Pressure relief valve for pressure equalization between a closed space and the surrounding atmosphere

Abstract

A pressure relief valve includes a valve housing and a drop-shaped body with a conical valve surface that cooperates with a conical valve seat at an upwardly directed blow-off opening of the valve housing. The drop-shaped body is connected to a lifting disc in the housing. The inner configuration of the housing provides an annular passage around the lifting disc which is smaller in area when the lifting disc (and drop-shaped body) is in its uppermost, fully open positioning as compared to its lowermost, closed positioning.

We claim:  
     
       1. A pressure relief valve for pressure equalization between a closed space and the surrounding atmosphere, comprising a valve housing provided at its top with a blow-off opening formed with an upwardly facing substantially conical valve seat, a drop-shaped body suitable for concentrating a flow of gas impinging on its underside to an upwardly directed jet, a substantially conical valve face for closing against said valve seat being formed on the downwardly facing portion of the rounded surface of said drop-shaped body, which thereby constitutes a valve body, and a lifting disc connected with said drop-shaped body and located at a lower level within the housing, said lifting disc having an outer diameter greater than the inner diameter of said valve seat, and stop means for defining a fully open position of the valve, the lifting disc being surrounded by a free passage slot in the fully closed position of the valve, said valve housing having an inner configuration such that the free passage area around the lifting disc is decreased when the drop-shaped body and the lifting disc are lifted from the fully closed to the fully open position. 
     
     
       2. The pressure relief valve of  claim 1  further comprising a valve stem that connects to the drop shaped body and comprises part of the valve body. 
     
     
       3. The pressure relief valve of  claim 2  wherein the housing has a pair of stem guides that support the stem. 
     
     
       4. The pressure relief valve of  claim 3  wherein the stem has an upper end portion that supports the drop shaped body. 
     
     
       5. The pressure relief valve of  claim 3  wherein the stem carries a weighted load. 
     
     
       6. The pressure relief valve of  claim 5  wherein the weighted load is positioned on the stem between the drop shaped body and the disc. 
     
     
       7. The pressure relief valve of  claim 3  wherein the stem guides include an upper stem guide positioned next to the blow off opening and a lower stem guide positioned below the lifting disc. 
     
     
       8. The pressure relief valve of  claim 1  further comprising a weighted load member attached to the drop shaped body and the lifting disc for movement therewith. 
     
     
       9. The pressure relief valve of  claim 1  wherein the valve housing has at least one guide that guides travel of the valve body. 
     
     
       10. The pressure relief valve of  claim 9  wherein the guide is positioned below the lifting disc. 
     
     
       11. A pressure relief valve for pressure equalization between a closed space and the surrounding atmosphere, comprising: 
         a )  a valve housing having a top, an upper level, and a lower level, the housing being provided at its top with a blow - off opening formed with an upwardly facing valve seat;    
         b )  a valve body that includes a tapered body suitable for concentrating a flow of gas impinging on its underside to an upwardly directed jet, said tapered body having a downwardly facing portion;    
         c )  a valve face for closing against said valve seat, the valve face being formed on the downwardly facing portion of said tapered body;    
         d )  the valve body including a lifting disc connected to said tapered body and located within the lower level of the housing, said lifting disc and tapered body being movable between fully open and fully closed positions, said lifting disk having an outer diameter greater than the inner diameter of said valve seat; and    
         e )  a stop that defines a fully open position of the tapered body and lifting disk;    
         f )  the lifting disc being surrounded by a passage area in the fully closed position; and    
         g )  said valve housing having an inner configuration such that the passage area around the lifting disc is decreased when the tapered body and the lifting disc are lifted from the fully closed to the fully open position.   
     
     
       12. The pressure relief valve of  claim 11  wherein the valve housing tapers to a smaller cross sectional area at the blow off opening. 
     
     
       13. The pressure relief valve of  claim 11  wherein the tapered body has a conical section. 
     
     
       14. The pressure relief valve of  claim 13  wherein the valve housing has at least one guide that guides travel of the valve body. 
     
     
       15. The pressure relief valve of  claim 14  wherein the guide is positioned below the lifting disc. 
     
     
       16. The pressure relief valve of  claim 14  wherein there are a pair of guides. 
     
     
       17. The pressure relief valve of  claim 16  wherein the pair of stem guides include an upper stem guide positioned next to the blow off opening and a lower stem guide positioned below the lifting disc. 
     
     
       18. The pressure relief valve of  claim 11  further comprising a valve stem that comprises part of the valve body. 
     
     
       19. The pressure relief valve of  claim 18  further comprising a weighted load member attached to the stem. 
     
     
       20. The pressure relief valve of  claim 19  wherein the stem has an upper end that supports the tapered body. 
     
     
       21. The pressure relief valve of  claim 20  wherein the weighted load is positioned in between the tapered body and the lifting disc. 
     
     
       22. A pressure relief valve for pressure equalization between a closed space and the surrounding atmosphere, comprising: 
         a )  a valve housing having upper and lower end portions, provided at its upper end portion with a blow - off opening formed with a valve seat;    
         b )  a tapered body suitable for concentrating a flow of gas impinging on its underside to an upwardly directed jet;    
         c )  a valve face for closing against said valve seat, said face being formed on the downwardly facing portion of the tapered body;    
         d )  an elongated valve stem having upper and lower end portions, wherein the tapered body is connected to the stem at the upper end portion of the valve stem, the stem being movably attached to the valve housing and movable between an upper fully open position and a lower fully closed position;    
         e )  a lifting disc connected to the lower end portion of the valve stem and located at the lower end portion of the housing, said lifting disc having an outer diameter greater than the inner diameter of the valve seat;    
         f )  a stop that limits upward movement of the stem to define the fully open position of the valve stem, the lifting disc being surrounded by a passage area in the fully closed position of the valve stem; and    
         g )  said valve housing having an inner configuration such that the passage area around the lifting disc is decreased when the tapered body, stem, and lifting disc are lifted together from the fully closed to the fully open position.   
     
     
       23. The pressure relief valve of  claim 22  further comprising a weighted load member attached to the tapered body and lifting disc for movement therewith. 
     
     
       24. The pressure relief valve of  claim 22  wherein the valve housing has at least one stem guide that supports the stem, positioned below the lifting disc. 
     
     
       25. The pressure relief valve of  claim 22  wherein the wherein the valve housing has at least one guide that guides travel of the tapered body. 
     
     
       26. The pressure relief valve of  claim 22  wherein there are a pair of stem guides that support the stem. 
     
     
       27. The pressure relief valve of  claim 26  wherein the stem guides include an upper stem guide positioned next to the blow off opening and a lower stem guide positioned below the lifting disc. 
     
     
       28. The pressure relief valve of  claim 27  wherein the housing has a generally cylindrically shaped portion at the lower end portion of the housing and the lifting disc is positioned next to said cylindrically shaped portion when the lifting disc is the fully closed position. 
     
     
       29. The pressure relief valve of  claim 28  wherein the housing has a frustoconically shaped portion above the cylindrically shaped portion. 
     
     
       30. The pressure relief valve of  claim 22  wherein the stem has an upper end portion that supports the tapered body. 
     
     
       31. The pressure relief valve of  claim 22  wherein the stem carries a weighted load. 
     
     
       32. The pressure relief valve of  claim 31  wherein the weighted load is positioned in between the tapered body and the lifting disc. 
     
     
       33. The pressure relief valve of  claim 22  further comprising a valve stem guide attached to the lower end portion of the valve housing. 
     
     
       34. A pressure relief valve for pressure equalization between a closed space and the surrounding atmosphere, comprising: 
         a )  a valve housing having an upper end portion and a lower end portion;    
         b )  an opening formed at the upper end portion of the valve housing, the opening having a valve seat;    
         c )  a valving member that is movably supported by the valve housing between fully opened and fully closed positions, the valving member including an elongated stem, a tapered body suitable for concentrating a flow of gas impinging on its underside to an upwardly directed jet, and a lifting disc;    
         d )  a valve face for closing against said valve seat, the valve face formed on the tapered body;    
         e )  wherein the lifting disc is connected to the stem, the lifting disc being located at the lower end portion of the housing, said lifting disc having an outer diameter greater that the inner diameter of the valve seat;    
         f )  a stop that limits travel of the valving member to define a fully open position of the valving member, the lifting disc being surrounded by a passage area in the fully closed position of the valving member; and    
         g )  the valve housing having an inner configuration such that the passage area around the lifting disc is decreased when the valving member is lifted from the fully closed to the fully open position.   
     
     
       35. The pressure relief valve of  claim 34  wherein the valve housing has separate upper and lower sections that are removably fastened together. 
     
     
       36. The pressure relief valve of  claim 35  wherein there are two spaced apart stem guides, one attached to the upper section of the valve housing and one attached to the lower section of the valve housing. 
     
     
       37. The pressure relief valve apparatus of  claim 34  further comprising a pair of spaced apart valve guide stems, at least one of which is positioned below the lifting disc.