Abstract:
A method enables a gas turbine engine to be operated. The method includes directing fluid flow from a source into an inlet of a valve, channeling the fluid flow entering an inlet portion of the valve towards an outlet portion of the valve such that a direction of the fluid flow is changed within the inlet portion, and controlling the amount of fluid flow entering the outlet portion of the valve by selectively positioning a valve disk coupled within the inlet portion of the valve by a valve disk axle. The method also comprises channeling the fluid flow from the inlet portion of the valve through the outlet portion of the valve and into a fluid supply pipe, wherein the valve outlet portion has a substantially right cylindrical shape such that a direction of fluid entering the body outlet portion remains substantially constant therethrough.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     This invention relates generally to gas turbine engines and more particularly, to valve assemblies used to regulate fluid flow for a gas turbine engine.  
         [0002]     Gas turbine engines typically include an engine casing that extends circumferentially around a compressor, and a turbine including a rotor assembly and a stator assembly. Within at least some known engines, a plurality of ducting and valves coupled to an exterior surface of the casing are used to channel fluid flow from one area of the engine for use within another area of the engine. For example, such ducting and valves may form a portion of an environmental control system (ECS).  
         [0003]     At least some known valve assemblies are used to control fluid flow that is at a high temperature and/or high pressure. Such valve assemblies include a substantially cylindrical valve body that is coupled between adjacent sections of ducting. The valve body includes a valve sealing mechanism that is selectively positionable to control fluid flow through the valve. More specifically, at least some known valves includes a piston/cylinder arrangement that is positioned external to the valve body and is coupled to the valve sealing mechanism to provide the motive force necessary to selectively position the valve sealing mechanism.  
         [0004]     Because the piston/cylinder arrangement is offset from the main valve body, a center of gravity of the valve assembly is typically displaced a distance from a centerline axis of the valve body. Such an eccentric center of gravity may induce bending stresses into the valve assembly, adjoining tubing, and supporting brackets during engine operation. Depending on the application, the physical size and weight of the piston/cylinder arrangement may also present difficulties during the duct routing phase of the engine design.  
       BRIEF SUMMARY OF THE INVENTION  
       [0005]     In one aspect, a method for operating a gas turbine engine is provided. The method comprises directing fluid flow from a source into an inlet of a valve, channeling the fluid flow entering an inlet portion of the valve towards an outlet portion of the valve such that a direction of the fluid flow is changed within the inlet portion, and controlling the amount of fluid flow entering the outlet portion of the valve by selectively positioning a valve disk coupled within the inlet portion of the valve by a valve disk axle. The method also comprises channeling the fluid flow from the inlet portion of the valve through the outlet portion of the valve and into a fluid supply pipe, wherein the valve outlet portion has a substantially right cylindrical shape such that a direction of fluid entering the body outlet portion remains substantially constant therethrough.  
         [0006]     In another aspect of the invention, a valve for use with a gas turbine engine is provided. The valve comprises a valve body including a valve inlet portion and an outlet portion. The inlet portion extends from an inlet to the body outlet portion. The body outlet portion forms a substantially right cylinder that extends from the inlet portion to a valve outlet, such that a direction of fluid flowing within the body outlet portion remains substantially unchanged between the body inlet portion and the valve outlet. The inlet portion includes a valve disk and at least one bend formed between the body outlet portion and the valve inlet such that a direction of fluid entering the valve body through the valve inlet is changed prior to entering the body outlet portion. The valve disk is pivotally coupled within the inlet portion for controlling fluid flow through the valve.  
         [0007]     In a further aspect, a gas turbine engine is provided. The engine includes a fluid supply pipe a valve configured to regulate an amount of fluid flow entering the fluid supply pipe. The valve includes a valve body comprising an inlet, an outlet, an inlet portion, and an outlet portion. The inlet portion extends between the inlet and the outlet. The outlet portion extends between the inlet portion and the outlet. The outlet portion has a substantially right cylindrical shape such that a direction of fluid entering the body outlet portion remains substantially constant therethrough. The inlet portion includes a valve disk and at least one bend formed between the inlet and the body outlet portion, such that a direction of fluid flowing through the body inlet portion is changed prior to entering the outlet portion. The valve disk is used to control fluid flow through the valve into the fluid supply pipe. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]      FIG. 1  is a side view of a gas turbine engine including a plurality of ducting coupled together by a plurality of valve assemblies;  
         [0009]      FIG. 2  is a cross-sectional view of one of the valve assemblies shown in  FIG. 1 ;  
         [0010]      FIG. 3  is an exploded perspective view of the valve assembly shown in  FIG. 2 ;  
         [0011]      FIG. 4  is a perspective view of an alternative embodiment of a valve assembly that may be used with the gas turbine engine shown in  FIG. 1 ; and  
         [0012]      FIG. 5  is a side view of the valve assembly shown in  FIG. 4 . 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0013]      FIG. 1  is a side view of a gas turbine engine  10  including a plurality of ducting  12  coupled together by a plurality of valve assemblies  14 . Engine  10  includes a high-pressure compressor assembly  16 , a combustor  18 , and a turbine assembly  20 . In one embodiment, compressor  16  is a high-pressure compressor. Engine  10  also includes a low-pressure turbine (not shown) and a fan assembly (not shown). In one embodiment, engine  10  is a CF34 engine commercially available from General Electric Company, Cincinnati, Ohio.  
         [0014]     In the exemplary embodiment, ducting  12  and valve assemblies  14  form a portion of an engine build up (EBU)  30 . More specifically, ducting  12  and valve assemblies  14  facilitate channeling and controlling, respectively, fluid flow at a high temperature, and/or at a high pressure, from one area of engine  10  for use in another area. For example, in one embodiment, fluid flowing through ducting  12  and valve assemblies  14  has an operating temperature that is greater than 1000° F. and/or an operating pressure of greater than 300 psi.  
         [0015]     In the exemplary embodiment, ducting  12  includes a Y-duct  32  that facilitates splitting EBU  30  into a pair of inlet duct assemblies  34  and  36  that are coupled to an engine casing  40  by a plurality of mounting bracket assemblies  42 . More specifically, inlet duct assemblies  34  and  36  are coupled in flow communication to compressor  18  for routing bleed air from compressor  18  for use in other areas, such as an environmental control system.  
         [0016]      FIG. 2  is a cross-sectional view a valve assembly  14 .  FIG. 3  is an exploded perspective view of valve assembly  14 . Valve assembly  14  includes a valve body  50  having a first body portion  52  and an integrally-formed second body portion  54 . In the exemplary embodiment, first body portion  52  is an inlet body portion, and second body portion  54  is an outlet body portion, and both will be described herein as such. In an alternative embodiment, first body portion  52  is an outlet body portion, and second body portion  54  is an inlet body portion. Inlet portion  52  extends from an assembly first end  56  to outlet portion  54 , and outlet portion  54  extends from inlet portion  52  to an assembly second end  60 . In the exemplary embodiment, assembly first end  56  is an assembly inlet, and assembly second end  60  is an outlet, and both will be described herein as such. In an alternative embodiment, assembly first end  56  is an assembly outlet for discharging fluids therefrom, and assembly second end  60  is an assembly inlet for receiving fluids therein. Valve assembly  14  is hollow and includes a bore  64  that extends between assembly inlet  56  and assembly outlet  60 . Valve assembly  14  also includes an exterior surface  66  that extends over inlet and outlet portions  52  and  54 , respectively.  
         [0017]     Valve assembly outlet portion  54  includes an interior surface  70  and a centerline  72 . Interior surface  70  extends through outlet portion  54  to outlet  60  and defines a portion of assembly bore  64 . Because outlet portion  54  is a right cylinder, assembly outlet  60  is substantially perpendicular to outlet portion centerline  72 .  
         [0018]     Outlet portion  54  also includes an integrally-formed mounting flange  76 , an inner shoulder  78 , and a pair of actuator system connector link mounts  80 . Flange  76  extends circumferentially from outlet portion exterior surface  66  around assembly outlet  60 , and includes a plurality of openings  84 . Openings  84  are each sized to receive a fastener  86  therethrough for coupling outlet portion  54  to a valve-inner cylinder  90 .  
         [0019]     Outlet portion shoulder  78  is positioned between flange  76  and actuator system mounts  80 . More specifically, a diameter d 1  of bore  64  within outlet portion  54 , defined by surface  70 , is substantially constant between assembly outlet  60  and shoulder  78 , and is larger than a diameter d 2  of outlet portion bore  64  extending between shoulder  78  and inlet portion  52 .  
         [0020]     Valve-inner cylinder  90  is a substantially right hollow cylinder that that extends from an inlet edge  94  to an outlet edge  96 , and includes an exterior surface  98  and an interior surface  100 . Exterior and interior surfaces  98  and  100 , respectively, define respective external and internal diameters d 3  and d 4  for cylinder  90 . Diameters d 3  and d 4  are substantially constant along cylinder  90  between edges  94  and  96 , and both diameters d 3  and d 4  are smaller than outlet portion bore diameter d 2 . Accordingly, valve-inner cylinder  90  is sized to be received within outlet portion  54 , such that cylinder  90  is substantially concentrically aligned with respect to outlet portion  54 .  
         [0021]     A mounting flange  106  extends radially outwardly and circumferentially from cylinder outlet edge  96 . Flange  106  is aligned substantially perpendicular to a centerline axis  108  extending through cylinder  90 , and includes a plurality of fastener openings  110  that are each sized to receive fastener  86  therethrough. More specifically, when valve-inner cylinder  90  is positioned within outlet portion  54 , cylinder fastener openings  110  are each substantially concentrically aligned with respect to each respective outlet portion flange fastener opening  84 , such that fasteners  86  extending through openings  110  and  84  secure valve-inner cylinder  90  in alignment within outlet portion  54 .  
         [0022]     A valve piston  120  is slidably coupled between valve-inner cylinder  90  and outlet portion  54 . More specifically, valve piston  120  is a substantially right hollow cylinder that that extends from an inlet edge  124  to an outlet edge  126 , and includes an exterior surface  128  and an interior surface  130 . Exterior and interior surfaces  126  and  130 , respectively, define respective external and internal diameters d 5  and d 6  for piston  120 . In the exemplary embodiment, diameters d 5  and d 6  are substantially constant between piston edges  124  and  126 , and both diameters d 5  and d 6  are larger than valve-inner cylinder external diameter d 3 . In an alternative embodiment, an inlet side of piston  120  has a smaller diameter than an outlet side of piston  120 , which as described in more detail below, facilitates piston  120  being double acting. Additionally, piston external diameter d 5  is slightly smaller than outlet portion bore diameter d 2 , such that when piston  120  is received within outlet portion  54 , piston external surface  128  is slidably coupled against outlet portion interior surface  70  between outlet portion shoulder  78  and inlet portion  52 .  
         [0023]     A seal assembly  131  extends circumferentially around piston outlet edge  126  to facilitate minimizing leakage of actuation air past piston outlet edge  126 . Seal assembly  131  is substantially perpendicular to a centerline axis  132  extending through cylinder  120 , and has an outer diameter d 7  that is slightly smaller than outlet portion bore diameter d 1 .  
         [0024]     Piston internal diameter d 6  is larger than valve-inner cylinder external diameters d 3  such that a gap  140  is defined between piston interior surface  130  and valve-inner cylinder external surface  98 . More specifically, gap  140  extends between seal assembly  131  and piston inlet edge  124 . A valve spring  150  extends circumferentially within gap  140  between valve-inner cylinder  90  and valve piston  120 , and as described in more detail below, is used to regulate operation of valve assembly  14 .  
         [0025]     Valve piston  120  also includes a pair of openings  154  that are extends diametrically aligned with respect to valve piston  120  and extend partially between exterior surface  128  and interior surface  130 . Openings  154  are each sized to receive a connecting rod  155  that enables valve piston  120  to be coupled to an actuator system connector link  156 .  
         [0026]     Valve inlet portion  52  includes an interior surface  160  that extends through inlet portion  52  to assembly inlet  56  and defines a portion of assembly bore  64 . In the exemplary embodiment, a diameter d 8  of inlet portion  52  remains substantially constant through inlet portion  52  between outlet portion  54  and assembly inlet  56 , and through an integrally formed bend  164  that is positioned between valve outlet portion  54  and assembly inlet  56 . In the exemplary embodiment, inlet portion  52  has a generally Z-shaped bend  164  such that assembly inlet  56  is substantially parallel to assembly outlet  60 . In an alternative embodiment, interior surface  160  is oriented substantially parallel to formed bend  164  to facilitate a smooth transition between adjoining ducting  12 . In a further alternative embodiment, valve assembly  14  includes piston  120 , but valve inlet portion  52  does not include bend  164 . Rather, in this alternative embodiment, valve inlet portion  52  is a substantially right cylinder.  
         [0027]     Valve inlet portion  52  includes a centerline  170  that extends between assembly inlet  56  and outlet portion  54 . More specifically, in the exemplary embodiment, between inlet  56  and bend  164 , centerline  170  is substantially parallel to outlet portion centerline  72 , and between bend  164  and outlet portion  54 , centerline  170  is substantially co-linear with outlet portion centerline  72 . Accordingly, within bend  164 , centerline  170  extends obliquely with respect to outlet portion centerline  72 . More specifically, within bend  164 , centerline  170  is obliquely offset an angle θ from outlet portion centerline  72 . In one embodiment, angle θ is equal between approximately six and twenty degrees. In the exemplary embodiment, angle θ is approximately equal thirteen degrees.  
         [0028]     Inlet portion diameter d 8  is smaller than bore diameter d 2  extending between outlet portion shoulder  78  and inlet portion  52 . Accordingly, a shoulder  182  is defined at the union of inlet and outlet portions  52  and  54 , respectively. Shoulder  182  provides a biasing contact for valve spring  150 , and includes an annular seat  184  has a diameter d 9  that is slightly smaller than valve inner cylinder external diameter d 3 , and as such facilitates positioning valve-inner cylinder  90  with respect to valve body  50 .  
         [0029]     Inlet portion  52  includes an opening  186  that extends diametrically through inlet portion  52  between inlet portion exterior surface  66  and interior surface  160 . In the exemplary embodiment, opening  186  is substantially parallel valve piston opening  154  and is sized to receive an actuator system axle  190  therethrough. More specifically, and as described in more detail below, each opening  186  extends through an actuator system inlet mount  188  that is integrally formed with inlet portion  52 .  
         [0030]     An actuator system  200  is coupled to valve body  50  to facilitate controlling fluid flow through valve assembly  14 . Specifically, actuator system  200  is coupled to valve inlet and outlet portions  52  and  54 , respectively, by connector link  156 . More specifically, an inlet side  202  of connector link  156  is coupled to axle  190  for controlling rotation of a sealing mechanism or sealing plate  206 .  
         [0031]     Sealing plate  206  has a substantially circular outer perimeter  208  and a substantially arcuate cross-sectional profile. In the exemplary embodiment, sealing plate  206  is formed with a constant radius such that plate  206  has a truncated spherical cross-sectional profile. Sealing plate  206  includes a front side  210  and an opposing rear side  212 . Plate  206  includes a centerline axis  214  extending therethrough, and a shaft bore  216  that extends therethrough and is sized to receive axle  190  therein. More specifically, axle  190  extends through shaft bore  216  and pivotally couples plate  206  within valve body  50 .  
         [0032]     Each plate side  210  and  212  defines a portion of shaft bore  216 . More specifically, bore  216  is not concentrically aligned with respect to plate centerline axis  214 , but rather extends obliquely through plate  206  with respect to centerline axis  214 . Accordingly, each side  210  and  212  includes a raised area  218  that extends outwardly from an outer surface  220  of plate  206  in a frusto-conical cross-section to define a portion of shaft bore  216 .  
         [0033]     Plate raised areas  218  enable axle  190  to extend through plate  206  within inlet portion bend  164 . More specifically, axle  190  is aligned substantially perpendicularly with respect to outlet portion centerline  72 , and is therefore aligned obliquely at angle θ with respect to bend centerline  170 . Accordingly, when plate  206  is in a fully open position, as shown in  FIGS. 2 and 3 , plate  206  is obliquely offset with respect to inlet portion bend  164 . However, because axle  190  is offset from plate centerline axis  214 , when plate  206  is rotated to a fully closed position, plate  206  is aligned substantially perpendicularly with respect to bend centerline  170  such that plate outer perimeter  208  circumferentially contacts inlet portion interior surface  160  in sealing contact, as described in more detail below. In one embodiment, valve assembly  14  includes a sensor to sense a position of plate  206  with respect to valve assembly, such as but not limited to an LVDT displacement transducer. Valve axle  190  is inclined at angle θ with respect to bend centerline  170  and with respect to plate centerline axis  214  to facilitate providing a continuous and substantially round sealing contact between plate outer perimeter  208  and interior surface  160 . More specifically, bend  164  enables plate  206  to be aligned substantially perpendicularly to interior surface  160  when plate  206  is fully closed, and causes axle  190  to be aligned substantially perpendicularly to the motion of piston  120 .  
         [0034]     Axle  190  is rotatably coupled to connector link inlet side  202  at each actuator system inlet mount  188  by a pair of bearings  230 , a valve lock  232 , and a pair of cranks  234 . More specifically, bearings  230  are rotatably coupled to axle  190  within each mount  188 , and are secured in position by seal members  236 . A seal member  236  nearest valve lock  232  are coupled to inlet portion  52  by a plurality of fasteners  240  that extend through seal member openings  242  and into integrally formed inlet mount openings  244  and into integrally formed inlet mount openings  244 . A seal member  236  opposite valve lock  232  are coupled to inlet portion  52  by an arcuate snap ring  245 . Seal members  236  facilitate preventing fluid leakage through inlet portion opening  186  and around axle  190 .  
         [0035]     Axle  190  is then inserted through each valve lock  232  prior to being coupled to connector link inlet side  202  by each respective crank  234 . Valve lock  232  facilitates maintaining axle  190  in rotational position, such that plate  206  may be maintained in an orientation, such as fully open or fully closed, with respect to valve body  50 .  
         [0036]     An outlet side  250  of each connector link  156  is coupled to valve piston  120  by connecting rod  155  through connector link mounts  80 . More specifically, each connector link mount  80  includes an integrally formed slot  252  that extends substantially parallel to outlet portion centerline  72 . Each slot  252  is sized to receive a slider  254  therein in slidable contact, and includes a slotted opening  256  that extends through slot  252 . Each connecting rod  155  is coupled to valve piston  120  and extends radially outward through slotted openings  256  and through sliders  254  to couple through a threaded nut  258  to connector link outlet side  250 . More specifically, a cover plate  260  is aligned with respect to slot  252  by a plurality of dowel pins  262  that extend through cover plate openings  266 .  
         [0037]     During operation, fluid enters valve assembly  14  through assembly inlet  56  and into valve body inlet portion  52 . Inlet portion bend  164  causes a direction fluid flowing within inlet portion  52  to be changed within inlet portion  52 . More specifically, fluid flow is turned through angle θ in the vicinity of plate  206 . Bend  164  enables axle  190  to be coupled substantially perpendicularly to movement of piston  120  which, as described in more detail below, facilitates converting rectilinear motion of piston  120  into rotary motion of sealing plate  206 . Accordingly, if plate  206  is in a fully closed position, plate  206  is substantially perpendicular to a direction of fluid flow within bend  164 . As such, plate outer perimeter  208  forms a substantially continuous seal circumferentially within inlet portion  52 , which facilitates preventing fluid flow through valve assembly  14 . More specifically, when plate  206  is rotated to the closed position, actuator or supply fluid is turned off and spring  150  biases sealing plate  206  through actuator system  200  in the fully closed position.  
         [0038]     Main actuation fluid enters valve piston  120  through a port  277  and operates against valve piston outlet face  126 . Additional actuation fluid operates on valve piston  120  in a gap  279  that is partially defined between valve piston inlet edge  124  and shoulder  182 . Accordingly, piston  120  is double actuated by the actuation fluid. More specifically, when plate  206  is desired to be rotated into a partially opened or modulated position, main pressurized actuator fluid is supplied to outlet portion  54  through port  277  into a gap  280  defined between valve piston seal assembly  131  and valve-inner cylinder mounting flange  106 . The fluid pressure of the actuator fluid forces piston  120  to translate, which in turn causes connectors links  156  to translate through slots  252 . The translational motion of links  156  causes subsequent rotational motion of valve cranks  234 . Rotation of cranks  234  causes rotation of axle  190  which causes plate  206  to rotate from the closed position, such that fluid flows past sealing mechanism  206  and downstream from valve assembly  14 .  
         [0039]     Annular seat  184  allows for axial thermal growth differences between valve-inner cylinder  90  and valve body  50 . Seat  184  also permits flid that has flowed downstream from seat  206  to enter gap  140 . Fluid pressure within gap  140  acts in opposition to the force induced by actuation fluid, which in conjunction with spring force induced by spring  150  causes plate  206  to self-regulate the flow of fluid. More specifically, if the downstream pressure decreases, the opposing force also decreases, which allows pressurized actuation fluid to force sealing mechanism  206  to open more fully to restore the regulated fluid flow at a predetermined pressure.  
         [0040]     Despite the offset of inlet portion  52  with respect to outlet portion  54 , a center of gravity  290  of valve assembly  14  is located substantially along outlet portion centerline  72 . Accordingly, bending stresses induced to valve assembly  14  during the operation of actuator system  200  are facilitated to be reduced in comparison to other known valves which have offset centers of gravity. As such, valve body  50  facilitates extending a useful life of valve assembly  14 . Furthermore, because center of gravity  290  is positioned along outlet portion centerline  72 , eccentricity induced bending stresses of adjoining ducting  12  are also facilitated to be reduced, which facilitates the use of mounting bracket assemblies  42  fabricated from lighter weight materials. In addition, valve assembly  14  requires less physical space envelopes than other known valve assemblies used for the same applications.  
         [0041]      FIG. 4  is a perspective view of an alternative embodiment of a valve assembly  300  that may be used with gas turbine engine  10  (shown in  FIG. 1 ).  FIG. 5  is a side view of valve assembly  300 . Valve assembly  300  is substantially similar to valve assembly  14  (shown in  FIGS. 2 and 3 ) and components of assembly  14  that are identical to components of valve assembly  300  are identified in  FIGS. 4 and 5  using the same reference numerals used in  FIGS. 2 and 3 . Accordingly, valve assembly  300  includes valve body  50 , inlet portion  52 , and outlet portion  54 . Additionally valve assembly  300  includes valve-inner cylinder  90 , valve piston  120 , and an actuator system  302 . Actuator system  302  is substantially similar to actuator system  200  and includes a pair of pivot links  303  coupled to sealing plate  206  by a wishbone link  304 .  
         [0042]     More specifically, each wishbone link  304  includes a pair of outlet ends  156  and a connector actuator coupler  312 . Each wishbone link outlet end is coupled to outlet portion  54  by connecting rods  155  extending through mounts  80 . More specifically, each wishbone link mount  80  includes slot  252  and slider  254 . Each connecting rod  155  is coupled to valve piston  120  and extends radially outward through slotted openings  256  and through sliders  254  to couple through bushing  258  to pivot link outlet side  250 . More specifically, cover plate  260  is coupled to each pivot link mount  80  by fasteners  262  that extend through cover plate openings  266  into openings  268  formed integrally within each link mount  80 .  
         [0043]     Each pivot links  303  is pivotally coupled to wishbone link  304  between wishbone link outlet end  156  and wishbone connector actuator coupler  312 . Pivot links  303  provide additional support to wishbone link  304  and facilitate maintaining wishbone link  304  in alignment with respect to valve assembly  300 .  
         [0044]     Wishbone link  304  extends partially circumferentially to couple together with an actuator rod  320  that extends laterally upstream towards an inlet actuator mount  188 . Within valve assembly  300 , inlet portion  52  includes only one actuator mount  188 , but also includes an integrally-formed axle seat  322  that is described in more detail below. Each wishbone link  304  is also pivotally coupled by a hinge pin  324  that is positioned between wishbone link outlet end  156  and wishbone connector actuator coupler  312 .  
         [0045]     Actuator rod  320  is coupled to actuator mount  188  with an axle  190  that is rotatably coupled to actuator rod  320  by a bearing  230 , a valve lock  232 , a crank  234 , and a yoke  330 . More specifically, bearing  230  is rotatably coupled to axle  190  within mount  188 , and is secured in position by a seal member  236 . Axle  190  is also inserted through valve lock  232  prior to being inserted through yoke  330  and coupled to actuator rod  320  by crank  234 . Yoke  330  provides additional support to actuator system  302 .  
         [0046]     Axle  190  does not extend diametrically through inlet portion  52 , but rather, an inner end  340  of axle  190  is rotatably coupled within a bearing assembly  342 . More specifically, bearing assembly  342  is seated within axle seat  322 . Accordingly, because valve assembly  300  includes only one opening  186  within inlet portion  52 , valve assembly  300  facilitates reducing blow-by leakage that may occur through openings  186 .  
         [0047]     The above-described valve assembly is cost-effective and highly reliable. The valve assembly includes a valve body that includes an integrally formed inlet and outlet portion. Because the portions are only offset by a minimal angle, the center of gravity of the assembly is located within the valve assembly and along a centerline of the outlet portion. As such, vibrational induced bending moments and eccentricity induced stresses to the valve body are facilitated to be reduced. As a result, the valve body facilitates extending a useful life of the valve assembly in a cost-effective and reliable manner.  
         [0048]     While the invention has been described in terms of various specific embodiments, those skilled in the art will recognize that the invention can be practiced with modification within the spirit and scope of the claims.