Burst disk assembly for high and ultra high vacuum containment vessels

Abstract

An improved burst disc assembly for use in pressure relief conduits for high vacuum and ultra-high vacuum containment vessels, the assembly having a body with inlet and outlet openings connected by an internal passage, a burst disc disposed within the internal passage and connected therein to hermetically isolate the inlet and outlet openings. The assembly further has a mounting structure connected to the body and outwardly extending therefrom that may be clamped between adjacent faces of a pair of metal seal flanges provided in the relief conduit to secure the assembly in position and hermetically seal the assembly in the conduit in a manner prohibit the passage of gas molecules from the surrounding environment into the containment vessel through the relief conduit. The mounting structure is formed from a soft metal material having substantially lower hardness value than that of the metal seal flange faces to enable adequate sealing. The connection between the mounting structure and the body further provides similar hermetic seal. Upon rupture of the burst disc, the assembly alone must be replaced while the metal seal flanges connecting the burst disc assembly to the containment vessel may be reused.

Having thus described the invention, what is claimed is: 
     
       1. An improved burst disc assembly for use in high vacuum and ultra-high vacuum containment vessels, the assembly comprising:
 a body having an external surface and internal passage therethrough connecting an inlet opening and an outlet opening; 
 a burst disc disposed within the internal passage between the inlet and outlet openings, the burst disc hermetically sealed within the internal passage; and 
 a mounting gasket extending radially outwardly from the external surface of the body, the mounting gasket configured to be disposed between adjacent parallel faces of a pair of selectively separable connection flanges, each face having a knife edge sealing structure projecting therefrom to engage the mounting gasket, support the burst disc assembly entirely within a pressure relief conduit fluidly connected to the containment vessel and to hermetically seal the burst disc assembly within the pressure relief conduit to preclude leakage into the containment vessel. 
 
     
     
       2. The burst disc assembly of  claim 1 , wherein the mounting gasket is formed of a material having a hardness that is significantly less than the material hardness of the knife edges and the adjacently disposed faces. 
     
     
       3. The burst disc assembly of  claim 2 , wherein the mounting gasket material is copper and the adjacently disposed faces and the knife edges are formed from stainless steel. 
     
     
       4. The burst disc assembly of  claim 1 , wherein the mounting gasket is bonded to the body, the bond creating a hermetic seal therebetween. 
     
     
       5. The burst disc assembly of  claim 4 , wherein the gasket is bonded to the body by fusing, brazing, or welding. 
     
     
       6. The burst disc assembly of  claim 1 , further comprising a protective cover connected to the outlet opening and configured to prevent contact with the burst disc by rigid objects outside of the containment vessel, the protective cover further permitting the passage of gas from the containment vessel to the surrounding atmosphere upon rupture of the burst disc cause by an overpressure condition in the containment vessel. 
     
     
       7. The burst disc assembly of  claim 6 , wherein the protective cover further includes a moveable indicator configured for movement between a normal state and a burst state, movement from the normal to the burst state being effected by an overpressure condition in the containment vessel causing rupture of the burst disc. 
     
     
       8. A burst disc assembly for use in a pressure relief conduit for a high vacuum or ultra-high vacuum containment vessel, the assembly comprising:
 a body having an external surface configured for insertion into the pressure relief conduit, the body having an inlet opening and an outlet opening connected by an internal passage; 
 a burst disc disposed within the internal passage between the inlet and outlet openings, the burst disc being hermetically sealed within the internal passage to prevent the passage of gas between the inlet opening and the outlet opening; and 
 a mounting structure extending radially outwardly from the body, the mounting structure interfacing with adjacent flange faces disposed in the relief conduit to position the mounting structure between the adjacent flange faces, the flange faces each having a sealing structure comprising a knife edge projecting from the flange face toward the mounting structure, the mounting structure interface with the sealing structures hermetically sealing the interface to prevent the passage of gas into the relief conduit through the interface between the flange faces and the mounting structure and retaining the assembly in a fixed position within the relief conduit, the mounting structure connection to the body further being hermetically sealed to preclude the passage of gas through an annular space between the external surface and the relief conduit. 
 
     
     
       9. The burst disc assembly of  claim 8 , wherein the mounting structure is formed of a material having a hardness that is significantly less than the material hardness of the adjacent flange faces. 
     
     
       10. The burst disc assembly of  claim 9 , wherein the mounting structure material is copper and the adjacent flange face material is a stainless steel. 
     
     
       11. The burst disc assembly of  claim 9 , wherein the mounting structure is bonded to the body using a bonding method which creates a hermetic seal therebetween. 
     
     
       12. The burst disc assembly of  claim 11 , wherein the bonding method includes fusing, brazing, or welding. 
     
     
       13. The burst disc assembly of  claim 8 , further comprising a protective cover connected to the outlet opening and configured to prevent contact with the burst disc by rigid objects outside of the containment vessel, the protective cover further permitting the passage of gas from the containment vessel to the surrounding atmosphere upon rupture of the burst disc cause by an overpressure condition in the containment vessel, the protective cover further including a moveable indicator configured for movement between a normal state and a burst state, movement from the normal to the burst state being effected by an overpressure condition in the containment vessel causing rupture of the burst disc.