Patent Publication Number: US-9841122-B2

Title: Gas valve with electronic valve proving system

Description:
RELATED APPLICATIONS 
     This application is related to U.S. application Ser. No. 13/326,366 filed Dec. 15, 2011 and entitled Gas Valve With Electronic Proof of Closure System, U.S. application Ser. No. 13/326,353 filed Dec. 15, 2011 and entitled Gas Valve With Electronic Valve Proving System, U.S. application Ser. No. 13/326,357 filed Dec. 15, 2011 and entitled Gas Valve with High/Low Gas Pressure Detection, U.S. application Ser. No. 13/326,691 filed Dec. 15, 2011 and entitled Gas Valve With Fuel Rate Monitor, U.S. application Ser. No. 13/326,355 filed Dec. 15, 2011 and entitled Gas Valve With Overpressure Diagnostics, U.S. application Ser. No. 13/326,358 filed on Dec. 15, 2011 and entitled Gas Valve With Valve Leakage Test, U.S. application Ser. No. 13/326,361 filed on Dec. 15, 2011 and entitled Gas Valve With Electronic Cycle Counter, and U.S. application Ser. No. 13/326,523 filed on Dec. 15, 2011 and entitled Gas Valve With Communication Link, all of which are incorporated by reference in their entireties and for all purposes. 
     TECHNICAL FIELD 
     The disclosure relates generally to valves, and more particularly, to gas valve assemblies. 
     BACKGROUND 
     Valves are commonly used in conjunction with many appliances for regulating the flow of fluid. For example, gas valves are often incorporated into gas-fired appliances to regulate the flow of gas to a combustion chamber or burner. Examples of such gas-fired appliances may include, but are not limited to, water heaters, furnaces, boilers, fireplace inserts, stoves, ovens, dryers, grills, deep fryers, or any other such device where gas control is desired. In such gas-fired appliances, the gas may be ignited by a pilot flame, electronic ignition source, or other ignition source, causing combustion of the gas at the burner element producing heat for the appliance. In many cases, in response to a control signal from a control device such as a thermostat or other controller, the gas valve may be moved between a closed position, which prevents gas flow, and an open position, which allows gas flow. In some instances, the gas valve may be a modulating gas valve, which allows gas to flow at one or more intermediate flow rates between the fully open position and the fully closed position. Additionally or alternatively, valves are used in one or more other applications for controlling a flow (e.g., a flow of a fluid such as a liquid or gas, or a flow of other material). 
     SUMMARY 
     This disclosure relates generally to valves, and more particularly, to gas valve assemblies. In one illustrative but non-limiting example, a valve assembly may be configured for controlling fuel flow to a combustion appliance, where the combustion appliance may cycle on and off during a sequence of operational cycles. The valve assembly may, in some cases, perform one or more valve proving tests during an operation cycle and/or between operational cycles to help ensure that the one or more valves properly close. 
     In one illustrative embodiment, the valve assembly may include a valve body having an inlet port and an outlet port with a fluid path extending between the inlet port and the outlet port. The valve assembly may include a first valve situated in the fluid path between the inlet port and the outlet port, and a second valve situated in the fluid path between the inlet port and the outlet port downstream of the first valve, with an intermediate volume defined between the first valve and the second valve. First and second valve actuators may be included in the valve assembly such that the first and second valve actuators may be capable of moving the first and second valves, respectively, between a closed position that closes the fluid path between the inlet port and the outlet path, and open position. 
     The valve assembly may include a pressure sensor in fluid communication with the intermediate volume between the first valve and the second valve for sensing a measure related to a pressure in the intermediate volume. A valve controller may be operatively coupled to the first valve actuator, the second valve actuator, and the pressure sensor. In some cases, the valve controller may be configured to identify both the first valve and the second valve are in a closed position, identify a measure related to a pressure change rate in the pressure sensed by the intermediate volume pressure sensor in the intermediate volume, and identify a measure that is related to a leakage rate based at least in part on the measure that is related to the pressure change rate in the intermediate volume and a measure that is related to a volume of the intermediate volume. The valve controller may be further configured to compare the measure related to the leakage rate to a threshold value, and output an alert signal if the measure related to the leakage rate crosses the threshold value. 
     In some instances, the valve controller may be configured to identify a predetermined duration, close both the first valve via the first valve actuator and the second valve via the second valve actuator, and identify a measure related to an initial pressure in the intermediate volume of the valve body. A threshold for the valve proving test may be determined by the valve controller based at least in part on both the measure related to the initial pressure and the identified predetermined duration. The valve controller may then identify a measure that is related to the pressure in the intermediate volume during the predetermined duration and compare the identified measure related to the pressure in the intermediate volume to the determined threshold value, and output an alert signal if the measure related to the pressure in the intermediate volume crosses the threshold value. 
     In some instances, a method of performing a valve proving test on a gas valve assembly may include closing both the first valve and the second valve, identifying a measure related to a pressure change rate in the pressure sensed by the intermediate volume pressure sensor, and identifying a measure that is related to a leakage rate based at least in part on the measure that is related to the pressure change rate in the intermediate volume and a measure that is related to a volume of the intermediate volume. Then, the method may include comparing the measure related to the leakage rate to a threshold value, and outputting an alert signal if the measure related to the leakage rate crosses the threshold value. 
     The preceding summary is provided to facilitate an understanding of some of the innovative features unique to the present disclosure and is not intended to be a full description. A full appreciation of the disclosure can be gained by taking the entire specification, claims, drawings, and abstract as a whole. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The disclosure may be more completely understood in consideration of the following detailed description of various illustrative embodiments in connection with the accompanying drawings, in which: 
         FIG. 1  is a schematic perspective view of an illustrative fluid valve assembly; 
         FIG. 2  is a schematic first side view of the illustrative fluid valve assembly of  FIG. 1 ; 
         FIG. 3  is a schematic second side view of the illustrative fluid valve assembly of  FIG. 1 , where the second side view is from a side opposite the first side view; 
         FIG. 4  is a schematic input side view of the illustrative fluid valve assembly of  FIG. 1 ; 
         FIG. 5  is a schematic output side view of the illustrative fluid valve assembly of  FIG. 1 ; 
         FIG. 6  is a schematic top view of the illustrative fluid valve assembly of  FIG. 1 ; 
         FIG. 7  is a cross-sectional view of the illustrative fluid valve assembly of  FIG. 1 , taken along line  7 - 7  of  FIG. 4 ; 
         FIG. 8  is a cross-sectional view of the illustrative fluid valve assembly of  FIG. 1 , taken along line  8 - 8  of  FIG. 2 ; 
         FIG. 9  is a schematic diagram showing an illustrative fluid valve assembly in communication with a building control system and an appliance control system, where the fluid valve assembly includes a differential pressure sensor connect to a valve controller; 
         FIG. 10  is a schematic diagram showing an illustrative fluid valve assembly in communication with a building control system and an appliance control system, where the fluid valve assembly includes multiple pressure sensors connected to a valve controller; 
         FIG. 11  is a schematic diagram showing an illustrative schematic of a low gas pressure/high gas pressure limit control; 
         FIG. 12  is a schematic diagram showing an illustrative schematic valve control and combustion appliance control, where the controls are connected via a communication link; 
         FIG. 13  is a schematic diagram showing an illustrative valve control and proof of closure system in conjunction with a combustion appliance; 
         FIGS. 14-17  are various illustrative schematic depictions of different methods for sensing a position and/or state of a valve within an illustrative valve assembly; 
         FIGS. 18 and 19  are schematic pressure versus time graphs illustrating pressure thresholds; 
         FIG. 20  is a schematic flow chart of an illustrative method of performing a valve proving system test; 
         FIG. 21  is a schematic flow chart of an illustrative method of performing a valve proving system test; and 
         FIGS. 22A and 22B  are schematic flow charts of an illustrative method of performing a valve proving system test. 
     
    
    
     While the disclosure is amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail. It should be understood, however, that the intention is not to limit aspects of the disclosure to the particular illustrative embodiments described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the disclosure. 
     DESCRIPTION 
     The following description should be read with reference to the drawings wherein like reference numerals indicate like elements throughout the several views. The detailed description and drawings show several illustrative embodiments which are meant to be illustrative of the claimed disclosure. 
     Any descriptors such as first, second, third, fourth, fifth, left right, up, down, bottom, top, are not meant to be limiting unless expressly indicated. Rather, such descriptors may be used to for clarity purposes to indicate how a feature relates to another feature. 
     Gas valves may be added to fluid path systems supplying fuel and/or fluid to appliances (e.g., burners, etc.) or may be used individually or in different systems. In some instances, gas safety shutoff valves may be utilized as automatic redundant valves. Redundancy is achieved, and often times required by regulatory agencies, by placing at least two safety shutoff valves in series. The aforementioned redundant valves may be separate valves fitted together in the field and/or valves located together in a single valve body, these redundant valves are commonly referred to as double-block valves. In accordance with this disclosure, these and other gas valves may be fitted to include sensors and/or switches and/or other mechanical or electronic devices to assist in monitoring and/or analyzing the operation of the gas valve and/or connected appliance. The sensors and/or switches may be of the electromechanical type or the electronic type, or of other types of sensors and/or switches, as desired. 
     In some cases, a gas valve assembly may be configured to monitor and/or control various operations including, but not limited to, monitoring fluid flow and/or fluid consumption, electronic cycle counting, overpressure diagnostics, high gas pressure and low gas pressure detection, valve proving system tests, valve leakage tests, proof of valve closure tests, diagnostic communications, and/or any other suitable operation as desired. 
     Valve Assembly 
       FIG. 1  is a schematic perspective view of an illustrative fluid (e.g., gas, liquid, etc.) valve assembly  10  for controlling fluid flow to a combustion appliance or other similar or different device. In the illustrative embodiment, the gas valve assembly  10  may include a valve body  12 , which may generally be a six sided shape or may take on any other shape as desired, and may be formed as a single body or may be multiple pieces connected together. As shown, the valve body  12  may generally be a six-sided shape having a first end  12   a , a second end  12   b , a top  12   c , a bottom  12   d , a back  12   e  and a front  12   f , as depicted in the various views of  FIGS. 1-6 . The terms top, bottom, back, front, left, and right are relative terms used merely to aid in discussing the drawings, and are not meant to be limiting in any manner. 
     The illustrative valve body  12  includes an inlet port  14 , an outlet port  16  and a fluid path or fluid channel  18  extending between the inlet port  14  and the outlet port  16 . Further, valve body  12  may include one or more gas valve ports  20  (e.g., a first valve port  20   a  and a second valve port  20   b , shown in  FIGS. 7 and 8 ) positioned or situated in the fluid channel  18 , one or more fuel or gas valve member(s) sometimes referred to as valve sealing member(s)  22  moveable within gas valve ports  20  (e.g., a first valve sealing member  22   a  within first valve port  20   a  and a second valve sealing member  22   b  within second valve port  20   b , as shown in  FIG. 7 ), one or more pressure sensor assemblies  24  (as shown in  FIG. 8 , for example), one or more position sensors  48 , and/or one or more valve controllers  26  (as shown in  FIG. 8 , for example) affixed relative to or coupled to the valve body  12  and/or in electrical communication (e.g., through a wired or wireless connection) with the pressure sensor assemblies  24  and the position sensor(s)  48 . 
     The valve assembly  10  may further include one or more actuators for operating moving parts therein. For example, the valve assembly  10  may have actuators including, but not limited to, one or more stepper motors  94  (shown as extending downward from bottom  12   d  of valve body  12  in  FIG. 1 ), one or more solenoids  96  (shown as extending upward from top  12   c  of valve body  12  in  FIG. 1 ), and one or more servo valves  98  (a servo valve  98  is shown as extending upward from top  12   c  of valve body  12  in  FIG. 1-3 , where a second servo valve has been omitted), where the servo valve  98  may be a 3-way auto-servo valve or may be any other type of servo valve. Other actuators may be utilized, as desired. 
     In one illustrative embodiment, the one or more solenoids  96  may control whether the one or more gas valve ports  20  are open or closed. The one or more stepper motors  94  may determine the opening size of the gas valve ports  20  when the corresponding gas valve sealing member  22  is opened by the corresponding solenoid  96 . Of course, the one or more stepper motors  94  may not be provided when, for example, the valve assembly  10  is not a “modulating” valve that allows more than one selectable flow rate to flow through the valve when the valve is open. 
     As shown, the valve body  12  may include one or more sensors and electronics compartments  56 , which in the illustrative embodiment, extend from back side  12   e  as depicted in  FIGS. 1, 2 and 4-6 . The sensors and electronics compartments  56  may be coupled to or may be formed integrally with the valve body  12 , and may enclose and/or contain at least a portion of the valve controllers  26 , the pressure sensors assemblies  24 , and/or the electronics required for operation of valve assembly  10  as described herein. Although the compartments  56  may be illustratively depicted as separate structures, the compartments  56  may be a single structure part of, extending from, and/or coupled to the valve body  12 . 
     The one or more fluid valve ports  20  may include a first gas valve port  20   a  and a second gas valve port  20   b  situated along and/or in communication with the fluid channel  18 . This is a double-block valve design. Within each gas valve port  20 , a gas valve sealing member  22  may be situated in fluid channel  18  and may be positioned (e.g., concentrically or otherwise) about an axis, rotatable about the axis, longitudinally and axially translatable, rotationally translatable, and/or otherwise selectively movable between a first position (e.g., an open or closed position) and a second position (e.g., a closed or open position) within the corresponding valve port  20 . Movement of the valve sealing member  22  may open and close the valve port  20 . 
     It is contemplated that valve sealing member  22  may include one or more of a valve disk  91 , a valve stem  92  and/or valve seal  93  for sealing against a valve seat  32  situated in fluid channel  18 , as best seen in  FIGS. 14-17 , and/or other similar or dissimilar components facilitating a seal. Alternatively, or in addition, valve sealing member  22  may include structural features and/or components of a gate valve, a disk-on-seat valve, a ball valve, a butterfly valve and/or any other type of valve configured to operate from a closed position to an open position and back to a closed position. An open position of a valve sealing member  22  may be any position that allows fluid to flow through the respective gas valve port  20  in which the valve sealing member  22  is situated, and a closed position may be when the valve sealing member  22  forms at least a partial seal at the respective valve port  20 , such as shown in  FIG. 7 . Valve sealing member  22  may be operated through any technique. For example, valve sealing member  22  may be operated through utilizing a spring  31 , an actuator  30  to effect movement against the spring  31 , and in some cases a position sensor  48  to sense a position of the valve sealing member  22 . 
     Valve actuator(s)  30  may be any type of actuator configured to operate the valve sealing member  22  by actuating valve sealing member  22  from the closed position to an open position and then back to the closed position during each of a plurality of operation cycles during a lifetime of the gas valve assembly  10  and/or of the actuator  30 . In some cases, the valve actuator  30  may be a solenoid actuator (e.g., a first valve actuator  30   a  and a second valve actuator  30   b , as seen in  FIG. 7 ), a hydraulic actuator, magnetic actuators, electric motors, pneumatic actuators, and/or other similar or different types of actuators, as desired. In the example shown, the valve actuators  30   a ,  30   b  may be configured to selectively move valves or valve sealing members  22   a ,  22   b  of valve ports  20   a ,  20   b  between a closed position, which closes the fluid channel  18  between the inlet port  14  and the outlet port  16  of the valve body  12 , and an open position. As discussed, the gas valve assembly  10  of  FIGS. 1-8  is an example of a gas safety shutoff valve, or double-block valve. In some cases, however, it is contemplated that the gas valve assembly  10  may have a single valve sealing member  22   a , or three or more valve sealing members  22  in series or parallel, as desired. 
     In some cases, the valve assembly  10  may include a characterized port defined between the inlet port  14  and the outlet port  16 . A characterized port may be any port (e.g., a fluid valve port  20  or other port or restriction through which the fluid channel  18  may travel) at or across which an analysis may be performed on a fluid flowing therethrough. For example, if a flow resistance of a valve port  20  is known over a range of travel of the valve sealing member  22 , the one of the one or more gas valve ports  20  may be considered the characterized port. As such, and in some cases, the characterized port may be a port  20  having the valve sealing member  22  configured to be in an open position and in a closed position. Alternatively, or in addition, a characterized port may not correspond to the gas valve port  20  having the valve sealing member  22 . Rather, the characterized port may be any constriction or feature across which a pressure drop may be measured and/or a flow rate may be determined. 
     Characterized ports may be characterized at various flow rates to identify a relationship between a pressure drop across the characterized port and the flow rate through the fluid channel  18 . In some cases, the pressure drop may be measured directly with one or more pressure sensors  42 ,  43 ,  44 , and/or  38 . In other cases, the pressure drop may be inferred from, for example, the current position of the valve member(s). These are just some examples. In some cases, the relationship may be stored in a memory  37 , such as a RAM, ROM, EEPROM, other volatile or non-volatile memory, or any other suitable memory of the gas valve assembly  10 , but this is not required. 
     In some cases, the gas valve assembly  10  may include a flow module  28  for sensing one or more parameters of a fluid flowing through fluid channel  18 , and in some instances, determining a measure related to a gas flow rate of the fluid flowing through the fluid channel  18 . The flow module  28  may include a pressure block or pressure sensor assembly  24 , a temperature sensor  34 , a valve member position sensor  48  and/or a valve controller  26 , among other assemblies, sensors, and/or systems for sensing, monitoring, and/or analyzing parameters of a fluid flowing through the fluid channel  18 , such as can be seen in  FIGS. 9 and 10 . 
     It is contemplated that the flow module  28  may utilize any type of sensor to facilitate determining a measure related to a flow rate of a fluid through fluid channel  18 , such as a pressure sensor, a flow sensor, a valve position sensor, a temperature sensor, a current sensor, a gas sensor, an oxygen sensor, a CO sensor, a CO 2  sensor, and/or any other type of sensor, as desired. In one example, the flow module  28 , which in some cases may be part of a valve controller  26 , may be configured to monitor a differential pressure across a characterized port, and in some cases, a position of one or more valve sealing members  22  of the gas valve assembly  10 . The information from monitoring may be utilized by the flow module  28  to determine and/or monitor the flow rate of fluid passing through the fluid channel  18 . For example, the flow module  28  may determine a measure that is related to a gas flow rate through the fluid channel  18  based, at least in part, on the measure that is related to the pressure drop across the characterized port along with the pre-stored relationship in the memory  37 . In some cases, the current position of one or more valve sealing members  22  of the gas valve assembly  10  may also be taken into account (e.g. is the valve 30% open, 50% open or 75% open). 
     In some instances, the flow module  28  may be configured to output the flow rate of fluid passing through the fluid channel  18  to a display or a remote device. In some cases, the flow module  28  may maintain a cumulative gas flow amount passing through the fluid channel  18  (e.g. over a time period), if desired. The measure related to a gas flow may include, but is not limited to, a measure of fuel consumption by a device or appliance that is connected to an outlet port  16  of the gas valve assembly  10 . 
     It is contemplated that the valve controller or valve control block  26  (see,  FIG. 8-10 ) may be physically secured or coupled to, or secured or coupled relative to, the valve body  12 . The valve controller  26  may be configured to control and/or monitor a position or state (e.g., an open position and a closed position) of the valve sealing members  22  of the valve ports  20  and/or to perform other functions and analyses, as desired. In some cases, the valve control block  26  may be configured to close or open the gas valve member(s) or valve sealing member(s)  22  on its own volition, in response to control signals from other systems (e.g., a system level or central building control), and/or in response to received measures related to sensed pressures upstream, intermediate, and/or downstream of the characterized valve port(s), measures related to a sensed differential pressure across the characterized valve port(s), measures related to temperature sensed upstream, intermediate, and/or downstream of the characterized valve port(s), and/or in response to other measures, as desired. 
     The memory  37 , which in some cases may be part of or in communication with the valve controller  26 , may be configured to record data related to sensed pressures, sensed differential pressures, sensed temperatures, and/or other measures. The valve controller  26  may access these settings and this data, and in some cases, communicate (e.g., through a wired or wireless communication link  100 ) the data and/or analyses of the data to other systems (e.g., a system level or central building control) as seen in  FIGS. 9 and 10 . The memory  37  and/or other memory may be programmed and/or developed to contain software to affect one or more of the configurations described herein. 
     In some instances, the valve controller  26  may be considered a portion of the flow module  28 , the flow module  28  may be considered part of the valve controller  26 , or the flow module  28  and valve controller  26  may be considered separate systems or devices. Illustratively, the valve controller  26  may be coupled relative to the valve body  12  and one or more gas valve ports  20 , where the valve controller  26  may be configured to control a position (e.g., open or closed positions, including various open positions) of the valve sealing member  22  within the valve port  20 . In some cases, the valve controller  26  may be coupled to and/or be in communication with local sensors including, but not limited to the pressure sensor assembly  24  (e.g., used for Low Gas/High Gas pressure limit functions, Valve Proving System tests, etc.), a flow sensor (e.g., for measuring gas consumption, etc.), a temperature sensor,  34  (e.g., to monitor temperature of a key component such as an actuator or other component, etc.), a position sensor  48 , a current draw sensor (e.g., for sensing the current draw of an actuator or the entire system, etc.), a gas sensor, an oxygen sensor, a carbon monoxide (CO) sensor, a carbon dioxide (CO 2 ) sensor, a cycle sensor and/or cycle counter, timers (e.g., to measure an amount of time to open the valve and/or close the valve), and/or other sensors and assemblies, as desired. 
     The valve controller  26  may include or may be in communication with one or more remote sensor inputs for receiving one or more sensed parameters form one or more remotely located sensors located outside of the valve body  12 , the valve ports  20 , and/or valve actuators  30 . Illustratively, the one or more remote sensors may include, but are not limited to, one or more of a pressure sensor, a flow sensor, a temperature sensor, a position sensor, a current draw sensor, a gas sensor, an oxygen sensor, a carbon monoxide (CO) sensor, a carbon dioxide (CO 2 ) sensor, a cycle sensor and/or cycle counter, and/or one or more other remote sensors. 
     In the illustrative embodiment of  FIG. 8 , the valve controller  26  may be configured to monitor a differential pressure across a characterized port. In some instances, the valve controller  26  may monitor a differential pressure across the fluid valve port  20  and/or monitor a measure related to a pressure upstream of a fluid valve port  20  (e.g., first valve port  20   a ) and/or a measure related to a pressure downstream of a fluid valve port  20  (e.g., second valve port  20   b ). The valve controller  26  may also be configured to monitor an axial position of the valve sealing member  22  in the valve port  20  (e.g., see  FIGS. 14-17 ). As a result, the valve controller  26  may determine a flow rate of fluid passing through the characterized port, where the valve controller  26  may determine the flow rate (and sometimes fluid consumption) based, at least in part, on the monitored differential pressure and/or monitored upstream and downstream pressures in conjunction with a pre-characterized relationship between the pressure drop across the characterized port and the flow rate. In some cases, the monitored axial positioning of the valve sealing member  22  may also be taken into account, particularly when the valve sealing member  22  may assume one or more intermediate open positions between the fully closed and fully opened positions. When so provided, the pre-characterized relationship between the pressure drop across the characterized port and the flow rate may depend on the current axial positioning of valve sealing member  22 . 
     In some instances, the valve controller  26  may include a determining block, which may include a microcontroller  36  or the like, which may include or be in communication with a memory  37 , such as a non-volatile memory. Alternatively, or in addition, the determining block (e.g. microcontroller  36 ) may be coupled to or may be configured within the valve control block or valve controller  26 . The determining block may be configured to store and/or monitor one or more parameters, which may be used when determining a measure that is related to a fluid flow rate through the fluid channel  18 . The determining block (e.g. microcontroller  36 ) may be configured to use the stored and/or monitored parameters (e.g. the relationship between a pressure drop across a characterized port and the flow rate through the fluid channel  18 ) stored in the memory  37  to help determine a measure that is related to a fluid flow rate through the fluid path or the fluid channel  18 . 
     Illustratively, the determining block (e.g. microcontroller  36 ) may be configured to determine and/or monitor a measure (e.g., a flow rate of fluid passing through the characterized port or other similar or different measure, as desired) based, at least in part, on stored and/or monitored measures including, but not limited to, measures related to pressure drop across a characterized valve port or other pressure related measures upstream and downstream of the characterized valve port(s), a temperature of the fluid flowing through the fluid channel  18 , and/or a measure related to a current position of the valve sealing member  22  at the gas valve port  20  or the size of an opening at the characterized port. In one example, a determining block (e.g. microcontroller  36 ) may include non-volatile memory that is configured to store opening curves of the valve assembly  10 , where the opening curves may characterize, at least in part, a flow rate as a function of a sensed axial position of valve sealing member  22 , and a sensed differential pressure across a characterized valve port  20  or an otherwise determined pressure at or adjacent a characterized valve port  20  (e.g., knowing a set-point of an upstream pneumatic pressure reducing valve (PRV), as the set-point pressure of the PRV may be substantially equal to the pressure at an inlet of the characterized valve port), and may facilitate determining an instantaneous and/or cumulative fluid (e.g., fuel) flow in the fluid channel  18  and/or consumption by an appliance in fluid communication with the valve assembly  10 . 
     It is contemplated that the determining block (e.g. microcontroller  36 ) may continuously or non-continuously control, store, and/or monitor a position (e.g., an axial or rotary position or open/closed state or other position) of the valve sealing member  22  within the valve port  20 , monitor a differential pressure across the characterized port, and/or monitor a temperature upstream and/or downstream of the characterized port. In addition, the microcontroller  36  may continuously or non-continuously determine the flow rate of the fluid passing through the characterized port, where the microcontroller  36  may be configured to record in its memory or in another location, an instantaneous flow rate of fluid flowing through the characterized port, a cumulative flow volume, and/or a determined instantaneous or cumulative (e.g., total) fluid consumption based on the positions of the valve sealing member(s)  22  and determined flow rates at an instant of time or over a specified or desired time period. In addition, the determining block (e.g. microcontroller  36 ) may be configured to report out the instantaneous flow rate, cumulative flow volume, total or cumulative fluid consumption over a given time period, and/or other determination and/or valve assembly conditions. The determining block (e.g. microcontroller  36 ) may report the instantaneous flow rate, cumulative flow rate, total or cumulative consumption of the fluid flowing through the characterized port, and/or other determination and/or valve assembly conditions to a system display  52  of an overall system controller  50  (e.g., a building/industrial automation system (BAS/IAS) controller), an appliance display  62  of an appliance/system controller  60  where the appliance may be configured to receive the flowing fluid, a display adjacent gas valve assembly  10 , or any other display, device, controller and/or memory, as desired. 
     In some instances, the valve controller  26  may include or be in communication with a valve actuator  30 , which in conjunction with the stepper motor  94  or other device is configured to position the valve sealing member  22  in the valve port  20 . The valve actuator  30  and/or the stepper motor  94  may be in communication with the microcontroller  36  of the valve controller  26 , and the microcontroller  36  may be configured to control, monitor, and/or record the position (e.g., axial position, radial position, etc.) of the valve sealing member  22  within the valve port  20  through the valve actuator  30  (e.g., the valve actuator  30  may be configured to effect the locking (e.g., the valve actuator  30  OFF) or the unlocking (e.g., the valve actuator  30  ON) of the valve sealing member  22  in a particular position) and the stepper motor  94  (e.g., stepper motor  94  may be configured to adjust the position of the valve sealing member  22  when it is not locked in a particular position), or through only the stepper motor  94 . Alternatively, or in addition, the microcontroller  36  may be configured to monitor and record the position of the valve sealing member  22  within the valve port  20  through a connection with a position sensor  48  or through other means. 
     The valve controller  26  may include an I/O or communications interface  110  with a communication protocol for transmitting data to and/or otherwise communicating with one or more remote device(s) that may be located remotely from valve assembly  10  (e.g., a combustion appliance including controller  60  located remotely from valve assembly  10 , a remote display, an electronic access tool or key, and/or other remote devices). The communications interface  110  may be a wired or wireless communication interface, where the wired or wireless communication interface  110  may be configured to be compatible with a predetermined communication bus protocol or other communication protocol. A wired link may be low voltage (e.g. 24V, 5V, 3V, etc.), which may reduce certain issues related to line-voltage wiring schemes. Illustratively, communications interface  110 , using the predetermined communication bus protocol or other communication protocol, may be configured to output and/or communicate one or more valve conditions, one or more measures related to valve conditions, one or more conditions related to a fluid flow through the fluid channel  18 , and/or one or more diagnostic parameters, conditions or events, to a device located adjacent or remote from the valve assembly  10 . 
     In an illustrative example of monitoring parameters sensed by sensors of or in communication with a valve assembly, the microcontroller  36  of the valve controller  26  may continuously or non-continuously monitor and record the position (e.g., axial position, radial position, etc.) of valve sealing member  22  within the valve port  20  through the valve actuator  30  and the stepper motor  94 , and the microcontroller  36  may indicate the sensed and/or monitored position of the valve sealing member  22  within the valve port  20  as a prescribed position of valve sealing member  22 . The prescribed position of the valve sealing member  22  may be the position at which the valve sealing member  22  was and/or is to be located, whereas a position of the valve sealing member  22  sensed by the position sensor system  48  may be considered an actual position of the valve sealing member  22  within the valve port  20 . 
     In the example, the valve controller  26  may be configured to perform electronic operational cycle counting or may include an electronic counter configured to count each operational valve cycle of the valve sealing members  22  during, for example, the lifetime of the gas valve assembly  10  or during some other time period. In some cases, the microprocessor  36  of the valve controller  26  may be configured to monitor a total number of operational cycles (e.g., the number of times the fuel valve sealing members  22  are operated from a closed position to an open position and back to a closed position) of the valve ports  20  and measures related thereto. In some cases, the microprocessor  36  may store such data in a non-volatile memory, such as the memory  37 , sometimes in a tamper proof manner, for record keeping and/or other purposes. The microprocessor  36  may monitor the number of cycles of the valve sealing members  22  in one or more of several different manners. For example, the microprocessor  36  may monitor the number of cycles of the valve sealing members  22  by monitoring the number of times the first main valve switch  72  and/or the second main valve switch  74  are powered or, where one or more control signals may be provided to the fuel valve actuator(s)  30  controlling when the fuel valve actuator(s)  30  selectively moves (e.g., opens or closes) the valve sealing member(s)  22 , the microprocessor  36  may monitor the one or more control signals. 
     The valve controller  26 , in some cases, may monitor the main valve switches  72 ,  74  by receiving signals directly from a device located remotely from the valve assembly  10  on which the main valve switches  72 ,  74  may be located (e.g. see  FIGS. 11-12 ). Switches ((main valve switches  72 ,  74  and safety switch  70  (discussed below)) may be any mechanism capable of performing a switching function including, but not limited to, relays, transistors and/or other solid state switches and circuit devices and/or other switches. The valve controller  26  may include an electrical port, sometimes separate from a communications interface  110  (discussed below), for receiving one or more control signals from the device located remotely from valve assembly  10 . The one or more control signals received via the electrical port may include, but are not limited to: a first valve port  20   a  control signal that, at least in part, may control the position of the first valve sealing member  22   a  via the first valve actuator  30   a , and a second valve port  20   b  control signal that, at least in part, may control the position of the second valve sealing member  22   b  via the second valve actuator  30   b.    
     As an alternative to monitoring control signals, or in addition, microprocessor  36  may monitor the number of cycles of valve sealing members  22  by monitoring data from a position sensor  48 . For example, microprocessor  36  of valve controller  26  may monitor position sensor  48  and record the number of times valve sealing members  22  are in an open position after being in a closed position and/or the number of times valve sealing members  22  are in a closed position after being in an open position and/or the number of times valve sealing members are operated from a close position to an open position and back to a closed position. These are just some examples. Further, if valve controller  26  is operating valve sealing members  22 , valve controller  26  may monitor the number of operational cycles by counting its own control signals sent to valve actuators  30  and/or stepper motors  94 . 
     The non-volatile memory, which may maintain and/or store the number of operational valve cycles, may be positioned directly on, or packaged with, valve body  12  (e.g., on or within memory of microcontroller  36 ) and/or may be accessible by the valve controller  26 . Such storage, placement, and/or packaging of valve cycle data may allow for replacement of components in the overall system (e.g., the an appliance control  60 , etc.) without losing the valve cycle data. In an illustrative instance, the valve cycle data may be securely stored, such that it may not be tampered with. For example, the valve cycle data may be stored in the memory  37  (e.g., non-volatile memory or other memory) of the valve controller  26  and the valve cycle data and/or other valve assembly  10  data may be password protected. 
     The microcontroller  36  of valve assembly  10  may be configured to compare a count of a total number of operational cycles of valve sealing members  22  to a threshold number of operational cycles. In an instance where the counted number of operational cycles of the valve sealing member(s)  22   t  approaches, meets, or exceeds the threshold number of cycles, the microcontroller  36  may initiate a warning and/or request a switch  69  in a limit string  67  to open and thus, remove or cut power to the valve switches  72 ,  74  and fuel valve actuator(s)  30 . Alternatively, or in addition, the microcontroller  36  may send a signal to initiate an alarm and/or put the system in a safety lockout, or the microcontroller  36  may be configured to take other action as desired. Illustratively, the microcontroller  36  may be configured to prevent fuel valve actuator(s)  30  from allowing the valve sealing member(s)  22  to open after the total number of operational cycles meets and/or exceeds the threshold number of operational cycles. In some instances, the threshold number of cycles may be related to the number of cycles for which the valve assembly  10  is rated (e.g., a maximum number of cycles before failures might be expected, etc.) or related to any other benchmark value. In addition, the microcontroller  36  may be configured to perform other diagnostics based on analyzing captured operational cycle data, where the other diagnostics may include number of cycles, time duration of cycles, and similar or different diagnostics, as desired. 
     In addition to the communication interface  110  being configured to output information to a device located adjacent or remote from the valve assembly  10 , the communication interface  110  may be configured to receive one or more inputs from the remote device or an adjacently positioned device. Illustrative inputs may include, but are not limited to: an acknowledgement of reception of one or more of the valve conditions, a user setting, a system setting, a valve command, and/or other similar or dissimilar input. 
     In some instances, the valve controller  26  may communicate through the I/O interface or communication interface  110  with a remotely located output block  46 , where the output block  46  may display and/or output a determined measure related to fluid flow rate through the fluid channel  18 , sometimes along with other data, information and controls sent from the valve controller  26  (see, for example,  FIGS. 9 and 10 ). The output block  46  may include a display and/or other remote systems, and the microcontroller  36  may be configured to send measures to a device control system  60  or building automation system or overall system controller  50  of the output block  46  for further monitoring and/or analysis. As discussed, the I/O interface may include a wired and/or wireless interface between the valve controller  26  (e.g., microcontroller  36 ) and the output block  46  systems (e.g., the building automation system or the overall system controller  50 , the combustion appliance management system  60 , handheld device, laptop computer, smart phone, etc.), where the connection between the valve controller  26  may or may not be made with the communication link  100  (e.g., the communication link  100  could, but need not be, the one and only one communication link). 
     In an illustrative operation, the valve controller  26  may be utilized in a method for communicating information between the valve assembly  10  and a combustion appliance controller  60 , where the combustion appliance controller  60  may be associated with a combustion appliance (e.g., a device separate from, and possibly remotely relative to valve assembly  10 ) for which the valve assembly  10  may control a flow of fuel. The operation may include sensing, with one or more sensor (e.g., pressure sensor assembly  24 ), one or more sensed parameters within the fluid channel  18  of the valve assembly  10 . The sensed parameter may be stored in the memory  37  (e.g., non-volatile memory or other memory) of the valve controller  26 . The valve controller  26  may determine one or more valve conditions (e.g., a safety event condition or other valve condition) based on the one or more sensed parameters. For example, the valve controller  26  may compare the one or more sensed parameters to a threshold parameter to determine one or more valve conditions. If one or more valve conditions have been determined, the valve controller  26  may be configured to send information that may be related to the one or more determined valve conditions from valve assembly  10  to the combustion appliance controller  60  (or other controller or device) across a communication link or bus  100  connected to a communications interface  110 . 
     In one example, upon receiving one or more determined valve conditions, such as a safety event condition, the combustion appliance controller  60  (or other controller or device) may be configured to open the safety switch  70 , such that power to a valve control signal that is coupled to one or more valve actuators  30  is cut, thereby automatically closing one or more valve ports  20  (e.g., closing valve sealing member(s)  22  of valve port(s)  20 ). In some cases, the safety switch  70  may be controlled by an algorithm in the combustion appliance controller  60 , where an output of the algorithm is affected by information passed via the communication link  100 . Additionally, or in the alternative, other feedback signals may affect an output of the algorithm, where the other feedback signals may or may not be passed via the communication link  100  and may or may not originate from the valve assembly  10 . 
     In other illustrative operations, a low gas pressure/high gas pressure event may be reported from the valve controller  26  to the combustion appliance controller  60 . In response to receiving a reported low gas pressure/high gas pressure event, the combustion appliance controller  60  may be configured to open the safety switch  70 . Further, in cases where a proof of closure event is reported to the combustion appliance controller  60  prior to ignition of the combustion appliance, an ignition sequence may not be started. In certain other instances where a Valve Proving System (VPS) sequence test is being performed, a combustion appliance controller  60  may use reported results of the VPS sequence test to make an evaluation. For example, if in the evaluation of the VPS test it were determined that a valve was leaking, the appliance controller  60  might be programmed to open safety switch  70 , to initiate a safety lockout, to initiate an alarm, and/or to take any other similar or dissimilar measure. 
     In other scenarios, the valve assembly  10  may be used as a control valve and in that case, the valve controller  26  may send a signal to the combustion appliance controller  60  indicative of a valve position, and the combustion appliance controller  60  may respond accordingly. These other scenarios, for example, may be applied in parallel positioning system applications, low fire switch applications, auxiliary switch applications, etc. Additionally, it is contemplated that the valve controller  26  may interact with remote devices in other similar and dissimilar manners within the spirit of this disclosure. 
     The pressure block or pressure sensor assembly  24  may be included in the flow module  28 , as seen in  FIGS. 9 and 10 , and/or the pressure sensor assembly  24  may be at least partially separate from the flow module  28 . The pressure sensor assembly  24  may be configured to continuously or non-continuously sense pressure or a measure related to pressure upstream and/or downstream of a characterized port and/or along other portions of the fluid channel  18 . Although the pressure sensor assembly  24  may additionally, or alternatively, include a mass or volume flow meter to measure a flow of fluid through the fluid channel  18 , it has been contemplated that such meters may be more expensive and difficult to place within or outside the valve assembly  10 ; thus, a useful, relatively low cost alternative and/or additional solution may include placing the pressure sensors  38 ,  42 ,  43 ,  44  and/or other pressure sensors within, about and/or integrated in the valve body  12  of the valve assembly  10  to measure the fluid flow through the fluid channel  18 , the pressures at the input and output ports, and/or other similar or different pressure related measures. The pressure sensors  38 ,  42 ,  43 ,  44  may include any type of pressure sensor element. For example, the pressure sensor element(s) may be MEMS (Micro Electro Mechanical Systems) pressure sensors elements or other similar or different pressure sensor elements such as an absolute pressure sense element, a gauge pressure sense element, or other pressure sense element as desired. Example sense elements may include, but are not limited to, those described in U.S. Pat. Nos. 7,503,221; 7,493,822; 7,216,547; 7,082,835; 6,923,069; 6,877,380, and U.S. patent application publications: 2010/0180688; 2010/0064818; 2010/00184324; 2007/0095144; and 2003/0167851, all of which are hereby incorporated by reference. 
     In some cases, the pressure sensor assembly  24  may include a differential pressure sensor  38  for measuring a differential pressure drop across a characterized valve port  20 , or across a different characterized port, as seen in  FIG. 9 . A pressure sensor assembly  24  including a differential pressure sensor  38 , may be exposed to both a first pressure  38   a  upstream of a characterized valve port and a second pressure  38   b  downstream of the characterized valve port. The differential pressure sensor  38  may send a measure related to the sensed differential pressure to the microcontroller  36  of the valve controller  26 , as seen from the diagram of  FIG. 9 . The microcontroller  36  may be configured to monitor the differential pressure across the characterized port with the differential pressure measures sensed by the differential pressure sensor  38 . 
     Alternatively, or in addition, an illustrative pressure sensor assembly  24  may include one or more first pressure sensors  42  upstream of a characterized valve port and one or more second pressure sensors  43  downstream of the characterized valve port, where the first and second pressure sensors  42 ,  43  may be in fluid communication with the fluid channel  18  and may be configured to sense one or more measures related to a pressure upstream and a pressure downstream, respectively, of the characterized valve port, as seen in  FIG. 10 . Where a second valve port (e.g., the second valve port  20   b ) may be positioned downstream of a first characterized valve port (e.g. the first valve port  20   a ) and forming an intermediate volume  19  between the first and second valve ports, the pressure sensor assembly  24  may include one or more third pressure sensors  44  in fluid communication with the intermediate volume  19 , which may sense one or more measures related to a pressure in the intermediate volume  19 . Where two characterized ports are utilized, the first pressure sensors  42  may be upstream of both characterized ports, second pressure sensors  43  may be downstream of both characterized ports, and the third pressure sensors  44  may be downstream from the first characterized port and upstream from the second characterized, but this is not required (e.g., first and second pressure sensors  42 ,  43  may be used to estimate the pressure drop across the valves). Additionally, or in the alternative, one or more differential pressure sensors  38  may be utilized to estimate the pressure drop across the first characterized port and/or the second characterized port. It is further contemplated that valve ports  20  may not be characterized ports. 
     The pressure sensors  42 ,  43 ,  44  may be configured to send each of the sensed measure(s) directly to the microcontroller  36 . The microcontroller  36  may be configured to save the sensed measures and/or related information to the memory  37  (e.g., non-volatile memory or other memory), and may perform one or more analyses on the received sensed measures. For example, the microcontroller  36 , which may be a portion of the flow module  28  and/or the valve controller  26 , may determine a measure that is related to a fluid flow rate through the fluid path based, at least in part, on the received sensed measures related to pressure upstream of the characterized port and on the received sensed measures related to pressure downstream of the characterized port. 
     Where a valve assembly  10  includes one or more valve ports  20 , the pressure sensor assembly  24  may include the first pressure sensor  42  positioned upstream of the first valve port  20   a  at or downstream of the inlet port  14 , as seen in  FIG. 11 . In addition, or alternatively, the pressure sensor assembly  24  may include a second pressure sensor  43  positioned downstream of the second valve port  20   b  at or upstream from the outlet port  16 . The valve assembly  10  may further include one or more third pressure sensors  44  downstream of the first valve port  20   a  and upstream of the second valve port  20   b . The pressure sensors  42 ,  43 ,  44  may be configured to sense a pressure and/or a measure related to the pressure in the fluid channel  18 , and to communicate the sensed measures to the valve controller  26 , which is physically coupled to or positioned within the valve body  12 . Where multiple pressure sensors  42 ,  43 ,  44  exist at or near one or more location (e.g., upstream of the valve ports  20 , intermediate of the valve ports  20 , downstream of the valve ports  20 , etc.) along the fluid channel  18 , at least one of the multiple pressure sensors may be configured to sense pressures over a pressure sub-range different from a sub-range over which at least one other of the multiple pressure sensors at the location may be configured to sense pressure, but this is not required. In some cases, and as shown in  FIG. 8 , the various pressure sensors may be mounted directly to a corresponding circuit board, such that when the circuit board is mounted to the valve body  12 , the pressure sensor is in fluid communication with a corresponding fluid port in the valve body  12 . 
     In some instances, such arrangements of pressure sensors  38 ,  42 ,  43 ,  44  within valve assembly  10 , along with the connection between the valve controller  26  and the pressure sensors  38 ,  42 ,  43 ,  44  may be used to emulate functions of high gas pressure (HGP) and low gas pressure (LGP) switches, which traditionally require wires and further housings extending to and from and/or attached to the valve body  12 . When the electronics and elements of the valve assembly  10  are configured to emulate LGP/HGP switches, gas-valve wiring connections and interactions may be at least partially avoided, eliminated or simplified. In some instances, such configuration of the valve controller  26  and the pressure sensors  38 ,  42 ,  43 ,  44  may reduce manual operations (e.g., manually adjusting a mechanical spring or other device of conventional high gas pressure (HGP) and low gas pressure (LGP) switches), and allow for a more precise fitting with the electronics of the valve assembly  10 . 
     In some cases, the pressure sensor assembly  24  may include one or more absolute pressure sensors  54  in communication with the microcontroller  36 . The absolute pressure sensor  54  may sense an atmospheric pressure adjacent the gas valve assembly  10 , and may be configured to communicate and transfer data related to the sensed atmospheric pressure to the microcontroller  36 . The microcontroller  36  may take into account the atmospheric pressure from the absolute pressure sensor  54  when determining the flow rate of fluid flowing through the characterized port and/or an estimate of fuel consumption by an attached appliance and/or when determining threshold values. Other sensors may be included in valve assembly  10 , for example, one other type of sensor may be a barometric pressure sensor. 
     As discussed, the valve assembly  10  and the flow module  28  thereof may include temperature sensor(s)  34 , as seen in  FIGS. 9-11 . The temperature sensor  34  may be positioned within the valve body  12  so as to be at least partially exposed to the fluid channel  18  and configured to sense a temperature of a fluid (e.g., gas or liquid) flowing through the fluid channel  18  and/or any other temperature in the fluid channel  18 . The temperature sensor  34  may have a first temperature sensor  34   a  at least partially exposed to the fluid channel  18  upstream of a characterized valve port, and/or a second temperature sensor  34   b  at least partially exposed to the fluid channel  18  downstream of the characterized valve port, as seen in  FIGS. 9 and 10 . When there is a first valve port and a second valve port (e.g., valve ports  20   a ,  20   b ), there may be a third temperature sensor  34   c  in fluid communication with intermediate volume  19  between the first and second characterized valve ports, if desired. The sensed temperature measure may be used by flow module  28  to, for example, compensate, correct, or modify a determined measure (e.g., a density of a fluid) that is related to, for example, a fluid flow rate of fluid flowing through the fluid channel  18 , which may help improve the accuracy of the flow rate calculation. In operation, the temperature sensor  34  (e.g., any or all of temperatures sensors  34   a ,  34   b ,  34   c ) may communicate a sensed temperature measure directly or indirectly to the valve controller  26  and/or the memory  37  (e.g., non-volatile memory or other memory) of the valve controller  26  (e.g., the memory in a microcontroller  36  or memory in another location) and/or the flow module  28 . The valve controller  26  may, in turn, utilize the sensed temperature to help increase the accuracy of a determined flow rate of fluid passing through a characterized port and/or increase the accuracy of a calculated fluid and/or fuel consumption quantity, as desired, and store the calculated flow rate of fluid passing through a characterized port and/or the calculated fluid and/or fuel consumption quantity in the memory  37  (e.g., non-volatile memory or other memory). Additionally, or in the alternative, in some instances the pressure sensors  38 ,  42 ,  43 ,  44  may utilize built-in temperature sensors that are used to internally compensate the pressure sensor over the operating temperature range. In such instances, the temperature reading may be accessible at the pressure sensor output (e.g., a digital communication bus) or at another location. 
     The flow module  28  of valve assembly  10  may further include a position sensor system that may be configured to continuously or discontinuously sense at least one or more of an axial position, a rotary position, and/or a radial position, of the valve sealing member  22  within or about the fluid valve port  20 . In some cases, the position sensor system may include more than one position sensors  48 , such that each position sensor  48  may monitor a sub-range of a valve&#39;s total travel. Moreover, the position sensor system may be utilized as a proof of closure switch system. The position sensor(s)  48  of the position sensor system may be situated or positioned in valve body  12  at or about a valve port  20 . For example, and in some instances, the position sensor(s)  48  may be fluidly isolated from the fluid channel  18  (e.g., fluidly isolated from the fluid channel  18  by the valve body  12 ), and radially spaced from an axis upon which a valve sealing member(s)  22  may axially and/or rotationally translate between a closed position and an open position, as seen in  FIGS. 14-17 . 
     An illustrative gas valve assembly  10  may include a first valve port  20   a  and a second valve port  20   b  (see  FIG. 7 ), and a first position sensor  48   a  monitoring the first valve sealing member  22   a  and a second position sensor  48   b  monitoring the second valve sealing member  22   b , where the position sensors  48   a ,  48   b  may be separate devices or may share an enclosure and/or other parts. In the illustrative instance, the first position sensor  48   a  may be fluidly isolated from the fluid channel  18  and radially spaced from a first axis of the first valve port  20   a , and the second position sensor  48   b  may be fluidly isolated from the fluid channel  18  and radially spaced from a second axis of second valve port  20   b  (see  FIGS. 14-17 ). 
     As discussed above, the position sensor  48  may be configured to detect a measure that is related to whether the valve sealing member  22  is in an open or closed position and/or a measure related to an intermediate position of the valve sealing member  22  within the fluid valve port  20 . In one example, the position sensor(s)  48  may be configured to provide a proof of closure (POC) sensor(s) for the valve port(s)  20  (e.g., the first valve port  20   a  and/or the second valve port  20   b ). 
     Where the valve sealing member(s)  22  have a range of travel (e.g., rotationally and/or axially) within the valve port(s)  20 , the position sensor(s)  48  may be configured to sense a current position of the valve sealing member(s)  22  anywhere along the range of travel of the valve sealing member(s)  22 . The position sensor  48  may then send (e.g., through electronic or other communication) sensed positioning data of the measure related to the position of the valve sealing member  22  to the determining block and/or microcontroller  36  and/or the memory  37  (e.g., non-volatile memory or other memory) of the valve controller  26  and/or the flow module  28 , where the microcontroller  36  may be configured to monitor the axial position of the valve sealing member  22  within the valve port  20  through the position sensor system  48 . 
     In some instances, the valve controller  26  may include an electronic circuit board and/or a wired or wireless communication link  100  may facilitate communication between the position sensor(s)  48  and the electronic circuit board or other device of the valve controller  26 . The valve controller  26  may be configured to further pass on positioning information to remote devices through communication lines (e.g., the communication link  100 ) and/or display positioning data of the valve sealing member  22  on one or more displays  76  attached to the valve assembly  10  and/or the remote devices, as seen in  FIG. 13 . The valve controller  26  may indicate a closed or open position of the valve sealing member  22  or a degree (e.g., 10%, 20%, 30%, etc.) of an opening of the valve sealing member  22  with one or more visual indicators on or comprising the display(s)  76 , as seen in  FIG. 13 , such as one or more light emitting diodes (LEDs) acting as a visual indication of a valve state and/or position, liquid crystal displays (LCDs), a touch screen, other user interfaces and/or any other display interfacing with or displaying information to a user. 
     In some instances, the position sensor system may include one or more switches  64  (e.g., a first switch  64   a  and a second switch  64   b , where the switch(es)  64  may be or may include relays or other switch types such as FETs, TRIACS, etc.) having one or more switched signal paths  66  and one or more control inputs  68  (e.g., a first control input  68   a  and a second control input  68   b ), as seen in  FIG. 13 . Illustratively, one switch  64  may be utilized for multiple position sensors  48 , or more than one switch  64  may be utilized for multiple position sensors (e.g., in a 1-1 manner or other manner), as desired. The control input  68  may set the state of the switched signal paths  66  to a first state or a second state or another state, as desired. As depicted in  FIG. 13 , the valve controller  26  may be coupled to the position sensor(s)  48 , and may control input  68  of switch  64 , where both the valve controller  26  and the position sensors  48  may be isolated from fluid communication with the fluid channel  18 . In some instances, the valve controller  26  may be configured to set the state of the switched signal path  66  to the first state when the first position sensor  48   a  senses that a first valve port  20   a  is not closed or the first valve sealing member  22   a  is not in a closed position, and to a second state when position sensor  48  senses that a first valve port  20   a  is closed or the first valve sealing member  22   a  is in a closed position. Similarly, the valve controller  26  may be configured to set the state of the switched signal path  66  to the first state when the second sensor  48   b  senses that the second valve port  20   b  is not closed or the second valve sealing member  22   b  is not in a closed position, and to a second state when the position sensor  48  senses that a second valve port  20   b  is closed or the second valve sealing member  22   b  is in a closed position. In the alternative, the valve controller  26  may be configured to set the state of the switched signal path  66  to the first state when at least one of the first and second sensors valve ports  20   a ,  20   b  are not closed or at least one of the first and second valve sealing members  22   a ,  22   b  are not in a closed position, and to a second state when the position sensor  48  senses that both first and second valve ports  20   a ,  20   b  are closed or both the first and second valve sealing members  22   a ,  22   b  are in closed positions. Similar or identical or different processes, as desired, may be utilized for each position switch  64  and control input  68 . 
     Illustratively, the valve sealing member(s)  22  may include a sensor element  80 , and position sensor(s)  48  may include one or more transducer or field sensors  82 . For example, valve sealing member(s)  22  may include a sensor element  80  (e.g., a magnet when using a field sensor  82 , a ferrous core when using a linear variable differential transformer (LVDT)  84 , or other sense element, and/or similar or dissimilar indicators) secured relative to and translatable with valve sealing member(s)  22 . Position sensor(s)  48  may include one or more field sensors  82  (e.g., magnetic field sensors, a LVDT  84 , Hall Effect sensors or other similar or dissimilar sensors), as seen in  FIGS. 14-15 . Field sensor  82  may be positioned within valve body  12  or may be positioned exterior to valve body  12  and radially spaced from a longitudinal axis of the valve port(s)  20  and/or the valve sealing member(s)  22 . The position sensor(s)  48  may be positioned so as to be entirely exterior to the fluid channel  18 . The meaning of entirely exterior of the fluid channel  18  may include all position sensors  48  and all electronics (e.g., wires, circuit boards) connected to the position sensor(s)  48  being exterior to fluid channel  18 . Where the position sensor(s)  48  includes an LVDT, the LVDT may be positioned concentrically around and radially spaced from the valve sealing member(s)  22 , as shown in  FIG. 15 , and/or the axis of LVDT may be spaced radially and parallel from the valve sealing members  22 . 
     In some cases, a strain gauge  86 , as depicted in  FIG. 16 , or other electromechanical sensor may also be utilized to sense a position of the valve sealing member  22  within an interior of the fluid channel  18  from a position fluidly exterior of the fluid channel  18  by sensing a strain level applied by the spring  31  in communication with valve sealing member  22 . Alternatively, or in addition, the valve sealing member(s)  22  may include one or more visual indicators  88  (e.g., a light reflector or other visual indicators), and the position sensor(s)  48  may include one or more optical sensors  90 , as seen in  FIG. 17 , where visual indicators may be any indicators configured to be viewed by optical sensors through a transparent window  87  sealed with an o-ring or seal  89  or through another configuration, such that optical sensors  90  may determine at least whether the valve sealing member(s)  22  is/are in a closed or open position. Where a visual position indicator  88  is utilized, and in some cases, a user may be able to visually determine when the valve sealing member(s)  22  is not in a closed position. 
     As may be inferred from the disclosure, the position sensor  48  may in some instances operate by detecting a position of a valve sealing member  22  and/or optionally the valve stem  92  or the like within a valve assembly  10  having a valve body  12 , where the valve sealing member  22  may be translatable with respect to the valve port  20  of the valve body  12  along a translation or longitudinal axis “A” within a valve port  20 . In some cases, the sensor element  80 , affixed relative to the valve sealing member  22 , may be positioned within the interior of the valve body  12  and may optionally fluidly communicate with the fluid channel  18 ; however, the position sensor  48  may be isolated from the fluid channel  18  and/or positioned exterior to the valve body  12 . In an illustrative embodiment, the valve sealing member  22  may be positioned at a first position within an interior of the valve port  20  along translation axis A. The first position of the valve sealing member  22  may be sensed with position sensor  48  by sensing a location of a sensor element  80  secured relative to the valve sealing member  22  with the position sensor  48 . Then, the position sensor  48  may automatically or upon request and/or continuously or discontinuously, send the sensed location and/or open or closed state of the valve sealing member  22  to the valve controller  26 . 
     It is contemplated that the valve controller  26  may electronically calibrate the closed position of the valve sealing member  22  and/or the valve stem  92 . Such a calibration may store the position of the valve sealing member  22  and/or the valve stem  92  when the valve sealing member  22  and/or the valve stem  92  is in a known closed position (e.g. such as during installation of the valve assembly  10 ). During subsequent operation, the position of the valve sealing member  22  and/or the valve stem  92  can be compared to the stored position to determine if the valve sealing member  22  and/or the valve stem  92  is in the closed position. A similar approach may be used to electronically calibrate other positions of the valve sealing member  22  and/or the valve stem  92  (e.g. fully open position, or some intermediate position), as desired. 
     Valve Proving System Test 
     The valve controller  26  may be configured to perform an electronic valve proving system (VPS) test on the valve assembly  10 , where all or substantially all of the structure required for the VPS may be integrated directly into the valve assembly  10 . When so provided, the direct integration may allow sensors and electronics needed for VPS testing to share a common housing. Alternatively or in addition, the VPS testing may be initiated by the appliance controller  60  (e.g., a burner controller). 
     In an illustrative operation, a VPS test may be performed on a valve assembly  10  that is coupled to a non-switched gas source, or other gas source, that is under a positive pressure during the VPS test to test the gas valve assembly  10  for leaks. Alternatively, or in addition, VPS tests may be performed on valve assemblies  10  in other configurations. 
     The valve assembly  10  may be in communication with the combustion appliance controller  60  or other device, and may at least partially control a fuel flow to a combustion appliance through the fluid channel  18 . Illustratively, the combustion appliance may cycle on and off during a sequence of operational cycles, where at least some of the operational cycles may include performing a VPS test prior to and/or after igniting received fuel during the corresponding operational cycle. For example, VPS tests may be performed on each valve port  20  prior to igniting received fuel during a corresponding operational cycle, VPS tests may be performed on each valve port  20  after a call for heat is satisfied (e.g., at the very end of an operational cycle), or a VPS test may be performed on a first valve port  20   a  prior to igniting received fuel during a corresponding operational cycle and on a second valve port  20   b  after a call for heat is satisfied. Illustratively, VPS tests may be automated processes that occur at every, or at least some, operational cycle(s) (e.g., once the VPS test has been set up by a field installer or at the original equipment manufacturer, the testing may not require the end user to participate in any way). 
     The structural set up of the valve assembly  10  for a VPS test may include the valve controller  26  being in communication with a pressure sensor  44  that may be in fluid communication with the intermediate volume  19  between the two valve ports  20  (e.g., the first valve port  20   a  and the second valve port  20   b , as seen in  FIG. 8 ). Where the valve controller  26  may be in communication with the pressure sensor  44 , the valve controller  26  may be configured to determine a measure related to a pressure (e.g., an absolute pressure, a gauge pressure, a differential pressure, and/or other measure) in the intermediate volume  19  during each VPS test performed as part of at least some of the operational cycles of the combustion appliance, or at other times. Alternatively, or in addition, the valve controller  26  may be in communication with one or more of the inlet pressure sensor  42 , the outlet pressure sensor  43 , and/or other pressure sensors (e.g., the differential pressure sensor  38  and/or other sensors), where the pressure sensors  38 ,  42 ,  43  sense measures related to the pressure upstream of the first port  20   a  and downstream of the second port  20   b , respectively, and communicate the sensed measures to the valve controller  26 . Although pressure sensors downstream of the ports (e.g., the pressure sensor(s)  43 ) may not be directly used to determine whether a valve is leaking, the downstream pressure sensor(s)  43  may, in some cases, monitor outlet pressure before, during, and/or after leakage tests of the valves and, in some cases, may facilitate determining which valve is leaking if a valve leakage is detected. 
     Due to the timing of the VPS test(s) before and/or after operational cycles, or both, the test(s) may be achieved in an amount of time consistent with the useful operation of an individual appliance (e.g., a short amount of time, 10-15 seconds, 5-30 seconds, or a longer amount of time) which may depend on one or more of the inlet pressure, initial pressure in the intermediate volume  19 , size of the intermediate volume  19 , volume of the appliance combustion chamber, length of time of the appliance pre-purge cycle, firing rate of the appliance burner, the leakage threshold level (e.g., allowed leakage level/rate), etc. In some instances, a VPS test duration may be fixed and saved in memory of the valve assembly  10 , the combustion appliance, and/or saved in other memory. For example, a VPS test duration may be fixed in memory of or accessible by a controller (e.g., the valve controller  26 , the combustion appliance controller  60 , or other controller) in a permanent manner, for a period of time, for a number of cycles, for each VPS test occurring before the VPS test duration is changed by a user or an automated system, and/or in any other suitable manner. Illustratively, a fixed VPS test duration may be modified by a user in the field by interacting with the valve controller  26  and/or the combustion appliance controller  60 . 
     Fixed VPS test duration or other predetermined duration (e.g., a duration during which pressure may be monitored in the intermediate chamber or other duration) may mitigate or eliminate the need to calculate a VPS test duration or other predetermined duration based on one or more factors at the time of initial install of a valve assembly  10 , such as, but not limited to, an expected inlet gas or fuel pressure or an allowed leakage rate. Rather, and in some cases, an installer may set the fixed duration at a desired duration without performing any calculations. Additionally or alternatively, when a fixed VPS test duration or other predetermined duration is utilized, an allowed leakage rate (e.g., as set by a standards setting body, a manufacturer, other entity, an installer or a user) may, in some cases, be adjusted during the life of the valve assembly  10  or combustion appliance. In some instances, the allowed leakage rate may be adjusted by a user by interacting with the valve controller  26  and/or the combustion appliance controller  60 . 
     In some cases, a VPS test duration or other predetermined duration may be fixed at the time of initial install of a valve assembly  10  by saving the set VPS test duration or other predetermined duration to the memory  37  (e.g., non-volatile memory or other memory) of the valve assembly  10  or other memory that may be located remotely, but in communication with the valve controller  26 . Alternatively or in addition, the VPS test duration or other predetermined duration may be stored in memory of the combustion appliance. During the install of the valve assembly  10 , an installer may program the VPS test duration or other predetermined duration in the valve controller  26  and/or the combustion appliance controller  60  to a fixed duration for all or substantially all required leakage levels and/or for all expected gas or fuel pressures in the fluid channel  18  (e.g., an inlet gas or fuel pressure upstream of the valve ports  20 ). In some cases, the VPS test duration or other predetermined duration may also be modified later by interacting with the valve controller  26  at the valve assembly  10  or remote from the valve assembly  10 . 
     In some cases, one or more VPS thresholds may be programmed into the valve controller  26 . In some cases, one or more VPS thresholds (e.g., a first and a second VPS sub-test threshold values) may be calculated. In some cases, the valve controller  26  may be configured to calculate one or more VPS thresholds based on one or more parameters and, in some instances, the valve controller  26  may be configured to store the VPS thresholds (e.g., VPS sub-test threshold values or other VPS test threshold values) in a memory for later use. The one or more parameters that the valve controller  26  may consider if it is determining a VPS test threshold may include, but are not limited to, a sensed pressure (e.g., a sensed pressure in the intermediate volume, an inlet pressure, or other pressure), a sensed temperature, a max flow rate of the system, a number of ON-OFF cycles operated up to a point in time, a volume of the fluid channel  18 , a volume of the intermediate volume  19 , an altitude of valve assembly  10  (e.g., for calculating and/or estimated an atmospheric pressure at the valve assembly  10  or for other purposes), a barometric pressure, an absolute pressure, a gas type (e.g., density), ANSI requirements, EN requirements, other agency requirements, an allowed VPS test duration, an allowed pressure measuring duration, and how small of a leak is to be detected (e.g., an allowed leakage rate, etc). Further, in the event that more than two sub-tests are performed as part of the VPS test, the valve controller  26  may utilize more threshold values than first and second VPS sub-test threshold values, if desired. 
     In some instances, one or more of the VPS thresholds may be determined or calculated for a VPS test, and may be used each time the VPS test is executed. Alternatively, one or more VPS thresholds may be re-determined or re-calculated before each of one or more VPS tests are executed. In one illustrative example, one or more VPS thresholds for a VPS test may be determined from a set VPS duration (e.g., a test duration or a duration less than a test duration), a known volume of the intermediate volume  19  of the valve (e.g., which may be programmed into the valve controller by a user and/or at the manufacturer), a specified leakage level sometimes per a safety standard or other standard, and/or a measure related to gas or fuel pressure provided at the inlet of the valve. Since the VPS test duration or other predetermined duration, the volume of the intermediate volume  19 , an altitude of the valve assembly  10 , and the specified leakage level (e.g., an allowed leakage level) may be known to the valve controller  26  (e.g., saved in memory  37  or other memory), the valve controller  26  may identify a measure related to a gas or fuel pressure in the fluid channel  18  before, during, or after a particular VPS test and can then calculate or determine one or more VPS threshold values for the particular VPS test. 
       FIGS. 18 and 19  are schematic pressure versus time graphs depicting pressure thresholds for pressure measured in the intermediate volume  19  of a valve assembly during a VPS test.  FIG. 18  depicts a graph where the intermediate volume is initially pressurized to a high pressure P H  at time=0, where the VPS test is testing leakage through the second valve port  20   b  and P H  may be equal to a pressure upstream of the first valve port  20   a  or other pressure indicative of a pressurized state in the intermediate volume  19 . Illustratively, the threshold pressure value (P THRESHOLD-H ) when the intermediate volume  19  is in a pressurized state is at some pressure less than the pressure P H . In such a pressurized state of the intermediate volume  19 , and in one example, P THRESHOLD-H  may be calculated from the following illustrative equation:
 
 P   THRESHOLD-H   =P   H −( dP/dt )* T   (1)
 
where dP/dt is the allowed change in pressure rate in the intermediate volume, and T is the predetermined duration over which pressure is monitored in the intermediate volume during the VPS test. The dP/dt value may represent an allowed leakage rate through the second valve, given the intermediate volume of the valve. For example, dP/dt may be proportional to the ratio of the allowed leakage rate to the intermediate volume. Pressure in the intermediate volume during the predetermined duration T is represented by line  150  in  FIG. 18 .
 
     In some instances, a pressure warning threshold P THRESHOLD-WH  may be calculated from equation (1), where dP/dt is a value that is less than the dP/dt that corresponds to the allowed leakage rate, to give a user a warning when the pressure in the intermediate volume  19  may be changing in a manner that indicates there may be a leak in the valve ports  20 , but not to the extent that the valve assembly  10  needs to be shut down. Illustratively, a pressure warning threshold may assist in identifying degradation of the valve assembly  10  by providing an indication to a user during a VPS test that valve assembly  10  is beginning to leak prior to a VPS test in which operation of the valve assembly  10  needs to be shut down, as shown in line  160   
       FIG. 19  depicts a graph where the intermediate volume is initially pressurized to a pressure P L  at time=0, where the VPS test is testing leakage through the first valve port  20   a  and P L  may be equal to a local atmospheric pressure or pressure downstream of the second valve port  20   b  or other pressure indicative of a depressurized state in the intermediate volume  19 . Illustratively, the threshold pressure value (P THRESHOLD-L ) when the intermediate volume  19  is in a depressurized state is at some pressure greater than the pressure P L . In such a depressurized state of the intermediate volume  19 , and in one example, P THRESHOLD-L  may be calculated from the following illustrative equation:
 
 P   THRESHOLD-L   =P   L +( dP/dt )* T   (2)
 
where dP/dt is the allowed change in pressure rate in the intermediate volume, and T is the predetermined duration over which pressure is monitored in the intermediate volume during the VPS test. the dP/dt value may represent an allowed leakage rate through the first valve, given the intermediate volume of the valve. For example, dP/dt may be proportional to the ratio of the allowed leakage rate to the intermediate volume. Pressure in the intermediate volume during the predetermined duration T is represented by line  170 , in  FIG. 19 .
 
     In some instances, a pressure warning threshold P THRESHOLD-WL  may be calculated from equation (2), where dP/dt is less than the dP/dt that corresponds to the allowed leakage rate, to give users a warning when the pressure in the intermediate volume  19  may be changing in a manner that indicates there may be a leak in the valve ports  20 , but not to the extent that the valve assembly needs to be shut down. As discussed above, a pressure warning threshold may assist in identifying degradation of the valve assembly  10  by providing an indication to a user during a VPS test that the valve assembly  10  is beginning to leak prior to a VPS test in which operation of the valve assembly  10  needs to be shut down, as shown in line  160 . 
     In some cases, the VPS test duration or other predetermined duration may not be used in calculating the threshold(s) for a VPS test. For example, as an allowed leakage level (e.g., an allowed leakage rate) may translate to an allowed rate of pressure change (dP/dt) during a VPS test, the one or more VPS thresholds may be set to be independent of the VPS test duration and may be or may primarily be a function of atmospheric pressure, allowed leakage rates, and/or a volume size of the intermediate volume  19  of the valve assembly  10 . 
     Illustratively, an equation for an allowed leakage level may be:
 
 Q   calculated   =dP/dt*V/P   atm *3600  (3)
 
where Q calculated  is the measured leakage rate in mass flow volume of liters/hour, dP/dt is a determined slope of a measured pressure over time (e.g., a differential pressure) in Pascals/second, V is the volume of the intermediate volume  19 , P atm  is the atmospheric pressure in Pascals, and 3600 represents the number of seconds in an hour. Although particular units are disclosed, other units may be utilized as desired. The volume of the intermediate volume  19  and the atmospheric pressure may, generally, be considered constants in this equation. Thus, from equation (3), an allowed leakage level/rate (provided by a safety standard or otherwise) may be used as a VPS threshold, and a measured change of pressure in the intermediate volume over time (dP/dt) may be entered into equation (3) to obtain Q calculated , which may be compared to the VPS threshold value to determine whether the valve assembly  10  passes the VPS test.
 
     Alternatively, or in addition, a VPS threshold may be a change of pressure over time (dP/dt) determined from equation (3), where Q calculated  is equal to an allowed leakage level and dP/dt is solved for by the controller  26  to determine the VPS threshold value. Then, a measured change of pressure in the intermediate volume over time may be directly compared to the determined VPS threshold value to determine if the valve assembly  10  passes the VPS test. 
     In some cases, an intermediate pressure, or a measure related thereto, in the intermediate volume may be measured by the inlet pressure sensor  42 , by the outlet pressure sensor  43 , by the intermediate pressure sensor  44 , and/or by other sensors. In instances when the intermediate pressure sensor  44  measures a measure related to the intermediate pressure in the intermediate volume  19 , the measure related to the initial pressure may be sensed or identified before both the first valve port  20   a  and the second valve port  20   b  are closed (e.g., the first valve port  20   a  may be opened and the second valve port  20   b  may be closed), after both the first valve port  20   a  and the second valve port  20   b  are closed (e.g., the second valve port  20   b  is closed and the first valve port  20   a  is closed after gas or fuel fills the intermediate volume), or both to allow the gas or fuel to flow into the intermediate volume  19  adjacent the intermediate pressure sensor  44  and maintain an inlet pressure. When the inlet pressure sensor  42  is used to provide a measure related to the initial pressure in the fluid channel  18  (e.g., inlet gas or fuel pressure or some other measure), the measure related to the initial pressure may be measured at any time with respect to a VPS test, including, but not limited to, before both the first valve port  20   a  and the second valve port  20   b  are closed, after both the first valve port  20   a  and the second valve port  20   b  are closed, or both. When the outlet pressure sensor  43  is used to provide a measure related to the initial pressure in the intermediate volume  19 , the measure related to the gas or fuel pressure in the fluid channel  18  may be measured when both of the first valve port  20   a  and the second valve port  20   b  are in an opened position. 
     Once a VPS test has been initiated by one or more of the valve controller  26  and the appliance controller  60 , the valve controller  26  may determine a threshold value, in a manner similar to as discussed above, and/or perform one or more other tasks related to the VPS test. For example, after initiating a VPS test, the valve controller  26  may identify a predetermined duration associated with the VPS test; measure, sense, or identify a measure related to a fuel pressure (e.g., an inlet gas or fuel pressure or other measure) or initial pressure in the intermediate volume  19 ; and/or determine one or more threshold values for the VPS test (e.g., based on one or more of the identified measure related to the fuel pressure or an initial pressure in the intermediate volume and the identified predetermined duration). The determined threshold values may then be saved in memory of or in communication with the valve controller  26  and used for comparison against an identified measure related to the pressure in the intermediate volume during the VPS test. In some instances, one or more thresholds (e.g., a first threshold, a second threshold, a third threshold, a fourth threshold, and/or one or more other thresholds) may be determined and saved in the memory  37  for use with the current VPS test or sub-tests of the current VPS test and/or for later use in subsequent VPS tests or sub-tests of VPS tests. 
     In an illustrative example, the valve controller  26  may include the memory  37  (e.g., non-volatile memory or other memory) that stores previously determined first VPS threshold value (e.g., for comparing to a pressure rise in the intermediate volume  19  or elsewhere) and a second VPS threshold value (e.g., for comparing to a pressure decay in the intermediate volume or elsewhere) utilized in performing a VPS test. Alternatively, or in addition, the memory may be located at a position other than in the valve controller  26 , such as any remote memory that may be in communication with the valve controller  26 . Such VPS thresholds may be used during subsequent VPS tests, or the VPS thresholds may be recalculated for use during a subsequent VPS test, as desired. 
     During a VPS test, a measure that is related to the pressure in the intermediate volume  19  may be measured, determined, and/or identified. In some cases, the measure that is related to the pressure in the intermediate volume  19  may be sensed via a pressure sensor that is exposed to the intermediate volume  19 . The valve controller  26  may further be configured to compare the measured, determined, and/or identified measure related to a pressure in the intermediate volume  19  (e.g. an absolute pressure, a gauge pressure, a pressure change rate, or other measure) to a first threshold value during a first valve leakage test, and/or to compare the measure that is related to a pressure in the intermediate volume  19  (e.g., an absolute pressure, a gauge pressure, a pressure change rate, or other measure) to a second threshold value during a second valve leakage test. After or while comparing the measure related to the pressure in the intermediate volume  19  to one or more of the threshold values, the valve controller  26  may output an alert signal or other signal if the measure meets and/or exceeds (e.g., crosses, etc.) the corresponding threshold value 
     The VPS test may be initiated by commanding the valve actuators  30  to open and/or close in a desired sequence. This sequence may be initialized and/or controlled through the valve controller  26  and/or through the combustion appliance controller  60 . When the VPS test is controlled by the valve controller  26 , the setup of the VPS settings may occur at a display/user interface  76  on board the valve itself or at a remote display (e.g., displays  52 ,  62  or other displays). When the VPS sequence is initialized and controlled remotely (e.g., remote from the valve controller  26 ) through the combustion appliance controller  60 , the valve controller  26  may be configured to detect if the VPS test or another test is occurring by monitoring gas valve assembly  10  and signals communicated to and/or from the valve assembly  10 . 
     When the VPS test is to be actuated or initiated at or through the combustion appliance controller  60 , the setup of the VPS settings may occur at a remote display (e.g., displays  52 ,  62  or other display(s)). The valve controller  26  may monitor the valve actuators  30   a ,  30   b , a first control signal (MV 1 ) controlling the first valve actuator  30   a  and a second control signal (MV 2 ) controlling the second valve actuator  30   b , and/or the states of the valve ports  20   a ,  20   b  (e.g., by monitoring the output of the position sensor(s)  48 ) to identify if the VPS test is occurring. The first and second control signals (MV 1  and MV 2 ) may be actuated by the combustion appliance controller  60  in communication with the valve assembly  10  or by the valve controller  26  or by a field tool in communication with the valve controller  26  or any other tool or individual in communication with the valve assembly  10 . Although the field tool and/or other tools may most often be used for actuating the first and second control signals (MV 1  and MV 2 ) in a valve leakage test, such similar or different tools may be used to operate a VPS test or for system level diagnostics and/or troubleshooting by a trained appliance technician in the field. 
     An illustrative method  200  of performing a VPS test, as shown in  FIG. 20 , may include closing  210  both the first valve port  20   a  and the second valve port  20   b  and identifying  212  a measure that is related to a pressure change rate in the pressure sensed by the intermediate volume pressure sensor  44 . The method  200  may include identifying  214  a measure related to a leakage rate. In one example, the measure related to a leakage rate may be based at least in part on the measure that is related to the pressure change rate in the intermediate volume and/or a measure that is related to the volume of the intermediate volume  19 . The measure related to the identified leakage rate may be compared  216  to a threshold value (e.g., an allowed leakage rate associated with a safety standard or other allowed leakage rate). An alert may then be outputted  218  if the measure related to the leakage rate meets and/or exceeds (e.g., crosses) the threshold value. 
     An illustrative method  300  of performing a VPS test, as shown in  FIG. 21 , may include identifying  310  a predetermined duration (e.g., a VPS test duration or a sub-test duration of the VPS test duration programmed into the valve controller  26  or other test duration) and closing  312  the first valve port  20   a  and the second valve port  20   b . In the method  300 , a measure related to an initial pressure in the intermediate volume  19  may be identified  314  and a threshold value may be determined  316 . The threshold value may be at least partially based on and/or related to one or more of the identified measure related to the initial pressure in the intermediate volume and the identified predetermined duration. Then, a pressure in the intermediate volume  19  of the valve assembly  10  may be identified  318  at some time after the initial pressure in the intermediate volume is determined and the identified pressure in the intermediate volume  19  may be compared  320  to the determined threshold value. If the pressure in the intermediate volume  19  crosses the determined threshold value, the valve controller  26  or other feature of the valve assembly may output  322  an alert signal. 
     In some instances, VPS tests may include performing  410  a first VPS sub-test and performing  440  a second VPS sub-test, as shown in method  400  in  FIGS. 22A and 22B . In method  400 , the valve controller  26  may cause, perform, and/or identify a first predetermined sequence (e.g., the first VPS test)  410 , as shown in  FIG. 22A . In performing  410  the first VPS sub-test, the first valve actuator  30   a  may open  412  the first valve port  20   a  (if not already opened) and the second valve actuator  30   b  may then close  414  the second valve port  20   b  (if not already closed) to pressurize the intermediate volume  19  between the first valve port  20   a  and the second valve port  20   b . The first valve actuator  30   b  may then close  416  the first valve port  20   a  to seal the pressurized intermediate volume  19 . In some cases, a predetermined duration associated with the first predetermined sequence may be identified  418 . 
     The valve controller  26  may cause, perform and/or identify this first predetermined sequence as a first sub-test  410  of a VPS test with the identified first predetermined duration. While performing the first VPS sub-test, a first measure of an initial pressure in the intermediate volume  19  may be identified  420  and a first VPS sub-test threshold value may be determined  422  (e.g., according to one of the threshold value determining techniques described herein or in another manner). Illustratively, the threshold value may be determined  422  based at least partially on one or more of the first measure of the gas pressure and the identified first test duration. In one or more other instances, the first VPS sub-test threshold value may be determined based on one or more other measures. 
     A measure related to the pressure (e.g., the pressure or a measure derived therefrom) in the intermediate volume  19  of the valve assembly may be identified  424  at some time after the initial pressure is identified and the valve controller  26  may be configured to compare  426  the measure that is related to the pressure in the intermediate volume  19  (e.g., a pressure, a pressure change rate, or other measure) to the determined first VPS sub-test threshold value prior to, during, and/or after the first sub-set VPS duration. After or while comparing the measure related to the pressure in the intermediate volume  19  to the first sub-test threshold value, the valve controller  26  may output  428  a first alert signal if the measure meets and/or exceeds (e.g., crosses, etc.) the first sub-test threshold value. The valve controller  26  may be configured to output the signal over the communication bus  100  or using a simple pair of contacts (e.g., relay contacts that close when a measured pressure surpasses a threshold pressure value) at or in communication with the appliance controller  60 , one or more of a local display, a remote device  50 ,  60  and/or a remote display  52 ,  62  of the remote device(s)  50 ,  60 . 
     The first sub-test of the VPS test may be configured to at least detect a leaking second valve port  20   b . The outputted first alert signal may indicate, or may cause to be indicated, a valve leakage within the valve assembly  10  (e.g., including an indication of which valve port  20  is leaking) and/or a measure of the magnitude of the valve leakage. If a leak is detected or a first alert signal sent, the valve controller  26 , the combustion appliance controller  60 , or other controller may disable operation of the valve assembly  10  in response to the alert signal, where disabling operation of the valve assembly  10  may include closing both the first valve port  20   a  and the second valve port  20   b.    
     In addition to identifying the first sub-test of a VPS test, the valve controller  26  may cause, perform, or identify the following second predetermined sequence (e.g., the second VPS test)  440 , as shown in the method  400  of  FIG. 22B . In performing the second predetermined sequence  440 , the second valve actuator  30   b  may open  442  the second valve port  20   b  (if not already opened) and the first valve actuator  30   a  may then close  444  the first valve port  20   a  (if not already closed) to depressurize the intermediate volume  19  between the first valve port  20   a  and the second valve port  20   b . The second valve actuator  30   a  may then close  446  the second valve port  20   b  to seal the depressurized intermediate volume  19 . In some cases, a predetermined duration associated with the second predetermined sequence may be identified  448 . 
     The valve controller  26  may cause or identify this second predetermined sequence as a second sub-test of a VPS test with a second predetermined duration that may be the same or different duration than the first predetermined duration. While performing the second VPS sub test, a second measure of an initial pressure in the intermediate volume  19  may be identified  450  and a second VPS sub-test threshold value may be determined  452  (e.g., according to one of the threshold value determining techniques described herein or in another manner). Illustratively, the second VPS sub-test threshold value may be determined based at least partially on one or more of the second measure of the gas pressure and the identified second test duration. In one or more other instances, the second VPS sub-test threshold value may be determined based on one or more other measures. 
     A measure related to the pressure in the intermediate volume  19  may be identified  454  or determined by the valve controller  26  at some time after identifying the initial pressure and the valve controller  26  may be configured to compare  456  the identified measure that is related to the pressure in intermediate volume  19  to the determined second VPS sub-test threshold value (e.g., where the second VPS sub-test threshold value is the same as or different than the first sub-test threshold value) prior to, during, or after a second predetermined duration. As contemplated, the first VPS sub-test and the second VPS sub-test of the VPS test may be performed in any order, as desired. 
     After or while comparing the identified measure related to the pressure in the intermediate volume  19  to the second sub-test threshold value, the valve controller  26  may output  458  a second alert signal if the measure meets and/or exceeds (e.g., crosses, etc.) the second sub-test threshold value. The valve controller  26  may be configured to output the second alert signal to one or more of a local display, a remote device  50 ,  60  and/or a remote display  52 ,  62  of the remote device(s)  50 ,  60 . 
     The second sub-test of the VPS test may be configured to at least detect a leaking first valve port  20   a . Illustratively, the outputted second alert signal may indicate, or may cause to be indicated, a valve leakage within the valve assembly  10  (e.g., which valve port  20  is leaking) and/or a measure of the magnitude of the valve leakage. If a leak is detected or a second alert signal sent, the valve controller  26 , the combustion appliance controller  60 , or other controller may disable operation of the valve assembly  10  in response to the alert signal, where disabling operation of the valve assembly  10  may include closing both the first valve port  20   a  and the second valve port  20   b.    
     A VPS test performed on the valve assembly  10  that may be similar to the VPS tests described above may include opening one of the first and second valve port  20   a ,  20   b  with the other of the first and second valve ports  20   a ,  20   b  remaining or being closed. After opening one of the first and second valve ports  20   a ,  20   b , closing the opened valve to close both valve ports  20   a ,  20   b  such that a first initial gas pressure may be present in intermediate volume  19 . An intermediate pressure sensor  44  may continuously or discontinuously sense a pressure in the intermediate volume  19 , including the first initial pressure therein, and send the sensed pressures to the valve controller  26 . The initial pressure in the intermediate volume  19  may be sensed at any time, for example, the initial pressure may be sensed after opening one of the valve ports  20   a ,  20   b  and before closing that opened valve port  20   a ,  20   b . The valve controller  26  may monitor (e.g., continuously or discontinuously), over time, the pressure in the intermediate volume  19  and determine or identify a first measure that is related to a pressure change rate within the intermediate volume  19  while both of the valve ports  20   a ,  20   b  are in a closed position. After determining or identifying the first measure that is related to a pressure change rate within the intermediate volume  19 , the valve controller  26  may compare the determined first measure related to a pressure change rate in the intermediate volume  19  to a first threshold value stored in the valve controller  26 . The valve controller  26  may then output to a display and/or remote device  50 ,  60  or other device an output signal that is related to the first measure related to the pressure change rate (e.g., a determined pressure change in the intermediate volume  19 , or other determined measure), where outputting the output signal may also include storing the determined first measure related to the pressure change rate in the memory  37  (e.g., non-volatile memory or other memory) on the valve controller  26 . Optionally, the valve controller  26  may output the output signal or an alert output signal if the determined or identified first measure meets and/or exceeds (e.g., crosses, etc.) the first threshold value. The output signal, however, may convey any information, as desired. For example, the output signal may convey information related to when (e.g. time stamp) the determined measure that is related to the pressure change rate meets and/or exceeds a threshold value, or other information related to or not related to the pressure in the intermediate volume  19 . In an alternative, or in addition, to providing the output signal, a visual and/or audible indicator may be provided to indicate if the valve assembly  10  passed or failed the VPS test. 
     In addition, or as an alternative, the first and/or second valve port  20   a ,  20   b  may be manipulated such that a second or different initial gas pressure may be present in the intermediate volume  19  while the first and second valve ports  20   a ,  20   b  are in the closed position. For example, the second valve port  20   b  may be closed, then the first valve port  20   a  may be opened to pressurize the intermediate volume  19  and then closed to seal in the second initial pressure. The second initial pressure may be substantially different than the first initial gas pressure, as the first initial pressure may be associated with a depressurized state of the intermediate volume  19  and the second initial pressure may be associated with a pressurized state of the intermediate volume  19 , for example. Similar to above, the intermediate pressure sensor  44  may sense pressure within the intermediate volume  19  and communicate the sensed pressure and measures related to the sensed pressures to the valve controller  26 . The valve controller  26  may monitor (e.g., continuously or discontinuously), over time, the pressure in the intermediate volume  19  and determine a second measure that is related to a pressure change rate within the intermediate volume  19  while both the valve ports  20   a ,  20   b  are in the closed position. 
     After determining the second measure that is related to a pressure change rate within the intermediate volume  19 , the valve controller  26  may compare the determined second measure related to a pressure change rate in the intermediate volume  19  to a second threshold value stored in the valve controller  26 . The valve controller  26  may then output to a display and/or remote device  50 ,  60  or other device an output signal that is related to the second measure related to a pressure change rate, where outputting the output signal may also include storing the determined second measure related to the pressure change rate in the memory  37  (e.g., non-volatile memory or other memory) on the valve controller  26 . Optionally, the valve controller  26  may output the output signal or a different output signal (e.g., an output signal including an alert) if the determined second measure meets and/or exceeds (e.g., crosses, etc.) the second threshold value. The output signal, however, may convey any information and the outputted signals may be outputted in any situation. Further, the output signal may be configured to provide, or cause to be provided, a visual and/or audible indicator to indicate if the valve assembly  10  passed and/or failed the VPS test. 
     The steps of the illustrative VPS test may be performed once such as when the gas valve assembly  10  is installed or during routine maintenance, and/or the steps may be repeated during each combustion cycle, or during one or more combustion cycles, of a combustion appliance. In any case, the valve controller  26  or other device, or even a user, may identify a trend in the stored determined measures related to the pressure change rate in the intermediate volume  19  or in other data sensed, calculated, and/or stored during the valve leakage tests. A determined trend may be used for any of many purposes, for example, a trend may be used to predict when the valve will require replacement and/or servicing, and/or to make other predictions. Further, a VPS test and/or leakage test may be initiated and/or operated dependent on or independent of an attached device (e.g., a combustion appliance controller  60 ). In such an instance, the valve controller  26  may be configured to initiate and operate a VPS test and/or leakage test independent of an attached device and may be configured to disable a heat call or other signal to and/or from an attached device, when appropriate. 
     Those skilled in the art will recognize that the present disclosure may be manifested in a variety of forms other than the specific embodiments described and contemplated herein. Accordingly, departure in form and detail may be made without departing from the scope and spirit of the present disclosure as described in the appended claims.