Patent Abstract:
An automatic degassing valve has a chamber with a float positioned therein to provide for automatically venting gas from a fluid system. The degassing valve includes an actuator lever having on one end a closure for sealing a vent and being attached at the other end to the float. Upward and downward movement of the float causes the actuator lever to close and open the vent. The degassing valve is made of corrosion resistant material and is readily disassembled and assembled for modification and repair.

Full Description:
RELATED APPLICATIONS 
   This application claims priority to U.S. Provisional Application No. 60/706,450, filed Aug. 9, 2005; titled “Automatic Vent Valve” and incorporated herein in its entirety by reference. 

   FIELD OF THE INVENTION 
   This invention relates generally to automatic degassing valves, and more particularly to such valves which vent gases from liquid processing lines or systems. 
   BACKGROUND OF THE INVENTION 
   Entrained gases of any kind in liquid processing systems can cause system problems such as pressure surges, overworked pumps, water hammer, deadhead, siphoning and pump failure. According, processor vent gases are vented from liquid processing systems through degassing valves which are disposed in fluid lines. When the liquids or gases being processed or produced are corrosive, such as for example, sodium hyperchlorate, hydrochloric acid or ozone, degassing valves are subject to more repaid degredation and failure which can lead to the aforementioned system problems. Moreover, it is desirable to have degassing valves which are readily repairable on site or are readily replaceable in order to avoid costly processing delays. 
   While the aforementioned problems occur primarily in system lines, tanks enclosing corrosive liquids are faced with similar problems and is desirable to provide degassings for enclosures, which vents resist corrosion are easy to repair. 
   Current degassing valves provided for these purposes do not adequately address the problems of corrosion and reparability. Consequently, there is a need for such degassing valves. 
   SUMMARY OF THE INVENTION 
   An automatic degassing valve is provided for entrapping and automatically venting gas from any desired type of liquid containing system by means of a valve mechanism which opens to vent air in accordance with the amount of air entrapped therein. Such an automatic vent valve has a valve unit and a float for controlling the operation thereof with improved connections between the float and the valve that are positive and accurate in operation and result in a compact device consuming minimum space. The automatic vent valve is simple and economical in construction and has working parts that are readily removable for purpose of repair or replacement and are corrosion resistant. 
   To facilitate the aforementioned features, the components are made of resinous material, such as but not limited to polyvinylchloride and polypropylene, with elastic elements made of, but not limited to, EPDM (ethylene/propylene/diene terpolymer) or fluoroelastomers (such as Viton® fluoroelastomers). 
   According to the present invention, the automatic degassing vent valve comprises a housing of corrosion resistant material defining a chamber having an inlet opening for receiving a liquid and a vent for venting gas from the liquid. A float of corrosion resistant material is within the housing, the float being movable between a first level when there is excessive gas in the chamber and a second level when liquid floating the float indicates no need to vent gas from the chamber. A normally open vent closure of corrosion resistant material seats against and seals the vent when the float is at the second level. A linkage of corrosion resistant material extends between the normally open vent closure and the float for causing the normally open vent closure to seat against and close the vent when the float is at the second level. Elastic elements for retaining the linkage adjacent to the degassing and on the float are also made of corrosion resistant material. 
   In a further aspect of the automatic degassing valve the corrosion resistant materials are resinous materials and/or fluoroelastomers. 
   In a further aspect of the automatic degassing valve, the vent is in a removable closure portion of the housing, and the linkage is a lever having a first end retained to the float by a first removable elastic element and retained to the closure by a second removable elastic element. 
   In still a further aspect of the automatic degassing valve, the removable closure portion of the housing is threaded for threaded engagement with a complementary threaded portion of the housing. The second removable elastic element is an elastic band which fits around the second end of the lever and is removably secured to the closure and the first removable elastic element an elastic ring which fits around the first end of the lever and retains the lever in a slotted portion of the float. 
   In still a further aspect of the automatic degassing vent valve, the removable closure portion is a threaded plug with the lever and float attached to the threaded plug for removal and insertion into the chamber as an assembled unit which is disassembled by releasing the elastic ring from the lever and releasing the elastic band from the arms on the closure. 

   
     BRIEF DESCRIPTION OF DRAWING 
     Various other features and attendant advantages of the present invention will be more fully appreciated as the same becomes better understood when considered in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the several views, and wherein: 
       FIG. 1  is a perspective view of the automatic degassing valve; 
       FIG. 2  is an elevation along lines  2 - 2  of  FIG. 1 ; 
       FIG. 3  is an exploded perspective view showing a closure with a float attached in axial alignment with a housing of the valve; 
       FIGS. 4 and 5  are perspective views of the closure and float assembled; 
       FIG. 6  is a perspective view of the closure and a closure support without the float, and 
       FIG. 7  is a schematic view of a system employing the automatic degassing valve of  FIGS. 1-6 . 
   

   DETAILED DESCRIPTION 
   Referring now to  FIG. 1  there is shown an automatic degassing valve  10  having a housing  12  which is closed by a closure plug  14  having a vent port  16  a gas such as but not limited to air. The closure plug  14  includes a pair of recesses  18  to facilitate removal of the closure plug from the housing  12 . Shown in dotted lines is an inlet port  20  which is coaxial with the cylindrical housing  12 . The automatic degassing valve  10  vents gases, such as but not limited to air, that is in liquids transported in fluid lines in a system with which the inlet port  20  communicates. 
   Referring now to  FIG. 2 , where an elevation through the assembled device of  FIG. 1  is shown, it is seen that the closure  14  has an external thread  22  that mates with an internal thread  24  of the housing  12  and seats against an O-ring seal  26 . The vent  16  is a bore through the closure  14  having internal threads  28  for receiving a threaded end of a vent tube (not shown). The inlet port  20  has internal threads  30  also for receiving the threaded end of a connection to a device having a liquid therein. The housing  12  has a chamber  32  which receives liquid through the inlet opening in the form of an inlet port  20 , which chamber  32  has a float  34  therein which is pushed upwardly by liquid in the chamber  32 . The float has a coupling  36 , which is a projection preferably unitary therewith that has a slot  38  therein. The slot  38  has a top wall  40  which engages an actuating lever  42  to pull a first end  44  of the actuating lever  42  downwardly when the float  34  moves downwardly. As will be explained hereinafter, downward movement of the float  34  occurs when a gas such as air accumulates in the top portion  46  of the chamber  32 , thereby moving the first end  44  of the actuating lever  42  downward and allowing accumulated air to vent through the vent portion  16 . 
   Since the elongated slot  38  has a length greater than the diameter of the actuating lever  42 , a lost motion connection is established between the lever  42  and the slot  38 . Consequently, there is an opportunity for gas to accumulate in the upper portion  46  of the chamber  32  before the actuating lever  42  is moved. In a preferred embodiment, the actuating lever has an elastic seat  50  at a second end  52  thereof which closes an orifice in an orifice plug  57  having an internal bore  56 . The elastic seat  50  is normally held by an O-ring seal against the orifice or mouth of the bore  56 , keeping the bore  56  closed and pivots on the edge of the orifice plug  57  to open. 
   Upon the float  34  dropping in the housing  12  due to gas accumulating in a portion  46  of the chamber  32 , the elastic seat  50 , preferably made of rubber, moves away from the mouth of the bore  56  and gas and is able to flow from top chamber portion  46  through the bore  56  and out through the vent port  16 . As the gas is vented, hydraulic pressure acts against the float  34  moving it upwards until the end of the coupling  36  abuts the bottom surface of the cylindrical plug  14 . This allows the elastic seat  50  at end  52  of actuating lever  42  to seat against the mouth of the bore  56  in the orifice plug  57 . 
   Referring now to  FIG. 3 , it is seen that the closure  14  assembles and disassembles from the housing  12  by rotating closure  14  to engage or disengage the external threads  22  on the closure with the internal threads  24  on the housing. It is also seen from  FIGS. 3 and 4  that the actuating lever  42  can be stabilized by a slot  62  in a U-shaped projection  60  that receives the actuating lever  42  so as to function as a stabalizing support. As is seen in  FIGS. 3-6 , a preferable arrangement for holding the second end  52  of the actuating lever to seat the flat elastic seat  50  against the open end of the bore  56  in the orifice plug  57  is to utilize an O-ring type elastic element  64 . The O-ring type elastic element  64  has its opposite ends received in grooves  66  and  68  disposed in arms  70  ( FIG. 4) and 72  ( FIG. 5 ) defining a bracket  74  that straddles the elastic seat  50 . 
   Referring now to  FIG. 6 , the plug  14  and actuating lever  42  are a sub-assembly with the float  34  being held onto the actuating lever by an O-ring  78  in a groove at the first end  44  of the actuating lever  42 . To attach float  34  to the actuating lever  42 , the shank of the actuating lever is inserted through slot  38  of the coupling  36 . O-ring  78  is then mounted in the groove at the first end  44  of the actuating lever  42  to hold the float on the actuating lever. If it is desired to replace an element such as the float  34 , for example, with a float of a different buoyancy, the float  34  may be changed by rolling off the O-ring  78  and sliding the shank of the lever  42  out of the elongated slot  38  so that the sub-assembly of the closure plug  14  and the actuator arm  42  which is shown in  FIG. 6  can receive a different float  34 . 
   In the preferred embodiment of this invention, the float  34  and unitary coupling  36  are preferably made of polypropylene as is the actuator arm  42 . The closure plug  14  and the U-shaped projection  60  that is preferably unitary therewith are made of a resinous material such as polyvinylchloride (PVC). The housing  12  is also preferably made of PVC. The elastic band  64  and O-ring  78  are preferably made of EPDM or a fluoroelastomer, such as a vinylidene fluoride/hexafluoropropylene copolymer. 
     FIG. 7  shows the degassing valve  10  of  FIGS. 1-6  employed in a system  100  wherein liquid is pumped from a tank  102  through a fluid line  103  including a pipe  104  by a pump  106 . The pipe  104  has a rise  108  so that the degassing valve  10  vents gas at a high point in the pipe. Downstream of the pump  106  an air release valve  110  and a second degassing valve  10 , both located in a high level in piping  112 , vent air and gas from the liquid. The degassing valves  10  serve in this example to vent trace amounts of gas during operation of the system  100  as the gas occurs. In the system  100  of  FIG. 7 , the degassing valve  10  in the pipe  104  is useful when sodium hypochlorate is being transported to supplement any degassing mechanism built into the pump  106 . 
   Without further elaboration, it is believed that one skilled in the art can, using the preceding description, utilize the present invention to its fullest extent. The preceding preferred specific embodiments are, therefore, to be construed as merely illustrative, and not limitative of the remainder of the disclosure in any way whatsoever.

Technology Classification (CPC): 5