Patent Publication Number: US-2021187525-A1

Title: Isolating valve

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
     This application claims priority to U.S. Provisional Application No. 62/950,738 filed Dec. 19, 2019, and entitled “ISOLATING VALVE,” the disclosure of which is hereby incorporated by reference in its entirety. 
    
    
     BACKGROUND 
     This disclosure relates to fluid spraying. More particularly, this disclosure relates to electrical isolation during spraying. 
     Electrostatic sprayers are used to spray a charged liquid, such as paint or water, onto a grounded object. The liquid is atomized as it is ejected from the spray gun and is charged as it moves past an electrode of the spray gun. The charged liquid is attached to the grounded object that the liquid is sprayed onto, thereby providing a more even coating to the object. 
     Water-based liquids, such as paints, can create a conduction path between the spray gun and the main fluid supply. However, because the main fluid supply is grounded, the spray gun and charged fluid must be isolated from that main fluid supply. As such, the supply tank directly connected to the spray gun must be electrically isolated from the main fluid supply. To refill the supply tank with additional fluid the user shuts down the electrostatic sprayer and discharges any charge prior to accessing the supply tank. The user then refills the supply tank and restarts the spraying system to resume electrostatic spraying. 
     SUMMARY 
     According to one aspect of the disclosure, an isolation valve includes an inlet module, an outlet module, and an actuating module. The inlet module includes a stem extending from a shuttle and including an internal flowpath extending from a first end of the stem connected to the shuttle to a fluid port through the stem; and a sleeve disposed around the stem and movable relative to the stem. The fluid port is disposed within the sleeve with the inlet module in the isolated state and the fluid port is disposed outside of the sleeve with the inlet module in the connected state. The outlet module includes a piston at least partially disposed within a piston bore through the outlet module. The actuating module is configured to actuate the isolation valve between an isolated state, where the inlet module is spaced from the outlet module such that a gap is disposed between the inlet module and the outlet module, and a connected state, where the inlet module is mechanically and fluidly connected to the outlet module. 
     According to another aspect of the disclosure, a method includes driving an isolation valve in a first direction from an isolated state, where an inlet module is spaced from an outlet module such that a gap is formed therebetween, to a first intermediate state, where contact is made between a stem of the inlet module and a piston of the outlet module; driving the isolation valve in the first direction from the first intermediate state to a second intermediate state, where contact is made between a sleeve through which the stem extends and the outlet module such that the sleeve is braced against the outlet module to prevent further movement of the sleeve in the first direction; driving the isolation valve in the first direction from the second intermediate state to a connected state, wherein the stem shifts relative to the piston as the isolation valve transitions to the connected state such that a fluid port through the stem is uncovered within the outlet module thereby opening a flowpath through the stem between an inlet port of the inlet module and an outlet port of the outlet module; and driving the isolation valve from the connected state to the second intermediate state, from the second intermediate state to the first intermediate state, and from the first intermediate state to the isolated state. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  is a schematic block diagram of an electrostatic spray system in a first state. 
         FIG. 1B  is a schematic block diagram of an electrostatic spray system in a second state. 
         FIG. 2A  is an isometric view of a first isolation valve in an isolated state. 
         FIG. 2B  is an isometric view of the first isolation valve in a connected state. 
         FIG. 2C  is an exploded view of the first isolation valve. 
         FIG. 3A  is a cross-sectional view of the first isolation valve in the isolated state. 
         FIG. 3B  is a cross-sectional view of the first isolation valve in a first intermediate state. 
         FIG. 3C  is a cross-sectional view of the first isolation valve in a second intermediate state. 
         FIG. 3D  is a cross-sectional view of the first isolation valve in the connected state. 
         FIG. 4  is an enlarged view of a first interface between a sleeve, a stem, and a piston of an isolation valve. 
         FIG. 5  is an enlarged view of a second interface between a sleeve, a stem, and a piston of an isolation valve. 
         FIG. 6A  is a cross-sectional view of the first isolation valve showing an inlet wash path. 
         FIG. 6B  is a cross-sectional view of the first isolation valve showing an outlet wash path. 
         FIG. 7A  is a cross-sectional view of a second isolation valve in the isolated state. 
         FIG. 7B  is a cross-sectional view of the second isolation valve in a first intermediate state. 
         FIG. 7C  is a cross-sectional view of the second isolation valve in a second intermediate state. 
         FIG. 7D  is a cross-sectional view of the second isolation valve in the connected state. 
         FIG. 8  is an enlarged view of detail  8  in  FIG. 7B  showing a third interface between a sleeve, a stem, and a piston of an isolation valve. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1A  is a schematic block diagram of electrostatic spray system  10  in a first state.  FIG. 1B  is a schematic block diagram of electrostatic spray system  10  in a second state.  FIGS. 1A and 1B  will be discussed together. Electrostatic spray system  10  includes main reservoir  12 ; isolation valves  14   a,    14   b;  pumps  16   a,    16   b;  and applicator  18 . Isolation valves  14   a,    14   b  include, respectively, inlet modules  20   a,    20   b;  outlet modules  22   a,    22   b;  and actuating modules  24   a,    24   b.    
     Electrostatic spray system  10  is configured to atomize and spray a liquid, such as water and water-based coatings, and charge the liquid droplets to a desired potential. For example, electrostatic spray system  10  can be configured to spray with a charge in the range of 50-120 kilovolts (kV). More specifically, electrostatic spray system can be configured to spray with a charge in the range of 60-100 kV. It is understood, however, that electrostatic spray system  10  can be configured to spray at any desired charge. Isolation valves  14   a,   14   b  can be sized to provide electrical isolation between charged components and earth ground potential P regardless of the charge. The charged droplets are directed towards an object to coat the object with the droplets. Electrostatic spray system  10  provides a continuous supply of the liquid to applicator  18  for application while isolating the liquid in main reservoir  12  from the liquid being sprayed to prevent shorting to earth ground. 
     Main reservoir  12  stores a supply of spray fluid for application on a substrate by applicator  18 , which can be an electrostatic spay gun of any desired configuration, either manual or automatic. Main reservoir  12  is electrically connected to earth ground potential P throughout operation. Applicator  18  must be electrically isolated from earth ground potential P to prevent shorting. Isolation valves  14   a,    14   b  facilitate electrical isolation while still allowing electrostatic spray system  10  to provide a continuous supply of spray fluid for use at applicator  18 . As such, the user does not need to turn off electrostatic spray system  10  to refill with liquid from main reservoir  12 . 
     Isolation valve  14   a  is disposed downstream of main reservoir  12 . Inlet module  20  of isolation valve  14   a  is fluidly connected to main reservoir  12  to receive fluid from main reservoir  12 . Inlet module  20   a  of isolation valve  14   a  is electrically connected to earth ground potential P due to the conductive nature of the spray liquid. 
     Actuating module  24   a  is connected to inlet module  20   a  and configured to drive inlet module  20   a  between an isolated state, shown in  FIG. 1A , and a connected state, shown in  FIG. 1B . For example, actuating module  24   a  can include an air cylinder and a shaft driven by a piston disposed in the air cylinder. Compressed air can be provided to the air cylinder to drive the piston, thereby driving the shaft, which is connected to inlet module  20   a  to drive inlet module  20   a.    
     Outlet module  22   a  is configured to connect with inlet module  20   a  to receive fluid from inlet module  20   a  with isolation valve  14   a  in the connected state. Outlet module  22   a  is spaced from inlet module  20   a  such that gap  26   a  is formed between inlet module  20   a  and outlet module  22   a  with isolation valve  14   a  in the isolated state. Gap  26   a  electrically isolates inlet module  20   a  and outlet module  22   a.    
     Pump  16   a  is disposed downstream of isolation valve  14   a  and upstream of isolation valve  14   b.  Pump  16   a  is fluidly connected to outlet module  22   a  to receive spray fluid from isolation valve  14   a.  Pump  16   a  is fluidly connected to inlet module  20   b  to provide spray fluid to inlet module  20   b.  Pump  16   a  is configured to store a supply of spray fluid and to drive the spray fluid downstream through isolation valve  14   b  and pump  16   b  to applicator  18 . For example, pump  16   a  can be a one-way positive displacement pump that includes both a chamber for holding a supply of spray fluid and an actuator, such as a piston, for driving the spray fluid downstream. In some examples, pump  16   a  is powered, such as pneumatically, among other options, to drive the spray fluid downstream out of pump  16   a.  Pump  16   a  can be refilled by the upstream fluid pressure driving fluid into pump  16   a.  Alternatively pump  16   a  can be actively driven through a suction stroke. 
     Isolation valve  14   b  is substantially similar to isolation valve  14   a.  In some examples, isolation valves  14   a,    14   b  are identical. Isolation valve  14   b  is disposed downstream of pump  16   a  and upstream of pump  16   b.  Inlet module  20   b  of isolation valve  14   b  is fluidly connected to pump  16   a  to receive fluid from pump  16   a.  Inlet module  20   b  of isolation valve  14   b  is electrically isolated from earth ground potential P due to gap  26   a  with electrostatic spray system  10  in the state shown in  FIG. 1A . Inlet module  20   b  is electrically connected to earth ground potential P with electrostatic spray system  10  in the state shown in  FIG. 1B  due to the conductive nature of the spray fluid. 
     Actuating module  24   b  is connected to inlet module  20   b  and configured to drive inlet module  20   b  between an isolated state, shown in  FIG. 1B , and a connected state, shown in  FIG. 1A . For example, actuating module  24   b  can include an air cylinder and a shaft driven by a piston disposed in the air cylinder. Compressed air can be provided to the air cylinder to drive the piston, thereby driving the shaft, which is connected to inlet module  20   b  to drive inlet module  20   b.  In some examples, actuating module  24   b  is electrically grounded throughout operation. To prevent shorting, inlet module  20   b  is electrically isolated from the grounded actuating module  24   b.  For example, the shaft or other components extending between and connecting actuating module  24   b  and inlet module  20   b  can be formed from a non-conductive material. In other examples, actuating module  24   b  is electrically isolated from earth ground potential P, such as by mounting isolation valve  14   b  in a non-conductive enclosure. 
     Outlet module  22   b  is configured to connect with inlet module  20   b  to receive fluid from inlet module  20   b  with isolation valve  14   b  in the connected state. In the isolated state, outlet module  22   b  is spaced from inlet module  20   b  such that gap  26   b  is formed between inlet module  20   b  and outlet module  22   b.  Gap  26   b  electrically isolates inlet module  20   b  and outlet module  22   b.  Outlet module  22   b  is electrically connected to applicator  18  throughout operation, such that outlet module  22   b  is charged whenever applicator  18  is charged. Gap  26   b  electrically isolates outlet module  22   b  from earth ground potential P throughout operation. 
     Pump  16   b  is disposed downstream of isolation valve  14   b  and is fluidly connected to outlet module  22   b  to receive spray fluid from isolation valve  14   b.  Pump  16   b  is fluidly connected to outlet module  22   b  to receive spray fluid from isolation valve  14   b.  Pump  16   b  is fluidly connected to applicator  18  to provide spray fluid to applicator  18 . Pump  16   b  is configured to store a supply of spray fluid and to drive the spray fluid downstream to applicator  18 . For example, pump  16   b  can be a one-way positive displacement pump that includes both a chamber for holding a supply of spray fluid and an actuator, such as a piston, for driving the spray fluid downstream. In some examples, pump  16   b  is powered, such as pneumatically, among other options, to drive the spray fluid downstream out of pump  16   b.  Pump  16   b  can be refilled by the upstream fluid pressure driving fluid into pump  16   b.  Alternatively pump  16   b  can be actively driven through a suction stroke. 
     During operation, electrostatic spray system  10  can provide a continuous supply of conductive spray fluid from main reservoir  12  to applicator  18  while maintaining electrical isolation between charged components and earth ground potential P. For the example discussed, electrostatic spray system  10  is assumed to initially be in the state shown in  FIG. 1A . Isolation valve  14   a  is in the isolated position, such that inlet module  20   a  is electrically isolated from outlet module  22   a.  Isolation valve  14   b  is in the connected position, such that inlet module  20   a  is electrically and fluidly connected to outlet module  22   b.    
     The user activates applicator  18 , such as by depressing a trigger of a spray gun forming applicator  18 . Pump  16   a  is activated and drives spray fluid downstream through isolation valve  14   b  and pump  16   b  and to applicator  18 . The spray fluid is ejected from applicator  18  as a fluid spray. Because applicator  18  is charged, each component fluidly connected to applicator  18  is also charged due to the conductive nature of the spray fluid. The charged components are isolated from earth ground potential P by gap  26   a  formed between inlet module  20   a  and outlet module  22   a.    
     The fluid level in pump  16   a  continues to drop until the fluid level reaches a refill level. For example, a sensor can be associated with pump  16   a  to determine the amount of fluid remaining in pump  16   a.  The sensor can be of any type suitable for sensing the fluid in pump  16   a  while maintaining electrical isolation of pump  16   a.  For example, the sensor can be an ultrasonic level sensor, fiber optical level sensor, scale configured to weigh pump  16   a,  float in the chamber of pump  16   a,  or be of any other configuration suitable for sensing the fluid remaining in pump  16   a.    
     When the fluid level in pump  16   a  reaches the refill level, electrostatic spray system  10  actuates to the state shown in  FIG. 1B . For example, a system controller can activate pump  16   b  and isolation valve  14   b  such that pump  16   b  actively drives spray fluid to applicator  18  and isolation valve  14   b  transitions from the connected state to the isolated state. Actuating module  24   b  pulls inlet module  20   b  away from and out of connection with outlet module  22   b,  thereby creating gap  26   b  between inlet module  20   b  and outlet module  22   b.  Gap  26   b  electrically isolates inlet module  20   b  from outlet module  22   b  such that the components upstream of gap  26   b  are electrically isolated from applicator  18  while the components downstream of gap  26   b  are charged. With gap  26   b  formed, each of isolation valve  14   a  and isolation valve  14   b  are in the isolated state. 
     Isolation valve  14   a  is then actuated from the isolated state to the connected state. Actuating module  24   a  drives inlet module  20   a  into connection with outlet module  22   a,  eliminating gap  26   a  from between inlet module  20   a  and outlet module  22   a.  With isolation valve  14   a  in the connected state, a fluid flowpath is created through isolation valve  14   a  between main reservoir  12  and pump  16   a.  The spray fluid flows from main reservoir  12 , through inlet module  20   a,  through outlet module  22   a,  and to pump  16   a.  The spray fluid refills pump  16   a.  The spray fluid can be driven to pump  16   a  in any desired manner. For example, a pump can be disposed upstream of isolation valve  14   a,  a pressure within main reservoir  12  can drive the fluid to pump  16   a,  and/or pump  16   a  can be actively controlled to draw spray fluid into pump  16   a.    
     With pump  16   a  refilled, isolation valve  14   a  is transitioned back to the isolated state from the connected state. Actuating module  24   a  pulls inlet module  20   a  out of connection with outlet module  22   a.  Gap  26   a  is reformed between inlet module  20   a  and outlet module  22   a,  electrically isolating outlet module  22   a  from earth ground potential P. At this point, each of isolation valve  14   a  and isolation valve  14   b  are in the isolated state. 
     With gap  26   a  reformed, isolation valve  14   b  is actuated from the isolated state to the connected state. Actuating module  24   b  drives inlet module  20   b  into connection with outlet module  22   b,  thereby eliminating gap  26   b.  A flowpath is thereby created through isolation valve  14   b.  Pump  16   a  is activated and begins driving the spray fluid downstream through isolation valve  14   b  and pump  16   b  and to applicator  18 . The spray fluid refills pump  16   b  as the spray fluid flow through pump  16   b,  such that pump  16   b  is primed to provide spray fluid to applicator  18  during the next refill cycle of pump  16   a.    
     Electrostatic spray system  10  can thereby provide a continuous supply of spray fluid from an electrically grounded main reservoir  12  to an electrically charged applicator  18  while maintaining electrical isolation between any grounded components and any charged components. While electrostatic spray system  10  is described as a continuous supply system, it is understood that isolation valve  14   a,    14   b  can provide electrical isolation in systems including only a single isolation valve  14   a,    14   b.  In such a system, isolation valve  14   a,    14   b  is placed in the connected state only when applicator  18  is discharged. 
       FIG. 2A  is an isometric view of isolation valve  14  in an isolated state.  FIG. 2B  is an isometric view of isolation valve  14  in a connected state.  FIG. 2C  is an exploded view of isolation valve  14 .  FIGS. 2A-2C  will be discussed together. Isolation valve  14  includes inlet module  20 , outlet module  22 , and actuating module  24 . 
     Inlet module  20  includes shuttle  28 ; sleeve  30 ; stem  32 ; inlet spring  34 ; shuttle lock nut  36 ; inner seals  38   a,    38   b  ( FIG. 2C ); valve seals  40   a,    40   b  ( FIG. 2C ); alignment pin  42  ( FIG. 2C ); floating connector  44  ( FIG. 2C ); washer  46  ( FIG. 2C ); and retaining nut  48  ( FIG. 2C ). Shuttle  28  includes shuttle block  50  and shuttle housing  52 . Shuttle block  50  includes slot  54   a  ( FIG. 2C ), housing bore  56   a  ( FIG. 2C ), and rail bores  58  ( FIG. 2C ). Shuttle housing  52  includes inlet port  60 , pin slot  62   a  ( FIG. 2C ), shuttle bore  64  ( FIG. 2C ), and alignment feature  66   a  ( FIG. 2C ). Sleeve  30  includes sleeve flange  68 . 
     Outlet module  22  includes base  70 ; piston  72  ( FIG. 2C ); piston seals  74  ( FIG. 2C ); piston seal retainer  76  ( FIG. 2C ); piston spring  78  ( FIG. 2C ); piston housing  80 ; alignment pin  81  ( FIG. 2C ); base lock nut  82 ; seal retainer  84  ( FIG. 2C ); cartridge rings  86   a,    86   b  ( FIG. 2C ); wiper seals  88   a,    88   b  ( FIG. 2C ); chamber seals  90   a,    90   b  ( FIG. 2C ); and end cap  92 . Base  70  includes outlet block  94  and outlet housing  96 . Outlet block  94  includes slot  54   b  ( FIG. 2C ), housing bore  56   b  ( FIG. 2C ), and rail bores  98  ( FIG. 2C ). Outlet housing  96  includes pin slot  62   b  ( FIG. 2C ); alignment feature  66   b  ( FIG. 2C ); wash ports  100   a,    100   b  (wash port  100   b  shown in  FIG. 6B ); outlet port  102 ; piston bore  104  ( FIG. 2C ); and housing ports  105  ( FIG. 2C ). Piston  72  includes piston head  106  ( FIG. 2C ) and piston shaft  108  ( FIG. 2C ). Piston housing  80  includes boost port  109 . 
     Actuating module  24  includes drive assembly  110 , alignment assembly  112 , drive block  114 , and drive lock nut  116 . Drive assembly  110  includes cylinder  118  and drive piston  120 . Alignment assembly  112  includes guide rails  122 , bearings  124  ( FIG. 2C ), and fasteners  126 . Drive block  114  includes rail bores  98  ( FIG. 2C ) and central bore  128  ( FIG. 2C ). 
     Isolation valve  14  is substantially similar to isolation valves  14   a,    14   b  ( FIGS. 1A and 1B ) and is configured for use in a spray system, such as electrostatic spray system  10  ( FIGS. 1A and 1B ). It is understood, however, that isolation valve  14  can be utilized in any application where electrical, mechanical, and/or fluid isolation between an inlet and outlet of a valve is desired. 
     Actuating module  24  is connected to inlet module  20  to actuate inlet module  20  between an isolated state ( FIG. 2A ) and a connected sate ( FIG. 2B ). In the isolated state, gap  26  is formed between inlet module  20  and outlet module  22  such that inlet module  20  is electrically, mechanically, and fluidly isolated from outlet module  22 . In the connected state, inlet module  20  is electrically, mechanically, and fluidly connected to outlet module  22 . 
     Drive assembly  110  is attached to inlet module  20 . Drive assembly  110  drives inlet module  20  between the isolated and connected states. Cylinder  118  is mounted to drive block  114 . Drive piston  120  extends from cylinder  118  through central bore  128  in drive block  114  and towards outlet module  22 . Drive lock nut  116  secures cylinder  118  to drive block  114 . Cylinder  118  includes an internal piston connected to drive piston  120 . Motive fluid, such as compressed air, is provided to cylinder  118  to actuate drive piston  120 . While drive assembly  110  is described as including a pneumatic actuator, it is understood that drive assembly  110  can include an actuator of any desired type, such as an electric actuator or a hydraulic actuator, among other options. As such, drive assembly  110  can include any sort of two-way drive for actuating inlet module  20 . Drive piston  120  can be formed from any desired material, such as metal, plastic, or ceramic, among other options. In some examples, drive piston  120  is formed from a non-conductive material to prevent shorting while isolation valve  14  is in the connected state. For example, isolation valve  14  is charged when in the connected state in examples where isolation valve  14  is functioning as isolation valve  14   b  in electrostatic spray system  10 . Drive piston  120  being formed from a non-conductive material prevents a conduction path from forming between inlet module  20  and cylinder  118 . 
     Alignment assembly  112  extends between drive assembly  110  and outlet module  22 . Alignment assembly  112  is configured to maintain alignment of inlet module on valve axis A-A as inlet module  20  transitions between the isolated and connected states. More specifically, inlet module  20  is guided to ensure concentricity between stem  32  and piston  72  as inlet module  20  engages with outlet module  22 . Guide rails  122  extend between rail bores  98  in drive block  114  and outlet block  94 . Fasteners  126  extend through rail bores  98  and into guide rails  122  to secure guide rails  122  to drive block  114  and outlet block  94 . Guide rails  122  are formed from non-conductive material to ensure that inlet module  20  is electrically disconnected from outlet module  22  in the isolated state. Shuttle block  50  rides on guide rails  122  via bearings  124 . Bearings  124  are disposed in rail bores  58  of shuttle block  50 . While alignment assembly  112  is described as including guide rails  122 , it is understood that alignment assembly  112  can include a guide of any type suitable for maintaining concentricity. For example, the guide can be a single rail on which shuttle block  50  rides, among other configurations. In other examples, inlet module  20  can be free-floating such that isolation valve  14  does not include an alignment assembly  112 . 
     Inlet module  20  receives spray fluid from an upstream location via inlet port  60 . Shuttle  28  is connected to drive piston  120  to be driven by drive piston  120  and is mounted on guide rails  122 . Shuttle housing  52  is mounted to shuttle block  50  to slide with shuttle block  50 . Shuttle housing  52  extends through housing bore  56   a  in shuttle block  50 . A first portion of shuttle housing  52  is disposed on a first side of shuttle block  50  that faces outlet module  22 . A second portion of shuttle housing  52  is disposed on a second side of shuttle block  50  that faces actuating module  24 . While shuttle housing  52  is described as separately formed from shuttle block  50 , it is understood that shuttle housing  52  and shuttle block  50  can be integrally formed as a single part or from more than two parts. Separately forming shuttle housing  52  and shuttle block  50  allows shuttle housing  52  and shuttle block  50  to be formed from different materials, providing a cost savings. For example, shuttle block  50  can be formed from aluminum and shuttle housing  52  can be formed from stainless steel. 
     Floating connector  44  is disposed in the second portion of shuttle housing  52 . Retaining nut  48  is attached to the second portion of shuttle housing  52  and retains floating connector  44  within shuttle housing  52 . Washer  46  is disposed between the flange of floating connector  44  and retaining nut  48 . While washer  46  is shown as a wave washer, it is understood that washer  46  can be of any type suitable for interfacing between the flange of floating connector  44  and retaining nut  48 . Drive piston  120  extends through retaining nut  48  and washer  46  and is connected to floating connector  44 . Drive piston  120  drives inlet module  20  via connection with floating connector  44 . 
     Shuttle lock nut  36  interfaces with the first portion of shuttle housing  52  extending through shuttle block  50 . Shuttle lock nut  36  secures shuttle housing  52  to shuttle block  50 . For example, shuttle lock nut  36  can include internal threading configured to interface with external threading on the first portion of shuttle housing  52 . While shuttle lock nut  36  and shuttle housing  52  are described as including interfaced threading, it is understood that shuttle lock nut  36  can lock with shuttle housing  52  in any desired manner. For example, shuttle lock nut  36  can interface with shuttle housing  52  by a bayonet connection, among other options. 
     Alignment feature  66   a  is formed as a portion of shuttle housing  52 . Alignment feature  66   a  interfaces with slot  54   a  to properly align shuttle housing  52  relative to shuttle block  50 . Alignment pin  42  extends between shuttle block  50  and shuttle housing  52  to further maintain alignment between shuttle block  50  and shuttle housing  52 . Pin slot  62   a  is formed in shuttle housing  52 . Alignment pin  42  is disposed in a receiving hole (shown in  FIGS. 3A-3D ) in shuttle block  50  and received by pin slot  62   a.    
     In the example shown, alignment feature  66   a  is D-shaped with the flat portion positioned in slot  54 . It is understood, however, that alignment feature  66   a  and slot  54   a  can be of any mating configuration suitable for locking shuttle housing  52  relative to shuttle block  50 . Alignment feature  66   a  can be integrally formed with shuttle housing  52 , as shown, or can be separately formed, similar to alignment pin  42 . 
     Inlet port  60  extends into shuttle housing  52  through the flat portion of alignment feature  66 . A supply line is connected to inlet port  60  to provide fluid to isolation valve  14 . For example, the supply line can extend from a reservoir, similar to main reservoir  12 , or from a pump, similar to pump  16   a.  A flowpath extends through shuttle housing  52  from inlet module  20  to an outlet port disposed in shuttle bore  64 . 
     Inlet spring  34 , sleeve  30 , and stem  32  are disposed concentrically and coaxially. Sleeve  30  is at least partially disposed within shuttle bore  64 . Inlet spring  34  extends around sleeve  30  and is at least partially disposed within shuttle bore  64 . Inlet spring  34  interfaces with shuttle housing  52  and sleeve flange  68  to bias sleeve  30  away from shuttle housing  52 . 
     Stem  32  extends through sleeve  30  into shuttle bore  64 . Inner seal  38   a  is disposed at the interface between stem  32  and shuttle housing  52 . Inner seal  38   b  is disposed about the exterior of stem  32  and is positioned within the bore extending through sleeve  30 . The first inner seal  38  provides a seal where stem  32  interfaces with the outlet of the flowpath extending through shuttle housing  52  from inlet port  60 . The second inner seal  38  provides a seal between stem  32  and sleeve  30  throughout operation. Inner seal  38   b  provides a dynamic, sliding seal between stem  32  and sleeve  30  to prevent spray fluid from migrating between stem  32  and sleeve  30 . Stem  32  is locked to shuttle housing  52  by interfaced threading between the end of stem  32  extending into shuttle housing  52  and shuttle housing  52 . The fluid flows through a flowpath extending axially through stem  32 . 
     Valve seals  40   a,    40   b  are disposed on an exterior of stem  32 . As discussed in more detail below, a portion of stem 32-projects radially and is disposed between valve seals  40   a,    40   b.  Valve seals  40   a,    40   b  provide a sealing interface between stem  32  and piston  72  and sleeve  30 , respectively. Inlet spring  34  biases sleeve  30  into contact with valve seal  40   b.    
     Outlet module  22  is disposed at an opposite axial end of isolation valve  14  from actuating module  24 . In the example shown, outlet module  22  is held in a static location during operation. Base  70  supports and houses various other components of outlet module  22 . Outlet block  94  is mounted to guide rails  122  by fasteners  126  extending through rail bores  98 . Outlet housing  96  is mounted to outlet block  94  and extends through housing bore  56   b.  A first portion of outlet housing  96  is disposed on a first side of outlet block  94  that faces inlet module  20 . A second portion of outlet housing  96  is disposed on a second side of outlet block  94  opposite the first side. While base  70  is described as being formed from outlet housing  96  and outlet block  94 , it is understood that base  70  can be formed from more than two components or formed from a single component. In examples where base  70  is formed from multiple components, the components can be permanently or removably joined. Separately forming outlet housing  96  and outlet block  94  allows outlet housing  96  and outlet block  94  to be formed from different materials, thereby saving costs. For example, outlet block  94  can be formed from aluminum and outlet housing  96  can be formed from stainless steel. 
     Base lock nut  82  interfaces with the second portion of outlet housing  96  extending through outlet block  94 . Base lock nut  82  secures outlet housing  96  to outlet block  94 . For example, base lock nut  82  can include internal threading configured to interface with external threading on the second portion of outlet housing  96 . While base lock nut  82  and outlet housing  96  are described as including interfaced threading, it is understood that base lock nut  82  can lock with outlet housing  96  in any desired manner. For example, base lock nut  82  can interface with outlet housing  96  by a bayonet connection, among other options. In some examples, both base lock nut  82  and piston housing  80  are threaded onto the same threaded portion of outlet housing  96 . 
     Alignment feature  66   b  is formed as a portion of outlet housing  96 . Alignment feature  66   b  interfaces with slot  54   b  to align outlet housing  96  relative to outlet block  94 . Alignment pin  81  extends between outlet block  94  and outlet housing  96  to further maintain alignment therebetween. Pin slot  62   b  extends into outlet housing  96 . Alignment pin  81  is disposed in a receiving hole (not shown) in outlet block  94  and is received by pin slot  62   b.  In the example shown, pin slot  62   b  extends into an area of outlet housing  96  disposed opposite outlet port  102 . 
     In the example shown, alignment feature  66   b  is D-shaped with the flat portion positioned in slot  54   b.  It is understood, however, that alignment feature  66   b  and slot  54   b  can be of any mating configuration suitable for locking outlet housing  96  to outlet block  94 . Alignment feature  66   b  can be integrally formed with outlet housing  96 , as shown, or can be separately formed, similar to alignment pin  81 . 
     Outlet port  102  extends into outlet housing  96 . Outlet port  102  is an exit port for the fluid flowing out of isolation valve  14 . In the example shown, outlet port  102  extends through the flat portion of alignment feature  66   b.  It is understood, however, that outlet port  102  can extend into base  70  at any desired location. Wash ports  100   a,    100   b  extend into outlet housing  96 . Wash port  100   a  is connected to a wash reservoir to receive wash fluid from the wash reservoir. Wash port  100   b  is configured to receive the used wash fluid from within outlet housing  96  and provides an exit port for the wash fluid to exit outlet housing  96 . 
     Cartridge rings  86   a,    86   b;  wiper seals  88   a,    88   b;  and chamber seals  90   a,    90   b  are disposed within piston bore  104  of outlet housing  96 . Piston bore  104  extends fully through outlet housing  96 . Seal retainer  84  is disposed within outlet housing  96  and retains cartridge ring  86   b,  wiper seal  88   b,  and chamber seal  90   b  within outlet housing  96 . End cap  92  is attached to an opposite end of outlet housing  96  from seal retainer  84  and retains cartridge ring  86   a,  wiper seal  88   a,  and chamber seal  90   a  within outlet housing  96 . 
     Piston  72  at least partially extends into outlet housing  96  and is at least partially disposed in piston housing  80 . Piston housing  80  is connected to outlet housing  96 . Piston head  106  is disposed within piston housing  80 . Piston seals  74  are disposed around piston head  106 . Piston seal retainer  76  is attached to piston  72  and retains piston seals  74  on piston  72 . Piston head  106  and piston seals  74  divide piston housing  80  into a dry chamber and a wet chamber. Piston spring  78  is disposed within the dry chamber of piston housing  80  and interfaces with piston  72 . In the example shown, piston spring  78  interfaces with piston seal retainer  76 . Piston spring  78  is configured to bias piston  72  towards shuttle housing  52 . Piston spring  78  is configured to return piston  72  to a position associated with the isolated state of isolation valve  14  when isolation valve  14  transitions to the isolated state. Piston shaft  108  interfaces with chamber seals  90   a,    90   b  with piston  72  in the position associated with the isolated state to prevent fluid from backflowing out of outlet housing  96 . 
     Boost port  109  extends through piston housing  80  and is in fluid communication with the dry chamber. Boost port  109  can be connected to a power source to provide additional force to drive piston  72  to the piston closed position. For example, an air compressor can be connected to boost port  109  to provide compressed air to piston housing  80  to provide additional force to drive piston  72 . While the power source is described as pneumatically driving piston  72 , it is understood that any desired type of boost assembly can be utilized, such as hydraulic fluid. 
     A wash fluid source is connected to wash port  100   a  in outlet housing  96 . During a wash cycle, the wash fluid flows through wash port  100   a  and enters the wet chamber through a first subset of housing ports  105 . Piston  72  is driven rearward by inlet module  20  as isolation valve  14  transitions from the isolated state to the connected state. The piston  72  shifting rearward creates suction in the wet chamber to draw the wash fluid into the wet chamber from the wash fluid source. Piston  72  is driven forward as isolation valve  14  transitions from the connected state to the isolated state. Piston  72  moving forward drives the wash fluid out of the wet chamber through a second subset of housing ports  105 . The wash fluid flows through the housing ports  105  to a wash chamber, discussed in more detail below, and exits outlet module  22  through wash port  100   b.    
     Piston shaft  108  extends from piston head  106  and into piston bore  104  in outlet housing  96 . Piston shaft  108  interfaces with each of cartridge rings  86   a,    86   b;  wiper seals  88   a,    88   b;  and chamber seals  90   a,    90   b  with isolation valve  14  in the isolated state. Piston shaft  108  interfaces with cartridge ring  86   b,  wiper seal  88   b,  and chamber seal  90   b  with isolation valve  14  in the connected state. Piston shaft  108  includes a hollow end disposed opposite piston head  106  to receive stem  32  with isolation valve  14  in the connected state. 
     During operation, isolation valve  14  is transitioned between the isolated state and the connected state depending on the requirements of the spray system. Isolation valve  14  is in the isolated state to provide electrical isolation and in the connected state to provide fluid. Outlet module  22  is maintained at a fixed position relative to inlet module  20 . While outlet module  22  is described as being maintained in a fixed position, it is understood that, in some examples, outlet module  22  can be actuated while inlet module  20  can be maintained in a fixed position. 
     When flow is desired through isolation valve  14 , actuating module  24  is activated. Drive piston  120  is driven by cylinder  118 , such as by compressed air provided to cylinder. Drive piston  120  drives inlet module  20  in a first direction towards outlet module  22  to place isolation valve  14  in the connected state. As isolation valve  14  transitions to the connected state, stem  32  initially enters the bore in piston shaft  108 . The connection between stem  32  and piston  72  concentrically aligns piston  72  and stem  32  on axis A-A to ensure concentricity as stem  32  transitions into piston bore  104  in outlet housing  96 . An end of piston  72  engages valve seal  40   a  to provide a fluid seal between piston  72  and stem  32 . The fluid seal between piston  72  and stem  32  prevents undesired fluid migration into the bore of piston  72  that receives stem  32 . 
     Drive piston  120  continues to drive inlet module  20 . Stem  32  pushes piston  72  rearward within outlet housing  96 . Stem  32  and piston  72  pass through each of cartridge ring  86   a,  wiper seal  88   a,  and chamber seal  90   a.  A portion of sleeve  30  also passes through cartridge ring  86   a,  wiper seal  88   a,  and chamber seal  90   a.  Inlet module  20  continues to transition until sleeve flange  68  engages outlet housing  96 . Sleeve  30  engaging outlet housing  96  prevents sleeve  30  from advancing any further within piston bore  104 . Inlet spring  34  compresses between sleeve  30  and shuttle housing  52  as inlet module  20  continues to transition to the connected state. 
     With sleeve  30  held static, actuating module  24  continues to push inlet module  20  into engagement with outlet module  22 . Stem  32  extends out of sleeve  30  and further into outlet module  22  thereby exposing the ports, discussed in more detail below, in stem  32  and opening a flowpath between inlet port  60  and outlet port  102 . The spray fluid enters isolation valve  14  through inlet port  60 , flows through a flowpath in shuttle housing  52  to stem  32 , flows through stem  32  and exits ports in stem  32  within outlet housing  96 , and flows through the flowpath in outlet housing to outlet port  102  where the fluid exits isolation valve  14 . 
     As isolation valve  14  transitions to the connected state, stem  32  continues to push piston  72  rearward. Piston head  106  is driven within piston housing  80 , increasing the volume of the wet chamber and creating suction in the wet chamber, thereby drawing wash fluid into the wet chamber from the wash fluid source. 
     Isolation valve  14  is transitioned from the connected state to the isolated state to stop flow and electrically isolate inlet module  20  from outlet module  22 . Drive piston  120  is driven in a second direction, opposite the first direction and draws inlet module  20  away from outlet module  22 . As inlet module  20  shifts in the second direction piston spring  78  maintains engagement between piston  72 . Maintaining engagement between piston  72  and stem  32  ensures that no undesired leakage occurs during the transition. 
     Stem  32  retracts into sleeve  30 , thereby closing the flowpath between inlet port  60  and outlet port  102 . Inlet spring  34  maintains sleeve  30  in contact with outlet module  22  as stem  32  retracts within sleeve  30 . Maintaining sleeve  30  in contact with outlet module  22  ensures that the ports through stem  32  are fully enclosed by sleeve  30  and that sleeve  30  engages with valve seal  40   b,  thereby preventing undesired leakage between sleeve  30  and stem  32 . 
     Piston  72  transitions through and reengages with chamber seal  90   a,  cartridge ring  86   a,  and wiper seal  88   a,  thereby sealing any pathway to outlet port  102 . As piston  72  transitions, piston head  106  reduces the volume of the wet chamber, thereby pumping wash fluid out of the wet chamber and to wash port  100   b  through the wash chamber defined at least in part by cartridge ring  86   a.  Stem  32  is pulled through the wash chamber as stem  32  exits outlet housing  96 . The wash fluid being actively driven into the wash chamber by piston  72  creates turbulence in the wash chamber to assist in cleaning the fluid off of stem  32  as stem  32  is withdrawn. Cleaning stem  32  prevents any residue from the fluid from entering between stem  32  and sleeve  30 , which could cause sticking or other undesired effects. For example, the spray fluid can be configured to cure in air, leading to undesired effects. The material curing on stem  32  and/or sleeve  30  can lead to damage to various seals, resulting in fluid leakage. 
     Actuating module  24  continues to drive inlet module  20 , returning inlet module  20  to the position associated with the isolated state. Inlet module  20  is thereby electrically isolated from outlet module  22 . 
     Isolation valve  14  provides significant benefits. Isolation valve  14  provides electrical isolation by generating an air gap between inlet module  20  and outlet module  22 . The air gap eliminates all fluid that could create a conductive path between inlet module  20  and outlet module  22 . In addition, stem  32  engaging piston  72  provides a fluid-tight connection as isolation valve  14  transitions between the connected and engaged states. The connection ensures that spray fluid does not leak and is not exposed to the air, which could cause undesired curing. In addition, piston  72  actively pumps wash fluid to clean the spray fluid off of stem  32  and piston  72 , further preventing undesired curing. Piston  72  pumps the wash fluid based on isolation valve  14  transitioning between states, thereby providing a simple, effective pump for driving the wash fluid. 
       FIG. 3A  is a cross-sectional view showing isolation valve  14  in the isolated state.  FIG. 3B  is a cross-sectional view showing isolation valve  14  in a first intermediate state.  FIG. 3C  is a cross-sectional view showing isolation valve  14  in a second intermediate state.  FIG. 3D  is a cross-sectional view showing isolation valve  14  in the connected state.  FIGS. 3A-3D  will be discussed together. Inlet module  20  and outlet module  22  of isolation valve  14  are shown. 
     Shuttle  28  ( FIGS. 3A and 3D ), sleeve  30 ; stem  32 ; inlet spring  34 ; shuttle lock nut  36  ( FIGS. 3A and 3D ); inner seals  38   a,    38   b;  valve seals  40   a,    40   b;  alignment pin  42  ( FIGS. 3A and 3D ); floating connector  44  ( FIG. 3A ); and retaining nut  46  ( FIG. 3A ) of inlet module  20  are shown. Shuttle  28  includes shuttle block  50  ( FIGS. 3A and 3D ) and shuttle housing  52  ( FIGS. 3A and 3D ). Shuttle block  50  includes pin bore  129   a  ( FIGS. 3A and 3D ). Shuttle housing  52  includes inlet port  60  ( FIG. 3A ), pin slot  62   a  ( FIGS. 3A and 3D ), and shuttle bore  64  ( FIGS. 3A and 3D ). Sleeve  30  includes sleeve flange  68 , sleeve body  130 , sleeve bore  132 , first sleeve end  134 , second sleeve end  136 , and sleeve taper  162  ( FIG. 3D ). Stem  32  includes first end  138 , second end  140 , stem ports  142 , stem passage  143 , and stem flange  144 . First end  138  includes stem taper  146 . 
     Outlet module  22  includes base  70 ; piston  72 ; piston seals  74  ( FIG. 3A ); piston seal retainer  76  ( FIG. 3A ); piston spring  78  ( FIG. 3A ); piston housing  80 ; alignment pin  81 ; base lock nut  82 ; seal retainer  84 , cartridge rings  86   a,    86   b;  wiper seals  88   a,    88   b;  chamber seals  90   a,    90   b;  end cap  92 ; and wash chamber  148 . Base  70  includes outlet block  94  and outlet housing  96 . Outlet block  94  includes pin bore  129   b.  Outlet housing  96  includes pin slot  62   b,  outlet port  102 , and piston bore  104 . Piston  72  includes piston head  106  ( FIG. 3A ) and piston shaft  108 . Piston shaft  108  includes receiving bore  150  and piston taper  152 . 
     Shuttle housing  52  is mounted to shuttle block  50 . Alignment pin  42  extends between pin bore  129   a  and pin slot  62   a.  Alignment pin  42  ensures proper alignment between shuttle housing  52  and shuttle block  50 . Inlet port  60  extends into shuttle housing  52  and is configured to receive fluid from an upstream fluid source, such as main reservoir  12  ( FIGS. 1A and 1B ). 
     Stem  32  extends into shuttle bore  64  and is attached to shuttle housing  52 . Stem  32  is cantilevered from shuttle housing  52  with first end  138  free and second end  140  connected to shuttle housing  52 . Stem  32  can be connected to shuttle housing  52  in any desired manner. For example, second end  140  can include external threading configured to interface with internal threading in shuttle housing  52 . Inner seal  38   a  is disposed at the interface between stem  32  and shuttle housing  52 . 
     Stem passage  143  extends through stem  32  from second end  140  to stem ports  142 . Stem ports  142  provides flowpaths for spray fluid to exit stem passage  143 . First end  138  is disposed on a first side of stem ports  142  and second end  140  is disposed on a second side of stem ports  142  opposite first end  138 . During operation, spray fluid enters stem passage  143  at second end  140  and flows through stem passage  143  to stem ports  142 . In some examples, the fluid source connected to inlet port  60  is pressurized such that spray fluid is present in stem passage  143  when isolation valve  14  is in the isolated state and when isolation valve  14  is in the connected state. 
     Stem  32  extends through and is coaxial with sleeve  30 . Stem  32  projects out of each end of the sleeve bore  132  extending through sleeve body  130 . Inner seal  38   b  is disposed on the exterior of stem  32  between the exterior of stem  32  and the interior of sleeve  30 . Inner seal  38   b  provides a dynamic, sliding seal between stem  32  and sleeve  30 . Inner seal  38   b  prevents fluid from migrating between stem  32  and sleeve  30 . Stem flange  144  extends radially from stem  32 . Valve seals  40   a,    40   b  extend around the exterior of stem  32  and are disposed on opposite sides of stem flange  144 . Both valve seals  40   a,    40   b  are disposed on first end  138 . Stem taper  146  is disposed at the end of first end  138 . Stem taper  146  encounters piston taper  152  and the interface therebetween aligns stem  32  within receiving bore  150  as stem  32  engages piston  72 . Stem taper  146  thereby assists in ensuring concentricity as inlet module  20  interfaces with outlet module  22 . 
     Sleeve  30  is supported by stem  32 . Sleeve  30  translates axially along stem  32 . Stem  32  and sleeve  30  are concentric and interaction between stem  32  and sleeve  30  maintains axial alignment on axis A-A. Sleeve flange  68  projects radially from sleeve body  130 . First sleeve end  134  extends from sleeve flange  68  towards stem flange  144 . Sleeve taper  162  is disposed at the distal end of first sleeve end  134 . Sleeve taper  162  is configured to interface with valve seal  40   b  to close the flowpath through inlet module  20  and prevents fluid from flowing out of inlet module  20  between first sleeve end  134  and stem  32 . Sleeve taper  162 , flange  144 , and valve seal  40   b  seal together. Stem  32  and sleeve  30  interface to seal any fluid in inlet module  20  from atmosphere. 
     Second sleeve end  136  extends from sleeve flange  68  towards shuttle  28 . Second sleeve end  136  can extend at least partially into shuttle bore  64 . Inlet spring  34  is disposed about second sleeve end  136  of sleeve  30 . Inlet spring  34  extends between sleeve flange  68  and shuttle housing  52 . Inlet spring  34  interfaces with sleeve flange  68  to bias sleeve  30  into sealing engagement with stem  32 . 
     Outlet housing  96  is mounted to outlet block  94 . Alignment pin  81  extends between pin bore  129   b  and pin slot  62   b.  Alignment pin  81  is substantially similar to alignment pin  42  and can be identical to alignment pin  42 . Alignment pin  81  prevents relative rotation between outlet block  94  and outlet housing  96  to maintain alignment. Outlet port  102  extends into outlet housing  96  and is configured to provide fluid to a location downstream of isolation valve  14 , such as pumps  16   a,    16   b  ( FIGS. 1A and 1B ). 
     Piston bore  104  extends through outlet housing  96  along axis A-A. Piston bore  104  includes portions having varying diameters to ensure proper alignment of elements within piston bore  104 . The central portion of piston bore  104  is disposed between chamber seals  90   a,    90   b  and forms an outlet chamber for receiving spray fluid. The central portion has diameter D 1 . A first portion of piston bore  104  extends from the central portion and is capped by end cap  92 . Cartridge ring  86   a  is disposed in the first portion between part of outlet housing  96  and end cap  92 . The first portion has diameter D 2 . A second portion of piston bore  104  extends from the central portion and is capped by seal retainer  84 . Cartridge ring  86   b  is disposed in the second portion between part of outlet housing  96  and seal retainer  84 . The second portion has diameter D 3 . Diameters D 2  and D 3  are larger than diameter D 1 . In some examples, diameters D 2  and D 3  are the same. It is understood however, that diameters D 1 , D 2 , and D 3  can have any desired relationship. Piston bore  104  can include further portions having varying diameters. For example, the portion of piston bore  104  between end cap  92  and cartridge ring  86   a  can have a diameter larger than diameter D 2 . 
     End cap  92  is attached to outlet housing  96  and encloses the first end of piston bore  104 . End cap  92  retains wiper seal  88   a,  cartridge ring  86   a,  and chamber seal  90   a  in piston bore  104 . Cartridge ring  86   a  is disposed between end cap  92  and chamber seal  90   a.  Cartridge ring  86   a  maintains chamber seal  90   a  in piston bore  104 . Cartridge ring  86   a  includes windows to allow fluid flow into and out of wash chamber  148  defined by cartridge ring  86   a.  In the example shown, end cap  92  supports wiper seal  88   a,  but it is understood that wiper seal  88   a  can be disposed within piston bore  104  in any manner suitable for positioning wiper seal  88   a  relative to sleeve  30 , stem  32 , and piston  72  and on axis A-A. A portion of end cap  92  contacts cartridge ring  86   a  to maintain cartridge ring  86   a  in piston bore  104 . 
     End cap  92  can be attached to outlet housing in any desired manner. For example, end cap  92  can be attached to outlet housing  96  by interfaced threading, a bayonet connection, or press-fitting, among other options. Cartridge ring  86   a  at least partially defines wash chamber  148  within piston bore  104 . As discussed in more detail below, wash chamber  148  is fluidly connected to wet chamber  156  to receive wash fluid from wet chamber  156 . Wash fluid flows through wash chamber  148  between wiper seal  88   a  and chamber seal  90   a.  Fluid in outlet module  22  is sealed from atmosphere by piston  72  interfacing with wiper seal  88   a  and chamber seal  90   a.    
     Wiper seal  88   b,  cartridge ring  86   b,  and chamber seal  90   b  are disposed at a second end of piston bore  104 . Seal retainer  84  is attached to outlet housing  96  and encloses the second end of piston bore  104  to retain wiper seal  88   b,  cartridge ring  86   b,  and chamber seal  90   b  within piston bore  104 . Cartridge ring  86   b  is disposed between seal retainer  84  and chamber seal  90   b.  Cartridge ring  86   b  maintains chamber seal  90   b  in piston bore  104 . A portion of seal retainer  84  contacts cartridge ring  86   b.  Wiper seal  88   b  is supported by seal retainer  94 . Seal retainer  84  can be attached to outlet housing  96  in any desired manner. For example, seal retainer  84  can be attached to outlet housing  96  by interfaced threading, among other options. 
     Piston housing  80  is attached to an end of outlet housing  96  proximate the second end of piston bore  104 . Piston  72  is at least partially disposed in piston housing  80  and extends into piston bore  104  through seal retainer  84 , wiper seal  88   b,  cartridge ring  86   b,  and chamber seal  90 . Piston head  106  is disposed in piston housing  80  and is movable within piston housing  80  along axis A-A. Piston shaft  108  extends from piston head  106  into piston bore  104 . Piston shaft  108  is movable within piston bore  104  along axis A-A. With isolation valve  14  in the isolated state, piston shaft  108  extends through each of seal retainer  84 ; cartridge rings  86   a,    86   b;  wiper seals  88   a,    88   b;  and chamber seals  90   a,    90   b.  With isolation valve  14  in the connected state, piston shaft  108  extends through seal retainer  84 , cartridge ring  86   b,  wiper seal  88   b,  and chamber seal  90   b.  An end of piston shaft  108  opposite piston head  106  includes piston taper  152 . Receiving bore  150  and the piston taper  152  are configured to facilitate alignment with stem  32  as stem  32  interfaces with piston  72 . 
     Piston seals  74  are disposed around piston head  106  and engage an inner wall of piston housing  80 . Piston seal retainer  76  is attached to piston head  106  and retains piston seals  74  on piston head  106 . Piston head  106  divides piston housing  80  into dry chamber  154  and wet chamber  156 . Piston spring  78  is disposed in dry chamber  154  and is configured to bias piston  72  towards a position associated with the isolated state, which is shown in  FIG. 3A . Wet chamber  156  is fluidly connected to wash chamber  148  via flowpaths extending through outlet housing  96 , as discussed in more detail below. 
     During operation, isolation valve  14  is initially in the isolated state shown in  FIG. 3A . Gap  26  is formed between inlet module  20  and outlet module  22  to electrically isolate inlet module  20  from outlet module  22 . Gap  26  is of a sufficient size to electrically isolate inlet module  20  and outlet module  22 . For example, the length of gap  26  can be at least 1 inch (2.54 cm) for every 10 kV of charge. In a 60 KV system, the length of gap  26  is at least 6 inches. 
     Isolation valve  14  is actuated from the isolated state in  FIG. 3A  to the connected state in  FIG. 3D  in response to a fluid connection being desired. Actuating module  24  (best seen in  FIGS. 2A-2C ) drives inlet module  20  towards outlet module  22 . Isolation valve  14  initially enters the first intermediate state shown in  FIG. 3B . In the first intermediate state, first contact is made between inlet module  20  and outlet module  22 . First end  138  of stem  32  enters receiving bore  150  in piston  72 . As first end  138  enters receiving bore  150 , stem taper  146  encounters piston taper  152 , which interfacing assists in guiding first end  138  into receiving bore  150 . Stem bore  150  is sized to tightly interface around first end  138  to further facilitate alignment. Stem taper  146 , piston taper  152 , stem bore  150 , and first end  138  thereby assist in maintaining concentricity between stem  32  and piston  72 . Piston  72 , and specifically piston taper  152 , contacts and seals against stem flange  144  and valve seal  40   a.    
     Inlet module  20  is driven further into engagement with outlet module  22  and transitions from the first intermediate state shown in  FIG. 3B  to the second intermediate state shown in  FIG. 3C . Each of piston  72  and sleeve  30  seal with stem  32  at stem flange  144  as isolation valve  14  transitions from the first intermediate state to the second intermediate state. The seam(s) at the interface between piston  72 , stem  32 , and sleeve  30  passes through wiper seal  88   a,  cartridge ring  86   a,  and chamber seal  90   a  during the transition to the second intermediate state. 
     With isolation valve  14  in the second intermediate state, second contact is made between inlet module  20  and outlet module  22 . The second contact is between sleeve  30  and outlet housing  96 . The second contact braces sleeve  30  such that stem  32  can shift relative to sleeve  30  while sleeve  30  is held at a static location. Sleeve flange  68  contacts and braces against outlet module  22  to maintain sleeve  30  in the position shown in  FIG. 3C . It is understood, however, that sleeve  30  can be braced in any desired manner. In the example shown, sleeve flange  68  braces against end cap  92 . 
     Inlet module  20  is driven from the second intermediate state to the connected state shown in  FIG. 3D . Sleeve  30  remains in the position shown in  FIG. 3C  as isolation valve  14  transitions from the second intermediate state to the connected state. With sleeve  30  held steady, each of shuttle  28  and stem  32  continue to transition towards outlet module  22 . Inlet spring  34  compresses between sleeve flange  68  and shuttle housing  52 . 
     Stem  32  proceeds further into piston bore  104  and pushes piston  72  rearward through piston bore  104 . Stem  32  shifts relative to sleeve  30  such that sleeve  30  disengages from stem flange  144 . Inner seal  38   b  remains between stem  32  and sleeve  30  to maintain a fluid seal and prevent fluid from migrating between stem  32  and sleeve  30 . Stem ports  142  are exposed within the portion of piston bore  104  between chamber seals  90   a,    90   b.  The portion of piston bore  104  between chamber seals  90   a,    90   b  can also be referred to as an outlet chamber. With stem ports  142  exposed in the outlet chamber, a flowpath is opened between inlet port  60  in inlet module  20  and outlet port  102  in outlet module  22 . The fluid enters inlet module  20  through inlet port  60 , enters stem  32  through second end  140 , flows through stem passage  143 , exits stem  32  through stem ports  142 , and exits outlet module  22  through outlet port  102 . Stem ports  142  are oriented to direct the fluid flow radially outward and into outlet module  22 . Sleeve taper  162  forms an extension of stem ports  142  with isolation valve  14  in the connected state. Stem ports  142  and sleeve taper  162  turn the spray fluid from an axial flow to provide a transition to the flowpath through base  70  to outlet port  102 . Turning the flow smooths flow of the spray fluid and prevents turbulence in the outlet chamber between chamber seals  90   a,    90   b.  A smoother flow provides a quicker and more efficient flow through isolation valve  14 . Isolation valve  14  is maintained in the connected state as fluid flows through isolation valve  14 . 
     When electrical isolation is desired, isolation valve  14  is transitioned from the connected state to the isolated state. Isolation valve  14  initially shifts from the connected state in  FIG. 3D  to the second intermediate state in  FIG. 3C . Stem ports  142  transition back within sleeve bore  132  such that stem ports  142  are covered by sleeve body  130 . Sleeve  30  reengages stem flange  144  and valve seal  40   b,  thereby sealing the flowpath from inlet port  60  through stem  32  and preventing any fluid from leaking between sleeve  30  and stem  32 . Inlet spring  34  maintains sleeve  30  in the position shown in  FIGS. 3C and 3D  as inlet module  20  is pulled from the connected state to the second intermediate state. Piston spring  78  biases piston  72  towards inlet module  20  thereby maintaining contact between piston  72  and stem flange  144  as isolation valve  14  transitions from the connected state to the second intermediate state. 
     Isolation valve  14  transitions from the second intermediate state shown in  FIG. 3C  to the first intermediate state shown in  FIG. 3B . The seam at the interface between piston  72 , stem  32 , and sleeve  30  passes through cartridge ring  86   a  and wiper seal  88   a.  As discussed in more detail below, piston  72  pumps wash fluid out of wet chamber  156  and to wash chamber  148  as isolation valve  14  transitions from the connected state to the isolated state. The wash fluid flows through wash chamber  148  as the wash fluid flows from wet chamber  156  to wash port  100   b  ( FIG. 6B ). The wash fluid being actively pumped by piston  72  into wash chamber  148  creates a turbulent flow in wash chamber  148 , which better cleans those portions of sleeve  30 , stem  32 , and piston  72  passing through wash chamber  148 . Wiper seal  88   a,  which can be a u-cup seal among other options, further removes fluid residue from the exterior of those portions of sleeve  30 , stem  32 , and piston  72  passing through wiper seal  88   a.  The lips of the u-cup of wiper seal  88   a  face rearward towards wet chamber  156  to facilitate wiping of fluid off of the exteriors of sleeve  30 , stem  32 , and piston  72 . 
     Isolation valve  14  transitions from the first intermediate state shown in  FIG. 3B  to the isolated state shown in  FIG. 3A . Stem  32  disengages from piston  72  and first end  138  exits receiving bore  150  in piston  72 , thereby creating air gap  26  between inlet module  20  and outlet module  22 . The length of air gap  26  continues to grow as inlet module  20  shifts away from outlet module  22 . Inlet module  20  continues to shift away from outlet module  22  until the air gap  26  is sized to electrically isolate inlet module  20  and outlet module  22 . The size of the air gap  26  can be based on the voltage utilized during spraying. Inlet module  20  is thereby electrically isolated from outlet module  22  and spraying can resume. 
     Isolation valve  14  provides significant advantages. Isolation valve  14  allows fluid flow when in the connected state and stops fluid flow when not in the connected state, without requiring the use of tools or other hardware. Isolation valve  14  prevents fluid from being exposed to the atmosphere and provides a physical isolation gap  26  when in the isolated state. This is especially useful when moving water-based fluids that are electrically charged, such as in an electrostatic spray system similar to electrostatic spray system  10 . Isolation valve  14  does not include any ball/seat check valves to seal fluid from atmosphere. Instead, stem  32  and sleeve  30  interface to seal fluid from atmosphere in inlet module  20  and piston  72  interfaces with chamber seals  90   a,    90   b  and wiper seals  88   a,    88   b  to seal fluid in outlet module  22  from atmosphere. In addition, the connecting geometry of stem  32 , sleeve  30 , and piston  72  ensures concentricity and proper alignment as isolation valve  14  transitions into the connected state. There are no springs or other difficult to access and clean components in the fluid flow path between inlet port  60  and outlet port  102 . 
       FIG. 4  is an enlarged cross-sectional view of interface  158  between sleeve  30 , stem  32 , and piston  72  with isolation valve  14  ( FIGS. 1A-3D ) in the first intermediate state shown in  FIG. 3B . Sleeve  30 ; stem  32 ; valve seals  40   a,    40   b;  piston  72 ; cartridge ring  86   a;  wiper seal  88   a;  chamber seal  90   a;  end cap  92 ; and outlet housing  96  are shown. Sleeve bore  132 , first sleeve end  134 , and sleeve taper  162  of sleeve  30  are shown. First end  138 , stem flange  144 , and stem seal grooves  164   a,    164   b  of stem  32  are shown. Stem flange  144  includes first flange side  166 , second flange side  168 , and free end  170 . Receiving bore  150  and piston taper  152  of piston  72  are shown. 
     Seams  160   a,    160   b  are formed at the interface  158  between piston  72 , stem flange  144 , and sleeve  30 . Interface  158  is a double seam in that seam  160   a  is formed at the interface between piston  72  and first flange side  166  and seam  160   b  is formed at the interface between sleeve  30  and second flange side  168 . Each of first flange side  166  and second flange side  168  are flat and extend radially relative to axis A-A. The distal ends of piston  72  and sleeve  30  are also flat to interface with first flange side  166  and second flange side  168 , respectively. Stem seal groove  164   a  is disposed on first flange side  166  of stem flange  144  and stem seal groove  164   b  is disposed on second flange side  168  of stem flange  144 . Valve seals  40   a,    40   b  are disposed in stem seal grooves  164   a,    164   b,  respectively. 
     Sleeve taper  162  is disposed at the distal end of first sleeve end  134 . Sleeve taper  162  extends annularly at first sleeve end  134 . Sleeve taper  162  provides a transition between sleeve bore  132  and the distal end of sleeve  30 . Sleeve taper  162  extends over and is in contact with valve seal  40   b,  thereby forming a seal to prevent fluid from entering between sleeve  30  and stem  32  at interface  158 . 
     Piston  72  extends over valve seal  40   a  and contacts first flange side  166  of stem flange  144 . More specifically, piston taper  152  extends over and is in contact with valve seal  40   a.  Sleeve  30  extends over valve seal  40   b  and contacts second flange side  168  of stem flange  144 . More specifically, sleeve taper  162  extends over and is in contact with valve seal  40   b.  Stem flange  144  is thus disposed between and separates the distal ends of piston  72  and sleeve  30 . Free end  170  of stem flange  144  is exposed and is not covered by either piston  72  or sleeve  30 . 
     During operation, stem flange  144  directly contacts the distal end of piston  72  to exert a pushing force on piston  72 . As isolation valve  14  transitions from the first intermediate state to the connected state, stem flange  144  exerts the force on piston  72  to drive piston  72  in direction R. Seams  160   a,    160   b  shift in direction R and pass through each of wiper seal  88   a,  cartridge ring  86   a,  and chamber seal  90   a,  respectively, as isolation valve  14  transitions to the connected state from the first intermediate state. Seams  160   a,    160   b  shift in direction F and passes through each of chamber seal  90   a,  cartridge ring  86   a,  and wiper seal  88   a,  respectively, as isolation valve  14  transitions to the first intermediate state from the connected state. 
     As seams  160   a,    160   b  shift in direction F, seams  160   a,    160   b  pass through wash chamber  148  defined by cartridge ring  86   a.  As discussed in more detail below, wash fluid is pumped through wash chamber  148  as piston  72  shifts in direction F. The wash fluid cleans seams  160   a,    160   b  to remove any residual spray fluid from seams  160   a,    160   b.  Seams  160   a,    160   b  pass through wiper seal  88   a  after passing through wash chamber  148 . Wiper seal  88   a  is configured to remove any residual fluid at seams  160   a,    160   b,  thereby preventing undesired curing of the spray material at seams  160   a,    160   b,  which could lead to sticking, among other issues. In the example shown, wiper seal  88   a  is a u-cup seal. It is understood, however, that wiper seal  88   a  can be of any type suitable for wiping the exterior of sleeve  30 , stem  32 , and piston  72  as seams  160   a,    160   b  pass through wiper seal  88   a.    
     Interface  158  facilitates alignment between sleeve  30 , stem  32 , and piston  72  during operation. The alignment facilitates efficient sealing as isolation valve  14  transitions between states. In addition, interface  158  provides a tightly interfaced, nearly joint-free surface for sliding over wiper seal  88   a  and chamber seal  90   a.  Interface  158  thereby preserves the integrity of the seals during the state transitions. Moreover, having minimal joints at interface minimizes any fluid residue sticking at interface  158 . Interface  158  also passes through wiper seal  88   a  as isolation valve  14  transitions out of the connected state. Wiper seal  88   a  removes residual fluid located at interface  158  to ensure that those portions of stem  32 , sleeve  30 , and piston  72  exposed to the atmosphere are clean of any fluid, which can cure when exposed to the atmosphere. 
       FIG. 5  is an enlarged cross-sectional view of interface  158 ′ between sleeve  30 , stem  32 ′, and piston  72  with isolation valve  14  ( FIGS. 2A-3D ) in the first intermediate state shown in  FIG. 3B . Sleeve  30 ; stem  32 ′; valve seals  40   a,    40   b;  piston  72 ; cartridge ring  86   a;  wiper seal  88   a;  chamber seal  90   a;  end cap  92 ; and outlet housing  96  are shown. Sleeve bore  132 , first sleeve end  134 , and sleeve taper  162  of sleeve  30  are shown. First end  138 ′; stem flange  144 ; stem taper  146 ; and stem seal grooves  164   a′,    164   b′  of stem  32 ′ are shown. Stem flange  144 ′ includes first flange side  166 ′, second flange side  168 ′, and free end  170 ′. Receiving bore  150  and piston taper  152  of piston  72  are shown. 
     Seam  160 ′ is formed at interface  158 ′ between piston  72 , stem flange  144 ′, and sleeve  30 . Interface  158 ′ is a single seam interface in that only a single seam  160 ′ is exposed on the exterior at interface  158 ′. Each of first flange side  166 ′ and second flange side  168 ′ are flat and extend radially relative to axis A-A. Free end  170 ′ of stem flange  144 ′ is sloped to mate with piston taper  152 . While free end  170 ′ is shown as sloped to mate with piston taper  152 , it is understood that free end  170 ′ can be sloped to mate with sleeve taper  162  and/or sloped in both the forward and rearward directions to mate with each of piston taper  152  and sleeve taper  162 . In some examples, free end  170 ′ can be flat, similar to free end  170  ( FIG. 4 ). 
     The distal ends of piston  72  and sleeve  30  are flat and contact each other to form seam  160 ′. Piston taper  152  extends annularly about axis A-A between a radially-inner end of the flat distal end and receiving bore  150 . Piston taper  152  is sloped to provide a face for actively engaging with and disengaging from valve seal  40   a.  Sleeve taper  162  extends annularly about axis A-A between a radially-inner end of the flat distal end of sleeve  30  and sleeve bore  132 . Sleeve taper  162  is sloped to provide a face for actively engaging with and disengaging from valve seal  40   b.  Sleeve taper  162  also provides an extension to the flowpaths through stem ports  142  (best seen in  FIG. 3D ) when isolation valve  14  is in the connected state ( FIG. 3D ). 
     Stem seal groove  164   a′  is disposed on first flange side  166 ′ of stem flange  144 ′ and stem seal groove  164   b′  is disposed on second flange side  168 ′ of stem flange  144 ′. Valve seals  40   a,    40   b  are disposed in stem seal grooves  164   a′,    164   b′,  respectively. In the example shown, stem seal groove  164   a′  extends further into stem  32  than stem seal groove  164   b′  such that stem seal groove  164   a′  is deeper than stem seal groove  164   b′.  As such, the base of stem seal groove  164   b′  can have a larger diameter relative to axis A-A than stem seal groove  164   a′.  While stem seal grooves  164   a′,    164   b′  have differing diameters, first flange side  166 ′ and second flange side  168 ′ can be the same length due to sloped free end  170 ′. In other examples, first flange side  166 ′ and second flange side  168 ′ can have different lengths. 
     Piston  72  extends over valve seal  40   a  and over free end  170 ′ of stem flange  144 ′. More specifically, piston taper  152  extends over and is in contact with valve seal  40   a.  Sleeve  30  extends over valve seal  40   b  and contacts piston  72 . More specifically, sleeve taper  162  extends over and is in contact with valve seal  40   b.  First end  138  of stem  32 ′ can be sized to contact the base of receiving bore  150  such that stem  32 ′ exerts a pushing force on piston  72  as isolation valve  14  transitions to the connected state. The distal end of sleeve  30  contacts the distal end of piston  72 . In some examples, sleeve  30  can also exert a pushing force on piston  72 . While each of stem  32 ′ and sleeve  30  are described as pushing piston  72 , it is understood that stem  32 ′ can be spaced from the bottom of receiving bore  150  such that the pushing force is exerted on piston  72  at interface  158 ′, similar to the example shown in  FIG. 4 . In other examples, stem  32 ′ can be sized such that sleeve  30  contacts piston  72  but little to no pushing force is exerted on piston  72  at interface  158 ′. 
     Seam  160 ′ shifts in direction R and passes through each of wiper seal  88   a,  cartridge ring  86   a,  and chamber seal  90   a,  respectively, as isolation valve  14  transitions from the first intermediate state to the connected state. Seam  160 ′ shifts in direction F and passes through each of chamber seal  90   a,  cartridge ring  86   a,  and wiper seal  88   a,  respectively, as isolation valve  14  transitions to the first intermediate state from the connected state. 
     As seam  160 ′ shifts in direction F, seam  160 ′ passes through wash chamber  148  defined by cartridge ring  86   a.  As discussed in more detail below, wash fluid is pumped through wash chamber  148  as piston  72  shifts in direction F. The wash fluid cleans seam  160 ′ to remove any spray fluid from seam  160 ′. Seam  160 ′ passes through wiper seal  88   a  after passing through wash chamber  148 . Wiper seal  88   a  is configured to remove any residual fluid at seam  160 ′. In the example shown, wiper seal  88   a  is a u-cup seal. It is understood, however, that wiper seal  88   a  can be of any type suitable for wiping fluid from seam  160 ′ as seam  160 ′ passes through wiper seal  88   a.    
     Interface  158 ′ facilitates alignment between sleeve  30 , stem  32 ′, and piston  72  during operation. The alignment facilitates efficient sealing as isolation valve  14  transitions between states. In addition, interface  158 ′ provides a tightly interfaced, nearly joint-free surface for sliding over wiper seal  88   a  and chamber seal  90   a.  Interface  158 ′ thereby preserves the integrity of the seals during the state transitions. Moreover, having minimal joints at interface minimizes any fluid residue sticking at interface  158 ′. Interface  158 ′ also passes through wiper seal  88   a  as isolation valve  14  transitions out of the connected state. Wiper seal  88   a  removes residual fluid located at interface  158 ′ to ensure that those portions of sleeve  30 , stem  32 ′, and piston  72  exposed to the atmosphere are clean of any fluid, which can cure when exposed to the atmosphere. 
       FIG. 6A  is a cross-sectional view of isolation valve  14  showing an inlet wash path.  FIG. 6B  is a cross-sectional view of isolation valve  14  showing an outlet wash path.  FIGS. 6A and 6B  will be discussed together. Inlet module  20  and outlet module  22  of isolation valve  14  are shown. Shuttle  28 , sleeve  30 , stem  32 , and inlet spring  34  of inlet module  20  are indicated. Shuttle  28  includes shuttle block  50  and shuttle housing  52 . Base  70 ; piston  72 ; piston seals  74 ; piston seal retainer  76 ; piston spring  78 ; piston housing  80 ; seal retainer  84 ; cartridge rings  86   a,    86   b;  wiper seals  88   a,    88   b;  chamber seals  90   a,    90   b;  end cap  92 ; and wash chamber  148  of outlet module  22  are indicated. Base  70  includes outlet block  94  and outlet housing  96 . Wash ports  100   a,    100   b  (collectively herein “wash port  100 ”); piston bore  104 ; housing ports  105 ; wash pathway  178 , and wash pathway  180  of outlet housing  96  are shown. Piston  72  includes piston head  106  and piston shaft  108 . 
     Wash ports  100   a,    100   b  are formed in outlet housing  96 . Wash port  100   a  is fluidly connected to a wash fluid source to receive wash fluid from the wash fluid source. For example, a reservoir of wash fluid can be disposed in an electrical isolation housing with the isolation valve. An inlet check valve is disposed between wash port  100   a  and the wash fluid source to prevent backflow of wash fluid through wash port  100   a.  The inlet check valve can be of any desired configuration, such as a ball and seat. The inlet check valve can be mounted directly to wash port  100   a  or disposed at any other location between wash port  100   a  and the wash fluid source. 
     Wash pathway  178  extends through outlet housing  96  from wash inlet port  100   a  to inlet ones of housing ports  105 . Housing ports  105  provide the wash fluid to wet chamber  156  defined in piston housing  80  between piston head  106  and outlet housing  96 . An inlet fluid flow is shown in  FIG. 6A  and indicated by arrows F 1 . 
     Wash port  100   b  is fluidly connected to a wash fluid receiver downstream of wash port  100   b.  In some examples, the wash fluid source and the wash fluid receiver can be the same reservoir, such that wash fluid is circulated through a fluid loop. In other examples, the wash fluid receiver is a different reservoir from the wash fluid source. An outlet check valve is disposed between wash port  100   b  and the wash fluid receiver to prevent backflow of wash fluid through wash port  100   b.  The outlet check valve can be of any desired configuration, such as a ball and seat. The outlet check valve can be mounted directly to wash port  100   b  or disposed at any other location between wash port  100   b  and the wash fluid receiver. 
     Wash pathway  180  extends through outlet housing  96  from outlet ones of housing ports  105  to wash port  100   b.  In some examples, housing ports  105  function as both the inlet and outlet ones of housing ports  105 . Wash chamber  148  is formed in a portion of wash pathway  180  passing through piston bore  104 . Wash chamber  148  is defined, at least in part, by cartridge ring  86   a  and between chamber seal  90   a  and wiper seal  88   a.  Wash chamber  148  is positioned within piston bore  104  such that the interface between stem  32 , sleeve  30 , and piston  72  passes through wash chamber  148  as isolation valve  14  transitions between states. An outlet fluid flow is shown in  FIG. 6B  and indicated by arrows F 2 . 
     During operation, piston  72  acts as a wash pump to pump wash fluid through the wash fluid circuit and to clean residual fluid from components exposed to spray fluid. Portions of stem  32 , sleeve  30 , and piston  72  are exposed to the spray fluid when isolation valve  14  is in the connected state. The interface between stem  32 , sleeve  30 , and piston  72  is exposed to the spray fluid, which can cure when exposed to atmosphere. To prevent undesired curing, the spray fluid is cleaned from stem  32 , sleeve  30 , and piston  72  as isolation valve  14  transitions to the isolated state. 
     Initially, isolation valve  14  transitions to the connected state from the isolated state. Stem  32  extends into piston  72  and inlet module  20  drives piston  72  in direction R. As piston  72  shifts rearward within piston bore  104 , piston head  106  shifts rearward within piston housing  80 . Piston head  106  shifting rearward increases the volume of wet chamber  156 . The increased volume of wet chamber  156  creates suction that opens the inlet check valve, thereby opening a flowpath between the wash fluid source and wet chamber  156 . Piston head  106  draws the wash fluid into wet chamber  156  through wash port  100   a,  wash pathway  178 , and housing port  105 . With isolation valve  14  in the connected state, piston head  106  stops moving rearward and the suction stroke of piston  72  is complete. 
     Isolation valve  14  then transitions from the connected state to the isolated state. Inlet module  20  shifts in direction F, thereby pulling stem  32  in direction F. Piston  72  maintains contact with stem  32  as stem  32  shifts in direction F. Piston spring  78  and/or pressurized fluid provided to dry chamber  154  through boost port  109  drive piston  72  in direction F to maintain that contact. As piston  72  shifts in direction F, piston head  106  is driven into wet chamber  156  and reduces the volume of wet chamber  156 . Piston  72  pumps the wash fluid out of wet chamber  156  and through wash pathway  180 . The wash fluid flows to wash chamber  148  and encounters those portions of stem  32 , sleeve  30 , and piston  72  passing through wash chamber  148 . A turbulent flow is created in wash chamber  148 , which further assists in cleaning. The wash fluid flows downstream from wash chamber  148  and exits outlet module  22  through wash port  100   b.  Wiper seal  88   a  is disposed on the exit side of wash chamber  148  and wipes sleeve  30 , stem  32 , and piston  72  clean. The wash fluid is actively pumped through wash chamber  148  as piston  72  shifts in direction F. Piston  72  completes the pumping stroke when piston  72  is in the position associated with the isolated state of isolation valve  14 . 
     In some examples, the wash system can function as an inlet/outlet system that circulates wash fluid from the wash fluid source with a single wash port  100 , such as wash port  100   b.  For example, wash port  100   b  can be fluidly connected to the wash fluid source to receive/deposit wash fluid from/into the wash fluid source. A wash pathway, such as wash pathway  180 , extends from the single wash port  100  and provides a fluid pathway between wash port  100  and wet chamber  156 . In the single port configuration, both the inlet flow and the outlet flow flow through the same wash pathway. 
     An example of the single port configuration utilizing wash port  100   b  is discussed in more detail. The inlet flow flows through wash pathway  180  counter to the arrows F 2  shown in  FIG. 6B . The outlet flow flows through wash pathway  180  in the direction of arrows F 2  shown in  FIG. 6B . The single port connection forces incoming wash fluid to follow the same path as the outgoing wash fluid and does not require check valves to control flow direction. During operation of the single port configuration, piston  72  continues to act as a wash pump to push the wash fluid. Isolation valve  14  transitions to the connected state from the isolated state. Stem  32  extends into piston  72  and inlet module  20  drives piston  72  in direction R. As piston  72  shifts rearward within piston bore  104 , piston head  106  shifts rearward within piston housing  80 . Piston head  106  shifting rearward increases the volume of wet chamber  156 , creating suction that draws the wash fluid into wet chamber  156  through wash port  100   b,  wash pathway  180 , and housing port  105 . With isolation valve  14  in the connected state, piston head  106  stops moving rearward and the suction stroke of piston  72  is complete. The isolation valve  14  then transitions from the connected state to the isolated state. Inlet module  20  shifts in direction F, thereby pulling stem  32  in direction F. Piston  72  maintains contact with stem  32  as stem  32  shifts in direction F. Piston spring  78  and/or pressurized fluid provided to dry chamber  154  through boost port  109  drive piston  72  in direction F to maintain that contact. As piston  72  shifts in direction F, piston head  106  is driven into wet chamber  156  and reduces the volume of wet chamber  156 . Piston  72  pumps the wash fluid out of wet chamber  156  and through wash pathway  180 . The wash fluid flows to wash chamber  148  and encounters those portions of stem  32 , sleeve  30 , and piston  72  passing through wash chamber  148 . A turbulent flow is created in wash chamber  148 , which further assists in cleaning. The wash fluid flows downstream from wash chamber  148  and exits outlet module  22  through wash port  100   b.  Wiper seal  88   a  is disposed on the exit side of wash chamber  148  and wipes sleeve  30 , stem  32 , and piston  72  clean. The wash fluid is actively pumped through wash chamber  148  as piston  72  shifts in direction F. Piston  72  completes the pumping stroke when piston  72  is in the position associated with the isolated state of isolation valve  14 . 
     The wash system of isolation valve  14  provides significant advantages. Piston  72  pumps the wash fluid on every state cycle of isolation valve  14 , thereby ensuring that the interface between stem  32 , sleeve  30 , and piston  72  is always washed to remove any residual spray fluid. In addition, piston  72  pumps the wash fluid based on isolation valve  14  changing states. Isolation valve  14  does not require any external components or pumps to drive the wash fluid. The wash system is built into isolation valve  14  and does not require any other system control to function. Moreover, wiper seal  88   a  is disposed on the exit side of wash chamber  148  and wipes sleeve  30 , stem  32 , and piston  72  clean to further ensure that no residual fluid remains on the exterior of those components. The single port wash configuration both pulls wash fluid through wash chamber  148  from the port  100  and drives the wash fluid through wash chamber  148  to the port  100 . Driving the fluid in both direction can further facilitate cleaning and provides a wash flow as isolation valve  14  is both transitioning to the connected state and transitioning from the connected state. 
       FIG. 7A  is a cross-sectional view of isolation valve  14 ′ in an isolated state.  FIG. 7B  is a cross-sectional view of isolation valve  14 ′ in a first intermediate state.  FIG. 7C  is a cross-sectional view of isolation valve  14 ′ in a second intermediate state.  FIG. 7D  is a cross-sectional view of isolation valve  14 ′ in the connected state.  FIGS. 7A-7D  will be discussed together. Inlet module  20 ′ and outlet module  22 ′ of isolation valve  14 ′ are shown. 
     Shuttle  28 ′ ( FIG. 7A ); sleeve  30 ; stem  32 ″; inlet spring  34 ; inner seal  38   a  ( FIG. 7A ); inner seal  38   b;  and valve seal  40   a  of inlet module  20 ′ are shown. Shuttle  28 ′ includes inlet port  60  and shuttle bore  64 . Sleeve  30  includes sleeve flange  68 , sleeve body  130 , sleeve bore  132 , first sleeve end  134 , second sleeve end  136 , and sleeve taper  162  ( FIG. 7D ). Stem  32 ″ includes first end  138 ″, second end  140 ″, stem ports  142 ″, stem passage  143 , stem flange  144 ″, and stem taper  146 ″. 
     Outlet module  22 ′ includes base  70 ′; piston  72 ′; piston seals  74  ( FIGS. 7A and 7B ); piston seal retainer  76 ′ ( FIG. 7A ); piston spring  78  ( FIG. 7A ); piston housing  80 ; seal retainer  84 ; cartridge ring  86   a′;  wiper seals  88   a,    88   b;  chamber seals  90   a,    90   b;  end cap  92 ′; wash chamber  148 ; and boost member  172  ( FIGS. 7A-7C ). Base  70 ′ includes outlet port  102  and piston bore  104 ′. Piston  72 ′ includes piston head  106 ′ and piston shaft  108 ′ ( FIGS. 7A and 7B ). Piston shaft  108 ′ includes receiving bore  150 , piston taper  152 ′ ( FIG. 7A ), and boost bore  174 . Piston housing  80  includes boost port  109 . 
     Isolation valve  14 ′ is substantially similar to isolation valve  14  (best seen in  FIGS. 2A-3D ). Isolation valve  14 ′ does not include soft seals at the interface between piston  72 ′, stem  32 ″, and sleeve  30 . Inlet module  20 ′ is fluidly connected to an upstream fluid source, such as main reservoir  12  ( FIGS. 1A and 1B ) or pump  16   a  ( FIGS. 1A and 1B ), among other options. Outlet module  22 ′ is fluidly connected to a downstream fluid receiver, such as pumps  16   a,    16   b  ( FIGS. 1A and 1B ) or applicator  18  ( FIGS. 1A and 1B ). Isolation valve  14 ′ shifts between the isolated state, where gap  26  is disposed between inlet module  20 ′ and outlet module  22 ′, and the connected state, where inlet module  20 ′ is mechanically and fluidly connected to outlet module  22 ′. 
     Shuttle  28 ′ is formed as a single part. It is understood, however, that shuttle  28 ′ can be formed from separate components joined together, similar to shuttle  28  ( FIGS. 2A-3D ). Stem  32 ″ extends into shuttle bore  64 . Second end  140 ″ is attached to shuttle  28 ′ within shuttle bore  64  and fluidly connected to inlet port  60 . Stem  32 ″ is cantilevered from shuttle  28 ′ and extends through sleeve body  130 . Stem taper  146 ″ is disposed at the end of first end  138 ″. Stem taper  146 ″ encounters piston taper  152 ′ and the interface therebetween aligns stem  32 ″ within receiving bore  150  as stem  32 ″ engages piston  72 ′. Stem taper  146 ″ thereby assists in ensuring concentricity as inlet module  20 ′ interfaces with outlet module  22 ′. Stem taper  146 ″ can be of any desired configuration for interfacing with piston taper  152 ′ and aligning stem  32 ″ in receiving bore  150 . For example, stem taper  146 ″ can be an annular curved portion. In some examples, stem taper  146 ″ can be hemispherical. 
     Stem passage  143  extends through stem  32 ″ from second end  140 ″ to stem ports  142 ″. Stem ports  142 ″ provides flowpaths for fluid to exit stem  32 ″. First end  138 ″ is disposed on a first side of stem ports  142 ″ and second end  140 ″ is disposed on a second side of stem ports  142 ″ opposite first end  138 ″. During operation, spray fluid enters stem passage  143  at second end  140 ″ and flows through stem passage  143  to stem ports  142 ″. In some examples, the fluid source connected to inlet port  60  is pressurized such that spray fluid is present in stem passage  143  both when isolation valve  14 ′ is in the isolated state and when isolation valve  14 ′ is in the connected state. 
     Sleeve flange  68  projects radially from sleeve body  130 . First sleeve end  134  extends from sleeve flange  68  towards stem flange  144 ″. Sleeve contour  162  is disposed at the distal end of first sleeve end  134 . Sleeve contour  162  is configured to interface with stem flange  144 ″ to close the flowpath through inlet module  20 ′ and prevents fluid from flowing out of inlet module  20 ′ between first sleeve end  134  and stem  32 ″. Stem  32 ″ and sleeve  30  interface to seal any fluid in inlet module  20 ′ from atmosphere. Second sleeve end  136  extends from sleeve flange  68  towards shuttle  28 ′. Inlet spring  34  extends between shuttle  28 ′ and sleeve flange  68  and is configured to bias sleeve  30  into contact with stem flange  144 ″. Inlet spring  34  is disposed about second sleeve end  136 . 
     Valve seal  40   a  is disposed on first end  138 ″. Inner seal  38   b  is disposed on second end  140 ″. Valve seal  40   a  is thus disposed on an opposite side of stem ports  142 ″ from inner seal  38   b.  Both stem flange  144 ″ and stem ports  142 ″ are disposed between valve seal  40   a  and inner seal  38   b.  Stem flange  144 ″ is disposed between stem seal groove  164   a′  and stem ports  142 ″. 
     Base  70 ′ is formed as a single part. It is understood, however, that base  70 ′ can be formed from separate components joined together, similar to base  70  ( FIGS. 2A-3D ). Outlet port  102  extends into base  70 ′ and provides an exit port for fluid to exit isolation valve  14 ′. Piston bore  104 ′ extends axially through base  70 ′ along axis A-A. Piston bore  104 ′ includes portions having varying diameters to ensure proper alignment of elements within piston bore  104 ′. The central portion of piston bore  104 ′ is disposed between chamber seals  90   a,    90   b  and forms an outlet chamber for receiving spray fluid. The central portion has diameter D 11 . A first portion of piston bore  104 ′ extends from the central portion and is capped by end cap  92 ′. Cartridge ring  86   a′  is disposed in the first portion between part of base  70 ′ and end cap  92 ′. The first portion includes two diameters, diameter D 12  and diameter D 13 . The first portion has diameter D 13  at the area defining wash chamber  148 . D 13  is larger than diameter D 12 . A second portion of piston bore  104 ′ extends from the central portion and is capped by seal retainer  84 ′. The second portion has diameters D 14  and D 15 . Diameter D 15  is larger than diameter D 14 . Diameters D 12 , D 13 , D 14 , and D 15  are larger than diameter D 11 . In some examples, D 12  and D 13  are the same diameter. In some examples, diameter D 12  is the same as diameter D 14 . In some examples, diameter D 13  is the same as diameter D 15 . It is understood however, that diameters D 11 -D 15  can have any desired relationship. 
     Wiper seals  88   a,    88   b;  cartridge ring  86   a;  and chamber seals  90   a,    90   b  are disposed in piston bore  104 ′. End cap  92 ′ is attached to base  70 ′. End cap  92 ′ retains wiper seal  88   a,  cartridge ring  86   a′,  and chamber seal  90   a  in piston bore  104 ′. Cartridge ring  86   a′  is disposed between end cap  92 ′ and base  70 ′. In the example shown, cartridge ring  86   a′  supports each of chamber seal  90   a  and wiper seal  88   a.  Cartridge ring  86   a′  includes windows to allows fluid flow into and out of wash chamber  148  defined by cartridge ring  86   a′.  Cartridge ring  86   a′  can be formed from two separate components, with a first component supporting cartridge seal  90   a  and a second component forming the windows into wash chamber  148  and supporting wiper seal  88   a.  In some examples, cartridge ring  86   a′  is formed from a single part. A portion of end cap  92 ′ contacts cartridge ring  86   a′  to maintain cartridge ring  86   a′  in piston bore  104 ′. 
     Seal retainer  84 ′ is attached to base  70 ′ and encloses an end of piston bore  104 ′ opposite end cap  92 ′. Seal retainer  84 ′ retains wiper seal  88   b  and chamber seal  90   b  in piston bore  104 ′. In the example shown, each of wiper seal  88   b  and chamber seal  90   b  are disposed within and supported by seal retainer  84 ′. A flange is formed in seal retainer  84 ′ to separate wiper seal  88   b  and chamber seal  86   b.    
     Piston housing  80  is attached to an end of base  70 ′ opposite end cap  92 ′. Piston head  106 ′ is disposed in piston housing  80  and is movable within piston housing  80  along axis A-A. Piston shaft  108 ′ extends from piston head  106 ′ into piston bore  104 ′. Piston shaft  108 ′ is movable within piston bore  104 ′ along axis A-A. Piston seals  74  are disposed around piston head  106 ′ and engage an inner wall of piston housing  80 . Piston seal retainer  76 ′ is attached to piston head  106 ′ and retains piston seals  74  on piston head  106 ′. Piston seal retainer  76 ′ includes a bore therethrough to allow boost member  172  to extend through piston seal retainer  76 ′ into communication with boost bore  109 . 
     Piston head  106 ′ divides piston housing  80  into dry chamber  154  and wet chamber  156 . Piston spring  78  is disposed in dry chamber  154  and is configured to bias piston  72 ′ towards a position associated with the isolated state. Boost member  172  extends into piston housing  80  through boost port  109  and through piston seal retainer  76 ′ into piston  72 ′. Boost member  172  is configured to provide pressurized fluid, such as compressed air or hydraulic fluid, to boost bore  174  to assist in driving piston  72 ′ from the position associated with the connected state to the position associated with the isolated state. It is understood, however, that boost member  172  can provide any desired fluid suitable for driving piston  72 ′. Wet chamber  156  is fluidly connected to wash chamber  148  via flowpaths extending through base  70 ′, as discussed in more detail above with regard to  FIGS. 6A and 6B . 
     Isolation valve  14 ′ is initially in the isolated state shown in  FIG. 7A . In the isolated state, gap  26  is disposed between inlet module  20 ′ and outlet module  22 ′ to electrically isolate outlet module  22 ′ and inlet module  20 ′. To initiate fluid flow through isolation valve  14 ′, inlet module  20 ′ is driven along axis A-A to the first intermediate state, shown in  FIG. 7B . In the first intermediate state gap  26  is no longer disposed between inlet module  20 ′ and outlet module  22 ′. 
     First end  138 ″ enters receiving bore  150  as isolation valve  14 ′ transitions to the first intermediate state. First contact is made between inlet module  20 ′ and outlet module  22 ′ in the first intermediate state. First end  138 ″ enters receiving bore  150  of piston  72 ′ and piston  72 ′ contacts stem flange  144 ″. As first end  138 ″ enters receiving bore  150 , valve seal  40   a  also enters receiving bore  150 . Valve seal  40   a  is thus disposed in receiving bore  150  between stem  32 ″ and piston  72 ′. Valve seal  40   a  provides a seal between stem  32 ″ and piston  72  that prevents fluid from migrating into receiving bore  150 . 
     Isolation valve  14 ′ transitions from the first intermediate state to the second intermediate state, shown in  FIG. 7C . Second contact is made between inlet module  20 ′ when sleeve flange  68  contacts outlet module  22 ′. Specifically, sleeve flange  68  contacts and is braced against end cap  92 ′ to inhibit further movement of sleeve  30  in direction R. It is understood, however, that sleeve flange  68  be braced in any desired manner. For example, sleeve flange  68  can directly contact another portion of outlet module  22 ′, such as base  70 ′, to prevent further movement of sleeve  30  in direction R. 
     As isolation valve  14 ′ transitions to the second intermediate state, stem  32 ″ pushes piston  72 ′ in direction R. More specifically, stem flange  144 ″ exerts a force on the end of piston  72 ′ contacting stem flange  144 ″ to push piston  72 ′ in direction R. Piston  72 ′ slides through wiper seal  88   a,  cartridge ring  86   a′,  and chamber seal  90   a.  Sleeve  30  also slides through wiper seal  88   a,  cartridge ring  86   a′,  and chamber seal  90   a  such that chamber seal  90   a  and wiper seal  88   a  seal against sleeve  30  with isolation valve  14 ′ in the second intermediate state. Piston  72 ′ shifting in direction R causes wet chamber  156  to increase in volume, thereby drawing wash fluid into wet chamber  156 . Piston spring  78  compresses within dry chamber  154 . 
     Isolation valve  14 ′ transitions from the second intermediate state to the connected state, shown in  FIG. 7D . With sleeve flange  68  braced against outlet module  22 ′, sleeve  30  is prevented from moving in direction R as isolation valve  14 ′ transitions from the second intermediate state to the connected state. Inlet spring  34  compresses between sleeve flange  68  and shuttle  28 ′. Stem  32 ″ continues to move in direction R and drives piston  72 ′ further in direction R. Stem  32 ″ shifts relative to sleeve  30  such that stem ports  142 ″ transition from inside of sleeve bore  132  to outside of sleeve bore  132 . Inner seal  38   b  slides within sleeve bore  132  and maintains a seal between sleeve  30  and stem  32 ″ to prevent fluid from migrating between sleeve  30  and stem  32 ″. 
     Stem ports  142 ″ are exposed within piston bore  104 ′. Stem ports  142 ″ are oriented to direct the fluid flow radially outward and into outlet module  22 ′. Stem ports  142 ″ being exposed within piston bore  104 ′ opens a flowpath between inlet port  60  and outlet port  102 . Isolation valve  14 ′ is thus open and can provide fluid to a downstream component. The fluid enters isolation valve  14 ′ through inlet port  60 , flows through the flowpath in shuttle  28 ′ to stem  32 ″, flows through stem passage  143  and enters piston bore  104 ′ through stem ports  142 ″, and flows downstream out of outlet module  22 ′ through outlet port  102 . Sleeve taper  162 ′ and stem flange  144 ″ are shaped such that sleeve taper  162 ′ and stem flange  144 ″ form an extension of stem ports  142 ″ with isolation valve  14 ′ in the connected state. Stem ports  142 ″ and the extended path between sleeve taper  162 ′ and stem flange  144 ″ turn the spray fluid from an axial flow to provide a transition to the flowpath through base  70 ′ to outlet port  102 . 
     Isolation valve  14 ′ shifts from the connected state to the isolated state to stop flow and electrically isolate inlet module  20 ′ and outlet module  22 ′. Isolation valve  14 ′ initially transitions from the connected state to the second intermediate state. As inlet module  20 ′ is pulled in direction F, stem  32 ″ is pulled in direction F due to the connection to shuttle  28 ′ such that stem  32 ″ retracts within sleeve bore  132 . Stem ports  142 ″ transition back into sleeve  30  and are covered by sleeve  30 . Sleeve  30  contacts and seals against stem flange  144 ″. Sleeve  30  covering stem ports  142 ″ and contacting stem flange  144 ″ closes the flowpath through inlet module  20 ′ and prevents fluid from exiting inlet module  20 ′. As such, the fluid within inlet module  20 ′ is sealed from atmosphere by the interface between sleeve  30  and stem flange  144 ″. 
     As isolation valve  14 ′ transitions to the second intermediate state, inlet spring  34  maintains sleeve  30  in the position associated with the connected state to ensure that stem  32 ″ is fully retracted within sleeve  30 . Piston spring  78  and/or pressurized fluid provided through boost member  172  push piston  72 ′ in direction F to maintain contact between piston  72 ′ and stem flange  144 ″ as stem  32 ″ shifts in direction F. 
     Isolation valve  14 ′ transitions from the second intermediate state to the first intermediate state. Each of piston  72 ′ and sleeve  30  maintain contact with stem flange  144 ″ as isolation valve  14 ′ transitions to the first intermediate state. Sleeve  30  and piston  72 ′ each shift in direction F through cartridge ring  86   a′  and wiper seal  88   a.  Piston  72 ′ reengages with wiper seal  88   a  and chamber seal  90   a  to seal any fluid in outlet module  22 ′ from atmosphere. 
     As piston  72 ′ shifts in direction F, the volume of wet chamber  156  decreases and piston head  106 ′ pumps wash fluid downstream to wash chamber  148  from wet chamber  156 . Wash fluid driven into wash chamber  148  by piston  72 ′ cleans those portions of isolation valve  14 ′ passing through wash chamber  148 , thereby washing spray fluid from those portions. Wiper seal  88   a  wipes the exterior of the components passing through wiper seal  88   a  to remove any residual fluid. Piston spring  78  and/or the pressurized fluid provided through boost member  172  drive piston  72 ′ in direction F and ensure that piston  72 ′ maintains contact with stem flange  144 ″ throughout the transition to the first intermediate state. While isolation valve  14 ′ is described as including both piston spring  78  and boost member  172 , it is understood that, in some examples, isolation valve  14 ′ includes only one or the other of piston spring  78  and boost member  172 . 
     Isolation valve  14 ′ then transitions from the first intermediate state to the isolated state. First end  138 ″ of stem  32 ″ is withdrawn from receiving bore  150 ′ of piston  72 ′. Piston  72 ′ disengages from stem flange  144 ″. As such, inlet module  20 ′ and outlet module  22 ′ are not in contact and gap  26  is reformed between inlet module  20 ′ and outlet module  22 ′. Inlet module  20 ′ continues to transition away from outlet module  22 ′ until gap  26  is of a sufficient size to electrically isolate inlet module  20 ′ from outlet module  22 ′. Isolation valve  14 ′ thus provides electrical isolation between earth ground potential P ( FIGS. 1A and 1B ) and any electrically charged components during spraying. 
     Isolation valve  14 ′ provides significant advantages. Isolation valve  14 ′ allows fluid flow when in the connected state and stops fluid flow when not in the connected state, without requiring the use of tools or other hardware. Isolation valve  14 ′ prevents fluid from being exposed to the atmosphere and provides a physical isolation gap  26  when in the isolated state. This is especially useful when moving water-based fluids that are electrically charged, such as in an electrostatic spray system similar to electrostatic spray system  10 . Isolation valve  14 ′ does not include any ball/seat check valves to seal fluid from atmosphere. Instead, stem  32 ″ and sleeve  30 ′ interface to seal fluid from atmosphere in inlet module  20 ′ and piston  72 ′ interfaces with chamber seal  90   a  and chamber seal  90   b  to seal spray fluid in outlet module  22 ′ from atmosphere. In addition, the connecting geometry of stem  32 ″, sleeve  30 , and piston  72 ′ ensures concentricity and proper alignment as isolation valve  14 ′ transitions into the connected state. There are no springs or other difficult to access and clean components in the fluid flow path between inlet port  60  and outlet port  102 . 
       FIG. 8  is an enlarged view of detail  8  in  FIG. 7B . Interface  158 ″ between sleeve  30 , stem  32 ″, and piston  72 ′ is shown. First sleeve end  134 , sleeve bore  132 , and sleeve taper  162  of sleeve  30  are shown. First end  138 ″, second end  140 ″, stem ports  142 ″, stem flowpath  143 , stem flange  144 ″, and stem seal grooves  164   a″,    164   b″  of stem  32 ″ are shown. Stem flange  144 ″ includes first flange side  166 ″, second flange side  168 ″, and free end  170 ″. Distal end  176  of piston shaft  108 ′ of piston  72 ′ is shown. 
     Seams  160   a″,    160   b″  are formed at interface  158 ″ between sleeve  30 , stem  32 ″, and piston  72 ′. Interface  158 ″ is a double seam interface in that seam  160   a″  is formed at the interface between piston  72 ′ and first flange side  166 ″ and seam  160   b″  is formed at the interface between sleeve  30  and second flange side  168 ″. Hard seals are formed at interface  158 ″ between sleeve  30  and stem flange  144 ″ and between piston  72 ′ and stem flange  144 ″. The seals are hard seals in that no soft seals, such as elastomeric o-rings, are disposed directly at interface  158 ″. 
     Stem flange  144 ″ projects generally radially from stem  32 ″. First flange side  166 ″ is flat and projects radially relative to axis A-A. Second flange side  168 ″ is contoured between stem port  142 ″ and free end  170 ″ such that second flange side  168 ″ extends both radially and axially. In some examples, second flange side  168 ″ can be flat. In other examples, second flange side  168 ″ can be curved. 
     Stem seal grooves  164   a″,    164   b″  are disposed annularly about stem  32 ″ on opposite sides of stem ports  142 ″. Valve seal  40   a  and inner seal  38   b  are disposed in stem seal grooves  164   a″,    164   b″,  respectively. Valve seal  40   a  is disposed on first end  138 ″. Inner seal  38   b  is disposed on second end  140 ″. Both stem flange  144 ″ and stem ports  142 ″ are disposed between valve seal  40   a  and inner seal  38   b.  Stem flange  144 ″ is disposed between stem seal groove  164   a″  and stem ports  142 ″. 
     Distal end  176  of piston  72 ′ includes a flat face configured to mate with and seal against first flange side  166 ″. While each of first flange side  166 ″ and distal end  176  are described as flat and radially-extending, it is understood that first flange side  166 ″ and distal end  176  can be of any suitable configuration for forming a hard seal between distal end  176  and stem flange  144 ″. 
     Sleeve taper  162  is disposed at the end of sleeve  30  and is configured to mate with and seal against second flange side  168 ″. Sleeve taper  162  interfacing with second flange side  168 ″ forms a fluid-tight hard seal between sleeve  30  and stem  32 ′. In the example shown, a radially-outer portion of sleeve taper  162  interfaces with and seats on second flange side  168 ″ while a radially-inner portion of sleeve taper  162  is spaced from second flange side  168 ″. It is understood, however, that sleeve taper  162  can be of any configuration suitable for forming a fluid-tight seal with second flange side  168 ″. 
     During operation, seams  160   a″,    160   b″  shift in direction R and pass through each of wiper seal  88   a,  cartridge ring  86   a′,  and chamber seal  90   a,  respectively, as isolation valve  14 ′ (best seen in  FIGS. 7A-7D ) transitions from the first intermediate state to the connected state. Seams  160   a″,    160   b″  shifts in direction F and passes through each of chamber seal  90   a,  cartridge ring  86   a′,  and wiper seal  88   a,  respectively, as isolation valve  14 ′ transitions to the first intermediate state from the connected state. 
     Stem taper  146 ″ interfaces with piston taper  152 ′ as isolation valve  14 ′ initially enters the first intermediate state from the isolated state. Piston taper  152 ′ is configured to contact stem taper  146 ″ and guide first end  138 ″ into receiving bore  150 . Piston taper  152 ′ and stem taper  146 ″ interfacing facilitates alignment of stem  32 ′ and piston  72 ′ on axis A-A to assist in ensuring concentricity between stem  32 ′ and piston  72 ′. 
     Stem flange  144 ″ directly contacts distal end  176  of piston  72 ′ to exert a pushing force on piston  72 ′ as isolation valve  14 ′ transitions to the connected state. Stem flange  144 ″ exerts the force on piston  72 ′ to drive piston  72 ′ in direction R. Seams  160   a″,    160   b″  shift in direction R and pass through wiper seal  88   a,  cartridge ring  86   a′,  and chamber seal  90   a.  As isolation valve  14 ′ transitions from the second intermediate state ( FIG. 7C ) to the connected state ( FIG. 7D ) sleeve  30  disengages from second flange side  168 ″. Sleeve  30  disengaging from second flange side  168 ″ opens a flowpath between sleeve  30  and stem flange  144 ″ that allows fluid to exit inlet module  20 ′ (best seen in  FIGS. 7A-7D ) through that flowpath. 
     To shut off flow, stem  32 ″ is pulled rearward and sleeve  30  reengages with second flange side  168 ″. Sleeve  30  engaging second flange side  168 ″ forms a fluid tight seal between sleeve  30  and stem flange  144 ″, thereby closing the flowpath and preventing additional fluid from exiting inlet module  20 ′. As isolation valve  14 ′ transitions to the isolated state, interface  158 ″ passes through wash chamber  148  within the outlet module  22 ′. As discussed in more detail in  FIGS. 6A and 6B , wash fluid is pumped through wash chamber  148  as piston  72 ′ shifts in direction F. The wash fluid cleans seams  160   a″,    160   b″  to remove any residual spray fluid from seams  160   a″,    160   b″.  After interface  158 ″ passes through wash chamber  148  wiper seal  88   a  removes any residual fluid from interface  158 ″. Piston  72 ′ reengages with each of chamber seal  90   a  and wiper seal  88   a  to seal the fluid passages within base  70 ′ from atmosphere. Distal end  176  disengages from first flange side  166 ″ as isolation valve  14  transitions to the isolated state. 
     DISCUSSION OF NON-EXCLUSIVE EMBODIMENTS 
     The following are non-exclusive descriptions of possible embodiments of the present invention. 
     An isolation valve includes an inlet module, an outlet module, and an actuating module. The inlet module includes a stem extending from a shuttle and including an internal flowpath extending from a first end of the stem connected to the shuttle to a fluid port through the stem; and a sleeve disposed around the stem and movable relative to the stem. The fluid port is disposed within the sleeve with the inlet module in the isolated state and the fluid port is disposed outside of the sleeve with the inlet module in the connected state. The outlet module includes a piston at least partially disposed within a piston bore through the outlet module. The actuating module is configured to actuate the isolation valve between an isolated state, where the inlet module is spaced from the outlet module such that a gap is disposed between the inlet module and the outlet module, and a connected state, where the inlet module is mechanically and fluidly connected to the outlet module. 
     The isolation valve of the preceding paragraph can optionally include, additionally and/or alternatively, any one or more of the following features, configurations and/or additional components: 
     The inlet module includes an inlet spring disposed between the sleeve and the shuttle. 
     The sleeve includes a sleeve flange projecting radially from the sleeve, and wherein the inlet spring interfaces with the sleeve flange. 
     The stem further includes a stem flange projecting radially from the stem, the piston contacts a first side of the stem flange with the isolation valve in the connected state, and the sleeve contacts a second side of the stem flange with the isolation valve in the isolated state. 
     The sleeve includes a tapered sleeve face and the second side of the stem flange includes a tapered flange face, wherein the tapered sleeve face contacts and seals against the tapered flange face. 
     The piston includes a flat piston face and the first side of the stem flange includes a flat flange face, wherein the flat piston face contacts and seals against the flat flange face with the isolation valve in the connected state. 
     A first dynamic seal disposed on the first side of the stem flange, wherein the piston contacts the first dynamic seal with the isolation valve in the connected state; and a second dynamic seal disposed on the second side of the stem flange, wherein the sleeve contacts the second dynamic seal with the isolation valve in the isolated state. 
     The first dynamic seal is disposed on a first side of the fluid port and the second dynamic seal is disposed on a second side of the fluid port such that the fluid port is disposed between the first dynamic seal and the second dynamic seal. 
     Each of the first dynamic seal and the second dynamic seal are disposed on a second end of the stem, and wherein the fluid port extends through the stem at a location between the first end and both of the first dynamic seal and the second dynamic seal such that each of the first dynamic seal and the second dynamic seal are disposed on the same side of the fluid port. 
     An interface between the piston, the sleeve, and the stem flange includes a single seam, one of the piston and the sleeve extends over a free end of the stem flange and contacts the other one of the piston and the sleeve, and the single seam is formed between the piston and the sleeve. 
     An interface between the piston, the sleeve, and the stem flange includes a double seam, the piston projects over a first dynamic seal disposed on the first side of the stem flange and contacts the first side of the stem flange, and the sleeve projects over a second dynamic seal disposed on the second side of the stem flange and contacts the second side of the flange. 
     The piston includes a piston head disposed in a piston housing attached to the outlet module, wherein the piston head divides the piston housing into a wet chamber and a dry chamber; and a piston shaft extending from the piston head and into the piston bore, the piston shaft including a receiving bore configured to receive a second end of the stem disposed opposite the first end of the stem. The outlet module includes a wash inlet port fluidly connected to the wet chamber to provide wash fluid to the wet chamber. The outlet module includes a wash outlet port fluidly connected to the wet chamber to receive wash fluid from the wet chamber and eject the wash fluid from the outlet module. 
     The piston is driven through a suction stroke by the inlet module as the isolation valve shifts from the isolated state to the connected state and the piston is driven through a pumping stroke as the isolation valve shifts from the connected state to the isolated state. The piston draws wash fluid into the wet chamber through the wash inlet port during the suction stroke. The piston pumps wash fluid from the wet chamber through the wash outlet port as the piston shifts through the pumping stroke. 
     The stem directly contacts the piston to exert a force on the piston and push the piston from a forward position associated with the isolated state to a rearward position associated with the connected state, thereby driving the piston through the suction stroke. 
     An outlet chamber defined within the piston bore; a wiper seal disposed within the piston bore on an inlet module side of the outlet chamber. The sleeve passes through the wiper seal as the sleeve enters and exits the piston bore. The piston contacts the wiper seal with the isolation valve in the isolated state and the sleeve contacts the wiper seal with the isolation valve in the connected state. 
     A cartridge ring disposed within the piston bore between the wiper seal and the outlet chamber. The cartridge ring defines a wash chamber through which the piston pumps wash fluid as the isolation valve transitions from the connected state to the isolated state. 
     No springs are disposed in a flowpath extending from the inlet port of the inlet module, through the stem, and to the outlet port of the outlet module. 
     An electrostatic spraying system includes a reservoir configured to store a supply of a spray fluid, wherein the reservoir is connected to earth ground potential; an applicator configured to be charged and to spray the spray fluid onto a surface; and the isolation valve disposed between the reservoir and the applicator, wherein the inlet module is fluidly connected to the reservoir and the outlet module is fluidly connected to the applicator. 
     A method includes driving an isolation valve in a first direction from an isolated state, where an inlet module is spaced from an outlet module such that a gap is formed therebetween, to a first intermediate state, where contact is made between a stem of the inlet module and a piston of the outlet module; driving the isolation valve in the first direction from the first intermediate state to a second intermediate state, where contact is made between a sleeve through which the stem extends and the outlet module such that the sleeve is braced against the outlet module to prevent further movement of the sleeve in the first direction; driving the isolation valve in the first direction from the second intermediate state to a connected state, wherein the stem shifts relative to the piston as the isolation valve transitions to the connected state such that a fluid port through the stem is uncovered within the outlet module thereby opening a flowpath through the stem between an inlet port of the inlet module and an outlet port of the outlet module; and driving the isolation valve from the connected state to the second intermediate state, from the second intermediate state to the first intermediate state, and from the first intermediate state to the isolated state. 
     The method of the preceding paragraph can optionally include, additionally and/or alternatively, any one or more of the following features, configurations and/or additional components: 
     Drawing, with the piston, wash fluid into a wet chamber of the outlet module as the isolation valve transitions from the first intermediate state to the connected state; and driving, with the piston, the wash fluid into a wash chamber through which an interface between the stem, the sleeve, and the piston passes as the isolation valve shifts from the connected state to the first intermediate state. 
     While the invention has been described with reference to an exemplary embodiment(s), it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment(s) disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.