Patent Publication Number: US-2003222235-A1

Title: Modular shut-off valve apparatus

Description:
BACKGROUND AND SUMMARY  
       [0001] The present disclosure relates to a shut-off valve apparatus and particularly, to a shut-off valve apparatus having a valve body and an operator that moves a valve in the valve body from a closed position to an opened position to permit material flow through the valve body. The present disclosure also relates to modular shut-off valve apparatus having various modules that couple together to form shut-off valves of different sizes and with different features.  
       [0002] Shut-off valves that open and close to control material flow in a conduit or piping system are known. Some conventional shut-off valves, such as ACTIONAIR® valves available from Maxon Corporation of Muncie, Ind., are electrically controlled, pneumatically actuated valves that are biased mechanically toward a closed position. Because pipes or conduits come in a number of different sizes and styles, shut-off valves are provided by valve manufacturers in a variety of sizes and styles. As a result, valve manufacturers must purchase, store, and assemble numerous shut-off valve components so that shut-off valves having different sizes can be provided to meet customer requirements.  
       [0003] According to the present disclosure, a valve apparatus for use with a source of pressurized air comprises a main valve module having a valve body and a valve member coupled to the valve body. The valve member is movable between a first position blocking material flow through the valve body and a second position permitting material flow through the valve body. The valve apparatus further comprises an operator coupled to the main valve module. The operator has a pneumatics module and an electronics module. The pneumatics module has a pneumatic actuator that, when actuated, moves the valve member from the first position to the second position. The pneumatic actuator is coupled to the source of pressurized air. The pneumatics module has an electrical actuator that, when energized, permits pressurized air from the source of pressurized air to reach the pneumatic actuator to actuate the pneumatic actuator. The electronics module has an electrical connector and at least one conductor that electrically couples the connector to the electrical actuator. The pneumatics module is situated between the electronics module and the main valve module.  
       [0004] In illustrative embodiments, the valve apparatus is configured to couple to pipes of a piping system and the electronics module is configured to decouple from the pneumatics module while the main valve module remains coupled to the pipes of the piping system. The pneumatics module remains coupled to the main valve module when the electronics module is decoupled from the pneumatics module. In addition, the source of pressurized air remains coupled to the pneumatics module when the electronics module is decoupled from the pneumatics module.  
       [0005] According to an aspect of this disclosure, a number of different shutoff valve assemblies are assembled from various components, such as operators, switch assemblies, main valve modules, and solenoid valve components. In addition, main valve modules are available to mate with pipes of different sizes. In some embodiments, pressurized air is supplied to the pneumatic actuator from pressurized air equipment that is situated in a facility remotely from the shut-off valve apparatus and in other embodiments, an air-delivery module is coupled to the pneumatics module to provide pressurized air to the pneumatic actuator.  
       [0006] Additional features will become apparent to those skilled in the art upon consideration of the following detailed description of illustrative embodiments exemplifying the best mode of carrying out the pneumatic exhaust controller as presently perceived. 
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0007] The detailed description particularly refers to the accompanying figures in which:  
     [0008]FIG. 1 is a perspective view of a shut-off valve apparatus according to this disclosure showing the shut-off valve apparatus having a main valve module, a pneumatic actuator module above the main valve module, and an electronics module above the pneumatic actuator module;  
     [0009]FIG. 2 is an exploded perspective view of the shut-off valve apparatus of FIG. 1 showing the electronics module in the lower left corner of the page, a tubular housing of the pneumatic actuator module in the upper right corner of the page, a pneumatic actuator beneath the tubular housing, a pneumatic exhaust controller coupled to a top plate of the pneumatic actuator, and the main valve module beneath the pneumatic actuator;  
     [0010]FIG. 3 is a sectional view of the shut-off valve apparatus of FIG. 1, taken through a vertical central axis of the shut-off valve apparatus, showing a piston of the pneumatic actuator in a raised position and a gate of the main valve module biased by a coil spring upwardly into a closed position blocking a horizontal passage formed in a valve body of the main valve module;  
     [0011]FIG. 4 is a sectional view of the shut-off valve apparatus, similar to FIG. 3, showing pressurized air being introduced through the pneumatic exhaust controller into a top region of a cylinder of the pneumatic actuator, the piston being forced downwardly by receipt of the pressurized air in the top region of the cylinder, the downward movement of the piston compressing the coil spring and moving the gate to an opened position unblocking the horizontal passage formed in the valve body;  
     [0012]FIG. 5 is a diagrammatic view showing five different types of main valve modules grouped in the lower right corner of the page, two different types of operators situated on the left side of the page, four different types of switch assemblies grouped in the upper right corner of the page, and a set of dashed lines indicating that each of the four switch assemblies are usable in an electronics module of each of the operators and indicating that each of the five main valve modules are connectable to a pneumatics module of each of the operators;  
     [0013]FIG. 6 is a perspective view of a pneumatic exhaust controller according to this disclosure, with portions broken away, showing a manifold block, a first portal near a bottom of the manifold block, a second portal (in phantom) near a top of the manifold block, a manifold cap coupled to a top portion of the manifold block, the manifold cap having an exhaust portal, and a solenoid coupled to a lower portion of the manifold block;  
     [0014]FIG. 7 is a part perspective, part diagrammatic view showing a cap and a first solenoid coil detached from a tube of the solenoid of the pneumatic exhaust controller of FIG. 6 and showing a plurality of other solenoid coils that are attachable to the tube of the solenoid in lieu of the first solenoid coil; and  
     [0015]FIG. 8 is a perspective view showing an alternative shut-off valve apparatus, an air-delivery module exploded away from a pneumatics module of the alternative shut-off valve apparatus, and a series of curved dashed lines indicating that the air-delivery module is coupleable to the pneumatic module. 
    
    
     DETAILED DESCRIPTION OF THE DRAWINGS  
     [0016] A shut-off valve assembly  280 , shown in FIGS.  1 - 4  has a main valve module  284  and an operator  286  that moves main valve module  284  between opened and closed positions. Operator  286  sets atop module  284  as shown in FIG. 1. Operator  286  comprises a pneumatics module  288  to which module  284  couples and an electronics module  290  situated above module  288 . Thus, pneumatics module  288  is situated between electronics module  290  and main valve module  284 . Module  288  of operator  286  includes a pneumatic actuator  282  which is actuated by pressurized air. Module  288  of operator  286  further includes a pneumatic exhaust controller  20  that operates to route pressurized air into pneumatic actuator  282  to move module  284  to the opened position and to exhaust pressurized air from pneumatic actuator  282  to move module  284  to the closed position.  
     [0017] Module  284  has a valve body  292  which is formed to include a horizontal passage  294  extending therethrough as shown in FIGS.  1 - 4 . Valve body is also formed to include a vertical passage  295  that extends upwardly from passage  294  as shown in FIGS. 3 and 4. Module  284  further comprises a rod  298  that extends upwardly through passage  295 , a gate  296  coupled to a lower portion of rod  298 , a disk  300  coupled to an upper portion of rod  298 , and a coil spring  310  situated between valve body  292  and disk  300 . Rod  298  and gate  296  are movable between a raised position, shown in FIG. 4, in which material is prevented from flowing through passage  294  and a lowered position, shown in FIG. 4, in which material is permitted to flow through passage  294 . The word “material” in this disclosure is intended to cover all types of gases, liquids, and solid materials, including granular materials, as well as combinations of these, that are capable of flowing through a passage. Spring  310  serves as a biaser that biases rod  298  and gate  296  to toward the raised position.  
     [0018] Gate  296  is a plate-like element having an opening  312  extending therethrough as shown in FIGS. 3 and 4. When gate  296  is in the lowered position, shown in FIG. 4, opening  312  is aligned with passage  294  and a blocking portion of gate  296 , which is the portion of gate  296  beneath opening  312 , is received in a chamber  314  that is formed in valve body  292  beneath passage  292 . When gate  296  is in the raised position, shown in FIG. 3, the blocking portion of gate  296  is situated in passage  294  to block the flow of material through passage  294 .  
     [0019] Illustrative module  284  is sometimes referred to as a “gate valve.” In lieu of the illustrative gate valve of FIGS.  1 - 4 , it is within the scope of this disclosure for module  284  of shut-off valve assembly  280  to be configured as a ball valve, a flapper valve, a needle valve, a plug valve, or any other suitable type of valve capable of moving to open and close passage  294  or a similar passage of appropriate configuration.  
     [0020] The lower portion of rod  298  is slotted and the upper portion of gate  296  is received in the slot of rod  298  as shown in FIGS. 3 and 4. Gate  296  is coupled to the lower portion of rod  298  by a pin  322  that extends through the lower portion of rod  298  and through the upper portion of gate  296 . Illustrative module  284  has a first valve ring  316  situated in passage  294  on one side of gate  296  and a second valve ring  318  situated in passage  294  on the other side of gate  296 . A wavy washer or spring  320  is compressed between a first shoulder  324  of valve body  292  and first valve ring  316 . Spring  320  acts through ring  316  and through gate  296 , which floats axially on pin  322 , to bias second valve ring  318  against a second shoulder  326  of valve body  292 . Thus, gate  296  is sandwiched between rings  316 ,  318 . Spring  320  imparts a sufficient amount of force on rings  316 ,  318  and gate  296  so that rings  316 ,  318  sealingly engage gate  296 . An o-ring  328  is provided at the interface between an outer periphery of ring  318  and valve body  292  to further seal passage  294  when gate  296  is in the raised position. In alternative embodiments, a rotary coupling, such as a spherical bearing or a ball-and-socket joint, joins rod  298  and gate  296  in lieu of the illustrative pin and slot arrangement.  
     [0021] Valve body  292  has a cylindrical wall  330  that surrounds and defines an upper portion of passage  295  as shown in FIGS. 3 and 4. Cylindrical wall  330  extends upwardly into an interior region of coil spring  310  and terminates at an upwardly facing surface  332  as shown best in FIG. 3. Rod  298  extends from gate  296  upwardly through cylindrical wall  220  and supports disk  300  above surface  332 . When rod  298  and gate  296  are in the raised position, disk  300  is spaced apart from surface  332 . When rod  298  and gate  296  are in the lowered position, disk  300  engages surface  332 . Thus, surface  332  of cylindrical wall  330  serves as a stop that limits the amount of downward movement of disk  300 , rod  298 , and gate  296 . A pair of o-rings  334  are coupled to valve body  292  and engage an outer surface of rod  298  to pneumatically seal the portion of passage  295  above  0 -rings  334  from the portion of passage  295  below o-rings  334 .  
     [0022] Pneumatics module  288  comprises pneumatic actuator  282 , controller  20 , and a housing  336  as shown in FIGS.  1 - 4 . Illustrative pneumatic actuator  282  has a top plate  338 , a bottom plate  340 , and a cylindrical wall  342  extending vertically between plates  338 ,  340 . Actuator  282  further comprises a piston  344  having a piston head  346  situated between plates  338 ,  340  in an interior region of cylindrical wall  342  and a piston rod  348  extending upwardly from piston head  346  through an opening  350  formed in top plate  338  as shown in FIGS. 3 and 4. Actuator  282  also has a first seal  352 , which is coupled to top plate  338  and which engages an outer surface of piston rod  348 , and a second seal  354 , which is coupled to piston head  346  and which engages an inner surface of cylindrical wall  342 . In one embodiment, actuator  282  is a pneumatic actuator available from, for example, Bimba Manufacturing Company of Monee, Ill. Suitable pneumatic actuators are available from other manufacturers as well.  
     [0023] Actuator  282  includes a controller  20 , which is coupled to top plate  338  with suitable couplers, such as illustrative bolts  360 . As shown in FIGS. 6 and 7, controller  20  has a manifold  22  including a manifold block  28  and a manifold cap  30 . Block  28  is formed to include a first portal  34 , shown in FIGS. 6 and 7 (in solid) and a second portal  40 , shown in FIGS. 6 and 7 (in phantom). Cap  30  is formed to include an exhaust portal  42 . A source of pressurized air (not shown) is coupled to first portal  34 . Controller  20  has a solenoid  26  coupled to manifold block  22  as shown, for example, in FIG. 2. When solenoid  26  is energized, pressurized air flows from portal  34  to portal  40 .  
     [0024] Top plate  338  has a pneumatic passage  356 , shown in FIGS. 3 and 4 (in phantom), through which pressurized air flows when either entering or exiting a space  358 , shown best in FIG. 4, defined between piston head  346  and top plate  338 . Controller  20  is coupled to top plate  338  of actuator  282  so that portal  40  of manifold block  28  of controller  20  is in pneumatic communication with passage  356 . Thus, pressurized air exiting manifold block  22  through portal  40  when solenoid  26  is energized, enters space  358  through passage  356  to actuate actuator  282 . An o-ring (not shown) or other suitable sealing member, such as a gasket, is provided around portal  40  at the interface between manifold block  22  and plate  338  to provide sealed interface between controller  20  and actuator  282 . Such an arrangement eliminates the need for additional components, such as threaded connectors, between portal  40  and passage  356 . When solenoid  26  is de-energized, pneumatic communication between portal  34  and portal  40  is blocked and the pressurized air in space  358  flows through portal  40  into manifold block  22  and then exhausts through portal  42 .  
     [0025] Housing  336  comprises a bottom piece  362  and a tubular upper piece  364  that couples to bottom piece  336 . Bottom plate  340  of actuator  282  couples to bottom piece  362  of housing  336  with suitable couplers, such as bolts  366 . The bottom portion of cylindrical wall  342  is received in a large opening defined by a cylindrical surface  368  that extends through bottom plate  340  as shown in FIGS. 3 and 4. Bottom piece  362  of housing  336  has a cylindrical surface  370  that extends therethrough and that is aligned with the interior surface of cylindrical wall  342  of actuator  282 . Upper piece  364  of housing  336  is coupled to and extends upwardly from bottom piece  362 . Controller  20  and the majority of actuator  282  are situated in an interior region  371  of upper piece  364 . In addition, upper piece  364  has an opening  372 , shown in FIGS. 1 and 2, that aligns with portal  34  of controller  20 . A fitting  374 , such as an NPT connector, has a hexagonal portion  376  that abuts piece  364  and a tubular portion  378  that extends from hexagonal portion  376  through opening  372  into pneumatic communication with portal  34 . An o-ring (not shown) or other suitable sealing member, such as a gasket, is provided between fitting  374  and manifold block  28 .  
     [0026] Valve body  292  has a square-shaped flange  380  that couples to bottom piece  362  of housing  336  with suitable couplers, such as bolts (not shown). Bolt-receiving apertures  382  are formed in the corner regions of flange  380  which permits shut-off valve module  284  to be coupled to pneumatics module  288  in any one of four orientations. For example, one orientation of module  282  relative to module  288  is shown in FIGS. 1, 3, and  4  and another orientation of module  282  relative to module  288  is shown in FIG. 2.  
     [0027] Disk  300 , along with portions of rod  298  and spring  310 , are received in the interior region of cylindrical wall  342  of actuator  282  beneath piston head  346  as shown in FIGS. 3 and 4. Spring  310  biases disk  300  into contact with piston head  346 . In addition, cylindrical wall  330  of valve body  292  extends upwardly through the opening defined by cylindrical surface  370  of piece  362  into the interior region of cylindrical wall  342  of pneumatic actuator  282 .  
     [0028] When piston  344  is in a raised position, shown in FIG. 3, and pressurized air is introduced into space  358  through controller  20 , piston  344  moves downwardly from the raised position to a lowered position, shown in FIG. 4. As piston  344  moves from the raised position to the lowered position, piston head  346  pushes disk  300 , rod  298 , and gate  296  downwardly against the bias of spring  310  from the raised position to the lowered position to open shut-off valve module  284 . Contact between disk  300  and surface  332  of cylindrical wall  330  limits the amount of downward movement of piston  344  relative to cylindrical wall  342  of actuator  282 . Module  284  remains open so long as space  358  is pressurized by an amount that overcomes the bias of spring  310 .  
     [0029] When solenoid  26  of controller  20  is de-energized the source of pressurized air is decoupled from space  358 . After the source of pressurized air is decoupled from space  358 , spring  310  forces disk  300  and piston  344  upwardly which, in turn, forces the air extant in space  358  out of actuator  282 , through passage  356 , into controller  20  through portal  40 , and then out of controller  20  through exhaust portal  42  into the interior region  371  of piece  364 . The air in interior region  371  communicates with the ambient environment around assembly  280  through a vertical passage  379  formed in bottom piece  362  of housing  336 . A filter  381  is situated in passage  379  as shown in FIGS. 3 and 4. The air in space  358  exhausts rapidly out of actuator  282  through controller  220  when solenoid  26  is de-energized so that shut-off valve module  282  closes quickly.  
     [0030] Electronics module  290  has a housing  382  with an interior region  384  as shown in FIGS. 3 and 4. Electronics module  290  also has a switch assembly  387  situated in interior region  384 . Switch assembly  387  comprises a bracket  386  coupled to housing  382  in interior region  384 , an electrical connector  388  coupled to bracket  386 , and one or more limit switches  390  coupled to bracket  386  as shown in FIGS. 3 and 4. Housing  382  comprises a main body  392 , a cover plate  394 , and an access plate  396 . Cover plate  394  couples to main body  392  with suitable couplers, such as bolts  398 , to cover an open top of main body  392 . Access plate  396  couples to main body  392  with suitable couplers (not shown) to cover an open side of main body  392 . Main body  392  is coupled to the top of upper piece  364  of housing  336  of module  288 .  
     [0031] Electronics module  290  fits on top of pneumatics module  288  so that vertical outer surfaces  393  of main body  392  are substantially coplanar with associated vertical outer surfaces  395  of piece  364  of housing  336  that lie thereunder as shown, for example, in FIG. 1. In an alternative embodiment, main body  392  of module  288  and piece  364  of housing  336  are formed as an integral unit. Illustratively, outer surfaces  393 ,  395  are substantially square-shaped in horizontal cross section. However, it is within in the scope of this disclosure for modules  288 ,  290  to have other configurations such that the horizontal cross sections of outer surfaces  393 ,  395  are, for example, circular, elliptical, triangular, rectangular, hexagonal, octagonal, and so on. In addition, it is within the scope of this disclosure for surfaces  393  not to be substantially coplanar with surfaces  395 . Thus, housing  336  and housing  382  may be configured in any shape and still be within in the scope of this disclosure so long as modules  288 ,  290  are able to couple together to form an operator that is capable of moving shut-off valve module  284  between the opened and closed positions.  
     [0032] Access plate  396  is removable from main body  392  so that connector  388  is accessible for coupling with a mating connector (not shown). Electrical signals are communicated to and from shut-off valve assembly  280  through connector  388 . For example, connector  388  is coupled electrically via cables  98  to solenoid  26  and electrical signals to energize and de-energize solenoid  26  are communicated to cables  98  through connector  388 . Cables  98  are routed from connector  388  through interior region  384  of housing  382  and downwardly into interior region  371  of piece  364 . Limit switches  390  are coupled electrically to connector  388  and provide signals indicative of the position of piston  344 .  
     [0033] An indicator tip  400  is coupled to the top of piston rod  348  as shown in FIGS.  2 - 4 . Tip  400  has a cam portion  402  that wipes against movable members (not shown) of limit switches  390  to move switches  390  from an OFF state to an ON state. When piston  344  is in the raised position, an upper limit switch  390  is in the ON state and a lower limit switch  390  is the OFF state. When piston  344  is in the lowered position, the upper limit switch  390  is in the OFF state and the lower limit switch  390  is in the ON state. The positions of switches  390  is communicated electrically through connector  388  to valve control equipment, such as, for example, a programmable logic controller.  
     [0034] Cover plate  394  has a cylindrical edge  399  defining an opening in cover plate  394  as shown in FIGS. 3 and 4. Housing  382  of module  290  has a transparent dome  404  that is coupled to cover plate  394  and that extends through the opening defined by edge  399  as also shown in FIGS. 3 and 4. When piston  344  is in the raised position, the upper portion of tip  400  is present in dome  404  and when piston  344  is in the lowered position, the upper portion of tip  400  is absent from dome  404 . Thus, the presence or absence of tip  400  in dome  404  provides a visual indication of whether valve module  284  is closed or opened, respectively.  
     [0035] Shut-off valve assembly  280  is well suited for use in industrial environments, such as in piping systems of manufacturing plants, chemical processing plants, petroleum refineries, and the like. Controller  20 , along with a majority of actuator  282 , is situated in interior region  371  of housing  336  as described above. In addition, switch assembly  387 , along with a portion of actuator  282 , is situated in interior region  384  of housing  382 . Thus, housings  336 ,  382  protect controller  20 , actuator  282 , and switch assembly  387  from inadvertent impacts and from the harsh conditions that are oftentimes found in industrial environments. Shut-off valve assembly  280  is configured so that electronics module  290  is removable from pneumatics module  288  without the need to disconnect pneumatic lines that are coupled to fitting  374  to deliver pressurized air to operator  286  and without the need to disconnect pneumatics module  288  from main valve module  284 . In addition, shutoff valve assembly  280  is configured so that operator  286  is removable from module  284  without the need to disconnect module  284  from the pipes, conduits, or lines to which module  284  is connected. After removal of operator  286  from module  284 , module  284  remains in the closed position.  
     [0036] Referring now to FIG. 5, an alternative operator  410  is illustrated beneath operator  286 . Operator  410  has a housing  412  which comprises a tubular piece  414 , a bottom plate  416  coupled to the bottom of piece  414 , and a partition plate  418  (in phantom) that subdivides housing  412  into an upper compartment and a lower compartment. The upper compartment above partition plate  418  is associated with an electronics module portion of operator  410  and the lower compartment below partition plate  418  is associated with a pneumatics module portion of operator  410 . Housing  412  also has a cover plate  394 , which is sized and configured the same as cover plate  394  of housing  382  of operator  286 , and an access plate (not shown), which is sized and configured the same as access plate  396  of operator  286 . Operator  410  further comprises a set of fasteners  398  and a dome  404  as was the case with operator  286 .  
     [0037] Operator  410  has a pneumatic actuator (not shown) that is similar to actuator  282  of operator  286  but that is slightly larger in diameter and in stroke length. However, operator  410  comprises controller  20  that is coupled to the associated “larger-size” actuator and that operates to direct pressurized air into and exhaust pressurized air from the “larger-size” actuator in the same manner as described above with reference to actuator  286 . Thus, piece  414  of housing  412  has an opening  372  through which pressurized air is provided to portal  34  of the associated controller  20 .  
     [0038] As shown diagrammatically in FIG. 5, a number of different types of switch assemblies and a number of different types of main valve modules may be used in conjunction with either operator  286  or operator  410 . In addition, an operator similar to operator  286 , but having a pneumatic actuator with a stoke length longer than operator  286 , is used in conjunction with certain switch assemblies and main valve modules. The embodiments having a pneumatic actuator with longer stroke length include a housing  1336 , which is similar to, but longer than, housing  336  as shown in FIG. 5 (in phantom). Thus, a “short stroke” operator  286  and a “long stroke” operator  286  are contemplated by this disclosure.  
     [0039] An entire product offering of shut-off valves is created by assembling the various operators, switch assemblies, and main valve modules in various ways. For example, in lieu of switch assembly  387 , a switch assembly  1387  may be used in “short stroke” operator  286 . A switch assembly  2387  and a switch assembly  3287  may be used either in the “long stroke” operator  286  or in operator  410 . In this example, therefore, the stroke length of the pneumatic actuator associated with operator  410  is substantially the same as the stroke length of the pneumatic actuator associated with the “long stroke” operator  286 . However, the piston diameters of the “short stroke” and “long stroke” operators  286  are substantially the same, such as for example 2.5 inches (6.35 cm), whereas the piston diameter of operator  410  is larger, such as for example 4 inches (10.16 cm).  
     [0040] A number of different sizes and styles of main valve modules are contemplated by this disclosure. For example, a module  1284  or a module  2284  may be coupled to “short stroke” operator  286  in lieu of module  284 . Modules (not shown) similar to modules  284 ,  1284 ,  2284 , but with certain components such as spring  310 , gate  296 , and rod  298  being configured with appropriate length, may be coupled to “long stroke” operator  286 . In addition, a module  3284  or a module  4284  may be coupled to operator  410 . It will be appreciated that the illustrative combinations of main valve modules  284 ,  1284 ,  2284 ,  3284 ,  4284  and operators  286 ,  410  are given as examples only and are not exhaustive of all of the sizes and styles of main valve modules that may be combined with operators  286 ,  410  in accordance with this disclosure. Thus, main valve modules similar to modules  284 ,  1284 ,  2284 , but appropriately scaled up in size, may be used with operator  410 . Similarly, main valve modules similar to modules  3284 ,  4284 , but appropriately scaled down in size and having proper stroke length, may be used with either “short stroke” operator  286  or “long stroke” operator  286 .  
     [0041] In some industrial environments where combustible gases or fluids are pumped through piping systems having shut-off valves, certain safety regulations, such as those established by the National Electrical Manufacturers Association (NEMA), require that hermetically sealed switches be used in these shut-off valves. Thus, to comply with these safety regulations, switch assemblies  1387 ,  3387  have hermetically sealed switches  1390  instead of switches  390 . Other applications may call for unsealed, general purpose switches or switches that are sealed to an intermediate level. Use of any and all types of switches in switch assemblies  387 ,  1387 ,  2387 ,  3387 , as well as other types of position sensors, such as optical sensors, magnetic sensors, linear variable displacement transducers, and the like, as well as their equivalents, are within the teachings of this disclosure.  
     [0042] In some applications, where an extra degree of certainty as to the whether the shut-off valve assembly is opened or closed, certain safety regulations call for redundant monitoring of the valve position. Thus, to comply with these safety regulations, switch assembly  2387  has a pair of upper switches  390  that are tripped by cam portion  402  when the associated rod and gate of the corresponding actuator are in the raised position (i.e. when the associated main valve module is in the closed position) and a pair of lower switches  390  that are tripped by cam portion  402  when the associated rod and gate of the corresponding actuator are in the lowered position (i.e. when the associated main valve module is in the opened position). Similarly, switch assembly  3387  has a pair of upper switches  1390  and a pair of lower switches  1390  that are tripped by cam portion  402  when the associated rod and gate of the corresponding actuator are in the raise and lowered positions, respectively. In the illustrative embodiments, switches  390 ,  1390  are the types of switches available from, for example, Honeywell Inc. of Freeport, Illinois. Suitable switches are available from other manufacturers as well.  
     [0043] Because the stroke lengths of the respective pneumatic actuators of the “long stroke” operator  286  and of operator  410  are longer than the stroke length of actuator  282  of “short stroke” operator  286 , a vertical distance  420  between the upper and lower switches  390 ,  1390  of switch assemblies  2387 ,  3387 , respectively, is larger than the vertical distance between the upper and lower switches  390 ,  1390  of switch assemblies  387 ,  1387 , respectively, as shown in FIG. 5. Thus, bracket  1386  of switch assemblies  2387 ,  3387  is configured slightly differently than bracket  386  of switch assemblies  387 ,  1387  to accommodate the difference in spacing between upper and lower switches  390 ,  1390 . This disclosure contemplates additional switch assembly embodiments covering every permutation of assembling brackets  386 ,  1386  and switches  390 ,  1390 . In addition, switch assemblies having only one upper switch or one lower switch, as well as switch assemblies having only a pair of upper switches or a pair of lower switches are within the scope of this disclosure. Switch assemblies, such as illustrative switch assemblies  2387 ,  3387 , having pairs of switches  390 ,  1390  are provided with connectors  1388  that are longer than connectors  388  to accommodate the additional electrical connections associated with the redundant switches  390 ,  1390 .  
     [0044] Illustrative main valve modules  284 ,  1284 ,  2284 ,  3284 ,  4284  each have a different type of pipe connector configuration as shown in FIG. 5. Module  284  has a threaded pipe connection configuration with threads  422  as shown best in FIGS. 1 and 2. Pipes (not shown) that mate with module  284  have threaded end regions that threadedly engage threads  422 . Module  1284  has a pair of flanges  424  with threaded couplers  426  that threadedly engage threads (not shown) of a valve body  1292  of module  1284  as shown in FIG. 5. Flanges  424  have a series of apertures  428  formed therein. Pipes (not shown) that mate with module  1284  have flanges (not shown) with apertures (not shown) that align with respective apertures  428  of flanges  424 . Suitable couplers, such as bolts (not shown) are received by apertures  428  and by the apertures of the flanges of the associated pipes to couple module  1284  to the pipes. In some embodiments, gaskets or other suitable sealing materials are interposed between flanges  424  and the flanges of the pipes that couple to module  1284 .  
     [0045] Module  2284  has a valve body  2292  and a pair of flanges  430  that are welded to valve body  2292 . Flanges  430  are formed to include apertures  428 , which are substantially similar to apertures  428  of flanges  424 . Pipes (not shown) that mate with module  2284  couple to flanges  430  in substantially the same manner as described above with regard to the manner in which pipes couple to flanges  424 . Module  3284  has a valve body  3292  and a pair of sockets  432  that are welded or otherwise coupled to valve body  3292 . Pipes (not shown) that mate with module  3284  couple to the outer ends of sockets  432  via threads or other suitable couplers. Module  4284  has a valve body  4292  and a pair of flanged sockets  434  that are welded or otherwise coupled to valve body  4292 . Flanged sockets  434  have flanges  436  at their respective outer ends which couple to flanges (not shown) of the pipes which mate with module  4284 .  
     [0046] Controller  20  is included as one of the components of each of operators  286 ,  410  as mentioned above. Additional details of controller  20 , as well as alternatives to controller  20 , are shown in described in co-pending U.S. patent application Ser. No. _______ (attorney docket 3053-69517), which is titled PNEUMATIC EXHAUST CONTROLLER, and in co-pending U.S. patent application Ser. No. ______ (attorney docket 3053-69322), which is titled SHUT-OFF VALVE APPARATUS, both of these co-pending applications being filed concurrently herewith and both of these co-pending patent applications being hereby incorporated by reference herein.  
     [0047] As shown in FIGS. 6 and 7, solenoid valve  26  of controller  20  comprises a first body  56 , a second body  58 , and a separation disk  60  interposed between bodies  56 ,  58 . Bodies  56 ,  58  and disk  60  are each formed to include a plunger-receiving bore  62 . In addition, body  56  is formed to include a first passage  64  and a second passage  66 . Each of passages  64 ,  66  communicates pneumatically with bore  62  of body  56 . In addition, each of passages  64 ,  66  extends horizontally from bore  62  through body  56 . Body  56  of solenoid valve  26  is mounted to a lower portion  32  of block  28  so that passage  64  formed in body  56  communicates pneumatically with a passage  50  formed in block  28  and so that passage  66  formed in body  56  communicates pneumatically with passage a  52  formed in block  28 .  
     [0048] Solenoid valve  26  has a plunger  46 , portions of which are situated within respective bores  62  of bodies  56 ,  58  and disk  60  as shown in FIG. 6. Solenoid valve  26  further comprises a spring  48  situated within bore  62  of body  56 , a member or vent tube  68 , and a vent cap  70 . An annular end portion  72  of vent tube  68  is received in bore  62  of body  56 . Spring  48  is maintained in a state of compression between end portion  72  of vent tube  68  and an annular shoulder portion  74  of plunger  46  as shown in FIG. 6. Disk  60  is fastened to body  56  with any suitable fastening means, such as, for example, adhesive, welding, bolts, pins, snaps, fingers, tabs or the like, to trap end portion  72  of vent tube  70  against body  56 .  
     [0049] Vent tube  68  extends from body  56  through bore  62  of disk  60  and through bore  62  of body  58 . Thus, vent tube  68  is supported in a cantilevered manner with respect to manifold  22 . A cylindrical threaded portion  69  of vent tube  68  extends outwardly beyond an end surface  76  of body  58  and vent cap  70  threads onto the outwardly extending, distal end portion  69 . The other portions of member  68  are cylindrical in some embodiments and have shapes other than cylindrical in alternative embodiments. For example, portions of member  68  may have square, rectangular, triangular, hexagonal, etc. cross sections. Vent cap  70  engages end surface  76  of body  58  to clamp body  58  against disk  60 . An o-ring  77 , shown in FIG. 6, is compressed radially between portion  72  of vent tube  68  and body  56 . A first annular seal or gasket  79  is compressed axially between body  58  and disk  60  and a second seal or gasket  81  is compressed axially between body  58  and vent cap  70 . O-ring  77  and the annular gaskets  79 ,  81  pneumatically seal the various interfaces between bodies  56 ,  58 , disk  60 , vent tube  68 , and vent cap  70 .  
     [0050] Vent tube  68  has a bore  84  in which a portion of plunger  46  is received as shown in FIG. 6 Vent tube  68  also has a vent passage  86  in pneumatic communication with bore  84  and a radially extending shoulder surface  88  extending between bore  84  and passage  86 . Vent cap  70  has a vent chamber  90  in pneumatic communication with passage  86  of tube  68 , an annular groove  92  formed in a hexagonal outer periphery  94 , and a plurality of orifices  96  providing pneumatic communication between chamber  90  and groove  92 . One or more cables  98  extend from body  58  of solenoid valve  26 . Wires in cables  98  couple electrically to coil  44  to carry the electrical signals that energize and de-energize solenoid valve  26 .  
     [0051] Plunger  46  is magnetized so that an electrical field created by coil  44  when solenoid valve  26  is energized moves plunger  46  against the bias of spring  48  from a first position, shown in FIG. 6, to a second position (not shown). When plunger  46  is in the first position, an end surface  100  of plunger  46  is biased by spring  48  into sealing engagement with an inner surface  110  of body  56  to block pneumatic communication between passage  64  and passage  66 . When plunger  46  is in the second position, surface  100  is spaced apart from surface  110  and, in addition, an end surface  112  of plunger  46  is biased by the electrical field of energized coil  44  into sealing engagement with shoulder surface  88  of vent tube  68  to block pneumatic communication between bores  62 ,  84  and vent passage  86 .  
     [0052] When plunger  46  is in the second position, pressurized air is able to move through portal  34 , through passage  50  of block  28 , through passage  64  of body  56 , between end surface  100  of plunger  46  and inner surface  110  of body  56 , through passage  66  of body  56 , through passage  52  of block  28 , and out of portal  40 . Sealing engagement between end surface  112  of plunger  46  and shoulder surface  88  of vent tube  68  prevents the pressurized air from flowing through the space between plunger  46  and bore  84  of vent tube  68  and into vent passage  86 . When plunger  46  is in the first position, pressurized air is able to vent to the ambient surroundings through portal  40 , passage  52 , passage  66 , bores  62 , bore  84 , vent passage  86 , cavity  90 , and orifices  96 .  
     [0053] Depending upon the environment or application in which valve assembly  280  is used, other types of solenoid coils, such as a hermetically sealed solenoid coil, may be required by safety regulations in lieu of illustrative solenoid coil  44  which is a general purpose coil. Solenoid coils having intermediate levels of sealing, such as those that are explosion proof or intrinsically safe, may also be required or desired. Body  58 , coil  44 , and seals  79 ,  81  are coupled together and are attachable to and detachable from member  68  as a unit (hereinafter referred to as “coil unit 44, 58, 79, 81”).  
     [0054] To replace coil unit  44 ,  58 ,  79 ,  81  with another coil unit having a different type of coil, vent cap  70  is unthreaded from member  68 , coil unit  44 ,  58 ,  79 ,  81  is moved axially off of member  68 , the new coil unit is placed on member  68 , and cap  70  is threaded back onto member  68 . Thus, solenoid valve  26  is configured to permit easy attachment and detachment of coil units as shown in FIG. 7 by phantom blocks  500 ,  502 ,  504 ,  506  which indicate 1−X types of solenoid coils. When cap  70  is decoupled from member  68  for removal and replacement of the coil unit, the other portions of controller  20  remain assembled together as shown in FIG. 7. Of course, during the initial assembly of solenoid valve  26 , coil units are not interchanged, but rather, the desired type of coil unit is selected from the various types of coil units available and is mounted onto member  68 . In the illustrative embodiment, solenoid valve  26  is, for example, a Series 8 solenoid valve available from Nass Magnet of Hanover, Germany. Suitable solenoid valves are available from other manufacturers as well.  
     [0055] As is evident from the above discussion, a number of different shut-off valve assemblies are assembled from various components, such as “short stroke” and “long stroke” operators  286 , operator  410 , switch assemblies  387 ,  1387 ,  2387 ,  3387  (with various configurations of switch sealing and/or redundancy), main valve modules  284 ,  1284 ,  2284 ,  3284 ,  4284  (with various configurations of pipe connectors), and with various types of coil units. In addition, modules  284 ,  1284 ,  2284 ,  3284 ,  4284  are available to mate with pipes of different sizes. In one example of a shut-off valve assembly product line according to this disclosure, modules  284 ,  1284 ,  2284 ,  3284 ,  4284  each are available in sizes that couple to pipes having the following diameters: 0.75″ (1.905 cm); 1″ (2.54 cm); 1.25″ (3.175 cm); 1.5″ (3.81 cm); 2″ (5.08 cm); 2.5″ (6.35 cm); 3″ (7.62 cm); 4″ (10.16 cm); and 6″ (15.24 cm). In this particular example, “short stroke” operator  286  is used with modules  284 ,  1284 ,  2284 ,  3284 ,  4284  that are sized for pipes of 3″ (7.62 cm) diameter or less; “long stroke” operator  286  is used with modules  284 ,  1284 ,  2284 ,  3284 ,  4284  that are sized for pipes ranging from 2.5″ (6.35 cm) to 4″ (10.16 cm); and operator  410  is used with modules  284 ,  1284 ,  2284 ,  3284 ,  4284  that are sized for pipes of 4″ (10.16 cm) and 6″ (15.24 cm). Thus, there is some overlap in the exemplary product line for some of the pipe diameters. In addition, coil springs  310  having different spring constants (i.e. force per unit length characteristics) may be included in each of modules  284 ,  1284 ,  2284 ,  3284 ,  4284 . The higher the spring constant, the faster that the associated module  284 ,  1284 ,  3284 ,  4284  will move from the opened position to the closed position.  
     [0056] In some embodiments, the pressurized air that passes through controller  20  and that actuates the pneumatic actuator, such as actuator  282 , of the associated shut-off valve assembly is “shop air” which is generated by pressurized air equipment of a facility and which supplied to the shut-off valve assembly via high pressure air lines routed through the facility. Some facilities do not have pressurized air equipment for generating shop air and other facilities do not have high pressure air lines routed to all of the locations throughout the facility having shut-off valve assemblies. According to this disclosure, an alternative embodiment shut-off valve assembly  580  has an air-delivery module  582  as shown in FIG. 8.  
     [0057] Illustratively, shut-off valve assembly  580  has many of the same components as shut-off valve assembly  280 . However, the following description of the use of air-delivery module  582  with shut-off valve assembly  580  is applicable to all of the shut-off valve embodiments described herein. As shown in FIG. 8, assembly  580  comprises main valve module  282  and operator  286  which, in turn, comprises pneumatics module  288  and electronics module  290 . The main difference between assembly  580  and assembly  280  is the configuration of upper piece  364  of housing  336  of pneumatics module.  
     [0058] Air-delivery module  582  has a housing  520  that is configured with an interior region that receives a pressure source  522 , shown in FIG. 8 (in phantom). Pressure source  522  comprises any device, such as a pump or a compressor, that is capable of producing a suitable amount of pressure for actuating actuator  282  of operator  286 . Module  582  has appropriate couplers and/or brackets (not shown) which mount pressure source  522  to housing  520 . In some embodiments, interior region of housing  520  is lined or filled with insulation or padding to attenuate the noise produced by pressure source  520  when operating.  
     [0059] Module  582  has an electrical cord  524  that extends from pressure source  522  out of housing  520  and that terminates at an electrical plug  526  which mates with a standard electrical outlet (not shown) to provide electrical power to pressure source  522 . Housing  520  has a square-shaped flange  528 , each corner region of flange  528  being formed to include an aperture  530 . Flange  528  is also formed to include an inlet aperture  532  and an outlet aperture  534 . A set of threaded apertures  536  are tapped into piece  364  on the same wall of piece  364  that has opening  372  formed therein. In addition to opening  372 , which communicates with portal  34  of controller  20 , piece  364  has an opening  538  that communicates with interior region  371  of module  288 .  
     [0060] A set of screws  540  are provided for mounting module  582  to operator  286 . Each screw  540  extends through a respective aperture  530  formed in flange  528  and threadedly engages a respective threaded aperture  536  formed in piece  364  of housing  336 . Thus, when module  582  is mounted to operator  286 , flange  528  abuts the surface  395  of piece  364  having openings  372 ,  538 . Aperture  532  of flange  528  is aligned with and communicates pneumatically with opening  538  when module  582  is mounted to operator  286 . Similarly, aperture  534  of flange  528  aligns with and communicates pneumatically with opening  372  when module  582  is mounted to operator  286 . A pair of o-rings  542  are interposed between flange  528  and piece  364  to pneumatically seal the interface between openings  372 ,  538  and apertures  534 ,  532 , respectively. Apertures  532 ,  534  have recessed or countersunk portions that receive portions of o-rings  542  to prevent  0 -rings  532 ,  534  from moving out of proper alignment with respective openings  372 ,  538  and apertures  532 ,  534 .  
     [0061] Module  582  has an electrical connector  544  coupled to flange  528  and operator  286  has an electrical connector  546  coupled to piece  364  of housing  336 . When module  522  is mounted to operator  286 , connector  544  mates with connector  546  automatically. To actuate pneumatic actuator  282  of module  286 , an electrical control signal is provided to pressure source  522  through connectors  544 ,  546  and the associated wiring. The control signal to operate pressure source  522  is one of the electrical signals that is received by connector  388  of electronics module  290 . In addition, the control signal to operate pressure source  522  is sent substantially simultaneously with the signal that energizes solenoid valve  26  of controller  20 .  
     [0062] When pressure source  522  receives the appropriate control signal, pressure source  522  operates to deliver pressurized air to space  358  through aperture  534 , opening  372 , controller  20 , and passage  356 . Receipt of pressurized air in space  358  moves piston  344  downwardly, thereby moving module  284  from the closed position to the opened position. The air which is pressurized by pressure source  522  is received from interior region  371  of housing  336  through opening  538  and aperture  532 . As mentioned above, interior region  371  communicates with the ambient environment through passage  379  in which filter  381  is situated. Thus, as pressure source  522  draws air from interior region  371 , ambient air moves into interior region  371  through passage  379  and filter  381 . In alternative embodiments, pressure source  522  receives air through an opening and/or filter (not shown) formed in portions of housing  520  other than flange  528 .  
     [0063] The rate at which pressure source  522  delivers pressurized air to space  358  determines how quickly module  284  moves from the closed position to the opened position. If pressure source  522  has a relatively low capacity, then module  284  may open relatively slowly. However, in many applications the speed at which module  284  opens is not of primary concern, so long as module closes quickly in an emergency situation, for example. As described above, controller  20  is configured to exhaust air rapidly from space  358  when solenoid  26  is de-energized so that module  284  closes quickly. Therefore, use of module  522  to deliver pressurized air to operator  286 , rather than using high pressure “shop air,” does not affect the closing speed of module  284 .  
     [0064] In applications where it is desirable to open module  284  quickly, then an alternative air-delivery module may be provided. In such an alternative air-delivery module, pressure source  522  operates to pressurize the interior region of housing  520 . When solenoid  26  is energized, the pressurized air from the interior region of housing  520  moves through aperture  534 , opening  372 , controller  20 , passage  356  and into space  358  to actuate actuator  282 . Thus, in the alternative air-delivery module, housing  520  serves as a pressure reservoir. In some embodiments, cord  524  and plug  526  are omitted and pressure source  522  receives electrical power via connectors  544 ,  546  and the associated wiring. In other embodiments, one or more control switches (not shown) that control the operation of pressure source  522  and/or solenoid valve  26  are mounted to either housing  520  of module  582  or to operator  286 .  
     [0065] Although certain illustrative embodiments have been described in detail above, variations and modifications exist within the scope and spirit of this disclosure as described and as defined in the following claims.