WO2023012449A1

WO2023012449A1 - Gas cylinder refilling system, gas cylinder, filling station, and gas cylinder refilling method

Info

Publication number: WO2023012449A1
Application number: PCT/GB2022/051843
Authority: WO
Inventors: Dijon STOLS
Original assignee: Sensify (UK) Limited
Priority date: 2021-08-04
Filing date: 2022-07-18
Publication date: 2023-02-09
Also published as: EP4381222A1; GB202111257D0; MX2024001548A; GB2609618A

Abstract

Gas cylinder refilling system (40). A plurality of gas cylinders (10) are provided comprising a computer readable identifier (9) and a irremovable valve (2). Each valve (1) has a filling restriction mechanism (6) operable to switch between a filling state and a restricted state. A filling device (20) is provided for filling the gas cylinders (10) and comprises a filling nozzle (23) connectable to a valve (2) of a cylinder, an identifier reader (25), and a restrictor actuator (22). A controller (30) verifies a cylinder (10) based on the respective computer readable identifier (9) read by the identifier reader (25). In response to a positive verification, the controller (30) controls the restrictor actuator (22) to switch the filling restriction mechanism (6) to a filling state for filling the gas cylinder (10).

Description

GAS CYLINDER REFILLING SYSTEM, GAS CYLINDER, FILLING STATION, AND GAS CYLINDER REFILLING METHOD

[ 001 ] The present invention concerns a gas cylinder refilling system, a gas cylinder, a filling station, and gas cylinder refilling method . The present disclosure is particularly relevant to gas fuel cylinders and L G cylinders , and systems and methods for filling the same .

[ 002 ] Gas fuel cylinders , such as those that contain liquified petroleum gas (L G) , are widely used in various applications such as cooking, heating and as fuel for vehicles . In order to distribute the fuel , it is necessary to pressurise the cylinders due to the gas ' s low boiling temperature , and hence the need to prevent evaporation . However, the provision of a pressurised and highly flammable substance inherently raises safety issues and consequently the manufacture , distribution and refilling of such canisters is regulated .

[ 003 ] In this respect , the gas cylinders themselves are critically important to the safe handling of gas fuels . As such, many fuel suppliers will retain ownership of their gas cylinders , with the cylinder merely being supplied to a customer for the purpose of using the gas contents . The cylinder is then refilled after use . As such, a gas cylinder will normally be re-used multiple times by potentially multiple customers over its lifetime . Under this model , the fuel supplier would normally be able to withdraw older or faulty cylinders from circulation when a customer returns a cylinder for refilling . A deposit refund is also often offered by suppliers to incentivise the return of unwanted cylinders . [ 004 ] There are however shortcomings with this conventional system . Specifically, once a cylinder enters circulation, there is no guarantee that it will be handled correctly . For example , a customer may have their cylinder refilled through an unauthorised third-party supplier, rather than through an authorised supplier dealership . This can occur both knowingly and unknowingly, with some unscrupulous suppliers passing themselves off as authorised dealers . Unauthorised refilling creates a number of issues . Firstly, an unauthorised supplier may short fill the cylinders or use an inferior product to undercut a legitimate provider . They may also use inappropriate filling equipment or skip important routine servicing and safety checks that would normally be undertaken at the re-fill stage . Consequently, a cylinder may be , for instance , contaminated by an inferior product , damaged during refilling, or not adequately maintained . This in itself is undesirable from a safety standpoint but is exacerbated because cylinders are shared over their lifespan by multiple customers . As such, a future customer may receive a contaminated or damaged cylinder unknowingly .

[ 005 ] The present invention therefore seeks to address the above issues .

[ 006 ] According to a first aspect of the present invention, there is provided a gas cylinder refilling system, comprising : a plurality of gas cylinders , each comprising a computer readable identifier and a valve irremovably attached to a cylinder shell , wherein each valve comprises a filling restriction mechanism operable to switch between a filling state for filling the gas cylinder and a restricted state for preventing gas inflow; a filling device for fill ing the gas cylinders , the filling device comprising a filling noz z le connectable to a respective valve of a cylinder to be filled, an identifier reader for reading a respective computer readable identifier from the cylinder to be filled, and a restrictor actuator for controlling the respective filling restriction mechanism of the cylinder to be filled; and a controller for controlling the f illing device , wherein the controller verifies the cylinder to be filled based on the respective computer readable identifier read by the identifier reader and, in response to a positive verification, the controller controls the restrictor actuator to switch the filling restriction mechanism to a filling state for filling the respective gas cylinder .

[ 007 ] In this way, the refilling of a gas cylinder may be prevented unless it can be identified and verified electronically based on the cylinder' s computer readable identifier . That is , the filling restriction mechanism may prevent the valve from admitting a gas refill unless it is unlocked by the restrictor actuator . As such, an unauthorised supplier is prevented from refilling the cylinder because an authorised filling device will not have the requisite controller or restrictor actuator required for switching the filling restriction mechanism to a filling state . Equally, the refilling of an unsuitable cylinder using an authorised filling device may also be prevented if desired because the unsuitable cylinder will fail its verification by the controller . For instance , a third-party manufactured cylinder may not have a suitable computer readable identifier . Equally, a previously authorised cylinder which has now exceeded a maximum number of refills or has been recalled by the manufacturer may be flagged such that it fails verification by the controller and therefore cannot be refilled . Accordingly, a system may be provided that requires a unique lock-and-key exchange between the cylinder and filling device to restrict refilling to approved suppliers . Consequently, cylinder maintenance , compliance standards , and product quality can be maintained . At the same time , the attractiveness of stealing a cylinder, or attempting to refill it using an unauthorised supplier is significantly reduced . Indeed, once empty, a cylinder is rendered functionally useless due to the inability to refill it without positive verification . Furthermore , the irremovable valve prevents reuse of the cyl inder shell . As such, gas suppliers are provided with control over their cylinders , mitigating the risk of theft or misuse , whilst maintaining safety compliance and customer loyalty . The verification step may also be used to provide usage and analytics data for optimising supplier operations .

[ 008 ] In embodiments , the filling device further comprises a flow actuator operable to switch between a filling state for releasing gas through the filling noz z le and a restricted state for preventing gas outflow, and wherein the controller, in response to the positive verification, controls the flow actuator to switch to a filling state for releasing gas through the filling noz z le for f illing the gas cylinder . In this way, a fil ling operation may be automatically initiated by the controller once the cylinder has been verified .

[ 009 ] In embodiments , the gas cylinder refilling system further comprises a data store for storing cylinder information for each of the plurality of cylinders ; and wherein the controller is configured to verify the cylinder to be filled by identifying the respective cylinder information based on the read computer readable identifier . In this way, the system may store information about each cylinder and verification may be undertaken based on the stored data . As such, the status information for each cylinder may be managed and updated centrally, thereby allowing cylinders to be tracked, and servicing and removal programs to be accurately enforced .

[ 0010 ] In embodiments , the data store is a remote server data store and the controller is conf igured to transmit the read computer readable identifier to the remote server data store . In this way, a plurality of controllers may access a central data store , thereby permitting verification and monitoring of gas cylinders over large regions and territories . In embodiments , the remote server data store may be a cloud server .

[ 0011 ] In embodiments , the controller is configured to transmit update data to the remote server data store for updating the stored cylinder information for the respective cylinder to be filled . In this way, the stored cylinder information can be updated during refills to provide suppliers with up to date status information and tracking of usage statistics .

[ 0012 ] In embodiments , the cylinder information comprises data for least one of a cylinder ID, a manufacturer ID, a date of cylinder manufacture , an owner ID, a serial number, a tare weight , a cylinder si ze , and an inspection date , a filling capacity, a last fill date , a last fill volume , servicing information, safety check information, customer information, usage history, and delivery location .

[ 0013 ] In embodiments , the computer readable identifier comprises data for least one of a cylinder ID, a manufacturer ID, a date of cylinder manufacture , an owner, a serial number, a tare weight , a cylinder si ze , and an inspection date .

[ 0014 ] In embodiments , the system further comprises a scale for weighing the cylinder to be filled, and the controller is configured to determine a quantity of gas for filling the respective gas cylinder based on a weighed cylinder weight , a cylinder tare weight and a cylinder si ze value for the cylinder . In this way, the partially empty cylinders may be refilled to reduce wastage , and the risk of overfilling is mitigated .

[ 0015 ] In embodiments , the controller is configured to , in response to a negative verification, control the restrictor actuator to maintain the filling restriction mechanism in the restricted state for preventing gas inflow . In this way, the valve may be locked in its restricted state to prevent refilling .

[ 0016 ] In embodiments , the filling restriction mechanism comprises a gate moveable between a closed position for blocking a gas pathway into the cylinder shell , and an open position where the gas pathway is unobstructed, and wherein the restrictor actuator is operable to move the gate from the closed position to the open position to switch the filling restriction mechanism to the filling state . In this way, a moveable gate may be used to restrict or enable filling .

[ 0017 ] In embodiments , the restrictor actuator comprises one of : ( i ) an actuator arm operably extendable to engage the gate for moving it into the open position, and ( ii ) an inductor coil operable for inducting a magnetic field, wherein the gate is magnetic and the inductance of a magnetic field by the inductor coil in combination with a pressure differential generated by the gas inflow moves it into the open position . In this way, actuation of the restrictor actuator may be effected by direct mechanical engagement or using a generated magnetic field in combination with a pressure differential .

[ 0018 ] In embodiments , the computer readable identifiers are Radio-Frequency Identification, RFID, tags , and each of the valves comprises one RFID tag embedded into the valve body . In this way, a passive RFID tag may be used to transmit the computer readable identifier to the identifier reader based on an interrogation pulse emitted by the identifier reader . As such, the valve does not require its own internal power source , thereby facilitating operation over the lifetime of the cylinder .

[ 0019 ] According to a second aspect of the present invention, there is provided a gas cylinder, comprising : a cylinder shell for containing a gas ; a valve irremovably attached to the cylinder shell and being connectable to a filling noz z le of a filling device for filling the gas cylinder ; and a computer readable identifier for reading by an identifier reader of the filling device , wherein the valve comprises a filling restriction mechanism operable to switch between a filling state for filling the gas cylinder and a restricted state for preventing gas inflow under the control of a restrictor actuator of the filling device .

[ 0020 ] According to a third aspect of the present invention, there is provided a filling station for filling a gas cylinder having a computer readable identifier and a valve comprising a filling restriction mechanism operable to switch between a filling state and a restricted state , the filling station comprising : a filling device having a filling noz z le connectable to the valve , an identifier reader for reading the computer readable identifier, and a restrictor actuator for controlling the filling restriction mechanism; and a controller for controlling the f illing device , wherein the controller verifies the cylinder based on the computer readable identifier read by the identifier reader and, in response to a positive verification, the controller controls the restrictor actuator to switch the filling restriction mechanism to a filling state for filling the respective gas cylinder .

[ 0021 ] According to a fourth aspect of the present invention, there is provided gas cylinder refilling method, comprising the steps of : receiving a gas cylinder at a filling device comprising a filling noz z le , an identifier reader, a restrictor actuator, and a controller ; connecting the filling noz z le to a valve irremovably attached to a cylinder shell of the cylinder ; reading a computer readable identi fier from the cylinder using the identifier reader ; verifying the cylinder by the controller based on the computer readable identifier read by the identifier reader ; and controlling, by the controller, the restrictor actuator to switch a filling restriction mechanism of the cylinder from a restricted state for preventing gas inflow to filling state for filling the gas cylinder .

[ 0022 ] I llustrative embodiments of the present invention will now be described with reference to the accompanying drawings in which :

Figure 1 shows a front view of a gas refilling system according to an illustrative embodiment ;

Figure 2 shows a perspective view of the top of a gas cylinder according to an illustrative embodiment ; Figure 3 shows a perspective view of the valve of the cylinder shown in Figure 2 ;

Figure 4 shows a side view of a filling device according to an illustrative embodiment ;

Figure 5 shows a perspective view of a filling device unit attached to the valve shown in figures 2 and 3 ; and

Figure 6 shows a perspective view of a controller used in the system shown in figure 1 .

[ 0023 ] Figure 1 shows a gas cylinder refilling system 40 according to an illustrative embodiment . The system comprises a plurality of gas cylinders 10 which are fillable at a plurality of filling stations . The filling stations each have a filling device 20 and are controlled by a controller 30 . Although four filling stations are controlled by one controller 30 in this embodiment , it will be understood that different numbers of filling stations may be provided in different controller configurations . For example , a single filling station may be provided controlled by a single controller . Equally, a distributed system may be provided, with a plurality of stations controlled remotely by a common controller . In this embodiment , each filling station is associated with a weighing scale 26 for weighing the gas cylinder 10 during the filling process .

[ 0024 ] Figure 2 shows a perspective view of the top of a gas cylinder 10 in further detail . The gas cylinder 10 comprises a shell 1 forming the main body of the cylinder, terminating at its top with a neck 5 defining an aperture into the interior cavity . A valve 2 is secured into the aperture defined by the neck 5 and comprises an outlet port 4 through which stored gas can exit the cylinder 10 , and which can be used to feed gas into the cylinder 10 during ref illing . The valve 2 is provided with a handwheel 3 which controls a gate for the primary opening and closing of the valve during consumer use . For example , if a charged cylinder 10 is stored, the handwheel 3 may be rotated for closing the gate to prevent gas leakage .

[ 0025 ] Figure 3 shows the valve 2 separated from the cylinder shell 1 . In this embodiment , the valve 2 is primari ly formed of brass . The base of the valve 2 is provided with a threaded section 12 which threads onto a corresponding thread provided on the interior face of the neck 5 of the cylinder shell 1 . During cylinder assembly, the threaded section 12 is first coated in an adhesive prior to threading into the neck 5 such that the valve 2 becomes irremovably bonded to the cylinder shell 1 once the adhesive has cured . That is , whilst the valve 2 may be theoretically be separated from the shell 1 , this would require specialist tooling and would in all likelihood damage parts of the shell and valve . Consequently, in every practical sense , the valve 2 is irremovable once fitted, since separation would sacrifice the parts , and would only normally be attempted if it was necessary for decommissioning and recycling . In other embodiments , other means for irremovably securing the valve 2 to the shell 1 may be used . For example , a mechanical one-way lock may be provided whereby any attempt to release the lock would result in breakage of the shell and/or valve .

[ 0026 ] The body 7 of the valve 2 supports an RFID tag 9 embedded within a resin . As such, the RFID tag 9 forms an integral part of the valve 2 , and consequently an integral part of the assembled cylinder 10 . The RFID tag 9 is encoded with an unique identifier for identifying the cylinder, along with a data set including details of the cylinder manufacturer, the date of manufacture , the cylinder owner (normally the gas supplier) , the tare weight , and the date of inspection before the cylinder entered into service .

[ 0027 ] The rear of the body 7 is provided with a relief or safety release valve 8 , which releases gas if the internal pressure exceeds a threshold . This provides a safety mechanism for preventing over-pressurisation . The bonnet at the top of the body 7 is provided with a grip 11 for gipping by the filling device 20 during a filling operation, as is described below .

[ 0028 ] As mentioned above , the front of the valve 2 is provided with an outlet port 4 . The outlet port 4 is connected to the body 7 through a filling restriction mechanism 6 . The filling restriction mechanism 6 comprises an interior gate which is seated within the fluid communication channel extending between the outlet port 4 and the cylinder interior . The filling restriction mechanism 6 is switchable between a closed and open state based on movement of the interior gate . In the closed state , the interior gate forms a one-way valve allowing pressurised gas stored within the cylinder 10 to flow out (when the handwheel 3 is in the open position) , but restricting the inflow of gas . As such, filling of the cylinder is prevented when the filling restriction mechanism 6 is in its closed state . The open state is effected when an actuator within the filling device moves the interior gate such that the fluid communication channel is unobstructed, thereby allowing gas to be fed into the cylinder for filling .

[ 0029 ] It will be understood that different configurations of the valve 2 are possible . For example , a side fill valve has been shown in Figure 3 , but vertical fill valves are also envisaged. Equally, a more compact design may be adopted without the handwheel 3 in which, for instance, the filling restriction mechanism 6 also functions as an open/close controller, with the valve 2 being held closed unless actuated by an actuator within the filling device 20 or connector to a gas consuming device.

[0030] Figure 4 shows a side view of the filling device 20 shown in Figure 1. The filling device 20 comprises a nozzle 23 which is insertable into the outlet port 4 of the valve 2 for feeding gas into the cylinder 10. The nozzle 23 is connected to a gas feed (not shown) via a control sub-unit 22 which includes a feed valve for controlling the flow of gas supplied through the nozzle 23, as well as housing the local electronic processors and a communications module for communication with the controller 30. An RFID reader 25 is provided on a projecting arm extending from the control subunit 22 such that, when the nozzle 23 is inserted into the outlet port 4, the RFID antenna 25 is aligned with the RFID tag 9 embedded into the valve 2. As such, the RFID antenna 25 may emit an electromagnetic interrogation pulse, which generates a return signal from the RFID tag 9 which is then received and processed by the control sub-unit 22 and communicated to the controller 30.

[0031] The filling device 20 further comprises an engagement arm 24 and a pneumatic actuator 21. As shown in Figure 5, the engagement arm 24 fits around the grip 11 of the valve 2. During connection, the nozzle 23 is aligned with the outlet port 4, and the pneumatic actuator 21 is activated to drive the nozzle 23 and control sub-unit 22 forward. This forces the nozzle 23 into a mating engagement with the outlet port 4, while the rear of valve 2 at grip 11 is braced by the engagement arm 24 . As such, the noz z le 23 may be forcibly held into engagement with the outlet port 4 to prevent separation or leakage during a filling operation .

[ 0032 ] Figure 6 shows a perspective view of the controller 30 shown in figure 1 . As shown, the controller includes a touch screen display 31 , as well as filling device connection ports 32 and weighing scale connection ports 33 . The connection ports 32 , 32 form wired connections with the respective filling devices 20 and weighing scales 26 within each filling station . As such, the controller 30 may receive cylinder data read from RFID antenna 25 through one of the filling device connection ports 32 and in response , transmit verification instructions back to the respective control subunit 22 indicating whether a filling operation has been approved or denied . In other embodiments , wireless connections may alternatively be used . The controller 30 is communicatively connected to a cyl inder database stored on a cloud server via an internet access point . The cylinder database includes a record entry for each authorised cylinder including a unique cylinder identifier, the manufacturer' s identifier, the date the cylinder was manufactured, the owner' s identifier, a serial number, a tare weight , the cylinder' s si ze and specifications , and a last inspection date , a last refill date , a record of the last fill volume , servicing information, safety check information, usage history, and delivery location .

[ 0033 ] In this connection, in use , an empty cylinder 10 will be positioned on the weighing scale 26 associated with one of the filling devices 20 . The engagement arm 24 of the filling device i s fitted around the grip 11 of the valve 2 and a user will align the noz z le 23 with the outlet port 4 . Once aligned, a manual trigger is pressed to activate the pneumatic actuator 21 for driving the noz z le 23 into a mating engagement with the outlet port 4 . As the control sub-unit 22 is also moved forward, the RFID antenna 25 is brought into alignment with the RFID tag 9 provided on the cylinder' s valve 9 . The filling station user may also then turn handwheel 3 for opening the primary valve gate .

[ 0034 ] The RFID antenna 25 generates an interrogation signal which causes the RFID tag 9 to transmit , in response , its unique identifier for identifying the cylinder, along with the accompanying data set . This data is then transmitted via the control sub-unit 22 through to the controller 30 . The controller 30 also receives a cylinder weight measurement from the weighing scale 26 .

[ 0035 ] Based on the received data, the controller 30 verifies the cylinder 10 to determine i f it is authorised to be refilled . In this embodiment , the received data is transmitted to the remote cloud server for processing, but it will be understood that in other embodiments the cylinder database may be stored locally and/or the verification processing may be performed locally .

[ 0036 ] Under the verification process , the cylinder identifier is used to locate the respective record entry for the cylinder . I f no cylinder identifier has been read, or an cylinder identifier is read which does not correspond to a record entry in the cylinder database , the controller 30 may generate an alert on the display 31 for the fill ing station user to notify them that the cylinder is not an authorised cylinder . Depending on the filling station preferences and access rights , filling of the cylinder may still be permitted . For instance , this may allow the filling station to be used to refill another manufacturer' s cylinders at the discretion of the station owner .

[ 0037 ] In situations where the cylinder identifier corresponds to a record entry in the cylinder database , the remaining data set may then be interrogated to determine if there are any reasons not to authorise filling . For instance , if the cylinder has been flagged for recall or the period since the last maintenance inspection has exceeded a threshold, the controller 30 may generate an alert on the display 31 to notify the filling station user that verification of the cylinder 10 has been refused . At the same time , the controller 30 instructs the control sub-unit 22 to actuate the actuator contained within the outlet port 4 to ensure the filling restriction mechanism 6 is locked into its closed state . This may help to prevent loosening of the filling restriction mechanism' s 6 interior gate , thereby ensuring filling is prevented .

[ 0038 ] I f the verification process determines the cylinder 10 is approved for refilling, the controller 30 may generate an alert on the display 31 to notify the filling station user that the cylinder 10 has been approved for filling and the filling process i s about to begin . The controller 30 may then instruct the control sub-unit 22 to actuate the actuator contained within the outlet port 4 to move the interior gate of the filling restriction mechanism 6 to its open state . As such, a fluid communication channel is established between the noz z le 23 and the interior of the cylinder shel l 1 . Once the filling restriction mechanism 6 is opened, the control sub-unit 22 then controls its feed valve for releasing the flow of gas through the noz z le 23 to fill the cylinder 10 . The filling operation is controlled by controller 30 based on the measured weight of the cylinder and the cylinder specification data and tare weight ( i . e . the unladen weight of the cylinder) provided through either the RFID data set or retrieved from the stored cylinder database entry . As such, the control ler 30 can determine how much gas i s required to refill the cylinder 10 . Based on this , the controller 30 may control the control sub-unit 22 to close the feed valve once the required volume of gas has been introduced . The controller 30 may receive a gas inflow measurement to assist with this . It will also be understood that in other embodiments , the gas pressure may be measured to effect filling cut-off , without the need for weight measurements , or in combination with the measured cylinder weight .

[ 0039 ] Once the cylinder has been filled, the controller 30 transmits update data to the cloud server for updating the respective cylinder' s record in the cylinder database . For example , the record entry for the last refill date can be updated . I f a safety inspection has been undertaken during the filling process , the filling station user may also input this through the touch screen display 31 , and the cylinder database record may be updated accordingly . As such, the gas supplier may be provided with an up-to-date record and history of both cylinder usage and safety inspection information . For instance , if a station user notices the start of degradation of parts of the cylinder, this may be flagged to prompt monitoring during subsequent filling operations .

[ 0040 ] In a scenario where an attempt is made to refil l a cylinder 10 at an unauthorised fil ling station, ref illing is prevented by the filling restriction mechanism 6 . That is , a conventional filling noz z le is unable to actuate the interior gate to open the fluid communication channel for allowing gas inflow . As such, an authorised cylinder 10 cannot be refilled at an unauthorised filling station . Accordingly, misuse of the cylinder is prevented .

[ 0041 ] It will be understood that the embodiment illustrated above shows applications of the invention only for the purposes of illustration . In practice the invention may be applied to many different configurations , the detailed embodiments being straightforward for those skil led in the art to implement .

[ 0042 ] In this connection, for example , although in the above embodiment a mechanically actuated operated filling restriction mechanism is described, it will be understood that other mechanisms are also possible , such as a magnetically actuated gate . Furthermore , in more complex embodiments , the valve may comprise an integrated processor for electrically controlling the gate . In such embodiments , additional security may be provided by having the processor perform an authentication process through the computer readable identif ier and reader, whereby a security key transmitted from the filling device to the valve 2 is required to unlock the filling restriction mechanism 6 . The security key may be encoded and updated periodically via a remote controller server to prevent hacking of the system .

Claims

1 . A gas cylinder refilling system, comprising : a plurality of gas cylinders , each comprising a computer readable identifier and a valve irremovably attached to a cylinder shell , wherein each valve comprises a filling restriction mechanism operable to switch between a filling state for filling the gas cylinder and a restricted state for preventing gas inflow; a filling device for filling the gas cylinders , the filling device comprising a filling noz z le connectable to a respective valve of a cylinder to be filled, an identifier reader for reading a respective computer readable identifier from the cylinder to be filled, and a restrictor actuator for controlling the respective filling restriction mechanism of the cylinder to be filled; and a controller for controlling the filling device , wherein the controller verifies the cylinder to be filled based on the respective computer readable identifier read by the identifier reader and, in response to a positive verification, the controller controls the restrictor actuator to switch the filling restriction mechanism to a filling state for filling the respective gas cylinder .

2 . A gas cylinder refilling system according to claim 1 , wherein the filling device further comprises a flow actuator operable to switch between a filling state for releasing gas through the filling noz z le and a restricted state for preventing gas outflow, and wherein the controller, in response to the positive verification, controls the flow actuator to switch to a filling state for releasing gas through the filling noz z le for filling the gas cylinder .

3 . A gas cylinder refilling system according to claim 1 or 2 , further comprising a data store for storing cylinder information for each of the plurality of cylinders ; and wherein the controller is configured to verify the cylinder to be filled by identifying the respective cylinder information based on the read computer readable identifier .

4 . A gas cylinder refilling system according to claim 3 , wherein the data store is a remote server data store and the controller is configured to transmit the read computer readable identifier to the remote server data store .

5 . A gas cylinder refilling system according to claim 4 , wherein the controller is configured to transmit update data to the remote server data store for updating the stored cylinder information for the respective cylinder to be filled .

6 . A gas cyl inder refilling system according to any of claims 3 to 5 , wherein the cylinder information comprises data for least one of a cylinder ID, a manufacturer ID, a date of cylinder manufacture , an owner I D, a serial number, a tare weight , a cylinder si ze , and an inspection date , a filling capacity, a last fill date , a last fill volume , servicing information, safety check information, customer information, usage history, and delivery location .

7 . A gas cylinder refilling system according to any preceding claim, wherein the computer readable identifier comprises data for least one of a cylinder ID, a manufacturer ID, a date of cylinder manufacture , an owner, a serial number, a tare weight , a cylinder si ze , and an inspection date .

8 . A gas cylinder refilling system according to any preceding claim, further comprising a scale for weighing the cylinder to be filled, and the controller is configured to determine a quantity of gas for filling the respective gas cylinder based on a weighed cylinder weight , a cylinder tare weight and a cylinder si ze value for the cylinder .

9 . A gas cylinder refilling system according to any preceding claim, wherein the controller is configured to , in response to a negative verification, control the restrictor actuator to maintain the filling restriction mechanism in the restricted state for preventing gas inflow .

10 . A gas cylinder refilling system according to any preceding claim, wherein the filling restriction mechanism comprises a gate moveable between a closed position for blocking a gas pathway into the cylinder shell , and an open position where the gas pathway is unobstructed, and wherein the restrictor actuator is operable to move the gate from the closed position to the open position to switch the filling restriction mechanism to the filling state .

11 . A gas cylinder refilling system according to claim 10 , wherein the restrictor actuator comprises one of :

( i ) an actuator arm operably extendable to engage the gate for moving it into the open position, and

( ii ) an inductor coil operable for inducting a magnetic field, wherein the gate is magnetic and the inductance of a magnetic field by the inductor coil in combination with a pressure differential generated by the gas inflow moves it into the open position . 21

12 . A gas cylinder refilling system according to any preceding claim, wherein the computer readable identifiers are Radio-Frequency Identification, RFID, tags , and each of the valves comprises one RFID tag embedded into the valve body .

13 . A gas cylinder, comprising : a cylinder shell for containing a gas ; a valve irremovably attached to the cylinder shell and being connectable to a filling noz z le of a fill ing device for filling the gas cylinder ; and a computer readable identifier for reading by an identifier reader of the filling device , wherein the valve comprises a filling restriction mechanism operable to switch between a filling state for filling the gas cylinder and a restricted state for preventing gas inflow under the control of a restrictor actuator of the filling device .

14 . A filling station for filling a gas cylinder having a computer readable identifier and a valve comprising a filling restriction mechanism operable to switch between a filling state and a restricted state , the filling station comprising : a filling device having a filling noz z le connectable to the valve , an identifier reader for reading the computer readable identifier, and a restrictor actuator for controlling the filling restriction mechanism; and a controller for controlling the filling device , wherein the controller verifies the cylinder based on the computer readable identifier read by the identif ier reader and, in response to a positive verification, the controller controls the restrictor actuator to switch the filling 22 restriction mechanism to a fill ing state for filling the respective gas cylinder .

15 . A gas cylinder refilling method, comprising the steps of : receiving a gas cylinder at a filling device comprising a filling noz z le , an identifier reader, a restrictor actuator, and a controller ; connecting the fi lling noz z le to a valve irremovably attached to a cylinder shell of the cylinder ; reading a computer readable identifier from the cylinder using the identifier reader ; verifying the cylinder by the controller based on the computer readable identifier read by the identifier reader ; and controlling, by the controller, the restrictor actuator to switch a filling restriction mechanism of the cylinder from a restricted state for preventing gas inflow to filling state for filling the gas cylinder .