Sealed valve and related structure

Abstract

A metal diaphragm valve including a multiple ply metal diaphragm structure comprised of a plurality of thin circular metal elements each having a planar annular rim surrounding a dome-shaped interior portion superimposed one on top of another with their annular rims fixed together to seal the hollow interior portion of a valve bonnet. A diaphragm contacting surface including at least two areas of different degrees of curvature, one of which is cruciform in shape, is mounted for axial movement in the valve bonnet. A method of making the metal diaphragm structure and a hermetically sealed valve assembly are also disclosed.

We claim: 
     
       1. A valve assembly comprising a valve body defining an inlet passage and an outlet passage intersecting a body cavity, a valve seat,   flow controlling means in said cavity including a valve closure element mounted for axial movement toward and away from said valve seat,   a bonnet assembly fixed to said body to close said cavity and including plunger means disposed for axial movement toward and away from said valve seat,   a dome-shaped metal diaphragm disposed between said flow controlling means and said bonnet assembly to seal at least a portion of said body cavity on one side of the diaphragm from fluid on the opposite side thereof,   a diaphragm contacting surface on said plunger means comprising a flat center portion, a gradual convexly curved surface extending radially outward from said center portion and four surfaces of greater slope than said convexly curved surface equally spaced around the periphery of said diaphragm contacting surface and extending inward toward said center portion, and   means for axially moving said plunger means to contact the domed surface of said diaphragm and deflect said diaphragm whereby said valve closure element is moved to sealingly engage said valve seat and close said inlet passage.   
     
     
       2. The valve assembly defined by claim 1 wherein said center portion of the diaphragm contacting surface is circular and said four surfaces of greater slope are spaced from said center portion and from each other by said convexly curved surface. 
     
     
       3. The valve assembly defined by claim 1 wherein said convexly curved surface is of spherical curvature and said four surfaces spaced around the pheriphery of said diaphragm contacting surface are planar surfaces spaced from one another and from said center portion by said surface of spherical curvature. 
     
     
       4. The valve assembly defined by claim 1 wherein said flow controlling means includes a closure stem fixed to a valve closure element and mounted for axial sliding movement in a control cartridge and means biasing said closure element to a position spaced from said valve seat. 
     
     
       5. .[.A.]. .Iadd.An .Iaddend.actuating and control assembly for a valve having a dome-shaped metal diaphragm fixed in a body cavity to seal an area on the convexly curved side of said diaphragm from fluid on the opposite side thereof comprising: a closure element,   means mounting said closure element on the fluid side of said diaphragm for axial movement toward and away from a valve seat,   plunger means having a convexly curved diaphragm contacting surface facing the convexly curved surface of said diaphragm   and including at least two areas of different degrees of curvature, one of said areas being cruciform in shape and having a slope less than the slope of the areas between the legs of the cruciform to provide a cross-shaped primary diaphragm deflecting pattern and relief areas for portions of the diaphragm between the legs of said pattern,   means mounting said plunger means for axially aligned movement with said closure element and concentric with said diaphragm, and   means for axially moving said plunger means to contact and deflect said convexly curved surface of said diaphragm and move said closure element into sealing engagement with said valve seat.   
     
     
       6. The actuating and control assembly defined by claim 5 wherein said diaphragm contacting surface includes a flat center portion. 
     
     
       7. The actuating and control assembly defined by claim 5 wherein said area of cruciform shape is of spherical curvature and said areas between the legs of said cruciform shape are planar surfaces. 
     
     
       8. The actuating and control assembly defined by claim 7 wherein the radius of curvature of said spherically curved cruciform shape is at least as great as the radius of curvature of the oppositely disposed surface of said diaphragm. 
     
     
       9. A hermetically sealed valve comprising: a body defining inlet and outlet passages intersecting a body cavity,   a valve seat,   a bonnet fixedly engaged with said body to close said cavity, said bonnet having a through bore opening into a hollow interior bounded by a .Iadd.radially extending .Iaddend.depending annular surface,   a valve stem mounted for axial movement in said through bore and plunger means in said hollow bonnet portion,   a valve closure means disposed opposite said valve seat and mounted for axial movement toward and away from said seat,   a metal diaphragm disposed across the hollow interior portion of said bonnet between said plunger means and said closure means and circumferentially welded to said .Iadd.radially extending .Iaddend.depending annular surface to seal the interior of said bonnet from fluid present in the body cavity,   a circumferentially continuous weld between said bonnet and said body to seal against fluid leakage around said bonnet, and   means for moving said stem and plunger means to deflect said diaphragm and move said closure means to sealingly engage said valve seat.   
     
     
       10. The hermetically sealed valve defined by claim 9 wherein a peripheral groove adjacent said depending annular surface provides a radially extending lip to said bonnet, said metal diaphragm has a dome-shaped interior portion surrounded by a flat annular rim and said rim is welded to said bonnet between said radially extending lip and a metal ring to seal the interior portion of said bonnet. 
     
     
       11. The hermetically sealed valve defined by claim .[.10.]. .Iadd.9 .Iaddend.wherein said metal diaphragm is comprised of a plurality of thin .Iadd.substantially .Iaddend.circular metal elements with their respective annular rims fused together and to .[.the oppositely disposed surfaces.]. .Iadd.said depending annular surface .Iaddend.of said bonnet.[.and said metal ring.].. 
     
     
       12. A valve assembly comprising: a valve body defining an inlet passage and an outlet passage intersecting a body cavity,   a valve seat,   flow controlling means in said cavity including a valve closure element mounted for axial movement toward and away from said valve seat,   a valve bonnet fixed to said body to close said cavity and including plunger means mounted for axial movement toward and away from said valve seat,   a dome-shaped metal diaphragm structure disposed transversly across said body cavity between said flow controlling means and said bonnet, said diaphragm structure comprising a plurality of thin circular metal elements each having a planar annular rim surrounding a dome-shaped interior portion superimposed one on top of another with their annular rims fixed together,   an oppositely disposed convexly curved diaphragm contacting surface on said plunger means having at least two areas of different degrees of curvature, one of said areas being cruciform in shape and of a slope less than the slope of the areas between the legs of the cruciform to provide a cross-shaped primary diaphragm deflecting pattern and relief areas for portions of the diaphragm between the legs of said pattern, and   means for moving said plunger means to deflect the dome-shaped portion of said diaphragm and move said closure element to sealingly engage said valve seat.   
     
     
       13. The valve assembly defined by claim 12 wherein said diaphragm contacting surface includes a flat circular center portion, said area which is cruciform in shape is of spherical curvature and said areas between the legs of the cruciform are planar surfaces disposed at an angle of inclination greater than the slope of curvature of said cruciform area. 
     
     
       14. The valve assembly defined by claim 13 wherein the radius of curvature of said spherically curved curciform shape is at least as great as the radius of curvature of the oppositely disposed surface of said diaphragm and said diaphragm contacting surface is bounded by a circular edge having a diameter less than the diameter of the dome-shaped interior portion of said diaphragm. 
     
     
       15. The valve assembly defined by claim 12 wherein said valve bonnet includes a depending annular surface and the annular rims of said metal elements are welded together and to said depending annular surface to seal the interior of said bonnet from fluid present in the body cavity. 
     
     
       16. The valve assembly defined by claim 15 wherein a circumferentially continuous weld is provided between said valve bonnet and said valve body to provide a metal barrier and seal against fluid leakage around said valve bonnet. .Iadd. 17. The hermetically sealed valve defined by claim 9 wherein said metal diaphragm has a dome-shaped interior portion surrounded by a flat annular rim and said rim is welded to said bonnet at said radially extending depending annular surface. .Iaddend..Iadd. 18. The hermetically sealed valve defined by claim 17 wherein said metal diaphragm comprises a plurality of thin circular metal elements each having an annular rim surrounding a dome-shaped interior portion superimposed one on top of another with the convex surface of each metal element received within and complementary to the concave surface of each successive element and the annular rims fixed together to provide a rigid circumferential edge to the composite structure while permitting independent, sequential flexure of the dome-shaped interior portions of said structure under an applied load. .Iaddend. .Iadd. 19. The hermetically sealed valve defined by claim 9 wherein said plunger means comprises a cup shaped diaphragm plunger having an internal cylindrical bore terminating in a bearing surface, the diameter of which is adapted to slidably receive a stem collar provided on said valve stem. .Iaddend. .Iadd. 20. The hermetically sealed valve defined by claim 9, wherein said metal diaphragm has a dome-shaped interior portion surrounded by a flat annular rim and said rim is welded on one side to said bonnet around said radially extending annular surface and to an aligned metal ring on the opposite side. .Iaddend. .Iadd. 21. The hermetically sealed valve defined by claim 20, wherein said metal diaphragm is comprised of a plurality of thin circular metal elements with their respective annular rims welded together and to oppositely disposed annular surfaces of said bonnet and said metal ring. .Iaddend..Iadd. 22. The hermetically sealed valve defined in claim 9, further including support structure mounted within said body cavity for slidably supporting said valve closure means, and a metal ring disposed between the rim of said diaphragm and support structure aligned with said diaphragm rim and welded to said diaphragm rim. .Iaddend..Iadd. 23. The hermetically sealed valve defined by claim 22, further including resilient means within said support structure biasing said closure means toward said diaphragm and away from said seat. .Iaddend.