Patent Publication Number: US-2015068618-A1

Title: Valve assembly

Description:
TECHNICAL FIELD  
     The present disclosure relates to a valve, and more specifically to the valve present on a fluid reservoir or tank. 
     BACKGROUND  
     A diesel exhaust fluid (DEF) tank associated with an aftertreatment system of an engine may be filled using a pressurized fill system. However, when DEF present within the tank solidifies, an expansion in a volume of the DEF may cause the tank to get damaged. In some situations, this may lead to rupture of the tank. 
     U.S. Published Application Number 2012/0186677 relates to an exhaust after-treatment system associated with a diesel engine including a diesel exhaust fluid storage unit. The storage unit includes a diesel exhaust fluid tank and a vent system coupled to the tank and configured to regulate flow of air into the tank and fluid vapour out of the tank. 
     SUMMARY OF THE DISCLOSURE  
     In one aspect of the present disclosure, a valve is provided. A body of the valve is configured to receive a supply of fluid. The body includes an inlet. A chamber is defined within the body. A seat member is disposed within the chamber. The seat member includes apertures defining a fluid flow path from the inlet into the chamber. A plunger is disposed through the body and in fluid communication with the chamber. The plunger includes a tubular wall defining a conduit therethrough. A float is attached to a distal end of the plunger. The plunger and the float are configured to move relative to the body and the seat member between an open position and a closed position. The apertures in the seat member are positioned radially outward of the tubular wall of the plunger. 
     In another aspect, a diesel exhaust fluid (DEF) tank is provided. A valve is positioned at a top surface of the tank. The valve has an inlet configured to receive a supply of DEF. The valve includes a body defining a chamber within the body. A seat member is disposed within the chamber. The seat member includes apertures defining a DEF flow path from the inlet into the chamber. A plunger is disposed through the body and in fluid communication with the chamber. The plunger includes a tubular wall defining a conduit therethrough. A float is attached to a distal end of the plunger. The plunger and the float are configured to move relative to the body and the seat member between an open position and a closed position. The apertures in the seat member are positioned radially outward of the plunger tubular wall. 
     In yet another aspect, a valve assembly is provided. The valve assembly includes a body configured to receive a supply of fluid. The body defines a chamber within the body. The body comprises an inlet. A seat member is disposed within the chamber. The seat member includes apertures defining a fluid flow path from the inlet into the chamber. A plunger is disposed through the lower portion and in fluid communication with the chamber. The plunger includes a tubular wall defining a conduit therethrough. A float is attached to a distal end of the plunger. The plunger and the float are configured to move relative to the body and the seat member between an open position and a closed position. The apertures in the seat member are positioned radially outward of the plunger tubular wall. 
     Other features and aspects of this disclosure will be apparent from the following description and the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         FIG. 1  is a perspective view of an exemplary diesel exhaust fluid (DEF) tank, according to one embodiment of the present disclosure; 
         FIG. 2  is a cross sectional view of the tank of  FIG. 1  having a valve in an open position attached to the tank; 
         FIG. 3  is a cross sectional view of the valve of  FIG. 2 , the valve being in a closed position; and 
         FIG. 4  is a cross sectional view of another configuration of the valve, according to another embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION  
     Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or the like parts. The present disclosure relates to a reductant delivery and supply system  100  associated with an aftertreatment module of an engine (not shown). The aftertreatment module may be used to treat an exhaust stream which leaves the engine. The exhaust stream generally contains emissions which may include nitrogen oxides (NOx), unburned hydrocarbons, and particulate matter. The aftertreatment module is generally designed to reduce the content of NOx, unburned hydrocarbons, particulate matter, or other components of the emissions prior to the exhaust stream being released from the engine. 
     The reductant delivery and supply system  100  may include a storage tank or a Diesel Exhaust Fluid (DEF) tank, a dosing module (not shown) and other components for supplying a reductant, such as DEF, to the aftertreatment module. Alternative liquid reductants may comprise ammonia or any other reducing agent.  FIG. 1  illustrates a perspective view of an exemplary DEF tank  102 , hereinafter referred to as the tank  102 , according to one embodiment of the present disclosure. The tank  102  may be positioned inside a machine (not shown). The tank  102  may be fluidly connected to the dosing module via a port  104  for supplying the DEF into the exhaust stream of the engine. The tank  102  may be made of a polymer, a metal or any other known material. Parameters related to the tank  102 , such as, shape, dimensions, material used and location of the tank  102  may vary as per the system requirements. 
     A receiving element  106  may be attached to the tank  102  for receiving the DEF into the tank  102  from an external source (not shown) of DEF supply. In one embodiment, the receiving element  106  may be positioned on a top surface of the tank  102 . The receiving element  106  may be fluidly connected to a receptacle  108  positioned on a frame (not shown) of the machine. A hose  110 , a flexible pipe or any other filling line defining a conduit therein for a flow of the DEF into the receiving element  106  may be utilized to form the connection between the receiving element  106  and the receptacle  108 . The receptacle  108  is configured to receive a source of DEF supply therein, in order to provide the flow of DEF into the tank  102 . In one embodiment, the source of DEF supply may include a nozzle (not shown) from the external source. A person of ordinary skill in the art will appreciate that any other known method to fill the tank  102  may also be utilized without any limitation. 
       FIG. 2  illustrates a cross sectional view of the tank  102 . A valve  202  is coupled to a receiving element  106  such that the valve  202  fluidly connects the receiving element  106  and the tank  102 . In one embodiment, the valve  202  may be positioned within a receiver port  204  positioned on the top surface of the tank  102 . As illustrated, the valve  202  may be connected to the receiving element  106  and extend into the tank  102  through the receiver port  204 . The receiver port  204  may be welded, brazed or soldered to the tank  102 . Alternatively the receiver port  204  may be threadedly coupled to the tank  102 , as shown in the exemplary embodiment. The type of connection between the receiver port  204  and the tank  102  may be based on the material used to form the receiver port  204  and the tank  102  respectively. For example, when the tank  102  is made of metal, the receiver port  204  may be welded to the top surface of the tank  102 . 
     The valve  202  may include a body  206  having an upper portion  208  and a lower portion  210  defining a longitudinal axis X-X of the valve  202 . As shown in the accompanying figures, the upper portion  208  of the valve  202  may be coupled to the receiving element  106 . For example, the upper portion  208  of the valve  202  may be threadedly coupled to the receiving element  106 . As illustrated, threads provided on an inner surface of the receiving element  106  may be configured to mate with corresponding threads provided on an outer surface of one end of the upper portion  208  of the valve  202 . In one embodiment, a sealing ring  212  may be provided between the receiving element  106  and the upper portion  208  of the body  206  for preventing leakage of the DEF therebetween. 
     Also, the upper portion  208  of the body  206  may be coupled to the receiver port  204  for holding the valve  202  in position on the top surface of the tank  102 . Another end of the upper portion  208  of the valve  202  may be received into and coupled to the receiver port  204  using any known method in the art. As shown, the upper portion  208  of the valve  202  may be threadedly coupled to the receiver port  204 . In one embodiment, a sealing ring  214  may be provided between the outer surface of the upper portion  208  of the valve  202  and the tank  102  for sealing the valve  202  with respect to the tank  102 . 
     The upper portion  208  may include a collar  216  configured to be located adjacent to a top surface of the receiver port  204  and rest thereon when the valve  202  is assembled into the tank  102 . Further, the upper portion  208  of the body  206  may define an inlet  218  therein. The inlet  218  may be positioned along the longitudinal axis X-X. The inlet  218  of the body  206  may be configured to receive the DEF flow from the receiving element  106  when the tank  102  is being filled. The upper portion  208  of the body  206  may be coupled to the lower portion  210  of the body  206 . For example, the upper portion  208  of the body  206  may be threadedly coupled to the lower portion  210 . Alternatively, the upper and lower portions  208 ,  210  may be coupled using any other known means, or be portions of an integrally formed body  206 . Accordingly, the lower portion  210  of the body  206  may be partially positioned within the upper portion  208  of the body  206 , and may further extend into the tank  102 . 
     The lower portion  210  of the body  206  may have a hollow configuration such that a chamber  220  is defined within the lower portion  210  of the body  206 . In one embodiment, the lower portion  210  of the body  206  may have a substantially cylindrical configuration. A person of ordinary skill in the art will appreciate that the shape and dimensions of the upper and lower portions  208 ,  210  of the body  206  may vary based on the application. Also, the upper and lower portions  208 ,  210  of the body  206  may be made from a metal, a plastic, a composite, or any other suitable material. 
     A seat member  222  is disposed within the body  206  of the valve  202 . More particularly, the seat member  222  is positioned within the chamber  220  of the body  206 . For example, the seat member  222  may be positioned at a location at which the upper and lower portions  208 ,  210  of the body  206  are coupled. In another example, the seat member  222  may be positioned within the lower portion  210  of the body  206 . The seat member  222  may be made of rubber, metal, plastic, or any other suitable material. In one embodiment, the seat member  222  may be fitted into the chamber  220  and held in position within a step, a groove, a chamfer or any other locking means provided within the body  206  of the valve  202 . In one embodiment, the seat member  222  may have a substantially circular configuration such that the seat member  222  may form a good fit within the body  206  of the valve  202 . 
     A number of apertures  230  are provided through the seat member  222 . These apertures  230  may define a fluid flow path for the DEF from the inlet  218  of the body  206  into the chamber  220  of the lower portion  210  of the body  206 . The apertures  230  may be provided in a circumferentially spaced apart arrangement near a periphery of the seat member  222 . In one embodiment, the apertures  230  may have a kidney-shaped design. Alternatively, the apertures  230  may have a circular shape or any other configuration. 
     Further, a plunger  232  is disposed within the body  206  of the valve  202 . More particularly, the plunger  232  may be disposed within the lower portion  210  of the body  206  and may extend into the tank  102 . The plunger  232  may have a tubular wall  234  defining a conduit  236  within the plunger  232  for fluidly connecting the chamber  220  of the valve  202  with the tank  102 . The plunger  232  may be positioned at a distal end of the body  206  with respect to the receiving element  106 , and may selectively allow the DEF to flow from the chamber  220  of the valve  202  into the tank  102  based on a position of the valve  202 . 
     As shown in the accompanying figures, the chamber  220  is sized to be larger than the plunger  232  such that the chamber  220  defined within the body  206  of the valve  202  surrounds a portion of the plunger  232  which is disposed within the body  206 . In one embodiment, an external fillet  237  may extend from the lower portion  210  of the body  206  into the tank  102 . The external fillet  237  may taper from the lower portion  210  of the body  206  and is shaped to surround a portion of the plunger  232  enclosed therein. The external fillet  237  may guide movement of the plunger  232  with respect to the chamber  220  of the body  206 . Sizing of the external fillet  237  may be such that DEF is prevented from leaking between the lower portion  210  of the body  206  and the plunger  232 . 
     One end of the plunger  232  which is received into the chamber  220  of the valve  202  may include a lip  238  extending circumferentially from the tubular wall  234 . This may serve as a stop for holding the plunger  232  within the chamber  220  of the body  206  when the valve  202  is in an open position. A float  240  may be fixed to a distal end of the plunger  232 . The float  240  is configured to be positioned within the tank  102  and may surround the distal end of the plunger  232 . Also, the plunger  232  may be configured to pass through the float  240 , such that a fluid flow path is defined through the conduit  236  of the plunger  232  into the tank  102 . 
     The operation of the valve  202  will now be described in detail. Referring to  FIG. 2 , the valve  202  is shown in the open position. The DEF may be supplied to the receiving element  106  from the receptacle  108  via the hose  110 . Further, the DEF may flow into the inlet  218  of the body  206  of the valve  202 . The DEF may then enter into the chamber  220  of the body  206  by passing through the apertures  230  defined within the seat member  222 . The DEF may flow through the chamber  220  into the conduit  236  of the plunger  232  and thereby enter into the tank  102 . Arrows shown in  FIG. 2  are indicative of a direction of the flow of DEF. 
     As a level of the DEF within the tank  102  increases, the DEF inside the tank  102  may come in contact with the float  240  disposed within the tank  102 . A buoyancy force of the DEF may cause the plunger  232  and the float  240  to move relative to the body  206  and the seat member  222  of the valve  202 . More particularly, the plunger  232  and the float  240  may move in a vertically upward direction into the chamber  220  of the body  206 . In one embodiment, the movement of the plunger  232  within the chamber  220  may be guided by the part of the lower portion  210  of the body  206  between the open position and a closed position. 
       FIG. 3  is a cross sectional view of the valve  202  in the closed position, according to one embodiment of the present disclosure. When in the closed position, the plunger  232  may come in contact and seal against a lower section of the seat member  222 . In one embodiment, a sealing surface  302 , such as, for example, a gasket, may be located on the lower section of the seat member  222 . This sealing surface  302  may be positioned so as to cooperate with the lip  238  of the plunger  232  when the valve  202  is in the closed position. The sealing surface  302  may be attached to the seat member  222  by any known means. 
     Moreover, a position of the plunger  232  with respect to the seat member  222  is such that the conduit  236  defined by the plunger  232  is isolated or fluidly disconnected from the chamber  220  of the valve  202  in the closed position. When the valve  202  is in the closed position, as the DEF is received through the inlet  218  of the valve  202 , the DEF may flow through the apertures  230  and accumulate within the chamber  220  of the valve  202  surrounding the portion of the plunger  232  received into the body  206 . It should be noted that the apertures  230  provided within the seat member  222  are positioned in a manner such that the apertures  230  lie radially outward of the tubular wall  234  of the portion of the plunger  232  disposed within the body  206 . The DEF accumulated within the chamber  220  of the valve  202  may be prevented from entering into the tank  102  based on the sealing of the plunger  232  against the seat member  222 . The DEF accumulated within the chamber  220  of the valve  202  may exert a radial pressure perpendicular to the longitudinal axis X-X and therefore does not exert a downward force on the plunger  232 , which would tend to open the valve  202  by moving the plunger  232  into the tank  102 . 
       FIG. 4  illustrates a cross section view of another embodiment of the valve  202 ′, according to the present disclosure. In this embodiment, the upper portion  208 ′ of the body  206 ′ is shaped differently from that shown in  FIGS. 2 and 3 . The receiving element (not shown) is inserted into and coupled within the inlet  218 ′ of the body  206 ′. Further, the seat member  222 ′ is positioned within the lower portion  210 ′ of the body  206 ′. Also, a guiding member  402  is fixedly attached to a lower surface of the lower portion  210 ′ of the body  206 ′. The guiding member  402  has a hollow configuration and is sized to surround a portion of the plunger  232  extending into the tank  102 . The guiding member  402  is configured to guide the movement of the plunger  232  and the float  240 ′ with respect to the body  206 ′ and the seat member  222 ′ of the valve  202 ′. The float  240 ′ may include a circumferential channel surrounding the distal end of the plunger  232  for receiving the DEF therein. The working of the valve  202 ′ is as described in connection with  FIGS. 2 and 3 . 
     It should be noted that the components of the valve  202 ,  202 ′ such as the upper portion  208 ,  208 ′, the lower portion  210 ,  210 ′, the seat member  222 ,  222 ′, the plunger  232  and the float  240 ,  240 ′ may be unitary components, an integrated component or any combination thereof based on the system requirements. 
     INDUSTRIAL APPLICABILITY  
     Expansion of the DEF within the tank on solidification may cause rupturing of the tank design known in the art. The valve  202 ,  202 ′ disclosed herein may provide a simple and cost effective solution for shutting-off the DEF supply to the tank  102  when the DEF level within the tank  102  exceeds a predetermined threshold. Accordingly, space may be provided within the tank  102  to allow the DEF to expand without causing damage to the tank  102 . Also, a mounting location of the valve  202 ,  202 ′ with respect to the tank  102  is such that the body  206  of the valve  202 ,  202 ′ is not in contact with the DEF present within the tank  102 , thereby avoiding freezing damage concerns and additional leak paths that may arise with respect to the tank  102 . The valve  202 ,  202 ′ is attachable from outside of the tank  102  allowing for ease of assembly and removal. The valve  202 ,  202 ′ may be utilized in connection with any storage unit which is filled by known pressurized fill systems for controlling a level of fluid filled in the storage unit. 
     While aspects of the present disclosure have been particularly shown and described with reference to the embodiments above, it will be understood by those skilled in the art that various additional embodiments may be contemplated by the modification of the disclosed machines, systems and methods without departing from the spirit and scope of what is disclosed. Such embodiments should be understood to fall within the scope of the present disclosure as determined based upon the claims and any equivalents thereof.