Patent Publication Number: US-8973595-B2

Title: Battery-powered control valve and operation thereof

Description:
BACKGROUND 
     Valves are often used to control the flow of fluids and/or gases. Since the valves may be located in remote and/or dangerous areas, controlling the valves is important. 
     SUMMARY 
     In some aspects, the present disclosure describes a method. The method may include receiving an instruction to actuate a valve. The method may also include receiving a first period of time. The method may also include applying energy to the valve for the first period of time. The method may also include comparing a first state of the valve with a state in the instruction. The method may also include determining a second period of time by increasing the first period of time. The method may also include applying energy to the valve for the second period of time. The method may also include determining that a second state of the valve matches the state in the instruction. 
     Receiving the instruction to actuate may include receiving an instruction to open the valve and/or receiving an instruction to close the valve. Receiving the instruction to actuate may include receiving the instruction through wireless communication. Receiving the first period of time may include retrieving a default period of time associated with actuating the valve to the state in the instruction. The default period of time may be about 10 ms or about 30 ms. The first period of may be a period of time previously used to actuate the valve to the state in the instruction. Applying the energy to the valve may include applying current to a coil of a solenoid latching valve. Applying the energy to the valve may include charging a capacitor with energy from a battery and using the capacitor to apply current to the valve. 
     Comparing the first state of the valve with the state in the instruction may include determining that the first state of the valve does not match the state in the instruction. Comparing the first state of the valve with the state in the instruction may include determining a pressure in an area adjacent to the valve, determining the first state of the valve based at least in part on the pressure, and determining that the first state of the valve does not match the state in the instruction. Determining the second period of time may include increasing the first period of time by a fixed period of time or increasing the first period of time by a percentage. Determining that the second state of the valve matches the state in the instruction may include overwriting the first period of time with the second period of time. 
     In some aspects, the present disclosure describes a method. The method may include receiving an instruction to actuate a valve. The method may also include receiving a first period of time. The method may also include applying energy to the valve for the first period of time. The method may also include determining a pressure in an area adjacent to the valve. The method may also include determining a first state of the valve based on a comparison between the pressure and a threshold. The method may also include comparing the first state of the valve with the state in the instruction. The method may also include determining a second period of time by increasing the first period of time. The method may also include applying energy to the valve for the second period of time. The method may also include determining that a second state of the valve matches the state in the instruction. 
     In some aspects, the present disclosure describes a method. The method may include receiving, by a communication device, an instruction to open a valve. The method may also include determining a first period of time. The method may also include applying energy to the valve for the first period of time. The method may also include determining that the valve is open. The method may also include receiving an instruction to close the valve. The method may also include determining a second period of time. The method may also include applying energy to the valve for the second period of time. The method may also include determining that the valve is closed. The first period of time may not be equal to the second period of time. 
     In some aspects, the present disclosure describes a system. The system may include a communication device that receives an instruction to actuate a valve from a remote unit, a processing unit, a battery, a capacitor, a pressure sensor, and a memory. The memory may store instructions that, when executed by the processing unit, cause the processing unit to: receive a first period of time; operate the battery and the capacitor to apply energy to a valve for the first period of time; determine a first state of the valve based on a comparison between a threshold and a pressure measurement from the pressure sensor disposed in a gas outlet adjacent to the valve; determine the first state of the valve does not match a state in the instruction; determine a second period of time by increasing the first period of time; operate the battery and the capacitor to apply energy to the valve for the second period of time; and determine a second state of the valve matches the state in the instruction. 
     In some aspects, the present disclosure describes a method. The method may include receiving, by a wireless communication device, an instruction to actuate a valve. The method may also include receiving a period of time. The method may also include applying energy from a battery to the valve for the period of time. Receiving the instruction may include receiving the instruction via radio frequency communication. Applying the energy from the battery may include charging a capacitor with energy from the battery; and using the capacitor to apply current to a coil of a solenoid latching valve. Applying the energy from the battery may include operating a DC/DC converter to convert a voltage on the capacitor to a voltage for operating the solenoid latching valve. 
     In some aspects, the present disclosure describes a system. The system may include a wireless communication device that receives an instruction to actuate a valve from a remote unit, a processing unit, a battery, a capacitor, and a memory. The memory may store instructions that, when executed by the processing unit, cause the processing unit to: receive a period of time; and operate the battery and the capacitor to apply energy to a valve for the period of time. 
     In some aspects, the present disclosure describes a method. The method may include receiving an instruction to actuate a valve. The method may also include receiving a first period of time. The method may also include applying energy to the valve for the first period of time. The method may also include determining a first state of the valve matches the state in the instruction. The method may also include increasing a number of actuations of the valve. The method may also include comparing the number of actuations of the valve and a threshold. The method may also include overwriting the first period of time with a second period of time when the number of actuations of the valve equals the threshold. 
     Overwriting the first period of time may include determining the second period of time based on a default period of time, determining the second period of time by decreasing the first period of time, determining the second period of time by decreasing the first period of time by a fixed period, or determining the second period of time by decreasing the first period of time by a percentage. The method may also include resetting the number of actuations of the valve when the number of actuations equals the threshold. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The foregoing and other objects, aspects, features, and advantages of the disclosure will become more apparent and better understood by referring to the following description taken in conjunction with the accompanying drawings, in which: 
         FIG. 1  is a block diagram of an exemplary system for operating a battery-powered control valve; 
         FIG. 2  is a block diagram of an exemplary computing device that may be used in the system of  FIG. 1 ; and 
         FIGS. 3-7  are flow diagrams of exemplary methods for operating a battery-powered control valve. 
     
    
    
     The features and advantages of the present disclosure will become more apparent from the detailed description set forth below when taken in conjunction with the drawings, in which like reference characters identify corresponding elements throughout. In the drawings, like reference numbers generally indicate identical, functionally similar, and/or structurally similar elements. 
     DETAILED DESCRIPTION 
     Valves may be used for the control of flow of fluids and/or gases (also referred herein as “flow valves”). Flow valves may use springs to maintain a default position. The default position may be open or closed. A flow valve with a default open position by a spring may be called a normally opened flow valve. A flow valve with a default closed position by a spring may be called a normally closed flow valve. In some implementations, gas pressure may be used to operate a pneumatic actuator which may provide a force for affecting the position of the flow valve. For example, by applying pressure to a pneumatic actuator, the actuator may move a flow valve against the force of the spring into a new position. If the pressure is removed, the spring of the flow valve may return the flow valve to the default position. 
     The flow valve may be opened or closed according to a pressure of gas applied to the actuator. A control valve may be operated (e.g., opened and/or closed) to connect or disconnect the actuator from the pressure of a flow of gas. The amount of energy required to operate the control valve may vary according to environment conditions, such as temperature and/or humidity. The amount of energy required may vary according to other factors, such as the design of the control valve, the extent of the control valve&#39;s corrosion, and/or the pressure of gas from the gas source. 
     Applying amounts of energy that operate the control valve under extreme conditions may ensure consistent successful operation, but such expenditures may be wasteful. Further, should the control valve use such high levels of energy, the control valve may require a wired connection to a large power supply. Since applications may be located in remote and/or dangerous locations, the susceptibility of the wired connections to environmental conditions may impact the system&#39;s reliability. 
     Referring now to  FIG. 1 , a system  100  for operating a battery-powered control valve is shown and described. In general overview, a gas source  105  may connect to a gas inlet  110 . A pressure regulator  115  may regulate the pressure of gas flowing from the gas source  105 , through the gas inlet  110 , to a control valve  120 . The control valve  120  may be a three-way valve with connections to a gas vent  125  and a gas outlet  130 . When the control valve  120  is closed, the control valve  120  may connect the gas inlet  110  to the gas vent  125 . When the control valve  120  is open, the control valve  120  may connect the gas inlet  110  to the gas outlet  130 , which may direct the flow of gas to the flow valve  135 . 
     The control valve  120  may be connected to a control unit  140 , which may include a battery  142 , a capacitor  144 , a pump  146 , a DC/DC converter  147 , a processing unit  148 , and a communication device  150 . The communication device  150  may receive an instruction from one or more remote devices to actuate the control valve  120  (e.g., open or close the valve). The instruction may include the desired state of the control valve  120 . 
     The processing unit  148  may determine a period of time for powering the control valve  120  to actuate the control valve  120  to the desired state. The processing unit  148  may operate the battery  142  and/or pump  146  to charge the capacitor  144 . In some implementations, the processing unit  148 , battery  142 , and/or pump  146  may maintain the capacitor  144  in a fully charged state. The processing unit  148  may operate the DC/DC converter  147  to power the control valve  120  for the period of time, using energy stored on the capacitor  144 . 
     A pressure sensor  155  may be disposed in a gas outlet  160  adjacent to the control valve  120 . The pressure sensor  155  may measure the flow of gas in the outlet  160 . The processing unit  148  may use data from the pressure sensor  155  to determine the state of the control valve  120 . For example, if the data indicates the pressure in the gas outlet  160  exceeds a threshold, the control valve  120  is open (e.g., gas is flowing from the gas inlet  110  to the gas outlet  160 ). If the data falls below the threshold, the control valve  120  is closed (e.g., no gas is flowing into the gas outlet  160 , and the gas outlet  160  may be connected to a region at atmospheric pressure). 
     If the control valve  120  is not in the desired state included in the instruction, the processing unit  148  may increase the period of time for powering the control valve  120 . The powering unit  148  may operate the DC/DC converter  147  to power the control valve  120  for the increased period of time. The processing unit  148  may determine the state of the control valve  120  based on updated data from the pressure sensor  155 . The powering unit  148  may continue increasing the period of time for powering the control valve  120  until the control valve is actuated to the desired state included in the instruction. 
     In further detail, in operation, when the system  100  is installed and/or reset (e.g., recovering from system failure), the processing unit  148  may initialize the period of time for powering the control valve  120  to open the control valve  120  (also referred to herein as “open period of time”). The processing unit  148  may initialize the period of time for powering the control valve  120  to close the control valve  120  (also referred to herein as “close period of time”). In some implementations, the processing unit  148  may initialize the open and close periods of time to default values. In some implementations, the default value for the open period of time may be different from the default value for the close period of time. The processing unit  148  may receive the default values from a remote unit operated by a user to control the system  100  remotely. The processing unit  148  may retrieve the default values from memory (e.g., a buffer in the control unit  140 , a cache for the processing unit  148 ). 
     The communication device  150  may receive an instruction from a remote unit (not shown), which may be operated by a user to control the system  100  remotely. In some implementations, the communication device  150  may receive the instruction using wireless communication. For example, the device  150  may receive the instruction via radio frequency communication. The communication device  150  may send the instruction to the processing unit  148 . 
     The processing unit  148  may determine a desired state of the control valve  120  based on the instruction. For example, the processing unit  148  may analyze the instruction at a bit reserved for the desired state of the control valve  120 . A bit set to one (1) may correspond to an instruction to open the control valve  120  and the bit set to zero (0) may correspond to an instruction to close the control valve  120 , or vice versa. In some implementations, the processing unit  148  may determine the instruction is an instruction to open the control valve  120 . In some implementations, the processing unit  148  may determine the instruction is an instruction to open the control valve  120 . Although operations and/or implementations may be described herein in the context of instructions to open the control valve  120 , any of the steps described herein in any combination may be applied for instructions to close the control valve  120 . 
     The processing unit  148  may determine the open period of time. The processing unit  148  may retrieve the open period of time from memory. The processing unit  148  may determine an amount of energy needed to power the control valve  120  for the open period of time. The processing unit  148  may determine the amount of energy based at least in part on the open period of time and/or at least one parameter of the capacitor  144 . For example, the processing unit  148  may determine the amount of energy based on the capacitance of the capacitor  144 , the voltage at which the capacitor  144  operates, any other parameter of the capacitor  144 , or any combination thereof. 
     The processing unit  148  may operate the battery  142  and/or pump  146  to charge the capacitor  144 . In some implementations, the processing unit  148  may operate the battery  142  and/or pump to maintain the capacitor  144  in a fully charged state. In some implementations, the pump  146  may charge the capacitor  144  to a higher voltage than the battery  142  (e.g., 5.3V). The DC/DC converter  147  may convert the voltage on the capacitor  144  to the voltage for operating the control valve  120  (e.g., 12 V). 
     In some implementations, the processing unit  148  may operate the DC/DC converter  147  to power the control valve  120 . The DC/DC converter  147  may apply stored energy on the capacitor  144  to the control valve  120 . In some implementations, the control valve  120  may be a latching solenoid valve. The DC/DC converter  147  may apply a current to a coil of the solenoid. The DC/DC converter  147  may apply the current for the open period of time. In response to the current, a magnet of the solenoid valve may latch and hold the valve in a state (e.g., open). 
     If the current causes the control valve  120  to open, gas may flow from the gas inlet  110  through the control valve  120  into the gas outlet  160 . As the gas enters the outlet  160 , the pressure in the gas outlet  160  may increase quickly and/or fluctuate before stabilizing. In some implementations, the processing unit  148  may allow a period of time to elapse, as the pressure stabilizes (also referred to herein as a “stabilization period”). Exemplary stabilization periods may include 15 seconds, 20 seconds, and 240 seconds, although other values may be used. 
     The pressure sensor  170  may determine the pressure in the gas outlet  160 . The pressure sensor  170  may send the pressure to the processing unit  148 . The processing unit  148  may compare the pressure in the gas outlet  150  to a pressure threshold. If the pressure in the gas outlet  150  falls below the pressure threshold, the processing unit  148  may determine that the control valve  120  is closed. If the pressure in the gas outlet  150  equals or exceeds the pressure threshold, the processing unit  148  may determine that the control valve  120  is open. 
     If the processing unit  148  determines the control valve  120  is closed, the processing unit  148  may increase the open period of time. The processing unit  148  may increase the open period of time by a period of time, a percentage, or any other metric for increasing the period (also referred to herein as “open increment”). For example, the processing unit  148  may increase the open period of time by 30 ms, although other values may be used. In another example, the processing unit  148  may increase the open period of time by the length of the default open period of time. In some implementations, the processing unit  148  may determine that the increased open period of time exceeds a maximum period of time for applying power to the control valve  120 . The processing unit  148  may maintain the open period of time at the maximum period of time. In some implementations, the processing unit  148  may overwrite the stored, prior open period of time with the increased and/or maximum open period of time. 
     The processing unit  148  may operate the battery  142  and/or pump  146  to charge the capacitor  144  to a fully charged state. The processing unit  148  may operate the DC/DC converter  147  to power the control valve  120  for the increased period of time. After the DC/DC converter  147  and capacitor  144  power the control valve  120 , the processing unit  148  may determine the state of the control valve  120 . If the control valve  120  is still closed, the processing unit  148  may continue increasing the period of time for powering the control valve  120  until the control valve  120  opens. 
     In some implementations, the processing unit  148  may store the number of unsuccessful attempts to open the control valve  120 . After each unsuccessful attempt, the processing unit  148  may increment the number of unsuccessful attempts. The processing unit  148  may reset the number of unsuccessful attempts to open the control valve  120  to zero (0) when the control valve  120  opens. When the control valve  120  does not open, the processing unit  148  may compare the number of unsuccessful attempts with a threshold (also referred to herein as “attempt threshold”). If the number of unsuccessful attempts equals the threshold, the processing unit  148  may allow a period of time to elapse before powering the control valve  120  (also referred to herein as a “wait period”). Thus, the system  100  may contemplate waiting for temporary conditions, such as unfavorable temperatures or heavy winds, to subside before further expending the battery&#39;s  142  energy to power the control valve  120 . In some implementations, after the wait period elapses, the processing unit  148  may reset the number of unsuccessful attempts to zero (0). 
     Any values may be used for the attempt threshold and/or the wait period. In some implementations, the attempt threshold may be 15. In some implementations, the attempt threshold may be 5, 10, or 20, although other values may be used. In some implementations, the wait period may be 600 seconds. In some implementations, the wait period may be between about 0 seconds and about 60,000 seconds, although other ranges of values may be used. 
     In some implementations, the processing unit  148  may store a number of consecutive successful actuations for the currently stored open period of time. The processing unit  148  may reset a number of consecutive successful actuations to zero (0) when use of an open period of time retrieved from memory fails to open the control valve  120  (e.g., the period of time needs to be increased). In some implementations, when use of a retrieved open period of time successfully opens the control valve  120 , the processing unit  148  may increase the number of consecutive successful actuations. For example, the processing unit  148  may increment the number. 
     After a threshold number of consecutive successful actuations, the processing unit  148  may attempt to decrease the open period of time. Thus, the system  100  contemplates management of battery use. For example, under adverse conditions, the control valve  120  may open after the system  100  powers the control valve  120  for the maximum period of time. The maximum period of time may be stored, and the processing unit  148  may continue to retrieve this maximum period each time the control valve is to be opened. However, since adverse conditions may have subsided, shorter periods of time may be sufficient to open the control valve  120 . Decreasing the open period of time may avoid continuing to expend maximum energy for each actuation. 
     In some implementations, the processing unit  148  may compare the number of consecutive successful actuations with a threshold (also referred to herein as “consecutive actuation threshold”). In some implementations, the threshold may be twenty-four (24) consecutive successful actuations, although other values may be used. 
     When the number of consecutive successful actuations equals the threshold, the processing unit  148  may decrease the open period of time. In some implementations, the processing unit  148  may decrease the open period of time by a fixed period (e.g., 10 ms, 30 ms). In some implementations, the processing unit  148  may decrease the open period of time by any percentage. For example, the percentage may be 10%. Thus, when the open period of time is 100 ms, the processing unit  148  may decrease the period by 10 ms. When the open period is 160 ms, the processing unit  148  may decrease the open/close period by 16 ms. The control unit  150  may power the control valve  120  for the decreased open period of time. If the decreased open period did not open the control valve  120 , the processing unit  148  would increase the period of time, according to any of the steps described herein. 
     In some implementations, the processing unit  148  may decrease the open period of time by resetting the open period of time to a default value. For example, the processing unit  148  may retrieve a default value from memory and set the open period to the default value. In some implementations, the default value for the open period of time may be 30 ms. The control unit  150  may power the control valve  120  for the default open period of time. If the default open period did not open the control valve  120 , the processing unit  148  would increase the period of time, according to any of the steps described herein. 
     In some implementations, the processing unit  148  may store a number of consecutive successful actuations that opened the valve  120  and a number of consecutive successful actuations that closed the valve  120 . Thus, the processing unit  148  may record the successes for the open period of time separately from the successes for the close period of time. In some implementations, when the number of consecutive successful actuations that opened the valve  120  equals a first threshold, the processing unit  148  may decrease the open period of time. The close period of time may remain unchanged. Likewise, when the number of consecutive successful actuations that closed the valve  120  equals a second threshold, the processing unit  148  may decrease the close period of time. The open period of time may remain unchanged. 
     In some implementations, the processing unit  148  may store a total number of consecutive successful actuations. The total number may include the number of consecutive successful actuations that opened the valve  120  and the number of consecutive successful actuations that closed the valve  120 . When the total number equals a third threshold, the processing unit  148  may decrease both the open and close periods of time, according to any of the steps described herein. 
     In some implementations, to close the control valve  120 , the control unit  150  applies a reverse current to a solenoid in the control valve  120  relative to the current applied to open the valve  120 . 
     In some implementations, in operation, the communication device  150  may receive overlapping instructions from the remote unit. The most recently received instruction may override prior instructions. For example, the communication device  150  may receive an instruction to open the control valve  120 . At any time before the control unit  140  finishes powering to open the valve  120 , the communication device  150  may receive an instruction to close the valve  120 . In some implementations, the communication device  150  may receive the later instruction while the battery  140  is charging the capacitor  144 . In some implementations, the communication device  150  may receive the later instruction while the capacitor  144  is powering the control valve  120 . 
     In some implementations, upon receipt of the instruction to close the valve  120 , the processing unit  148  may halt execution of the instruction to open the valve  120  (e.g., halt charging of the capacitor  144 , halt powering of the valve  120 ). The processing unit  148  may compare data from the pressure sensor  155  with the pressure threshold to determine the state of the control valve  120 . If the control valve  120  is still closed, the processing unit  148  may conclude processing both instructions because the control valve&#39;s  120  state matches the desired state of the most recently received instruction. The capacitor  144  may maintain any energy stored thereon, thereby preserving energy expended from the battery  142 . 
     If the control valve  120  has opened, the processing unit  148  may operate the battery  142  and/or pump  146  to charge the capacitor  144  based on the close period of time. 
     In some implementations, the processing unit  148  may determine the state of the control valve  120  upon receipt of instructions to actuate the valve  120 . The processing unit  148  may use data from the pressure sensor  155  to determine the current state of the valve  120 . If the current state matches the desired state in the instruction, the processing unit  148  may conclude processing of the instruction. In some implementations, the communication device  150  may send a message to the remote until indicating the current state of the control valve  120 . If the states do not match, the processing unit  148  may retrieve the period of time corresponding to the desired state and power the control valve  120 , according to any combination of the steps described herein. 
     In some implementations, the processing unit  148  may determine that the control valve  120  may be stuck. The control unit  150  may power the control valve  120  for the open period of time a predetermined number of times (e.g., 3 times, 5 times). In some implementations, when the control valve  120  is stuck, the processing unit  148  may increase the open period of time in a logarithmic manner. In some implementations, if the control unit  150  attempts a predetermined threshold of unsuccessful actuations to open the control valve  120 , the control unit  150  may send an error signal to the remote unit. Personnel from the remote unit may arrange for workers to fix the valve  120  in the field. 
     The system  100  may experience shocks due to environmental factors, among other conditions. Such shocks may disrupt the control valve  120  and change its state (e.g., the shock may open a previously closed valve). In some implementations, the processing unit  148  may monitor the state of the valve  120 . For example, the processing unit  148  may compare data from the pressure sensor  155  with the pressure threshold every 2 hours, although other periods of time may be used. If the valve&#39;s  120  state does not match the desired state in the most recently received instruction, the control unit  150  may power the control valve  120  back into the desired state. 
     In some implementations, the control unit  150  may store parameters for operating the control valve  120  upon start-up. The control unit  150  may retrieve these parameters when the control unit  150  is installed on another system, recovers from system failure, resumes operations after battery replacement, or in any other situation. In some implementations, the start-up state of the control valve  120  may be “open.” The processing unit  148  determines the state of the control valve using pressure from the pressure sensor  155 . If the control valve  120  is not open, the control unit  150  powers the control valve to open, according to any of the steps described herein. In some implementations, the user of the system  100  may configure the start-up parameters. 
     In some implementations, the processing unit  148  may store parameters for operating the control valve  120  under failsafe conditions. For example, the processing unit  148  may operate according to the parameters if the communication device  150  loses contact the remote unit (e.g., radio frequency communications fail). For example, the remote unit may periodically send the communication device  150  a test signal to verify communication is possible. The remote unit may send the test signal every fifteen (15) minutes, although any other periods of time may be used. If the communication device  150  has not received and/or processed a test signal within a predetermined period of time (e.g., 45 minutes), the processing unit  148  may operate the control valve  120  according to the parameters. For example, the state of the control valve  125  under failsafe conditions may be “closed.” If the control valve  120  is open, the control unit  150  may operate to close the valve  120 . 
     In some implementations, the communication device  150  may send information about the system  100  to the remote unit. The device  150  may send information on a periodic basis (e.g., every three hours). Exemplary information may include the status of the battery (e.g., low battery, remaining energy in battery), state of the control valve  120 , and/or state of the pressure sensor  155  (e.g., operational, communicating with processing unit  148 ), and/or information about any other component of the system  100 . Exemplary information may include the total number of attempts to actuate the control valve  120 , which the remote unit may use to gauge the battery life. Exemplary information may include the total number of actuations of the control valve  120 , which the remote unit may use to gauge the remaining lifespan of the control valve  120 . 
     Any period of time described herein may be configured by a user of the system  100 . In some implementations, the system  100  includes default values for the periods of time (e.g., default open and close periods, open and close decrements, maximum open and close periods, stabilization periods, wait periods). The system  100  may allow a user to change any of the values. In some implementations, some of the values may not be changed. For example, a maximum open or close period may be determined by the parameters of the capacitor  144 ; thus, a user may not increase the maximum open or close period. 
     In some implementations, the open and close periods may be expressed in milliseconds, although other units of time may be used. The default open period of time may be about 30 ms. In some implementations, a user of the system  100  may configure the default open period of time. The default open period of time may be set between about 1 ms and about 50 ms, although other ranges of values may be used. In some implementations, the user may configure the maximum open period of time. For example, the maximum open period of time may be set to 200 ms, although other values may be used. 
     In some implementations, the user may configure the open increment. In some implementations, the open increment may be set to the default open period of time, although other periods of time may be used. Thus, any open period of time used by the processing unit  148  may be a multiple of the default value. For example, if the default open period of time is set to 30 ms, possible open periods of time for applying energy to open the control valve  120  may include 60 ms, 90 ms, 120 ms, 150 ms, and/or 180 ms. 
     In some implementations, the default close period of time may be about 10 ms. In some implementations, a user of the system  100  may configure the default close period of time. The default close period of time may be set between about 1 ms and about 50 ms, although other ranges of values may be used. In some implementations, the user may configure the maximum close period of time. For example, the maximum close period of time may be set to 200 ms, although other values may be used. 
     In some implementations, the user may configure the close increment. In some implementations, the close increment may be set to the default close period of time, although other periods of time may be used. Thus, any close period of time used by the processing unit  148  may be a multiple of the default close period of time. For example, if the default open period of time is set to 10 ms, possible close periods of time for applying energy to close the control valve  120  may include 20 ms, 30 ms, 40 ms, 50 ms, and/or 60 ms. 
     In some implementations, the user may configure the wait period. The wait period may be about 600 seconds, although other values may be used. In some implementations, the user may configure the stabilization period. The user may configure the stabilization period to be between about 15 seconds and about 240 seconds, although other ranges of values may be used. In some implementations, the stabilization period may be about 20 seconds. 
     In some implementations, the pressure threshold may be expressed in pounds per square inch (e.g., psi). The pressure threshold may be 45 psi. In some implementations, the pressure threshold may be between about 0 psi and about 200 psi. The pressure threshold may be expressed in any other unit, as would be appreciated by one of ordinary skill in the art (e.g., bars, pascals, torr, atmospheres). The pressure threshold may be configured by a user of the system  100 . 
     In some implementations, the battery  142  may have a low operating current. The operating current may be too low to actuate the control valve  120 . In some implementations, the battery  142  may be used with a capacitor  144  and/or DC/DC converter  147 . By transferring energy from the battery to the capacitor  144  and using a DC/DC converter  147  to power the control valve  120  via the capacitor  144 , the system  100  may function using a battery with a low operating current. 
     In some implementations, any of the functionality described herein may be implemented in software, hardware, firmware, or any combination thereof. 
     In some implementations, an air compressor may be substituted for the gas source  105 . 
     In some implementations, the gas inlet  110  may include compression fitting-equipped tubing. The tubing may withstand gas pressure of about 125 psig. 
     In some implementations, the pressure regulator  115  may receive a flow of gas at pressures up to about 125 psig. The pressure regulator  115  may output a flow of gas at different pressures. For example, the pressure regulator  115  may output a flow of gas at 105 psig. 
     In some implementations, a gas filter (not shown) may be disposed proximate to the pressure regulator  114 . The gas filter may filter particles up to about 50 μm, although filters designed to filter particles of different sizes may also be used (e.g., 3-100 μm). 
     In some implementations, the control valve  120  may draw less than 13 W, although valves  120  that draw other levels of wattage may be used (e.g., 5 W, 20 W). 
     In some implementations, the control valve  120  may operate at 24 V, although valves that operate at other voltages may be used. The control valve  120  may be explosion-proof (e.g., XP). The control valve  120  may be a general purpose valve. In some implementations, the control valve  120  may include a two-wire or three-wire solenoid. In some implementations, the control valve  120  may be used in a Division I hazardous area. The control valve  120  may be compatible with natural gas. 
     Exemplary control valves  120  include: the Series 20 Magnetic Latching Valves, as manufactured by Peter Paul Electronics Co., Inc. of New Britain, Conn.; the 30125-2.2-2R-B5+12V-DC-16-LC Magnetic Latching Valves, as manufactured by Rotex Automation Ltd. of Gujarat, India; the LHLA series, manufactured by the Lee Company of Westbrook, Conn.; the S10MML series, manufactured by Pneumadyne, Inc. of Plymouth, Minn. and the EF HVL283693001-12vdc, manufactured by ASCO Valve, Inc. of Florham Park, N.J. 
     In some implementations, the capacitor  144  may supply 13 W at an operational voltage for at least 50 ms. Exemplary capacitors include: 1.5-2.5 F, 5V capacitors, manufactured by Nesscap Co., Ltd. of Yongin-si, Gyeonggi-do, Republic of Korea; 0.5-3.0 F, 5V capacitors, manufactured by Cooper Bussmann, of St. Louis, Mo.; HS208 capacitors manufactured by Cap-XX Ltd. of Lane Cove, Australia. 
     In some implementations, the pressure sensor  155  may compensate for temperature. The pressure sensor  155  may be a 1% accurate sensor, although sensors with other sensitivities may be used (e.g., 2%). In some implementations, the pressure sensor  155  may communicate with the processing unit  148  and/or communication device  150  via wireless communication. For example, the pressure sensor  155  may transmit data about the pressure in the gas outlet  130  via radio frequency communication. Exemplary pressure sensors may include the Model 4425 pressure sensor manufactured by Measurement Specialities, of Hampton, Va. 
     In some implementations, the communication device  150  may include a radio frequency card. In some implementations, the processing unit  148  may include a MSP430F4619 processor. In some implementations, the battery  142  may include one or more battery units. For example, the battery  142  may include a single “D” cell battery. The battery  142  may include two (2) “D” cell batteries. The battery  142  may include four (4) “D” cell batteries. In some implementations, the battery may be non-rechargeable. In some implementations, the battery  142  may be a 3.6 V battery. In some implementations, the battery  142  may supply energy to operate the control valve  120 , the pressure sensor  155 , or both. In some implementations, a battery  142  used in the system  100  may operate at least the control valve  120  for up to 10 years without replacement. In some implementations, a battery  142  used in the system  100  may operate at least the control valve  120  for more than 10 years without replacement. 
     The systems, software, and methods described herein can be implemented advantageously in one or more computer programs that are executable on a programmable system including at least one programmable processor coupled to receive data and instructions from, and to transmit data and instructions to, a data storage system, at least one input device, and at least one output device. Each computer program can be implemented in a high-level procedural or object oriented programming language, or in assembly or machine language if desired. In any case, the language can be a compiled or interpreted language. Suitable processors include, by way of example, both general and special purpose microprocessors. Generally, a processor will receive instructions and data from a read-only memory and/or a random access memory. Generally, a computer will include one or more mass storage devices for storing data files, such devices include magnetic disks, such as internal hard disks and removable disks magneto-optical disks and optical disks. Storage devices suitable for tangibly embodying computer program instructions and data include all forms of non-volatile memory, including, by way of example, semiconductor memory devices, such as EPROM, EEPROM, and flash memory devices; magnetic disks such as, internal hard disks and removable disks; magneto-optical disks; and CD ROM disks. Any of the foregoing can be supplemented by, or incorporated in, ASICs (application-specific integrated circuits). 
     An example of one such type of computer is shown in  FIG. 2 , which shows a block diagram of a programmable processing system (system)  211  suitable for implementing or performing the apparatus or methods described herein. The system  211  includes a processor  220 , a random access memory (RAM)  221 , a program memory  222  (for example, a writeable read-only memory (ROM) such as a flash ROM), a hard drive controller  223 , and an input/output (I/O) controller  224  coupled by a processor (CPU) bus  225 . The system  211  can be preprogrammed, in ROM, for example, or it can be programmed (and reprogrammed) by loading a program from another source (for example, from a floppy disk, a CD-ROM, or another computer). 
     The hard drive controller  223  is coupled to a hard disk  230  suitable for storing executable computer programs, including programs embodying the present methods, and data including storage. The I/O controller  224  is coupled by an I/O bus  226  to an I/O interface  227 . The I/O interface  227  receives and transmits data in analog or digital form over communication links such as a serial link, local area network, wireless link, and parallel link. 
     Elements of different implementations described herein may be combined to form other implementations not specifically set forth above. Other implementations not specifically described herein are also within the scope of the following claims. 
     Referring now to  FIG. 3 , a flow diagram  300  for an exemplary method for operating a battery-powered control valve is shown and described. The method may include receiving an instruction to actuate a valve (step  301 ). A control unit  140  may receive the instruction from a remote unit. A communication device  150  of the control unit  150  may receive the instruction. The communication device  150  may receive the instruction wirelessly. In some implementations, the communication device  150  may receive the instruction via radio frequency communication. The instruction to actuate the valve may be an instruction to open a control valve ( 120 ). The instruction may be an instruction to close a control valve ( 120 ). Although the steps of the method are described herein regarding an instruction to open the valve, similar steps may be performed for an instruction to close the valve, as would be appreciate by one of ordinary skill in the art. 
     The method may include receiving a first period of time (step  305 ). In some implementations, the processing unit  148  may receive the first period of time from a remote unit. In some implementations, the processing unit  148  may receive the period of time by retrieving the period from a memory. The first period of time may be a period of time for powering a control valve  120  to open the valve. In some implementations, the first period of time may be a default value (e.g., 30 ms). In some implementations, the first period of time may be a period of time used in a prior successful attempt to open the control valve  120 . 
     The method may include applying energy to the valve for the first period of time (step  310 ). In some implementations, the processing unit  148  determines an amount of energy that would be applied to the control valve  120  to open the valve. The amount of energy may be based on the first period of time, a capacitance of the capacitor  144 , the voltage at which the control valve  120  may be operated, and/or any other factor, in any combination. A battery  142  may be used to charge the capacitor  144  with at least the determined amount of energy. The capacitor  144  may be charged so that the capacitor  144  may power the control valve  120  for the first period of time. In some implementations, when the capacitor  144  reaches an operational threshold of the control valve  120 , the processing unit  148  may operate the DC/DC converter  147  to power the control valve  120  for the first period of time. 
     The method may include comparing a first state of the valve with the state in the instruction. In some implementations, the processing unit  148  may allow a predetermined period of time to elapse before determining the state of the control valve  120  (e.g., 20 seconds). A pressure sensor  155  may be disposed in a gas outlet  160  adjacent to the control valve  120 . The sensor  155  may measure pressure from gas flowing through the gas outlet  160 . 
     In some implementations, the processing unit  148  may compare the pressure with a threshold (e.g., 45 psi). When the pressure exceeds the threshold, the processing unit  148  may determine that the control valve  120  is open. When the threshold exceeds the pressure, the processing unit  148  may determine that the control valve  120  is closed. The processing unit  148  may compare the state of the control valve  120  with the desired state in the received instruction. If the states do not match, the processing unit  148  may determine that another attempt to actuate the control valve  120  may be made. 
     The method may include determining a second period of time by increasing the first period of time (step  315 ). In some implementations, the processing unit  148  may increase the first period of time by a predetermined period (e.g., 10 ms, 30 ms). The predetermined period may be equal to the default value of the open period of time. In some implementations, the processing unit  148  may increase the first period of time by a predetermined percentage (e.g., 10 ms). In some implementations, the processing unit  148  may increase the first period of time logarithmically. 
     The method may include applying energy to the valve for the second period of time (step  320 ). The energy may be applied according to any of the steps described herein, in any combination. 
     The method may include determining a second state of the valve matches the state in the instruction (step  325 ). The state of the control valve  120  after the control unit  150  has powered the valve  120  for the second period of time may be determined by any combination of steps described herein. In some implementations, the processing unit  148  may compare the state of the valve  120  with the desired state in the received instruction. When the states match, the processing unit  148  may determine that the use of the second period of time successfully actuated the control valve  120  (e.g., opened the valve  120 ). The processing unit  148  may store the second period of time. The processing unit  148  may overwrite the first period of time in memory with the second period. Thus, when the control unit  150  next receives an instruction to open the valve  120 , the processing unit  148  may retrieve the second period of time and the control unit  150  may power the control valve  120  for the second period. 
     Referring now to  FIG. 4 , another flow diagram  400  for an exemplary method for operating a battery-powered control valve is shown and described. The method may include receiving an instruction to actuate a valve (step  401 ), receiving a first period of time (step  405 ), and/or applying energy to the valve for the first period of time (step  410 ). Steps  401 ,  405 , and  410  may be performed according to steps described in reference to  FIG. 3 , or any other steps described herein. 
     The method may include determining a pressure in an area adjacent to the valve (step  415 ). A pressure sensor  155  may be disposed in a gas outlet  160  adjacent to a control valve  120 . The sensor  155  may measure the pressure of gas flowing through the valve  120  into the outlet  160 . In some implementations, after a predetermined period of time (e.g., the stabilization period described herein) has elapsed after the control unit  150  has powered the control valve  120 , the processing unit  148  may process the pressure from the sensor  155 . 
     The method may include determining a first state of the valve based on a comparison between the pressure and a threshold (step  420 ). The processing unit  148  may compare the pressure from the sensor  155  to a threshold (e.g., the pressure threshold described herein). If the pressure exceeds the threshold, the processing unit  148  may determine gas is flowing through an open control valve  120  into the gas outlet  160 . If the threshold exceeds the pressure, the processing unit  148  may determine that a closed control valve  120  substantially precludes a flow of gas into the outlet  160 . 
     The method may include comparing the first state of the valve with the state in the instruction (step  425 ), determining a second period of time by increasing the first period of time (step  430 ), applying energy to the valve for the second period of time (step  435 ), and determining a second state of the valve matches the state in the instruction (step  440 ). Steps  425 ,  430 ,  435 , and  440  may be performed according to steps described in reference to  FIG. 3 , or any other steps described herein. 
     Referring now to  FIG. 5 , another flow diagram  500  for an exemplary method for operating a battery-powered control valve is shown and described. The method may include receiving an instruction to open a valve (step  501 ). Step  501  may be performed according to steps described in reference to  FIG. 3  or  4 , or any other steps described herein. 
     The method may include determining a first period of time (step  505 ). The first period of time may be associated with opening a control valve  120  and/or an attempt to open the valve  120 . In some implementations, the first period of time may be a default value (e.g., 30 ms). In some examples, upon system  100  start-up and/or recovery, a processing unit  148  may initialize the first period of time to the default value. In some examples, after a number of consecutive successful actuations for opening the valve  120  has reached a threshold, as described herein, the processing unit  148  may initialize the first period of time to the default value. In some implementations, the first period of time may be a period previously used to open the control valve  120  successfully. In some implementations, the processing unit  148  may retrieve the first period of time from memory. 
     The method may include applying energy to the valve for the first period of time (step  510 ). Step  510  may be performed according to steps described in reference to  FIG. 3  or  4 , or any other steps described herein. 
     The method may include determining the valve is open (step  515 ). A pressure sensor  155  may be disposed in a gas outlet  160  adjacent to a control valve  120 . The sensor  155  may measure the pressure of gas flowing through the valve  120  into the outlet  160 . In some implementations, after a predetermined period of time (e.g., the stabilization period described herein) has elapsed after the control unit  150  has applying energy to the valve  120  for the first period of time, the processing unit  148  may process the pressure from the sensor  155 . The processing unit  148  may compare the pressure from the sensor  155  to a threshold (e.g., the pressure threshold described herein). When the pressure exceeds the threshold, the processing unit  148  may determine the control valve  120  is open and gas is flowing through the valve  120  into the gas outlet  160 . 
     The method may include receiving an instruction to close the valve (step  520 ). Step  520  may be performed according to steps described in reference to  FIG. 3  or  4 , or any other steps described herein. 
     The method may include determining a second period of time (step  525 ). The second period of time may be associated with closing a control valve  120  and/or an attempt to close the valve  120 . The second period of time may be different from the first period of time. The second period may be stored separately from the first period. In some implementations, the second period of time may be a default value (e.g., 10 ms). The default value for the second period may be different from the default value for the first period. 
     In some examples, upon system  100  start-up and/or recovery, a processing unit  148  may initialize the second period of time to the default value. In some examples, after a number of consecutive successful actuations for closing the valve  120  has reached a threshold, as described herein, the processing unit  148  may initialize the second period of time to the default value. In some implementations, the second period of time may be a period previously used to close the control valve  120  successfully. In some implementations, the processing unit  148  may retrieved the second period of time from memory. 
     The method may include applying energy to the valve for the second period of time (step  530 ). Step  530  may be performed according to steps described in reference to  FIG. 3  or  4 , or any other steps described herein. 
     The method may include determining the valve is closed (step  535 ). In some implementations, after a predetermined period of time (e.g., the stabilization period described herein) has elapsed after the control unit  150  has applying energy to the valve  120  for the second period of time, the processing unit  148  may process the pressure from the sensor  155 . The processing unit  148  may compare the pressure from the sensor  155  to a threshold (e.g., the pressure threshold described herein). When the threshold exceeds the pressure, the processing unit  148  may determine the control valve  120  is closed and no gas is flowing into the gas outlet  160 . 
     Referring now to  FIG. 6 , another flow diagram  600  for an exemplary method for operating a battery-powered control valve is shown and described. The method may include receiving an instruction to actuate a valve (step  601 ). A control unit  140  may receive the instruction from a remote unit. A communication device  150  of the control unit  140  may receive the instruction. The communication device  150  may be a wireless communication device  150 . For example, the device  150  may receive and/or transmit radio frequency signals. In some implementations, the instruction may include a desired state of a control valve  120 . For example, the instruction may be an instruction to open the control valve  120  or an instruction to close the control valve  120 . 
     The method may include receiving a period of time (step  605 ). The period of time may be associated with the desired state of the control valve  120  included in the instruction. For example, if the communication device  150  received an instruction to open the valve  120 , the period of time may be a period for powering the control valve  120  to attempt to open the valve  120 . In some implementations, the period of time may be a default valve, as described herein. In some implementations, the period of time may be a period previously used in a successful attempt to open the control valve  120 , as described herein. In some implementations, the processing unit  148  may retrieve the period of time from memory. 
     The method may include applying energy from a battery to the valve for the period of time (step  610 ). Step  610  may be performed according to steps described in reference to  FIGS. 3-5 , or any other steps described herein. 
     Referring now to  FIG. 7 , another flow diagram  700  for an exemplary method for operating a battery-powered control valve is shown and described. The method may include receiving an instruction to actuate a valve (step  701 ), receiving a first period of time (step  705 ), applying energy to the valve for the first period of time (step  710 ), and determining a first state of the valve matches the state in the instruction (step  715 ). Steps  701 ,  705 ,  710 , and  715  may be performed according to steps described in reference to  FIGS. 3-6 , or any other steps described herein. 
     The method may include increasing a number of actuations of the valve (step  720 ). The number of actuations of the valve may be a number of successful consecutive actuations to open the control valve  120 . The number may be a number of successful consecutive actuations to close the control valve  120 . In some implementations, the number may be a total number of successful actuations. A processing unit  148  may increase the number of actuations each time an attempt to actuate the control valve  120  succeeds. 
     The method may include comparing the number of actuations of the valve and a threshold (step  725 ) and overwriting the first period of time with a second period of time when the number of actuations of the valve equals the threshold (step  730 ). The threshold may be twenty-four (24) actuations, although any value may be used. The second period of time may be a default value (e.g., 30 ms for the open period, 10 ms for the close period). In some implementations, the processing unit  148  may determine the second period by decreasing the first period. The processing unit  148  may decrease the first period by a predetermined period (e.g., 10 ms, 30 ms). In some implementations, the processing unit  148  may decrease the first period by a predetermined percentage (e.g., 5%, 10%). The processing unit  148  may overwrite the first period in memory. 
     While various embodiments of the methods and systems have been described, these embodiments are exemplary and in no way limit the scope of the described methods or systems. Those having skill in the relevant art may effect changes to form and details of the described methods and systems without departing from the broadest scope of the described methods and systems. Thus, the scope of the methods and systems described herein should not be limited by any of the exemplary implementations and should be defined in accordance with the accompanying claims and their equivalents.