WO2024000009A1

WO2024000009A1 - Valve control device for testing aircraft refuelling hydrant dispensers

Info

Publication number: WO2024000009A1
Application number: PCT/AU2023/050135
Authority: WO
Inventors: Rick Andrew WILLIAMS; Henry Otto
Original assignee: Sunshine Refuellers Pty Ltd
Priority date: 2022-06-30
Filing date: 2023-02-28
Publication date: 2024-01-04

Abstract

Some embodiments relate to a control device for a pilot valve of a pit valve. The device includes: a housing; an air inlet coupling, configured to receive pressurized air from a pressurized air supply; an outlet coupling, configured to supply the pressurized air to the pilot valve; and control circuitry. The control circuitry is inside the housing and is configured to: maintain the supply of pressurized air to the pilot valve for a predetermined minimum time delay in response to a cut-off of the pressurized air supply to the inlet coupling; and equalize pressure between the inlet coupling and the outlet coupling after the predetermined minimum time delay.

Description

"Valve control device for testing aircraft refuelling hydrant dispensers”

Technical Field

[0001] The technical field relates generally to a valve control device for allowing testing of aircraft refuelling hydrant dispensers. Specific embodiments relate to control devices for pilot valves on hydrant pit valve devices.

Background

[0002] In typical hydrant refuelling operations, jet fuel is provided via a pit valve coupled to a pressurised underground hydrant system, through a dispenser valve and onto the aircraft. Furthermore, the fuel hydrants are subject to high pressure and flow rates. Accordingly, damage to a pit valve or hydrant valve, or malfunction of the hydrant dispenser can have severe consequences for the operation of an airport, including dangerous fuel spillages which impact ground operations and airplane departures. It is therefore beneficial to carefully and efficiently manage and test the operation of hydrants and aircraft fuelling operations. This may be typically achieved with an arrangement of air lanyard connections, and/or activation switches (commonly called deadman switches). The latter of these requires an operator to actively maintain (e.g. by manually squeezing) the operation of the activation switch. Upon release of the activation switch, a pilot valve on the hydrant pit valve will cause the pit valve to close. This may be done as part of normal operations or in the event of an emergency.

[0003] Industry regulations and best practice may require use of certain safety arrangements installed on the hydrant pit valve, to ensure that an activation switch is capable of effectively opening and closing the dispenser valve and the hydrant pit valve simultaneously. However, in doing so, both valves require operation testing to ensure they operate correctly. Valves, when connected to form a series, and when opened or closed simultaneously, make it difficult for personnel to assess which valve drives observed results of performance testing. [0004] It would be beneficial to provide a system or technique to address or ameliorate one or more of the problems or disadvantages associated with existing solutions for testing functional operation of the hydrant system, or to at least provide a useful alternative to such existing solutions.

[0005] Throughout this specification the word "comprise", or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.

[0006] Any discussion of documents, acts, materials, devices, articles or the like which has been included in the present specification is not to be taken as an admission that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the present disclosure as it existed before the priority date of each of the appended claims.

Summary

[0007] Some embodiments relate to a control device for a pilot valve of a pit valve, the device including: a housing; an air inlet coupling, configured to receive pressurized air from a pressurized air supply; an outlet coupling, configured to supply the pressurized air to the pilot valve; control circuitry, inside the housing, configured to: maintain the supply of pressurized air to the pilot valve for a predetermined minimum time delay in response to a cut-off of the pressurized air supply to the inlet coupling; and to equalize pressure between the inlet coupling and the outlet coupling after the predetermined minimum time delay.

[0008] The control circuitry may be configured to provide an output signal to control the pilot valve. The control circuitry may further comprise an emergency stop, configured to reduce air pressure at the outlet coupling to ambient pressure, in response to receiving an activation signal. [0009] The control device may further comprise an air reservoir configured to store a volume of pressurized air from the pressurized air supply; wherein the stored pressurized air is supplied to the outlet coupling. The control device may further comprise a one-way valve in connection with the air inlet coupling, configured to allow air to be charged and retained within the reservoir. The reservoir may be formed as a hollow tube. The reservoir may form a handle on the housing. The control circuitry may be configured to vent air stored in the reservoir responsive to a control signal. The control circuitry may further comprise an outlet valve configured to supply the vented air to the outlet coupling, responsive to a control signal.

[0010] The control circuitry may include a timer that is configurable to allow adjustment of the length of the predetermined minimum time delay to a selected time between 2 to 30 seconds.

[0011] The control device may further comprise a visible status indicator on the housing to display an indication of air supply status. The air supply status may comprise one or more of: air pressure within the control circuitry; supply of pressurized air to the control circuitry from the air inlet coupling; supply of pressurized air from the control circuitry to the outlet coupling; or length of predetermined time delay.

[0012] The control circuitry may be pneumatic control circuitry.

[0013] Some embodiments relate to a system for controlling air supply to a pilot valve of a pit valve, the system including: the device of the above described embodiments; an activation switch, configured to send an activation signal to a pressurized air supply; the pressurized air supply, configured to supply pressurized air to the device upon receipt of the activation signal; and the pilot valve of a pit valve, configured to activate in response to pressurized air received from the device.

[0014] Some embodiments relate to a system for controlling air supply to a pilot valve of a pit valve, the system including: an activation switch, configured to send an activation signal to a pressurized air supply; the pressurized air supply, configured to supply pressurized air to control circuitry upon receipt of the activation signal; the control circuitry, configured to: supply air from the air supply to the pilot valve,: maintain the supply of pressurized air to the pilot valve for a predetermined minimum time delay in response to a cut-off of the pressurized air supply; and to reduce the pressure of the air supply to the pilot valve after the predetermined minimum time delay and, the pilot valve, configured to activate in response to pressurized air received from the control circuitry.

[0015] Some embodiments relate to a method of controlling air supply to a pilot valve of a pit valve, the method comprising: supplying, by a pressurized air supply, pressurized air to the pilot valve of a pit valve; maintaining, by control circuitry, the supply of pressurized air to the pilot valve for a predetermined minimum time period in response to a cut-off of the pressurized air supply; and stopping, by the control circuitry, the supply of pressurized air to the pilot valve after the predetermined minimum time period.

[0016] The control circuitry may comprise: an inlet valve, connected to an air inlet coupling, and configured to enable air flow within the control circuitry from the supply of pressurized air; an air reservoir, connected to the valve and configured to receive and store air responsive to a control signal; an outlet valve, connected to the air reservoir, and configured to vent air stored in the reservoir to an air outlet coupling responsive to the control signal, to maintain the supply of pressurized air to the pilot valve; and a timer valve, configured to equalize pressure between the inlet coupling and the outlet coupling after the predetermined minimum time delay

[0017] The control circuitry may be pneumatic control circuitry.

[0018] The length of the predetermined minimum time delay may be between 2 to 30 seconds.

[0019] The method may further comprise: displaying, by the control circuitry, an indication of air supply status. The air supply status may comprise one or more of: air pressure within the control circuitry; supply of pressurized air to the pilot valve; length of predetermined time delay. The method may further comprise charging the air reservoir with pressurized air; and releasing, at the outlet valve, the pressurized air stored in the reservoir to the pilot valve.

[0020] Some embodiments relate to a control device for a pilot valve of a pit valve, the device including: a housing; an air inlet coupling, configured to receive a pressurized air supply; an outlet coupling, configured to supply the pressurized air to the pilot valve; control circuitry, inside the housing, configured to: maintain the supply of pressurized air to the pilot valve in response to a cut-off of the pressurized air supply to the inlet coupling; and equalize pressure between the inlet coupling and the outlet coupling responsive to an actuation input to the control circuitry. The actuation input may be manually input to the control circuitry.

Brief Description of Drawings

[0021] Figure 1 is a block diagram of an aircraft refuelling system, according to some embodiments;

[0022] Figure 2 is an interior perspective view of a control device for a pilot valve of a pit valve, according to some embodiments;

[0023] Figure 3 is an exterior perspective view of a control device for a pilot valve of a pit valve, according to some embodiments;

[0024] Figure 4 is an interior view of a control device for a pilot valve of a pit valve, according to some embodiments;

[0025] Figure 5 is a diagram view of the components of a control device for a pilot valve of a pit valve, according to some embodiments; [0026] Figure 6 is a diagram view of a control device for a pilot valve of a pit valve, during a dead-man closing test while the dead-man is open, according to some embodiments;

[0027] Figure 7 is a diagram view of a control device for a pilot valve of a pit valve, during a dead-man closing test when the dead-man is released, according to some embodiments;

[0028] Figure 8 is a diagram view of a control device for a pilot valve of a pit valve, during a dead-man closing test when the dead-man is released, and after a predetermined time delay has expired, according to some embodiments;

[0029] Figure 9 is a diagram view of a control device for a pilot valve of a pit valve, during an emergency stop operation, according to some embodiments;

[0030] Figure 10 is a flow chart of a method of operation of a control device for a pilot valve of a pit valve, according to some embodiments; and

[0031] Figure 11 is a flow chart of a method of operation of a control device for a pilot valve of a pit valve, according to some embodiments

Description of Embodiments

[0032] Aircraft refuelling systems rely on effective operation of multiple sets of valves, which operate under high pressure and flow rates. The jet fuel ait airports is stored in underground hydrant systems, which are dispensed through pit valves. Hydrant dispensers may be used to engage the hydrant pit valves, using a connected hydrant coupler valve. The hydrant dispenser allows physical connection to be made to the aircraft while providing filtration, metering, pressure control, and the ability to sample fuel delivered. Figure 1 is a block diagram of an aircraft refuelling system 100, according to some embodiments. In Figure 1, hydrant dispenser 115 is configured to connect to an aircraft by aircraft connection 105 to supply fuel from an engaged pit valve 130 from fuel line 126, by the operation of hydrant coupler valve 125. The operation of activation switch 110 can allow an operator to manually open and close the operation of the hydrant coupler valve 125 and pit valve 130 through the control supplied by air lines 121 and 122.

[0033] Activation switch 110 provides the system 100 with additional safety, requiring an operator to manually maintain an open connection, whereby release of the activation switch 110 causes both the hydrant coupler valve 125 and the pit valve 130 to close by the cessation of pressurized air through air lines 121 and 122. The activation switch 110 may be commonly known as a ‘deadman’ switch. When the activation switch 110 is held open, air lines 121 and 122 are configured to provide their respectively connected valves with a supply of pressurized air from the hydrant dispenser 115, thereby opening the valves.

[0034] For the purpose of valve performance testing, control device 120 is connected to air line 121 to control operation of a pilot valve 131 of the pit valve 130. As the valves 125 and 130 are connected in series during a refuelling operation, and are both simultaneously controlled by the activation switch 110, there is no reliable way to conduct testing on the opening and closing of the valves to observe faults in individual valves and associated systems, having the dual air lanyard connection depicted in Figure 1 by air lines 121 and 122, when connected in this arrangement. Accordingly, the control device 120 allows personnel to specify a delay period or minimum time delay to allow for a delayed closing of the put valve 130. The predetermined minimum time delay, or delay period, may be between 2-30 seconds, for example. An example default time delay period may be about 3 or about 5 seconds. In some embodiments, the time delay may not be configurable, and may be fixed at a predetermined time delay value, such as about 3 or about 5 seconds, for example. The time delay enables both an activation closing and opening test to be conducted on the hydrant coupler valve 125 and associated systems without disengagement of the dual air lanyard connection of air lines 121 and 122. [0035] In conventional hydrant dispenser operations, without the dual air lanyard supplied by air lines 121 and 122, the operator makes all necessary connections including connecting a lanyard cable to the pilot valve 131. Pulling the lanyard cable 132 allows the pit valve 130 to be closed both in an emergency and as part of normal operations.

[0036] To initiate fuel flow, the operator must manually open the pilot valve 131, which subsequently opens the pit valve 130. The operator must then activate the activation switch 110 which supplies air to the dispenser control valve, causing the pilot valve 131 to open.

[0037] However, when using the dual air lanyard and control device 120, the operator makes all necessary connections, including connecting a lanyard cable 132 to the pilot valve 131 and an air connection to the pilot valve 131. Pulling the lanyard cable allows the pit valve 130 to be closed both in an emergency and as part of normal operations. To initiate fuel flow, the operator activates the activation switch 110, which supplies air to dispenser control valve and the hydrant pit valve pilot 131. This causes the dispenser control valve and hydrant pit valve to open simultaneously.

[0038] Control device 120 may form an integrated part of another system for managing refuelling operations, such as a service vehicle, for example. In other embodiments, the control device 120 may be manually connectable to and removable from a separate system for managing refuelling operations, such as a service vehicle, for example.

[0039] Figure 2 is an interior perspective view of a control device 120 for a pilot valve 131 of a pit valve 130, according to some embodiments. In the depicted embodiment, the internal components of the control device 120 are arranged within housing 220. Housing 220 may comprise a rigid structure suitable to be used in and around heavy machinery and to protect the control circuitry 230 of the control device 120, and may accordingly be constructed from steel, or other metals to ensure minimal damage in use. The housing 220 may comprise a separable housing front 221 and housing back 222, which when joined, define an interior for the mounting of control circuitry 230. The housing front 221 and housing back 222 are removably affixed to each other by fixing means, such as screws, bolts, or other separable connections. The components of control circuitry 230 may be mounted on one or more of the housing front 221 or housing back 222. Air inlet coupling 210 and outlet coupling 205 may be mounted in the housing 220 to allow connection to air line 121 and pilot valve 131.

[0040] Figure 3 is an exterior perspective view of a control device for a pilot valve of a pit valve, according to some embodiments, and depicting an example of housing front 221 having control circuitry 230 components, the housing front defining a user interface 305. User interface 305 may comprise pressure gauge G9, emergency stop valve V8, test operation valve V7, test display gauge G6, delay control valve V10. User interface 305 may also display instructions to a user for operation of the control device 120.

[0041] Pressure gauge G9 may display the air pressure being supplied to the pilot valve 131 of pit valve 130, when the control device 120 is connected as part of the air line 121.

[0042] Emergency stop valve V8 may comprise a button in connection with a valve element, and be configured to immediately cease operation of the control device 120 and stop the delay of cessation of air supply to the pilot valve 131.

[0043] Test operation valve V7 may comprise a button in connection with a valve element, and be configured to initiate an activation opening and/or closing test when pressed by a user.

[0044] Delay control valve V10 may be a dial in connection a valve element, configured to specify the predetermined minimum time period for the control circuitry 230 to maintain the supply of pressurized air to the pilot valve 131 in response to a cutoff of the pressurized air supply to the inlet coupling 210. The predetermined minimum time period may be between 2-30 seconds, in order to allow testing of the connected valves during the predetermined minimum time period.

[0045] Test display gauge G6 may comprise a ram with a coloured end, which protrudes into a transparent covering to indicate status, for example. In such embodiments, when the system is ‘off’, the indicator simply appears to be clear. When the system is ‘on’, the coloured end of the ram is pushed (e.g. by internal air pressure) into the transparent covering so that it is readily visible. Gauge G6 may be a visible status indicator on the housing 220 to display an indication of air supply status. For example, the air supply status may comprise one or more of: air pressure within the control circuitry; supply of pressurized air to the control circuitry from the air inlet coupling; supply of pressurized air from the control circuitry to the outlet coupling; or length of predetermined time delay.

[0046] Handle reservoir 215 may comprise a length of hollow tube, or a hollow pipe section, in connection with the housing back 222, configured to allow a user to easily lift and carry the control device 120. Handle reservoir 215 may be an air reservoir, configured to store a volume of air. The stored air may be used to charge pneumatic components of the control circuitry 230. Air reservoir 215 may be configured to store a volume of pressurized air from the pressurized air supply from the hydrant dispenser 115, wherein the stored pressurized air is supplied to the outlet coupling 205.

[0047] The control circuitry 230 of control device 120 is configured to perform both an activation opening test and a closing test. Requirements for activation checks in the field of aircraft refuelling may relate to refuelling equipment and flow rates of fuel through-valves. For example, hose configuration requirements may be such that connected hoses give the maximum achievable flow rate (i.e. both deck hoses on vehicles with elevating work platforms). The activation test checks the controlled rapid shut-down of the pit valve 130 and hydrant coupler valve 125 in the event of an emergency and the controlled opening of the system for fuelling. Further requirements for example activation opening and closing checks are detailed below. [0048] Activation switch opening check: A minimum opening time may be specified for the valves 125, 130, to be opened in response to engaging the activation switch 110 when being opened, to avoid severe fuel surge through the vehicle supply system, from the pit valve 130, to the hydrant dispenser 115, to the aircraft connection 105. Surge is related to the maximum fuelling flow rate. Therefore the minimum opening time required is 5 seconds for vehicles with flow rates greater than 2000L per minute, and is a minimum of 3 seconds for vehicles with a fuelling rate of less than 2000L per minute. Rates exceeding these may cause undue stress to components or couplings of the refuelling system 100, and result in damage to the components, and/or increase the risk of fuel leakages and spills.

[0049] Activation switch closing: A maximum closing time may be specified as a criterion of the closing test. For example, the total time from release of the activation switch 110 until flow stops may not exceed 5 seconds. The time of valve closure from hydrant coupler valve 125 and pit valve 130 from when flow begins to decrease until flow stops shall not be less than 2 seconds (to avoid high pressure surges). A maximum permitted overrun defined in table 1 below shall be allowed to pass, measured from the release of the activation handle/button.

[0050]

Table 1

[0051] Industry regulatory bodies may require the activation opening and closing times, and closing volumes to be checked due to the criticality of activation functions to safe operations. Such tests may be performed at different frequencies. Furthermore, regulation requirements may mandate that checks be made to confirm the intermittent feature of the activation initiated shut-down of the flow in no more than 2 minutes.

[0052] Figure 10 is a flow chart of the steps of a method of operation of the control device 120 delaying the stop of pressurized air supply to a pilot valve 131.

[0053] At step 1005, use of the control device 120 to allow independent valve testing of activation performance first involves connecting the air supply from the hydrant dispenser 115 to the pilot valve 131. Commencement of testing should initially be done at lower flow rates, working towards the maximum, in case the introduction of independent testing reveals an issue with the activation switch 110 setup. Accordingly, step 1005 comprises supplying, by the pressurized air supply of hydrant dispenser 115, pressurized air to the pilot valve 131 of pit valve 130.

[0054] For the activation closing test, at step 1010, the control device 120 maintains the air supply to the pilot valve 131 for a period after the air supply from the hydrant dispenser 115 has dropped to zero, or to ‘ambient’ pressure. This ensures that the pilot valve 131 and the pit valve 130 remain open while the activation close test is being performed. Accordingly, step 1010 comprises maintaining the supply of pressurized air to the pilot valve 131 for a predetermined minimum time period in response to a cut-off of the pressurized air supply, by the control circuitry 230. Furthermore, performing the activation closing test with the control device 120 primes the control device 120 to be used for the activation opening test, by the storage of additional air pressure within the air reservoir 215.

[0055] After the activation closing test is complete, at step 1015, the control circuitry 230 stops supply of pressurized air to the pilot valve after the predetermined minimum time period.

[0056] For the activation opening test, the operation of control device 120 manual operation button (V7) supplies air to the pilot valve 131 to allow it to be opened in advance of the activation opening test being performed. [0057] Figure 4 is an interior view of a control device 120 for a pilot valve 131 of a pit valve 130, according to some embodiments. Figure 4 depicts the physical arrangement of pneumatic tubing (references A to K) of the control circuitry 130, that connect valves and gauges to the air supply line 121 and the pilot valve 131 by air inlet coupling 210 and outlet coupling 205, as depicted in Figures 5 - 9. Each of the air lines A, B, C, D, E, F, G, H, I, J and K provided by the pneumatic tubing shown in Figure 4 corresponds to air lines shown in Figures 5, 6, 7, 8 and 9.

[0058] Air inlet coupling 210 is configured to receive a pressurized air supply. The air supply may be provided from hydrant dispenser 115. Outlet coupling 205 is configured to supply the pressurized air to the pilot valve 131. The output of pressurized air from the outlet coupling 205 to the pilot valve 131 may be a control signal. The control signal may indicate to the pilot valve 131 to either open the valve or close the valve. In embodiments where the pilot valve 131 receives a pneumatic control signal, the opening control signal may comprise the presence of air pressure above a threshold value (for example, of more than about 35-35psi). In this embodiment, absence of the air pressure is defined a control signal to close the pit valve 130.

[0059] Control circuitry 130 may be housed inside the housing, and is configured to maintain the supply of pressurized air to the pilot valve 131 for a predetermined minimum time delay in response to a cut-off of the pressurized air supply to the inlet coupling 210. Control circuitry 130 is further configured to equalize pressure between the inlet coupling and the outlet coupling after the predetermined minimum time delay.

[0060] Figure 5 is a schematic diagram of the components of a control device 120 for a pilot valve 131 of a pit valve 130, according to some embodiments. In particular, the specific system configuration 500 of control device 120 shown in Figure 5 depicts a pneumatically operated version of the control circuitry 230. Valves VI and V2 may comprise single directional ball-valves or ‘non-return’ valves, allowing air flow in a single direction. VI and/or V2 may comprise one-way valve in connection with the air inlet coupling 210, configured to allow air to be charged and retained within the air reservoir 215. VI and/or V2 may comprise inlet valves. Valves V3, V4, V7, and V8 may comprise multidirectional valves. Valves V3, V4, V7, and V8 may comprise outlet valves, capable of venting air from within the control circuitry 230 to other components, or the environment. V5 may comprise a multidirectional ball valve, or ‘shuttle-valve’, configured to allow air to pass through one path or another path depending on its position. V10 may comprise a timer valve, accessible to a user as part of user interface 310, and configured to actuate after a predetermined minimum time delay. Gauge G6 may comprise a test display gauge as described previously. Gauge G9 may comprise a pressure gauge as described previously. Handle reservoir 215 may comprise an air reservoir as described previously. The components of control device 120 in the system configuration 500 are interconnected by the tubing, having references A to K, as depicted physically in Figure 4. Pneumatic valve port designations 10, 12 and 13 etc. describe the direction of air when pressure is applied at these ports. For example, port 10 (one-zero as opposed to ten) refers to air from port 1 being directed to port 0 when air pressure is applied at port 10, i.e. port 1 becomes blocked.

[0061] Figure 6 is a schematic diagram of a control device 120 for a pilot valve 131 of a pit valve 130, during a dead-man closing test while the activation switch 110 is open, according to some embodiments. The bolded circuit segments depicting the air flow under the first condition of the activation closing test. In the system configuration 600 shown in Figure 6, a supply of pressurized air from the hydrant dispenser 115 flows through air line 121 into the air inlet coupling 210. This pressurized airflow is then provided to V4 at port 10 and port 0, to V3 and port 12, port 4, and port 2, and to V7 at port 0. The pressurized airflow is further provided to G9, which displays the pressure of the air flow to a user. This causes the shifting of valve V3 by virtue of the application of air pressure at port 12, which simultaneously and resultantly allows air to pass to port 1 of shuttle-valve V5. The pressurized airflow flows through valves VI and V2 through their ‘open’ directions. This charges the airlines of the control device 120 in system configuration 600 with pressurized airflow, and also charges the air reservoir 215 and fills it with air. Furthermore, pressurized air flows from VI though V3 at port 4 to port 2, through V5 in its open positon from port 0 to port 3, through V8 from port 0 to port 2, and out through the outlet coupling 205 to supply air to the pilot valve 131. The air flow in this configuration shifts the poppet of shuttle- valve V5, which simultaneously and resultantly allows air to pass to the pit valve 130. G6 displays an ‘engaged’ or ‘active’ position to indicate air is flowing from the air inlet coupling 210 to the outlet coupling 205. In this configuration, no airflow is provided to the timer valve V10 as the spool of V4 is shut, by virtue of the application of air pressure on port 10, blocking the flow of air to the timer valve V 10.

[0062] Figure 7 is a schematic diagram of a control device 120 for a pilot valve 131 of a pit valve 130, during a dead-man closing test when the dead-man is released, according to some embodiments. In the system configuration 700 shown in Figure 7, upon release of the activation switch 110, the air supply to the device is stopped and pressure to the air inlet coupling 210 drops to close to zero, or ambient air pressure. The loss of air pressure at V4, port 10 results in the spool shifting by virtue of spring force, allowing the air in the charged portion of the circuit beyond VI to be released to the timer-valve V10. Air continues to be supplied to the pilot valve 131 of pit valve 13, due to the non-return valve V 1 not allowing the release of the air within the circuit beyond its outlet port. The state of the control device 120 in system configuration 700 continues until the predetermined time delay of timer valve V10 expires.

[0063] Figure 8 is a schematic diagram of a control device 120 for a pilot valve 131 of a pit valve 130, during a dead-man closing test when the dead-man is released, and after a predetermined time delay has expired, in a system configuration 800 according to some embodiments. After the predetermined time delay of timer valve V10 expires, air is passed from V 10 port 1 to port 2, which in turn shifts the spool of V3 by virtue of the application of air pressure at port 13. The movement of the spool of V3 allows the air pressure in the control circuitry 310, which is presently maintaining the pit valve 131 in the open position, to dissipate via V3 port 2 to port 4. This in turn ceases pressured air supply to the outlet coupling 205, and the lack of air pressure causes G6 to returning to clear or ‘not active’ display status. The air in the control circuitry 230 beyond the outlet port of VI is simultaneously vented through V3 by virtue of the flow path from V3 port 0 to port 3 being opened. The air in the control circuitry 230 beyond V10 port 2, and V3 port 13 vents once V3 shifts. Vented air may be vented into the environment. In some embodiments, vents may be provided in the housing 220 to allow vented air to escape from within the housing to the ambient environment. The air pressure remaining in the circuit is held in this phase between V2 and V7. This phase concludes the operation of the device under activation closing test conditions, with the air pressure stored between V2 and V7 being held for operation of the control device 120 under activation opening test conditions. Accordingly, the testing of the device under an activation closing test primes the device to be used for an activation opening test.

[0064] Figure 11 depicts a method 1100 of using the control device 120 to conduct an activation switch 110 opening test. When conducting the activation opening test, prior to activating the activation switch 110 on the hydrant dispenser 115, a user may confirm of air pressure of at least 100 Psi within the control device 120, this operation may be part of step 1105. A minimum of at least between 25-45psi is required for opening of typical pilot valves. In the system configuration 800 of control device 120, at step 1110, a user may press and hold down of the control button on valve V7 to release the air stored within the device reservoir 215 and associated equipment and circuitry via the flow path from V7 port 0 to port 2 of valve. At this point, air enters V5 at port 2, shifting the poppet, and then exits V5 at port 3. This flow of air is then supplied to the pit valve through the outlet coupling 205, and accordingly G6 displays an ‘engaged’ or ‘active’ indication as confirmation of air pressure in the circuit opening the pit valve 131. At this point, at step 1115, an operator may activate activation switch 110 and assess the hydrant dispenser performance.

[0065] Figure 9 is a schematic diagram of a control device 120 for a pilot valve 131 of a pit valve 130, during an emergency stop operation, according to some embodiments. The emergency stop may be configured to equalize pressure between the inlet coupling and the outlet coupling in response to receiving an activation signal. The emergency stop function may be configured to reduce the pressure of the air in the line between the control device 120 and the pilot valve 131 to ambient, or atmospheric pressure, and in turn cause the pilot valve 131 to close the pit valve 130. The activation signal may be an operator pressing the button of V8 to engage the emergency stop. The emergency stop function may be engaged at any state of the control device 120. Pressing of the button of V8 vents the air signal to the pilot valve 131, and shuts off the supply into that circuit by virtue of the flow path V8 port 1 to port 2 being interrupted, and port 2 venting to atmosphere via port 3, irrespective of any upstream inputs. The drop in air pressure supplied to the pilot valve 131 causes the pit valve 130 to close and the gauge G6 to operate and turn indicate that the hydrant pit valve is closed.

[0066] The emergency stop function incorporated by V8 may be upstream of the gauge G6, i.e. immediately upstream of the gauge status indicator, so that it cut the air supply off and drops the air in the line to the pit valve 130. This configuration lowers the risk of overwhelming the emergency stop vent, by the cessation of air supply. In some embodiments, the emergency stop function vents air out of the control circuitry 230.

[0067] The depicted embodiments of Figures 4-9 display a fully pneumatically operated control device 120. This allows for a greater ease of use for operators compared to devices having electrical components, as no batteries or power sources are required. Furthermore, the potential for electrical faults in the proximity of a refuelling line can introduce ignition risks for the jet fuel, in the case of equipment malfunction. However, in some embodiments, one or more of the components of the control circuitry 230 may be electrical components, such as programmable logic controllers, electric timer circuits, sensors or indicators or electrically switched valves.

[0068] Furthermore, in some embodiments the dropping of the air supply to the pilot valve after the hydrant dispenser 115 supply has dropped to zero may be achieved by manual means. This may comprise pressing a button on the device 100. In some embodiments, this may comprise a check valve to hold air to the pilot valve 131 and a manually operated dump valve, or a manual valve in the air supply to the pilot valve 131, which is closed when the pilot valve 131 has opened and closed in advance of the test being performed. The arrangement and configuration of the device 100 may be advantageously applied for dual air lanyard systems, providing technical advantages over existing solutions within the art. [0069] Some embodiments relate to a control device with manually operable control circuitry, in which the time circuit is omitted in favour of manually delayed input to equalize the pressure between inlet and outlet. For example, some embodiments relate to a control device for a pilot valve of a pit valve, where the device includes: a housing; an air inlet coupling, configured to receive a pressurized air supply; an outlet coupling, configured to supply the pressurized air to the pilot valve; control circuitry, inside the housing, configured to: maintain the supply of pressurized air to the pilot valve in response to a cut-off of the pressurized air supply to the inlet coupling; and equalize pressure between the inlet coupling and the outlet coupling responsive to an actuation input to the control circuitry. For example, the actuation input may be manually input to the control circuitry.

[0070] It will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the above-described embodiments, without departing from the broad general scope of the present disclosure. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive.

Claims

CLAIMS:

1. A control device for a pilot valve of a pit valve, the device including: a housing; an air inlet coupling, configured to receive pressurized air from a pressurized air supply; an outlet coupling, configured to supply the pressurized air to the pilot valve; control circuitry, inside the housing, configured to: maintain the supply of pressurized air to the pilot valve for a predetermined minimum time delay in response to a cut-off of the pressurized air supply to the inlet coupling; and equalize pressure between the inlet coupling and the outlet coupling after the predetermined minimum time delay.

2. The control device of claim 1, wherein the control circuitry is configured to provide an output signal to control the pilot valve.

3. The control device of claim 1 or claim 2, wherein the control circuitry further comprises an emergency stop, configured to reduce air pressure at the outlet coupling to ambient pressure, in response to receiving an activation signal.

4. The control device of any one of the preceding claims, further comprising an air reservoir configured to store a volume of pressurized air from the pressurized air supply; wherein the stored pressurized air is supplied to the outlet coupling.

5. The control device of claim 4, further comprising a one-way valve in connection with the air inlet coupling, configured to allow air to be charged and retained within the reservoir.

6. The control device of claim 4 or claim 5, wherein the reservoir is formed as a hollow tube.

7. The control device of claim 6, wherein the reservoir forms a handle on the housing.

8. The control device of any one of claims 4 to 7, wherein the control circuitry is configured to vent air stored in the reservoir responsive to a control signal.

9. The control device of claim 8, wherein the control circuitry further comprises an outlet valve configured to supply the vented air to the outlet coupling, responsive to the control signal.

10 The control device of any one of the preceding claims, wherein the control circuitry includes a timer that is configurable to allow adjustment of the length of the predetermined minimum time delay to a selected time between 2 and 30 seconds.

11. The control device of any one of the preceding claims, further comprising a visible status indicator on the housing to display an indication of air supply status.

12. The control device of claim 11, wherein the air supply status comprises one or more of: air pressure within the control circuitry; supply of pressurized air to the control circuitry from the air inlet coupling; supply of pressurized air from the control circuitry to the outlet coupling; or length of predetermined time delay.

13. The control device of any one of the preceding claims, wherein the control circuitry is pneumatic control circuitry.

14. A system for controlling air supply to a pilot valve of a pit valve, the system including: the device of any one of claims 1 to 13; an activation switch, configured to send an activation signal to a pressurized air supply; the pressurized air supply, configured to supply pressurized air to the control device upon receipt of the activation signal; and the pilot valve of the pit valve, configured to activate in response to pressurized air received from the control device.

15. A system for controlling air supply to a pilot valve of a pit valve, the system including: an activation switch, configured to send an activation signal to a pressurized air supply; the pressurized air supply configured to supply pressurized air to control circuitry upon receipt of the activation signal; the control circuitry, configured to: supply air from the air supply to the pilot valve; maintain the supply of pressurized air to the pilot valve for a predetermined minimum time delay in response to a cut-off of the pressurized air supply; and to reduce the pressure of the air supply to the pilot valve after the predetermined minimum time delay. and, the pilot valve, configured to activate in response to pressurized air received from the control circuitry.

16. A method of controlling air supply to a pilot valve of a pit valve, the method comprising: supplying, by a pressurized air supply, pressurized air to the pilot valve of a pit valve; maintaining, by control circuitry, the supply of pressurized air to the pilot valve for a predetermined minimum time period in response to a cut-off of the pressurized air supply; and stopping, by the control circuitry, the supply of pressurized air to the pilot valve after the predetermined minimum time period.

17. The method of claim 16, wherein the control circuitry comprises: an inlet valve, connected to an air inlet coupling, and configured to enable air flow within the control circuitry from the supply of pressurized air; an air reservoir, connected to the valve and configured to receive and store air responsive to a control signal; an outlet valve, connected to the air reservoir, and configured to vent air stored in the reservoir to an air outlet coupling responsive to the control signal, to maintain the supply of pressurized air to the pilot valve; and a timer valve, configured to equalize pressure between the inlet coupling and the outlet coupling after the predetermined minimum time delay

18. The method of claim 17, further comprising: charging the air reservoir with pressurized air; and releasing, at the outlet valve, the pressurized air stored in the reservoir to the pilot valve.

19. The method of any one of claims 16 to 18, wherein the control circuitry is pneumatic control circuitry.

20. The method of any one of claims 16 to 19, wherein the length of the predetermined minimum time delay is between 2 to 30 seconds.

21. The method of any one of claims 16 to 20, further comprising: displaying, by the control circuitry, an indication of air supply status.

22. The method of claim 21, wherein the air supply status comprises one or more of: air pressure within the control circuitry; supply of pressurized air to the pilot valve; or length of predetermined time delay.

23. A control device for a pilot valve of a pit valve, the device including: a housing; an air inlet coupling, configured to receive a pressurized air supply; an outlet coupling, configured to supply the pressurized air to the pilot valve; control circuitry, inside the housing, configured to: maintain the supply of pressurized air to the pilot valve in response to a cut-off of the pressurized air supply to the inlet coupling; and equalize pressure between the inlet coupling and the outlet coupling responsive to an actuation input to the control circuitry. The control device of claim 23, wherein the actuation input is manually inputontrol circuitry.