Valve, container with valve and use of the valve

Abstract

The invention relates to a valve, a container with the valve and the use of the valve. The valve, which is useful in a container to prevent an excessive pressure difference between the outside of the container and the inside of the container, comprises two blocking elements ( 1, 2; 110, 114 ), one of which ( 1; 110 ) allows fluid to enter the container when the external pressure exceeds the internal pressure by a predetermined magnitude, and the other of which ( 2; 114 ) allows fluid to enter the container when the internal pressure exceeds the external pressure by a predetermined magnitude.

1 . A valve configured to prevent an excessive pressure difference between the outside of a container and the inside of a container in which the valve is installed, comprising:
 a first valve mechanism comprising a first blocking element which can move between a closed position in which it prevents the passage of a fluid, and an open position in which it allows the passage of a fluid, between the outside and the inside, through a first part of the valve; and   a second valve mechanism comprising a second blocking element which can move between a closed position in which it prevents the passage of a fluid, and an open position in which it allows the passage of a fluid, between the inside and the outside, through a second part of the valve;   the first blocking element being associated to a first return element configured to exert a force on the first blocking element towards its closed position;   and the second blocking element being associated to a second return element configured to exert a force on the second blocking element towards its closed position;   each blocking element comprising a first contact surface configured to make contact with the outside of the container and a second contact surface configured to make contact with the inside of the container when the valve is assembled in the container, such that a fluid in contact with the respective contact surface exerts a pressure force on said contact surface;   the first valve mechanism being configured such that the first blocking element moves from its closed position to a position in which it allows the passage of the fluid, against the force exerted by the first return element, when the pressure on its first contact surface is X greater than the pressure on its second contact surface, X being a predetermined value;   and the second valve mechanism being configured such that the second blocking element moves from its closed position to a position in which it allows the passage of the fluid, against the force exerted by the second return element, when the pressure on the second contact surface is Y greater than the pressure on its first contact surface, Y being a predetermined value;   characterized in that   the area of the first contact surface of the first blocking element is substantially identical to the area of the second contact surface of the first blocking element, as regards the projection of said contact surfaces on the plane orthogonal to a movement direction of the first blocking element;   and in that   the area of the first contact surface of the second blocking element is substantially identical to the area of the second contact surface of the second blocking element, as regards the projection of said contact surfaces on the plane orthogonal to a movement direction of the second blocking element.   
   
   
       2 . A valve according to  claim 1 , wherein each of said first and second return element comprises a spring. 
   
   
       3 . A valve according to  claim 2 , wherein said springs are arranged coaxially with respect to one another. 
   
   
       4 . A valve according to  claim 3 , wherein the spring corresponding to the second return element is located inside the spring corresponding to the first return element. 
   
   
       5 . A valve according to  claim 1 , wherein the first blocking element and the second blocking element are arranged in an axially moving manner in a tubular casing. 
   
   
       6 . A valve according to  claim 1 , wherein the first valve mechanism is assembled coaxially with the second valve mechanism. 
   
   
       7 . A valve according to  claim 1 , wherein the movement direction of the first blocking element in its movement between its closed position and its open position is opposite to the movement direction of the second blocking element in its movement between its closed position and its open position. 
   
   
       8 . A valve according to  claim 1 , wherein both the first contact surface and the second contact surface of the first blocking element are substantially circular and with substantially identical diameters. 
   
   
       9 . A valve according to  claim 1 , wherein both the first contact surface and the second contact surface of the second blocking element are substantially circular and with substantially identical diameters. 
   
   
       10 . A valve according to  claim 1 , wherein the second blocking element has an end part penetrating though the second contact surface of the first blocking element, and another end part projecting through the first contact surface of the first blocking element. 
   
   
       11 . A valve according to  claim 1 , additionally comprising stress pre-regulation means for pre-regulating the stress of the return elements, which allow presetting the force that said return means exert on the corresponding blocking elements in their respective blocking positions. 
   
   
       12 . A valve according to  claim 11 , wherein said stress pre-regulation means comprise respective threaded elements which are assembled such that they are axially movable, by means of rotation, in the valve. 
   
   
       13 . A valve according to  claim 1 , wherein the return elements are arranged in leak-tight chambers inside the valve, such that they are protected from fluids present outside the container and inside the container when the valve is assembled in the container. 
   
   
       14 . A valve according to  claim 13 , wherein at least one of said leak-tight chambers has at least one wall provided with at least one weak area so to allow a controlled breaking in the event of an excessive pressure difference between the inside and the outside of the corresponding leak-tight chamber. 
   
   
       15 . A valve according to  claim 1 , wherein, when the first blocking element is in its open position, fluid can pass from outside to inside the container through holes located close to the first contact surface of the first blocking element. 
   
   
       16 . A valve according to  claim 1 , wherein, when the second blocking element is in its open position, fluid can pass from outside to inside the container through holes located close to the second contact surface of the first blocking element. 
   
   
       17 . A valve according to  claim 1 , wherein the first blocking element has, in correspondence with its first contact surface, a plurality of holes so as to allow the passage of a fluid from inside the container to outside when the valve is assembled in the container and when the second blocking element is in its open position. 
   
   
       18 . A valve according to  claim 17 , said holes being externally closed by the second blocking element when the latter is in its closed position. 
   
   
       19 . A valve according to  claim 18 , wherein the first blocking element comprises a first head in which said holes are located, a tubular body extending from said head, which body incorporates a longitudinal groove. 
   
   
       20 . A valve according to  claim 19 , wherein the second blocking element comprises a second head with a diameter greater than the distance between the farthest points of opposite holes of the first head, and a rod, which can be axially moved in the tubular body associated to the first head, extends perpendicularly from the second head. 
   
   
       21 . A valve according to  claim 20 , wherein there is a transverse bolt located in the rod which moves in an axial direction on the longitudinal groove. 
   
   
       22 . A valve according to  claim 19 , additionally comprising at least one central guide in which the tubular body associated to the first head moves in a guided manner. 
   
   
       23 . A valve according to  claim 22 , wherein the first return element is located between said central guide and the first head. 
   
   
       24 . A valve according to  claim 21 , wherein the second return element is located between the first head. 
   
   
       25 . A valve according to  claim 1 , comprising a flange configured to fix the valve to the opening of the container with the aid of fixing means. 
   
   
       26 . A container comprising at least one valve according to  claim 1 . 
   
   
       27 . A valve according to  claim 1 , comprising a flange configured to fix the valve to the opening of the container with the aid of fixing means. 
   
   
       28 . (canceled) 
   
   
       29 . A container according to  claim 26 , said container being a container located in a ship. 
   
   
       30 . The use of a valve according to  claim 1  in a container. 
   
   
       31 . (canceled)