valve body, one of said separate means of said second dual means including at least one dished metal ring gasket deformed at its peripheral edges into such metal-to-metal sealing engagement with both the lower stem and valve body.

A sealing system for a high pressure gate valve including a valve body having inlet and outlet conduits with a chamber therebetween, an upper stem reciprocably disposed in a bonnet mounted on the valve body, a gate mounted below and attached to the upper stem and reciprocably disposed in a gate seat mounted within the chamber and a reciprocating apparatus for moving the gate between a closed position where flow is blocked through the conduits and an open position where flow is permitted through the conduits, the improvement comprising:

• first seal means for providing a metal-to-metal sealing engagement between the upper stem and the bonnet, said first seal means including at least one dished metal ring gasket deformed at its peripheral edges into such metal-to-metal sealing engagement with both the upper stem and bonnet;
• and second seal means for providing a metal-to-metal sealing engagement between the upper stem and the bonnet in the open position, said second seal means including an annular enlargement portion on said upper stem engageable with an annular seat in said bonnet when such valve is in such open position.

A valve including a hollow body having a flow path therethrough and a port therethrough, rising stem gate means in the body reciprocable to control fluid flow through the body and including an actuator and a stem extending through the port in the body from the inside thereof, there being an annular pocket in the body around the stem, the pocket having a wall, said wall being substantially parallel to said stem, seal means in the pocket, and a packing gland engageable with the seal means for compressing the seal means, the seal means including at least one dished metal ring gasket and one sandwich ring adjacent thereto made of a more compliant material than the metal ring gasket, said dished metal ring gasket being deformed at its peripheral edges into metal-to-metal sealing engagement with said stem and said wall upon compression of said seal means by said packing gland.

A valve including a hollow body having a flow path therethrough and a port, stem gate means in the body for controlling fluid flow through the body and including a stem extending through the port in the body from the inside thereof, there being an annular pocket in the body around the stem, seal means in the pocket for preventing fluid from flowing from the body through the annular pocket, and compression means engageable with the seal means for compressing the seal means, the seal means including metal ring gaskets and means for urging each of the metal ring gaskets into metal-to-metal sealing engagement with both the stem and the pocket upon compression of the seal means by the compression means, each of said metal ring gaskets being deformed at its peripheral edges where such metal-to-metal sealing engagement is effected.

A subassembly of a seal system, the seal system used to prevent a flow of fluid along the wall of a moving stem and along a fixed wall closely positioned to the moving stem and parallel thereto, comprising

• a non-extrudable seal ring juxtaposed to and in sealing engagement with both the wall of the moving stem and the fixed wall for preventing such flow of fluid said non-extrudable seal ring being deformed at its peripheral edges into metal-to-metal sealing engagement with said fixed wall and said stem wall;
• an extrudable seal ring;
• said non-extrudable seal ring being positioned to prevent said extrudable seal ring from extruding under pressure between said non-extrudable seal ring and the wall of the moving stem and between said non-extrudable seal ring and the fixed wall.

A seal system between a fixed wall and a wall of a moving component, such walls being substantially parallel to each other, for preventing fluid flow from the fluid side of the seal to the atmospheric side of the seal, comprising:

• a sandwich ring;
• a metal ring gasket disposed between such fixed wall and such wall of such moving component;
• compression means for compressing said sandwich ring and said metal ring gasket and for deforming said metal ring gasket at its peripheral edges into metal-to-metal sealing engagement with both of such walls.