Abstract:
A device for flushing a hydrant includes a stem connected to a valve of the hydrant; and an actuation system including a biased translational system coupled to the stem. An actuation system for flushing a hydrant includes a fluid; a piston assembly movable by the fluid; and a biasing element at least indirectly biasing the piston assembly towards a stop position. A method of flushing a hydrant includes operating an actuation system coupled to the hydrant, the actuation system including a stored energy device, a piston assembly coupled to a stem of the hydrant; and a biasing element coupled to the stem, the stem connected to a valve of the hydrant; and opening the valve of the hydrant by releasing energy from the stored energy device against a piston plate of the piston assembly.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application 61/595,737, filed on Feb. 7, 2012, which is hereby incorporated herein in its entirety by reference. 
    
    
     FIELD 
     The current disclosure relates to fire hydrants. Particularly, the current disclosure relates to flushing of fire hydrants. 
     SUMMARY 
     A device for flushing a hydrant is disclosed and includes a stem connected to a valve of the hydrant; and an actuation system including a biased translational system coupled to the stem. 
     Also disclosed is an actuation system for flushing a hydrant including a fluid; a piston assembly movable by the fluid; and a biasing element at least indirectly biasing the piston assembly towards a stop position. 
     Also disclosed is a method of flushing a hydrant including operating an actuation system coupled to the hydrant, the actuation system including a stored energy device, a piston assembly coupled to a stem of the hydrant; and a biasing element coupled to the stem, the stem connected to a valve of the hydrant; and opening the valve of the hydrant by releasing energy from the stored energy device against a piston plate of the piston assembly. 
     Various implementations described in the present disclosure may include additional systems, methods, features, and advantages, which may not necessarily be expressly disclosed herein but will be apparent to one of ordinary skill in the art upon examination of the following detailed description and accompanying drawings. It is intended that all such systems, methods, features, and advantages be included within the present disclosure and protected by the accompanying claims. 
    
    
     
       DESCRIPTION OF THE FIGURES 
       The features and components of the following figures are illustrated to emphasize the general principles of the present disclosure and are not necessarily drawn to scale. Corresponding features and components throughout the figures may be designated by matching reference characters for the sake of consistency and clarity. Although dimensions may be shown in some figures, such dimensions are exemplary only and are not intended to limit the disclosure. 
         FIG. 1  is a cross-sectional view of a standard fire hydrant. 
         FIG. 2  is a cross-sectional view of a flushable hydrant in accord with one embodiment of the current disclosure in a resting state. 
         FIG. 3  is a cutaway view of the flushable hydrant of  FIG. 2  taken along a different cutting plane from  FIG. 2 . 
         FIG. 4  is a cross-sectional view of the flushable hydrant of  FIG. 2  in an actuated position. 
         FIG. 5  is a perspective view of the flushable hydrant of  FIG. 2  without a shroud. 
         FIG. 6  is a schematic representation of a compressed gas system of the flushable hydrant of  FIG. 2 . 
         FIG. 7  is an exploded perspective view of the flushable hydrant of  FIG. 2 . 
         FIG. 8  is an electrical schematic of the flushable hydrant of  FIG. 2 . 
     
    
    
     DETAILED DESCRIPTION 
     Disclosed are methods, systems, and apparatus associated with flushing fire hydrants. The disclosure provides apparatus, methods, and systems for flushing a fire hydrant. The fire hydrant in various embodiments may be flushed using a fluid actuation system. The fire hydrant in various embodiments may be flushed from a remote location using a remote communicator. 
     It is common in municipal water systems to flush water through fire hydrants to ensure adequate flow and pressure to the hydrants and to remove sediment from the piping system. Often, this can be a labor-intensive task, requiring technicians to go into the field to perform the flushing operation for each hydrant in the piping system. 
     Most standard fire hydrants in the United States of America and in many other parts of the world are “dry barrel hydrants,” meaning that the hydrant itself contains no water. Because fire hydrants are above-ground apparatus, a hydrant full of water could freeze and crack. Instead, water is flushed into the hydrant when it is needed. 
     Standard fire hydrants, such as standard fire hydrant  10 , seen in  FIG. 1 , contain a stem  12  that connects to a valve  14  in a shoe  16 . The shoe  16  is connected to a lower barrel  17 . The lower barrel  17  is connected to the upper barrel  18 . The upper barrel  18  is connected to a bonnet  24 . A nozzle  27  is also seen on the upper barrel  18 . The shoe  16  is in fluid communication with a water supply system, which is typically a municipal water supply. When water is needed or when the standard fire hydrant  10  needs to be opened to flush the water system, an operating nut  31  attached to the stem  12  is actuated to open the valve  14 , thereby allowing water to flow into the lower barrel  17  and the upper barrel  18 . A nozzle cap  26  can be removed to allow water to flush through the standard fire hydrant  10  or to provide water for firefighting or for other purposes. Typically, when a flushing operation is desired, a diffuser is connected to the nozzle  27  to reduce the velocity of the water stream exiting the standard fire hydrant  10 , although a diffuser may not be necessary in all applications. 
       FIG. 2  is a cross-sectional view of a flushable hydrant  100  in accord with one embodiment of the current disclosure. The flushable hydrant  100  of the current embodiment includes an assembly of various pieces that permits electronic flushing of the flushable hydrant  100 . In various embodiments, the flushable hydrant  100  includes an actuation system that includes a biased translational system for automated opening while maintaining a rotational manual override. 
     Seen in  FIG. 2 , much like a standard fire hydrant, the flushable hydrant  100  includes a stem  110  that communicates with a valve (not shown) to allow water to flush from a lower barrel (not shown) of a hydrant body  115  into an upper barrel  118  of the hydrant body  115 . To do this, an operating nut  120  is rotated thereby causing actuation of the stem  110 . The operating nut  120  includes an interface portion  122  and a body portion  124 . The body portion  124  includes a cavity  126 , which includes internal threading  128 . The internal threading  128  interacts with a plunger assembly  130 . The plunger assembly  130  includes a threaded actuator  132  sheathing a piston  134 . The threaded actuator  132  is not mechanically coupled to the piston  134  but instead is allowed to move freely up and down in the current view. The threaded actuator defines a square bore  133  and has a contact end  131 . The square bore  133  is square in cross-section. The piston  134  includes an upper portion  136  and a lower portion  138 . The lower portion  138  defines a bore  139 , which will be discussed later. Although only a cross-sectional view is shown, the upper portion  136  is square in cross-section so that the threaded actuator  132  does not rotate when the operating nut  120  rotates. Instead, the threaded actuator  132  translates downward in the current view thereby manually opening the valve (not shown). A coupling countersink  111  is seen in the stem  110 . The lower portion  138  fits into the coupling countersink  111  and is shown inserted therein. The stem  110  defines a bore  112 . A coupling shear pin  142  is inserted through both the bore  112  and the bore  139  to couple the plunger assembly  130  with the stem  110 . 
     The foregoing paragraphs describe a manual override system of the flushable hydrant  100  that allow the flushable hydrant  100  to be operated externally by an operator such as a fireman or technician. As such, the flushable hydrant  100  can be used in the same application as prior art fire hydrants. However, the flushable hydrant  100  is also operable by other means, as described below. 
     Coupled to the stem  110  is a top stop  144 . The top stop  144  provides bracing for one end of a biasing element  146 . In the current embodiment, the biasing element  146  is a helical spring, although it may be various types of biasing elements in various embodiments, including various types of springs, magnetic biasing, electromechanical biasing such as servomotor-actuation, electromagnetic biasing such as solenoid-actuation, and gravitational biasing, among others. The biasing element  146  is braced on its other end to a bottom stop  148 . Because the top stop  144  is coupled to the stem  110 , the biasing element  146  biases the flushable hydrant  100  to the closed position, as shown in  FIG. 2 . 
     As can be seen, the flushable hydrant  100  includes a shroud  149 . The shroud  149  of the current embodiment is made of steel that is 0.100 inches in thickness, although various materials and thicknesses may be used in various embodiments. The flushable hydrant  100  includes six compressed gas containers  150   a,b,c,d,e,f  ( 150   b,c,d,e  not shown). In various embodiments, various numbers, shapes, and configurations of compressed gas containers  150  may be used. In one exemplary embodiment, the shroud  149  is used as a compressed gas container  150  such that compressed gas fills the entire volume encompassed by the shroud. Such a configuration would obviate the need for separate compressed gas containers  150 . Other fluid media may be used in the system of the current embodiment aside from compressed gas. Compressed gas is intended solely as an exemplary embodiment. Additionally, myriad variations on the systems, methods, and apparatus of the current embodiment may be used in various embodiments, including variations that may obviate the need for a fluid system, in some embodiments. 
     Each compressed gas container  150   a,b,c,d,e,f  is designed to hold a predetermined volume of compressed gas at a predetermined pressure. All of the compressed gas containers  150   a,b,c,d,e,f  are in fluid communication with one another such that the compressed gas containers  150   a,b,c,d,e,f  act as a single container, although various embodiments may include various different configurations. 
     Fittings  152   a,b,c,d,e,f  provide a fluid communication route from each compressed gas container  150   a,b,c,d,e,f  to gas bores  154   a,b,c,d,e,f  in a hydrant seal plate  155 , respectively. Each fitting  152   a,b,c,d,e,f  in the current embodiment is made of brass, although other materials or configurations may be used. Each gas bore  154   a,b,c,d,e,f  is in fluid communication with a vein  156   a,b,c,d,e,f , respectively, which connects to an annulus groove  158 . Because all of the veins  156   a,b,c,d,e,f  are in fluid communication with the same annulus groove  158 , compressed gas may move between the compressed gas containers  150   a,b,c,d,e,f  to equalize pressure therein. Annular gaskets  162   a,b  are seen sealing the annulus groove  158 . 
     A hold down assembly  160  includes a hold down nut  164  and a stem body  166 . The hold down nut  164  is connected by threading  167  to threading  169  of the stem body  166 . The hold down assembly  160  sandwiches a bonnet  170  of the flushable hydrant  100 . The connection of the hold down assembly  160  and the bonnet  170  is sealed by a gasket  171 . 
     The stem body  166  defines a bias cavity  168  inside which the previously-mentioned biasing element  146  is seated. The stem body  166  also defines a pressure cavity  175 . Within the pressure cavity  175  is a piston assembly  180 . The piston assembly  180  includes a piston plate  182 , a washer  184 , a washer stop  186 , a cylinder body  188 , a bottom plate  189 , and a bottom plate stop  187 . In some embodiments, the bottom plate  189  and cylinder body  188  may be one piece. Annular gaskets  191   a,b  and  192   a,b  seal the space between the piston plate  182  and the bottom plate  189 . Piston gaskets  194   a,b  seal a piston void  199  defined within the space between the piston plate  182  and the stem body  166  on the opposing side of the piston plate  182  from the bottom plate  189 . The piston void  199  as shown has no volume. When the piston plate  182  moves, the piston void  199  becomes larger. The purpose of the piston gaskets  194   a,b  will become apparent below with reference to  FIG. 3 . 
     A fill port  196  can also be seen connected to the top of compressed gas container  150   a . The fill port  196  allows the compressed gas containers  150   a,b,c,d,e,f  to be filled with compressed gas. 
     As seen in  FIG. 3 , the cutting plane of the flushable hydrant  100  is orthogonal to the cutting plane of  FIG. 2 . A pressure regulation assembly  310  can be seen in the current view. An annulus connection line  315  connects through a bore in the hydrant seal plate  155  to the annulus groove  158 . As such, the annulus connection line  315  is in fluid communication with the annulus groove  158 . The pressure regulation assembly  310  also includes a piston void line  325  that connects through a fitting  327  to the stem body  166 . The stem body  166  includes a fill port  410  (not shown) leading to the piston void  199 . A proximity sensor  335  can be seen in the pressure cavity  175 . The pressure regulation assembly  310  also includes other features and apparatus (as will be described below) that allow the regulation of pressure through the pressure regulation assembly  310 . The pressure regulation assembly  310  controls the amount of gas that flows from the annulus connection line  315  to the piston void line  325 . 
     In operation, the flushable hydrant  100  can be actuated using the manual process described above. The flushable hydrant  100  can also be actuated by an actuation system. The actuation system may be connected to a remote communicator in various embodiments. One embodiment of an actuation system is described below, although one of skill in the art would understand that various elements may be altered or substituted in various modifications to the disclosure below without being considered outside the scope of the disclosure. 
     The stem  110  is capable of automatic actuation using the actuation system. The actuation system includes energy stored in the form of compressed gas, although various forms of stored energy may be used in various embodiments, including batteries, biasing elements such as springs and elastic, stored gravitational energy, mechanical batteries and flywheels, shape memory energy, and electromechanical storage, among other types of stored energy. Actuating the stem  110  using compressed gas is controlled by the pressure regulation assembly  310 . The pressure regulation assembly  310  may include a wireless communication module or another communication module in various embodiments. The pressure regulation assembly  310  receives instructions to open the flushable hydrant  100 . In response, the pressure regulation assembly  310 , which is connected in fluid communication by the annulus connection line  315  to the annulus groove  158 . The annulus groove  158  is connected to each vein  156   a,b,c,d,e,f . Each vein  156   a,b,c,d,e,f  is connected to each gas bore  154   a,b,c,d,e,f . Each gas bore  154   a,b,c,d,e,f  is connected to by each fitting  152   a,b,c,d,e,f  to each compressed gas container  150   a,b,c,d,e,f . The piston void line  325  connects the pressure regulation assembly  310  in fluid communication to the piston void  199 . Thus, the pressure regulation assembly  310  controls the release of compressed gas from the compressed gas containers  150   a,b,c,d,e,f  to the piston void  199 . 
     In operation, the pressure regulation assembly  310  is opened to allow compressed gas to travel from the compressed gas containers  150   a,b,c,d,e,f  to the piston void  199 . As pressure of the compressed gas in the compressed gas containers  150   a,b,c,d,e,f  is released into the piston void  199 , the increased pressure in the piston void  199  is applied to the surface area of the piston plate  182 . Pressure applied to an area creates a force on the piston plate  199  which is translated into the washer  184  and, thereby, into the washer stop  186 . The force on the washer stop  186  is translated into the stem  110  resulting in a downward force on the stem  110 . 
     As the compressed gas flowing from the compressed gas containers  150   a,b,c,d,e,f  to the piston void  199  increases, the downward force on the stem  110  increases. Eventually, the force on the stem  110  overcomes the closing pressure of the valve (not shown), causing the valve to open. When the valve opens, water is allowed to flush into and through the flushable hydrant  110 . As such, the actuation system operates as a biased translational system in the current embodiment. Various embodiments of biased translational systems may also be used in various embodiments. 
     To open the valve, the stem  110  moves downward as shown in  FIG. 4 . In the current view, the fill port  410  can be seen in the piston void  199 . The proximity sensor  355  (not shown) is covered by the piston plate  182  which causes the pressure regulation assembly  310  to close the gas pathway from the compressed gas containers  150   a,b,c,d,e,f  to the piston void  199 . 
     As can be seen, the biasing element  146  has compressed, thereby storing energy. The top stop  144  has moved downward in the view because it is connected to the stem  110 , as is the coupling shear pin  142 , the piston  182 , the washer  184 , and the washer stop  186 . In the current embodiment, all of these parts have moved until the piston plate  182  contacts the cylinder body  188  and the cylinder body  188  provides a mechanical stop. Other embodiments many include various configurations for stops. It should be noted that no other parts or subassemblies of the flushable hydrant  100  have moved in the current embodiment, although various configurations may be present in various embodiments. 
       FIG. 5  shows a perspective view of the flushable hydrant  100 . Compressed gas containers  150   a,b,f  can be seen in the view ( 150   c,d,e  are hidden from view). A battery  510  is held in place by a battery bracket  515 . An inflow valve  520  and an outflow valve  525  can be seen. Although an inflow valve  520  and an outflow valve  525  are used in the current embodiment, various types of pressure regulation mechanisms, systems, and methods may be used in various embodiments. Between the inflow valve  520  and the outflow valve  525  is a tee joint  530 . The tee joint  530  is connected on one side to the inflow valve  520 , on one side to the outflow valve  525 , and on one side to the piston void line  325  (shown in  FIG. 3 ). The inflow valve  520  and outflow valve  525  control the system. 
     Before any flushing takes place, pressure in the compressed gas containers  150   a,b,c,d,e,f  is at its highest, and there is no pressurization in the piston void  199 . To open the valve (not shown), as previously described, the outflow valve  525  closes and the inflow valve  520  opens. As such, the pressure in the piston void  199  increases until the force exerted on the piston plate  182  overcomes the closing pressure of the valve (not shown) at which point the valve opens. As previously described, pressure in the compressed gas containers  150   a,b,c,d,e,f  is much greater than necessary to open the valve (not shown). As such, when the proximity sensor  355  recognizes that the piston plate  182  has moved to open the valve (not shown), the inflow valve  520  closes. This feature helps preserve compressed gas in the compressed gas containers  150   a,b,c,d,e,f  because it may not be necessary for the pressure to equalize fully from the compressed gas containers  150   a,b,c,d,e,f  to the piston void  199  in order to open the valve (not shown). Preserving compressed gas allows more flushing cycles to occur without refilling the compressed gas containers  150   a,b,c,d,e,f.    
     Once water flushes into the flushable hydrant  100 , the pressure inside the upper barrel  118  equalizes with the system pressure. Thus, water in the system provides no closing pressure on the valve (not shown). Instead, closing pressure on the valve (not shown) is provided by the biasing element  146 , which becomes compressed due to the force on the piston plate  182 . 
     When it is desired to close the valve (not shown), the outflow valve  525  is opened while the inflow valve  520  remains closed. The exhaust line  535  vents to outside air. Without closed pressure in the piston void  199 , compressed gas is allowed to flow through an exhaust line  535  that is connected to the outflow valve  525 . The pressure in the piston void  199  is released, thereby relieving the downward force on the piston plate  182 . The release of the downward force allows the biasing element  146  to lift the stem  110  and, thereby, to close the valve (not shown). 
       FIG. 6  displays a schematic representation of the compressed gas system of the flushable hydrant  100 . In the current embodiment, the compressed gas containers  150   a,b,c,d,e,f  are in fluid communication with each other and are connected to the inflow valve  520 . The inflow valve  520  maintains any compressed gas in the compressed gas containers  150   a,b,c,d,e,f  until operation of the flushable hydrant  100  is desired as described above. When the flushable hydrant  100  is operated, the outflow valve  525  closes and the inflow valve  520  opens. This allows compressed gas to flow into the piston void  199 . When the proximity sensor  335  is activated as described above, the proximity sensor  335  sends a signal to the inflow valve  520  to close, cutting the flow of compressed gas from the compressed gas containers  150   a,b,c,d,e,f  to the piston void  199 . When it is desired to return the flushable hydrant  100  to resting state, the outflow valve  525  is opened, allowing compressed gas in the piston void  199  to escape and to exhaust. 
     An exploded view of the flushable hydrant  100  is seen in  FIG. 7 . In addition to features of the current embodiment that have already been mentioned, the exploded view of the flushable hydrant  100  also shows bolts holding the flushable hydrant  100  together, among other various features. 
     An electrical schematic can be seen in  FIG. 8 . The electrical schematic of  FIG. 8  is but one method of compiling the circuitry to achieve the desired result, and one of skill in the art would understand that variations to such an arrangement may be possible in various embodiments. 
     In the current embodiment, each of the inflow valve  520  and the outflow valve  525  are operational as electrical latching solenoids, although various types of pressure regulation mechanisms may be present in various embodiments. Each of the inflow valve  520  and the outflow valve  525  are normally closed in the current embodiment. 
     A first isolator  810  and second isolator  820  provide circuit isolation depending on the direction of current into the system. When current flows in one direction, one circuit is activated; when current flows in the opposite direction, another circuit is activated. As such, the electrical configuration of the current embodiment does not operate both the inflow valve  520  and the outflow valve  525  at the same time, although one of skill in the art would understand that a simple modification would allow such a configuration. 
     A switch  830  is controlled by the first isolator  810 . Switches  830 ,  840  are electrical switches in the current embodiment, such as transistors. Various embodiments may include variations of switches, including both electrical and mechanical switches. When it is desired to open the inflow valve  520 , current flows through the first isolator  810  and closes the switch  830 , allowing current to flow across the switch  830 . The current is allowed to flow through the proximity sensor  335  when the proximity sensor  335  is not activated. In other words, the proximity sensor  335  is normally shorted. The flowing current activates the inflow valve  520 , causing it to open, as described above. The first isolator  810  receives a feedback from the circuit to remain on so long as the proximity sensor  335  is shorted. This action provides the electrical latching of the solenoid in the inflow valve  520 . 
     As described above, the opening of the inflow valve  520  causes the piston plate  182  to travel in front of the proximity sensor  335 . When this occurs, the proximity sensor  335  is activated and provides an open in the circuitry. The feedback to the first isolator  810  is cut, and the switch  830  opens, deactivating the inflow valve  520  and retuning the solenoid in the inflow valve  520  to its normally closed position. 
     When it is desired to open the outflow valve  525 , current flows the opposite direction and activates the second isolator  820 , thereby closing a switch  840  and allowing current to flow to the outflow valve  525 . Because no proximity sensor is used with the outflow valve  525 , the system simply opens the outflow valve  525  for a preset duration using an RC (resistor-capacitor) configuration. In the current embodiment, the duration that the outflow valve  525  is opened is a few seconds, although various time durations may be used in various embodiments. Once the timing of the RC current has expired, the switch  840  opens, stopping current flow to the outflow valve  525 . When power to the solenoid of the outflow valve  525  is stopped, the outflow valve  525  returns to its normally closed position. Various electronic circuitry that is shown but not described would be understood by one of skill in the art. 
     It should be emphasized that the embodiments described herein are merely possible examples of implementations, merely set forth for a clear understanding of the principles of the present disclosure. Many variations and modifications may be made to the described embodiment(s) without departing substantially from the spirit and principles of the present disclosure. For example, compressed gas is but one method of actuation among many, including hydraulic, electromechanical, and gravitational, among others. Further, the scope of the present disclosure is intended to cover any and all combinations and sub-combinations of all elements, features, and aspects discussed above. All such modifications and variations are intended to be included herein within the scope of the present disclosure, and all possible claims to individual aspects or combinations of elements or steps are intended to be supported by the present disclosure. 
     One should note that conditional language, such as, among others, “can,” “could,” “might,” or “may,” unless specifically stated otherwise, or otherwise understood within the context as used, is generally intended to convey that certain embodiments include, while alternative embodiments do not include, certain features, elements and/or steps. Thus, such conditional language is not generally intended to imply that features, elements and/or steps are in any way required for one or more particular embodiments or that one or more particular embodiments necessarily include logic for deciding, with or without user input or prompting, whether these features, elements and/or steps are included or are to be performed in any particular embodiment. 
     Various implementations described in the present disclosure may include additional systems, methods, features, and advantages, which may not necessarily be expressly disclosed herein but will be apparent to one of ordinary skill in the art upon examination of the following detailed description and accompanying drawings. It is intended that all such systems, methods, features, and advantages be included within the present disclosure and protected by the accompanying claims.