Patent Publication Number: US-8528609-B2

Title: Refilling nozzle with vapor recovery relief valve

Description:
The present invention is directed to a refilling nozzle, and more particularly, to a refilling nozzle which has a relief valve to accommodate vehicles having onboard refueling vapor recovery systems. 
     BACKGROUND 
     At a typical refueling station, fuel is pumped from an underground storage tank through a fuel dispenser, a hose and associated nozzle to the vehicle fuel tank. As the fuel enters the vehicle fuel tank, hydrocarbon vapors from inside the tank are exhausted or forced out of the tank. Environmental laws and/or regulations may require that vapors emitted from the vehicle fuel tank during refueling be captured and returned to the underground fuel storage tank. The captured vapor is returned through the vapor path of the nozzle, hose, dispenser and underground piping system back to the ullage space of the underground fuel storage tank. Balanced refilling systems are configured such that vapor forced out a vehicle tank is moved toward the storage tank by the pressure of fluid flowing into the vehicle tank. 
     An increasing number of vehicles include an onboard refueling vapor recovery (“ORVR”) system configured to capture/reclaim the vapor that would otherwise be emitted from the fuel tank during refueling. The ORVR system routes or feeds the vapor to a capture canister which includes activated carbon. When the refueling process is complete and the vehicle engine is running, vapor in the capture canister is fed to the engine where the vapors are burned during the combustion process. 
     A liquid seal ORVR system (the most common ORVR system) is typically designed such that the vehicle fill pipe leading to the vehicle fuel tank has a progressively reduced inner diameter. This configuration ensures that fuel flowing into the fill pipe covers or extends continuously across the cross section of the fill pipe during refueling to form a liquid seal, which prevents fuel vapor from escaping through the fill pipe. The reduction in diameter of the fill pipe also causes a vacuum to be generated during refueling due to the venturi effect. The phenomenon, known as an injector effect, draws surrounding air/vapor into the fuel flow stream, and creates a positive pressure in the vehicle fuel tank that forces the vapors into the vapor capture canister carried on the vehicle. However, a vehicle equipped with an ORVR system (i.e. an ORVR vehicle) can create a negative pressure in the nozzle, which can interfere with the proper operation of the nozzle/refueling system. 
     SUMMARY 
     Accordingly, in one embodiment the invention is a nozzle system which includes a relief valve such that a negative pressure in the system can be alleviated. In particular, in one embodiment the invention is a nozzle system including a nozzle body configured to dispense fuel through a fuel path thereof into a vehicle tank. The nozzle body includes a vapor path configured such that vapor recovered from the vehicle tank during refueling is passable therethrough. The nozzle system further includes a main vapor valve positioned in the vapor path and configured to selectively block the vapor path. The main vapor valve is movable to a position wherein the main vapor valve does not block the vapor path. The nozzle system further includes a relief valve in fluid communication with the vapor path. The relief valve is configured to open to allow ambient air to enter into the vapor path when sufficiently low pressure is present in the vapor path, and the relief valve is generally aligned with the main vapor valve. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic representation of a refueling system shown in conjunction with a vehicle to be refueled; 
         FIG. 1A  is a detail view of the area designated in  FIG. 1 ; 
         FIG. 2  is a side view of a nozzle of the system of  FIG. 1 ; 
         FIG. 3  is a side cross section of the nozzle of  FIG. 2 ; 
         FIG. 4  is a side cross section of the nozzle of  FIG. 3 , with the lever raised, the main valves in their open positions, and the relief valve opened; 
         FIG. 5  is a side cross section of the nozzle of  FIG. 3 , with the relief valve exploded; and 
         FIG. 6  is a front perspective view of the nozzle of  FIG. 2 , with the relief valve and main valves exploded. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  is a schematic representation of a refilling system  10  including a plurality of dispensers  12 . Each dispenser  12  includes a dispenser body  14 , a hose  16  coupled to the dispenser body  14 , and a nozzle  18  positioned at the distal end of the hose  16 . Each hose  16  may be generally flexible and pliable to allow the hose  16  and nozzle  18  to be positioned in a convenient refilling position as desired by the user/operator. 
     Each dispenser  12  is in fluid communication with a fuel/fluid storage tank  22  via a fluid conduit  26  that extends from each dispenser  12  to the storage tank  22 . The storage tank  22  includes or is fluidly coupled to a fuel pump  28  which is configured to draw fluid out of the storage tank  22  via a pipe  30 . During refilling, as shown by the in-use dispenser  12 ′ of  FIG. 1 , the nozzle  18  is inserted into a fill pipe  38  of a vehicle fuel tank  40 . The fuel pump  28  is then activated to pump fuel from the storage tank  22  to the fluid conduit  26 , hose  16  and nozzle  18  and into the vehicle fuel tank  40  via a fuel path  36  of the system  10 . 
     The system  10  may also include a vapor path  34  extending from the nozzle  18 , through the hose  16  and a vapor conduit  24  to the ullage space of the tank  22 . For example, as shown in  FIG. 1A , in one embodiment the vapor path  34  of the hose  16  is received around, and generally coaxial with, an inner fluid path  36  of the hose  16 . The nozzle  18  may include a flexible vapor boot or bellows  31  ( FIGS. 2-6 ) of the type well known in the art which is coupled to, and circumferentially surrounds, a spout  32  of the nozzle  18 . The bellows  31  is designed to be compressed and form a seal about the spout  32  when the spout  32  is inserted into the fill pipe  38 . The bellows  31  help to capture vapors and route the vapors into the vapor path  34 . 
     In the illustrated embodiment the system  10  lacks any vapor or suction pump fluidly coupled to the vapor path  34 , and the recovered vapors are instead urged through the vapor path  34  and to the tank  22  by the increased pressure caused by fluid entering the vehicle fuel tank  40  in a so-called “balanced” system. Although  FIG. 1  illustrates one particular configuration of a system  10  in which the nozzle  18  may be utilized, it should be understood that the system  10  can be varied from the particular arrangement shown in  FIG. 1 . In one example, a fuel pump  28  can instead be positioned at each associated dispenser  12  in a so-called “suction” system, instead of the so-called “pressure system” shown in  FIG. 1 . Moreover, it should be understood that the system  10 /nozzle  18  disclosed herein can be utilized to store/dispense any of a wide variety of fluids, liquids or fuels, including but not limited to petroleum-based fuels, such as gasoline, diesel, natural gas, biofuels, blended fuels, propane, oil or the like, or ethanol the like. 
     As best shown in  FIGS. 3 and 4 , the nozzle  18  includes portions of the vapor path  34  and fluid path  36  of the system  10  therein, and is fluidly coupled to the hose  16  at a threaded outlet  42 . The nozzle  18  includes a main fluid valve  44  positioned in the fluid path  36  to control the flow of liquid therethrough and through the nozzle  18 . Similarly, the nozzle  18  includes a main vapor valve  46  positioned in the vapor path  34  to control the flow of vapor therethrough and through the nozzle  18 . 
     Both the main fluid valve  44  and main vapor valve  46  are carried on, or operatively coupled to, a main valve stem  48 . The bottom of the main valve stem  48  is positioned above the lever  50  which can be manually raised or actuated by the user. When the user raises the lever  50  and refilling conditions are appropriate, the lever  50  engages and raises the valve stem  48 , thereby opening the main vapor valve  46  and main fluid valve  44 . In particular, when raised, the main vapor value  46  engages and raises the upper valve stem portion  48   a , which carries the main vapor valve  46  thereon, opening the main vapor valve  46 . As shown in  FIG. 4 , the valve stems  48 ,  48   a , main fluid valve  44  and main vapor valve  46  are axially movable along the axis of the stems  48 ,  48   a . In some cases the valves  44 ,  46  may be arranged such that the main vapor valve  46  starts to open before the main fluid valve  44  when the lever  50  is raised, which can improve vapor capture. 
     A venturi poppet valve  52  is mounted in the nozzle  18  and positioned in the fluid path  36 . A venturi poppet spring  54  engages the venturi poppet  52  and urges the venturi poppet  52  to a closed position wherein the venturi poppet  52  engages an annular seating ring  56 . When fluid of a sufficient pressure is present in the fluid path  36  (i.e., during dispensing operations), the force of the venturi poppet spring  54  is overcome by the dispensed fluid and the venturi poppet  52  is moved to its open position, away from the seating ring  56 . 
     When the venturi poppet  52  is open and liquid flows between the venturi poppet  52  and the seating ring  56 , a venturi effect is created in radially-extending passages  58  extending through the seating ring  56  and communicating with a chamber  60  of a shut-off device  62 . The venturi passages  58 /chamber  60  are also in fluid communication with a tube  64  positioned within the spout  32  (the tube  64  is continuous, but not entirely shown in the cross sections of  FIGS. 3-5  due to its varying radial positioning along a length of the tube  64 ). The tube  64  terminates at, and is in fluid communication with, an opening  66  positioned on the underside of the spout  32  or near the distal end thereof. The tube  64 , along with the venturi passages  58  and other portions exposed to the venturi pressure, form or define a sensing path  68  which is fluidly isolated from the fluid path  36  and vapor path  34  within the nozzle  18 . 
     When the venturi poppet valve  52  is open and fluid flows through the fluid path  36 , the venturi or negative pressure in the chamber  60  and sensing path  68  draws air through the opening  66  and tube  64 , thereby dissipating the negative pressure. When the opening  66  is blocked, such as when fluid levels in the tank  40  during refilling reach a sufficiently high level, the source of pressure dissipation is blocked, which causes a sudden decrease in pressure in the chamber  60 . The decrease in pressure in the chamber  60  of the shut-off device  62  causes an associated diaphragm of the shut-off device  62  to be moved, thereby enabling an associated plunger  70  to move downwardly. The plunger  70  then moves downwardly, causing the lever  50  to move to its position in  FIG. 3 , causing the main fluid and main vapor valves  44 ,  46  to close. Thus, sufficiently low pressure in the sensing path  68  causes the shut-off mechanism  62  to close the main valves  44 ,  46 . 
     It should be understood that the shut-off device  62  can take any of a wide variety of forms such as those shown in, for example, U.S. Patent Application Publication No. US 2007/0267089 to Gray et al. (the entire contents of which are hereby incorporated by reference), U.S. Pat. No. 2,582,195 to Duerr (the entire contents of which are hereby incorporated by reference), U.S. Pat. No. 4,453,578 to Wilder (the entire contents of which are hereby incorporated by reference), U.S. Pat. No. 5,421,382 to Leininger et al. (the entire contents of which are hereby incorporated by reference), or U.S. Pat. No. 5,121,777 to Leininger et al. (the entire contents of which are hereby incorporated by reference). 
     Refueling systems that utilize a vapor boot  31  and a shut-off device  62 , as described above, can experience nuisance or premature automatic shutoffs due to the vacuum generated by a liquid seal ORVR system. In particular, the vacuum created by an ORVR vehicle during refueling can sufficiently lower the pressure in the sensing path  68 , thereby triggering the shutoff device  62  of the nozzle  18  before the fuel tank  40  is full. This requires the customer/operator to re-engage the nozzle  18 , thereby adding wear and tear on the refueling components, and causing aggravation to the customer/operator. Alternately, or in addition, the vacuum created by an ORVR vehicle during refueling can cause vapor to be pulled from the underground storage tank  22 , which can cause pressure imbalances in the system, and cause nuisance shut-offs at other nozzles  18 /dispensers  12 . 
     Standard or non-ORVR vehicles (i.e. vehicles lacking an ORVR system) can also experience a temporary vacuum in the vehicle tank fill pipe in a condition known as “vapor collapse.” In particular, the ullage space in the vehicle fuel tank can sometimes reside at an elevated temperature and/or pressure. When fuel from the underground storage tank is dispensed into the tank of a hot vehicle, the vapor in the hot vehicle tank is rapidly chilled by the cooler fuel, thereby correspondingly reducing the pressure in the ullage space of the vehicle fuel tank. As the vapor in the vehicle tank shrinks, a negative pressure or vacuum is created in the vehicle tank ullage space and fill pipe  38 , resulting in vapor collapse, which can also cause nuisance shut-offs or other problems as described above 
     Accordingly, the nozzle  18  may include a relief valve  72  mounted or incorporated therein to accommodate reduced pressure in the system/fill pipe  38 . As best shown in  FIGS. 2-5 , the relief valve  72  is positioned adjacent to, or fluidly communicates with, the vapor path  34 , on the one hand and the outside/ambient environment on the other. Although the relief valve  72  directly communicates with the vapor path  34 , the relief valve  72  indirectly communicates with the sensing path  68  since a reduced pressure applied by the tank  40  to the sensing path  68  would also be applied to the vapor path  34 . As best shown in  FIGS. 5 and 6 , the nozzle  18  may include an upper opening  74 , which is generally cylindrical in the illustrated embodiment, in which the relief valve  72  is received. A valve housing  76  is closely received in the upper opening  74 . The valve housing  76  is generally sealed/continuous in the axial direction, except for a center or valve seat opening  78  and a pair of flow openings  80  located on either side of the center opening  78 . 
     The relief valve  72  includes a flapper  82  with a generally flat, circular body portion or movable portion  83  and a central barbed tip  84  extending upwardly from the body portion  83 . The barbed tip  84  is configured to fit through the center opening  78  of the valve housing  76  to securely couple the flapper  82  to the valve housing  76 . The body portion  83  of the flapper  82  is generally flexible and resilient, and configured to generally cover and extend radially past the flow openings  80  of the valve housing  76 . The relief valve  72 /flapper  82  can be made of any of a variety of materials. However, in one embodiment the relief valve  72 /flapper  82  is made of flurosilicone, which remains stable in the presence of fuels and petroleum product, and remains stable and flexible at low temperatures. 
     An O-ring  86  is positioned between the valve housing  76  and the wall of the upper opening  74  of the nozzle  18  to seal the relief valve  72 . Finally, a retaining ring  88  is positioned on top of the valve housing  76 , and received in the nozzle  18 , to secure the valve housing  76 /relief valve  72  in place. 
     The relief valve  72  is movable between its closed position, wherein the relief valve  72  generally seals the openings  80  and blocks ambient air from entering into the vapor path  34  ( FIG. 3 ), and an open position ( FIG. 4 ), wherein the body portion  83  moves away from the valve housing  76  such that the relief valve  72  allows ambient air to enter into the vapor path  34 . The relief valve  72  is biased into its closed position by the position and nature of materials of the flapper  82 /body portion  83 . However, when the pressure in the vapor path  34  is sufficiently low relative to ambient atmosphere, the body portion  83  is pulled away from the openings  80 /valve housing  76 , thereby allowing air to flow through openings  80 /valve housing  76 , as shown by an arrowed path  91  in  FIG. 4 . 
     Thus, in this manner, when a low pressure is present in the vapor path  34 , such as due to refueling an ORVR vehicle, or due to a vapor collapse event, the relief valve  72  opens to allow surrounding, ambient air to enter into the vapor path  34  to alleviate the negative pressure in the tank  40 /fill pipe  38 , the vapor path  34  and the sensing path  68 , and avoid nuisance shut-offs and undesired pressures in the system. In one embodiment, the relief valve  72  opens at a pressure differential of between about 1.5 inches and about 2.5 inches water column, and more particularly about 2 inches water column in one case, although the valve  72  can be adjusted as desired to accommodate the specific operating characteristics of any particular system. 
     Once sufficient air has entered into the vapor path  34  and the vacuum is sufficiently alleviated, the relief valve  72  returns to its closed position. In this manner, the nozzle  18  can operate smoothly and avoid nuisance shutoffs, without user intervention. The relief valve  72  also relieves the vacuum from ORVR vehicles before the vacuum has a chance to act on the underground storage tank  22 , thereby helping to manage the pressure of the underground storage tank  22  and avoiding excessively strong vacuum pressures from being generated therein. Conversely, when a positive pressure is in the vapor path  34  (such as when refueling non ORVR vehicles), the relief valve  72  is closed, and in fact biased further closed by the positive pressure, thereby preventing vapors from escaping into the atmosphere. 
     The relief valve  72  is, in the illustrated embodiment, generally coaxially mounted with the main vapor valve  46  and main fluid valves  44  (and/or mounted directly above the main vapor valve  44  and main fluid valve  46 , and immediately adjacent to the main vapor valve  46 ). Thus, as can be seen in  FIGS. 3-5 , when the relief valve  72  is assembled, the main vapor valve spring  90 , which biases the main vapor valve  46  to its closed position, engages the underside of the valve housing  76 , which acts as the valve seat for the relief valve  72 . 
     This mounting arrangement is advantageous in that the valve housing  76 /relief valve  72  serves the dual function of both providing relief venting functions, as described above, and providing access to the main vapor valve  46  and main fluid valve  44 . In particular, if access is required to the main vapor valve  46  and/or main fluid valve  44 , the relief valve  72  can be removed, and access is thereby provided to the main vapor valve  46  and main fluid valve  44  via the upper opening  74 . This arrangement also provides ease of manufacturing, as the main fluid valve  44 , main vapor valve  46 , and relief valve  72  can each be assembled in/through the upper opening  74 . This configuration also reduces the number of openings in the nozzle body  18 , thereby increasing the strength and integrity of the nozzle body  18 , and reducing potential leak points. 
     In addition, in the illustrated embodiment the relief valve  72  is positioned at or adjacent to the highest position of the vapor path  34  in the nozzle  18  when the nozzle  18  is in its refilling position (i.e., in one case, when the spout  32  is angled downwardly and/or the axis of the outlet  42 , or the adjacent fluid path  36  or vapor path  34 , extend generally horizontally, as shown in  FIGS. 2-4 ). This positioning of the relief valve  72  helps to minimize any chances that fluid, such as fuel, that enters into the vapor path  34  would escape through the relief valve  72 . 
     In particular, when a user tops off their tank  40 , fuel could be forced into the vapor path  34 . If the relief valve  72  were to be located in a relatively low-lying position, fluid in the vapor path  34  could more easily reach the relief valve  72 . In order to ensure a light-weight design, the relief valve  72  may not be fluid tight, and therefore fluid in the vapor path  34  might be able to escape through the relief valve  72 , thereby contaminating the surrounding environment. However, by placing the relief valve  72  at a relatively high position in the vapor path  34 , the chances of such contamination are minimized. If the relief valve  72  is not positioned at the highest position of the vapor path  34  in the nozzle  18 , it may be positioned within at least about 1 inch, or at least about 0.5 inches, in either horizontal distance or vertical height, of such highest position. 
     The particular position of the relief valve  72  above the main vapor valve  46  and main fluid valve  44  is also advantageous since the relief valve  72  is positioned away from the lever  50 /operator&#39;s hand, so that the operator&#39;s hand, when grasping the nozzle  18 , does not block or interfere with operation of the relief valve  72 . The positioning of the relief valve  72  also ensures that the relief valve  72  does not bump against the vehicle during refueling, or against the dispenser body  14  when the nozzle  18  is holstered. 
     In some systems, manufacturers may place holes, vents, apertures or openings (collectively termed “openings” herein) in the bellows to allow ambient air to be drawn in into the bellows, thereby alleviating pressure when the nozzle is used with an ORVR vehicle. However, while such openings may alleviate pressure when used in conjunction with ORVR vehicles, when the associated nozzle is used with a non-ORVR vehicle, the openings allow vapor to escape therethrough, particularly since the inside of bellows of balanced systems are typically at a positive pressure when non ORVR vehicles are refilled. Thus, the bellows  31  used with the nozzle  18  described herein may be generally continuous, and lack any openings, or any significant openings formed therein (i.e. in one case, openings having a total surface area of greater than about 0.15 mm 2 ) to form a closed volume, which helps to ensure greater vapor capture. 
     In some cases, a cover may extend around the nozzle  18  to provide a finished appearance and protect the nozzle  18  from ambient conditions. If a cover is used, and the cover extends over the relief valve  72 , the cover may include one or more openings positioned over the relief valve  72  to ensure the relief valve  72  can introduce air into the vapor path  34  to enable proper operation of the relief valve  72 . 
     Although the relief valve  72  is illustrated in the form of a flapper, diaphragm or umbrella valve (collectively termed a diaphragm valve herein), it should be understood that the relief valve  72  can take the form of any wide variety of valves which allow flow therethrough at the desired pressure, including but not limited to check valves and the like. As described above, in the illustrated embodiment, the relief valve  72  is positioned upstream from the main vapor valve  46  with respect to the direction of the flow of recovered vapor through the vapor path  34 . This arrangement ensures that the relief valve  72  is isolated from the underground storage tank  22  when the main vapor valve  46  is in the closed position, which helps to ensure the relief valve  72  is not opened due to negative pressures in the underground storage tank  22 . 
     Although the invention is shown and described with respect to certain embodiments, it should be clear that modifications and variations will be apparent to those skilled in the art upon reading the specification, and the present invention includes all such modifications and variations.