FIRE EXTINGUISHERS

An adapter for a fire extinguisher includes a cylinder which has an internal volume for storage of an extinguishing agent and a neck through which the internal volume may be accessed, a release valve, and a dip tube. The adapter defines a first flow path through the adapter for the extinguishing agent during introduction or charging of the extinguishing agent into the internal volume of the cylinder. The adapter at least partially defines or accommodates a second flow path for the extinguishing agent through the adapter during discharging of the fire extinguisher of which the adapter is part. The first and second flow paths are different.

CROSS-REFERENCE TO RELATED APPLICATION(S)

The present application claims priority to European Application No. 22210689.0 filed on Nov. 30, 2022, the contents of which are incorporated by reference herein in their entirety.

BACKGROUND

This disclosure relates to fire extinguishers, and in particular pressurized fire extinguishers that include a dip tube.

Fire extinguishers with a dip tube typically also include a cylinder that may be pressurized, an extinguishing agent that is stored in the cylinder until the fire extinguisher is discharged, typically to fight a fire, and a valve that actuates and/or controls the discharge of the fire extinguisher. The dip tube is attached to the release valve and held in a desired position within the internal volume of the cylinder by the dip tubes attachment to the release valve. The desired position is typically one in which the dip tube is not in contact with the walls of the cylinder. The use of a dip tube both assists in achieving a desired performance when the fire extinguisher is discharged, and in maximising the volume of extinguishing agent that the fire extinguisher discharges.

SUMMARY

According to a first aspect of the present disclosure there is provided an adapter for a fire extinguisher comprising a cylinder which has an internal volume for the storage of an extinguishing agent and a neck through which the inside of the cylinder may be accessed, a release valve, and a dip tube. The adapter defines a first flow path through the adapter for the extinguishing agent for use when the extinguishing agent is introduced or charged into the internal volume of the cylinder. The adapter at least partially defines or accommodates a second flow path for the extinguishing agent through the adapter for use when the fire extinguisher of which the adapter is part is discharged. The first and second flow paths are different.

The second flow path is accommodated by the adapter when a part of the dip tube and part of the release valve are engaged with and within a bore or passage defined by the adapter and the second flow path is defined by those parts of the dip tube and release valve.

In an embodiment of the above embodiment, the adapter is so configured that the first flow path is not disrupted if the dip tube is engaged with the adapter and the dip tube is blocked.

In an embodiment of any of the above embodiments, the adapter is so configured that the first flow path does not include the extinguishing agent passing from the adapter and flowing through the dip tube.

In an embodiment of any of the above embodiments, the first flow path has a lower resistance to the flow of extinguishing agent than the second flow path.

It is known that the conditions under which the extinguishing agent is introduced into the internal volume of a fire extinguisher (when the fire extinguisher is being prepared for deployment to a position in which the fire extinguisher will sit until it is used, also termed discharged) are different from the conditions when the fire extinguisher is discharged. In particular, the internal pressure of the extinguishing agent is significantly higher when the fire extinguisher is discharged than when the extinguishing agent is being introduced into the cylinder. Known Fire extinguishers, once the release valve and dip tube have been engaged with the cylinder include only one flow path for the extinguishing agent.

An advantage of the present disclosure is that the configuration of the adapter allows for the difference in the conditions under which the extinguishing agent follows the first flow path and the second flow path. And in particular that the extinguishing agent will flow along the second flow path when the fire extinguisher is discharged but not when the cylinder is being charged with extinguishing agent.

More specifically, the extinguishing agent will flow along a dip tube when the fire extinguisher is discharged as a result of the internal pressure of the extinguishing agent, whereas attempts to charge the cylinder with extinguishing agent through a dip tube will, at best, lead to very slow charging of the cylinder with extinguishing agent, and at worst the dip tube will become blocked because the extinguishing agent is not at sufficient pressure to force it along the dip tube.

For non-liquid extinguishing agents, for example dry powder extinguishing agents, it is not desirable or in some circumstances possible to introduce a dip tube into the extinguishing agent once the extinguishing agent has been placed into the cylinder. This is because of the risk of damage to the dip tube and/or the difficulty of accurately locating the dip tube within the cylinder. This risk and difficulty is enhanced when a non-linear dip tube is to be used in the fire extinguisher. The adapter of the present disclosure is advantageous because it allows the cylinder to be charged with extinguishing agent whilst the dip tube is in the cylinder and connected to the adapter and located in the desired position for the dip tube within the cylinder.

In an embodiment of the above embodiment, the adapter comprises a cylinder engagement element, a through bore and at least one filling hole. The cylinder engagement element is configured to engage with the neck of a cylinder. The adapter defines the through bore, and the through bore extends between a first mouth opening through a first portion of the adapter and a second mouth opening through a second portion of the adapter. The adapter is so configured that when the adapter is engaged with the cylinder the first mouth of the through bore opens outside the cylinder and the second mouth opens within the cylinder or the neck of the cylinder. The first mouth of the through bore is configured to engage with the release valve, and the second mouth is configured to engage with a dip tube. Each filling hole extends between a first hole end which is a hole in a surface that defines the through bore, and a second hole end. When the adapter is engaged with the cylinder the second hole end is located both in a part of a surface of the adapter that is within the cylinder or the neck of the cylinder, and in a position from which there is a flow path for extinguishing agent from the second hole end to the internal volume of the cylinder.

It is to be understood that in this description when a first element is described as “engaged with” a second element this indicates that the elements are physically interlocked with each other and that the interlocking has continued until further performance of the action that caused the interlocking has ceased to be possible. For example if the first element includes an external screw thread and the second element includes a compatible internal screw thread, the elements are engaged with each other when the screw threads have been screwed together until further screwing together of the screw threads was no longer possible.

In an embodiment of the above embodiment, the adapter is configured to engage with a cylinder which is so configured that the neck of the cylinder extends in an axial direction away from the outer surface of the cylinder, the neck defines a hollow passage extending between a free end of the neck and the internal volume of the cylinder, and the neck comprises an adapter engagement element. In some embodiments the adapter engagement element has the form of an internal screw thread. In some other embodiments the adapter engagement element has the form of an external screw thread.

In an alternative embodiment of the above embodiment, the adapter is configured to engage with a cylinder which is so configured that the neck of the cylinder extends in an axial direction into the internal volume of the cylinder, the neck defines a hollow passage extending between the internal volume of the cylinder and the outer surface of the cylinder, and the neck comprises an adapter engagement element. In some embodiments the adapter engagement element has the form of an internal screw thread.

In an alternative embodiment of the above embodiment, the adapter is configured to engage with a cylinder which is so configured that the neck of the cylinder extends between the inner surface of the cylinder and the outer surface of the cylinder, and the neck comprises an adapter engagement element. In some embodiments the adapter engagement element is an internal screw thread.

An advantage of the adapter of the present disclosure is that without changing the functioning or dimensions of the remaining elements of the adapter, the configuration of the adapter can be chosen to allow the adapter to be engaged with any pre-existing fire extinguisher cylinder. This allows the adapter of the present disclosure to be retro-fitted to pre-existing fire extinguisher cylinders. This is advantageous because it allows the adapter to be used with locally approved types of cylinders, and existing cylinders with minimal engineering changes to the adapter.

In an embodiment of any of the above embodiments, the second mouth is so configured that the engagement between the adapter and the dip tube is a sliding fit and the adapter comprises a lock element configured to lock the dip tube in position relative to the adapter. The dip tube is a sliding fit within the second mouth.

In an embodiment of any of the above embodiments, the through bore of the adapter is linear.

In an embodiment of any of the above embodiments, the adapter comprises a stop element, and the stop element defines a part of the second mouth that is furthest from the second portion of the adapter. The stop element is configured to prevent more than a predetermined length of a first end of the dip tube from being inserted into the second mouth.

In an embodiment of the above embodiment, the stop element has the form of an annular ring.

In an embodiment of any of the above embodiments, the adapter is so configured that the first hole end of each filling hole is closed when the release valve is engaged with the adapter. The closure of the first hole end of each filling hole occurs as a result of part of the release valve blocking or closing the first end hole or by the release valve causing the first hole end to open into a closed volume within the through bore of the adapter. A closed volume is one in which the only flow path into or out of the volume is through a filling hole. The effect of the closure of the filling hole is that when the fire extinguisher of which the adapter is a part is discharged, the extinguishing agent and/or any propellent gas in which the extinguishing agent may be entrained cannot leave the internal volume of the cylinder via the filling hole.

In an embodiment of any of the above embodiments, the first portion of the adapter comprises one or more first indexing elements, the second portion of the adapter comprises one or more second indexing elements, and the first and second indexing elements are aligned with each other. A first and second index mark are aligned with each other when the radial direction from the central axis of the first mouth to the first index mark is the same as the radial direction from the central axis of the second mouth to the second index mark.

In an embodiment of any of the above embodiments, the adapter comprises a seal element, and the seal element is positioned in the through bore between the second mouth and the first hole end of the filling hole or holes.

In an embodiment of any of the above embodiments, there are one, two, three or four filling holes.

In an alternative embodiment of the above embodiment, there are five or more filling holes.

The minimum size and number of the filling holes is determined by the rate of flow of extinguishing agent that can be achieved through the filling holes and by the need for the filling holes not to become blocked by the extinguishing agent when extinguishing agent is being charged or introduced into the internal volume at the pressures used for the introduction of the extinguishing agent.

According to a second aspect of the present disclosure there is provided a fire extinguisher comprising a cylinder having a neck through which the inside of the cylinder may be accessed, a release valve, an adapter according to the first aspect of the present disclosure, and a dip tube.

In an embodiment of any of the above embodiments, the release valve comprises an adapter engagement element and a discharge passage. The discharge passage is configured to be in fluid communication with the through bore of the adapter when the release valve is engaged with the adapter, and a part of the length of the discharge passage is surrounded by the adapter engagement element. The first mouth of the adapter is configured to engage with the valve engagement element of the release valve.

In an embodiment of any of the above embodiments, the dip tube comprises one or more entry holes; and the dip tube is so configured that the dip tube may be fixed to the adapter in an orientation relative to the adapter such that the one or more entry holes are in a predetermined part of the internal volume of the cylinder when the adapter is engaged with the cylinder.

The entry holes are configured to allow the extinguishing agent and any propellent gas into the dip tube when the fire extinguisher in which the dip tube is located is discharged.

In an embodiment of any of the above embodiments, the through bore in the adapter is linear, and the release valve comprises a valve dip tube. The valve dip tube extends from the discharge passage of the release valve towards the second mouth of the adapter when the release valve is engaged with the adapter. The valve dip tube is linear, dimensioned to be a loose or sliding fit within the through bore of the adapter, and sufficiently long that when the release valve is engaged with the adapter the valve dip tube closes the first hole end of the or each filling hole.

In an embodiment of any of the above embodiments, the adapter comprises a seal element, and the seal element is positioned in the through bore between the second mouth of the adapter and the first hole end of the or each filling hole. When the release valve is engaged with the adapter the seal element forms a pressure tight seal between the valve dip tube and the surface defining the through bore.

In an embodiment of any of the above embodiments, the adapter engagement element of the release valve is so configured that when the release valve is engaged with the adapter the adapter engagement element closes the first hole end of each filling hole.

In an embodiment of any of the above embodiments, the adapter comprises a seal element, and the seal element is positioned in the through bore between the second mouth of the adapter and the first hole end of the or each filling hole. When the release valve is engaged with the adapter the seal element forms a pressure tight seal between the adapter engagement element of the release valve and the surface defining the through bore.

In an embodiment of any of the above embodiments, the fire extinguisher comprises an extinguishing agent in the form of a dry powder.

According to a third aspect of the present disclosure there is provided a method of charging a fire extinguisher comprising:providing a cylinder with a neck through which the inside of the cylinder may be accessed, an adapter according to the first aspect of the present disclosure, a dip tube, and a release valve;engaging a first end of the dip tube with the second mouth of the through bore of the adapter;inserting a second end of the dip tube through the neck and engaging the adapter with the neck of the cylinder;introducing a predetermined amount of extinguishing agent into the cylinder;engaging the release valve with the first mouth of the through bore of the adapter with the result that the first hole end of each filling hole in the adapter is closed; andpressurizing the cylinder through the release valve.

The extinguishing agent may be introduced into the cylinder by any appropriate method including, but not limited to, using a funnel or a pumped source of extinguishing agent.

In an embodiment of any of the above embodiments, the extinguishing agent is a dry powder extinguishing agent.

In an embodiment of any of the above embodiments, the method comprisesproviding a cylinder with a predetermined vertically lowest part of the cylinder when the fire extinguisher is orientated for use;providing an adapter in which the first portion of the adapter comprises one or more first indexing elements, the second portion of the adapter comprises one or more second indexing elements, and the first and second indexing elements are aligned with each other;providing a dip tube comprising one or more entry holes, in which the dip tube is so configured that the one or more entry holes may be in the predetermined vertically lowest part of the cylinder when the fire extinguisher is orientated for use;before engaging a first end of the dip tube with the second mouth of the through bore of the adapter, the adapter is engaged with the neck of the cylinder and the orientation of the adapter relative to the predetermined vertically lowest part of the cylinder when the fire extinguisher is orientated for use is noted using the indexing element of the first portion; andwhen engaging the first end of the dip tube with the second mouth of the through bore of the adapter the indexing elements on the second portion of the adapter are used to orientate the dip tube so that once the adapter is engaged with the neck of the cylinder the entry holes of the dip tube are in the predetermined vertically lowest part of the cylinder when the fire extinguisher is orientated for use.

The apparatus of the first and second aspects of the present disclosure can include one or more, or all, of the features described above as appropriate. The method of the third aspect of the present disclosure can include one or more, or all, of the features described above as appropriate.

DETAILED DESCRIPTION

With reference toFIG.1, a fire extinguisher2comprises a cylinder4to which a pair of mounting brackets6are attached. The cylinder4has a cylindrical hollow neck8through which the inside of the cylinder4may be accessed. The cylinder4and neck8have a common central axis A.

The fire extinguisher2is configured to be attached vertically beneath a horizontal surface5, for example a ceiling. The mounting brackets6are used to attach the fire extinguisher2to the ceiling5. In alternative non-illustrated embodiments the fire extinguisher may be alternatively orientated. For example the cylinder may be orientated so that the neck of the cylinder is the vertically uppermost. The possible orientations are limited by a requirement that the release valve is vertically above the dip tube.

Engaged with the neck8is an adapter10, and engaged with the adapter10is a release valve12. The release valve12includes a valve actuator14and a discharge mouth16. The valve actuator14may be a known form of fire extinguisher actuator, for example, but without limitation, the valve actuator14may be an actuator that causes the fire extinguisher2to discharge an extinguishing agent88stored in the cylinder4when the actuator14reaches a predetermined temperature. The extinguishing agent88(seeFIG.5) is discharged through the discharge mouth16.

The cylinder4is a cylinder suitable for use as part of a fire extinguisher. A pair of mounting brackets6are attached to the outer surface29of the cylinder4.

The cylinder4has a cylindrical hollow neck8. The neck8defines a hollow passage20that extends from the outer end18of the neck8to the inner surface28of the cylinder4(seeFIG.2). Inner surface28substantially defines the internal volume22of the cylinder4(seeFIGS.5and7).

With reference toFIGS.2and5, greater detail of the neck8, adapter10and the inside of the cylinder4are shown. The neck8extends in an axial direction away from the cylinder4and a radially inner surface24of the neck8defines the passage20. A portion of the inner surface24extending from the outer end18towards the cylinder4is an adapter engagement element26which has the form of an internal thread.

In some non-illustrated embodiments of the cylinder4the neck8may extend between the inner surface28of the cylinder4and the outer surface29of the cylinder4and be defined by the portion of the cylinder4that surrounds the passage20. In some non-illustrated embodiments of the cylinder4the adapter engagement element26may extend for the whole of the distance from the outer end of the neck to the internal surface of the cylinder. In some other non-illustrated embodiments of the cylinder4the neck8may have a smooth inner surface24and some or all of the radially outer surface of the neck8may be an adapter engagement element with the form of an external screw thread.

The adapter10includes a cylinder engagement element30in the form of an external thread. The cylinder engagement element30is configured to engage with the adapter engagement element26of the cylinder4. This is advantageous because different adapters10according to the present disclosure can be configured to engage with different configurations of cylinder4/neck8without changing the other features of the adapter10. The cylinder engagement element30and adapter engagement element26are so configured that screwing them together until a stop surface32of the adapter10abuts the outer end18of the neck8forms a pressure tight or substantially pressure tight engagement between the neck8and the adapter10. In some embodiments a suitable pressure resistant seal34may be located between the stop surface32and outer end18. The adapter10has a central axis which is co-axial with central axis A when the adapter10is engaged with the cylinder4.

The adapter10also includes a linear through bore36defined by a bore surface38of the adapter10. The through bore36has a circular cross-section in the plane perpendicular to central axis A, and extends between a first mouth opening40through a first portion42of the adapter10and a second mouth44opening through a second portion46of the adapter10. When the cylinder engagement element30and adapter engagement element26of the cylinder4are engaged with each other the first portion42is in the atmosphere surrounding the cylinder4and the second portion46is within the passage20or internal volume22. The first and second mouths40,44each have a central axis which is co-axial with central axis A when the adapter10is engaged with the cylinder4.

The first mouth40is configured to engage with the release valve12and includes a valve engagement element48in the form of a conical internal thread. The valve engagement element48decreases in diameter from the surface of the first portion42of the adapter10to the diameter of the through bore36.

The second mouth44is configured to engage with a dip tube50, and includes an axially extending length of an inner surface52of increased diameter relative to the through bore36. The inner surface52is in the form of a screw thread which is configured to be threadedly connected to a screw thread (not shown) formed in a first end portion54of the dip tube50.

In an alternative non-illustrated embodiment, the increased diameter of the second mouth/inner surface of the second mouth is such that a first end portion of the dip tube is a sliding fit within the inner surface.

The maximum amount of the first end portion54of the dip tube50that can be inserted into the second mouth44is governed by a stop ring66which is formed at the edge of the increased diameter surface52. A lock element in the form of an internally threaded bore56and grub screw58are provided to lock the dip tube50in position relative to the adapter10. The threaded bore56extends through the adapter10from an outer surface60to the inner surface52. The grub screw58is adapted to engage with the thread of the threaded bore56and can be tightened so that the grub screw58bears on a part of the end portion54of the dip tube to fix or lock the position and orientation of the dip tube50relative to the adapter10.

Extending through the adapter10between the bore surface38and outer surface60are four filling holes62(of which only three are shown). The filling holes62are of a size such that extinguishing agent88may flow through the filling holes without blocking or clogging the filling holes62. The adapter10is so configured that the outer surface60of the adapter10is spaced from the inner surface24of the neck8by a sufficient distance that the extinguishing agent88can flow along the portion of the passage20between the outer surface60and inner surface24and into the internal volume22without blocking or clogging that part of the passage20.

Positioned between the end of the second mouth44closest to the first mouth40and the filling holes62is an annular seal element64.

With reference toFIG.3, an end view of the illustrated embodiment of the adapter10shows the first mouth40and the first portion42. The first portion40includes a plurality of first index marks84. The first index marks84are each separated by an angle of 45 degrees around the central axis of the first mouth.

With reference toFIG.4, a second end view of the illustrated embodiment of the adapter10shows the second mouth44and the second portion46. The second portion46includes a plurality of second index marks86. The second index marks86are each separated by an angle of 45 degrees around the central axis of the second mouth.

With reference toFIGS.3and4, the first and second index marks84,86are aligned with each other. A first and second index mark84,86are aligned with each other when the radial direction from the central axis of the first mouth to the first index mark84is the same as the radial direction from the central axis of the second mouth to the second index mark86.

With reference toFIG.5, the dip tube50is longitudinally extending and so configured that the portion of the dip tube that includes the entry holes68is closer to the part of the cylinder4diametrically opposite to the mounting brackets6than other parts of the cylinder4when correctly orientated relative to the adapter10. This has the effect of maximising the quantity of extinguishing agent88that can enter the dip tube50via the entry holes68when the fire extinguisher2is discharged. The entry holes68are of sufficiently large dimensions that extinguishing agent may enter the dip tube50without becoming blocked by the extinguishing agent when the internal volume22is pressurized to a predetermined pressure. The predetermined pressure is a pressure that will cause the fire extinguisher to perform as it is designed to perform.

With reference toFIGS.2and6, the release valve12includes an adapter engagement element70and a discharge passage74. The adapter engagement element70includes an external conical thread72which is configured to be engageable with the valve engagement element48of the first mouth40of the adapter10.

The adapter engagement element70extends from a main body76of the release valve12to an engagement end78and the diameter of the conical thread decreases from the intersection of the adapter engagement element70with the main body76to the engagement end78.

The engagement end78of the adapter engagement element70is adapted to receive a linear valve dip tube80. The valve dip tube80projects into the through bore36of the adapter and past the seal element64when the release valve12is engaged with the adapter10. The valve dip tube80is so dimensioned that the open ends of the filling holes62in the bore surface38are closed by the valve dip tube80. The seal element64forms a pressure tight seal between the valve dip tube80and the bore surface38. If the closure of the filling holes62by the valve dip tube80is not pressure tight, a closed volume is formed between the seal element64, bore surface38, valve engagement element48/adapter engagement element70and valve dip tube80.

The main body of the release valve12defines a part of the discharge passage74that fluidly connects the part of the discharge passage74surrounded by the adapter engagement element70and the discharge mouth16. A valve element82which is controlled by the actuator14controls the flow of extinguishing agent (not shown inFIGS.2and6) along the discharge passage74.

The release valve12also includes a known system (not shown) that allows the cylinder internal volume22to be pressurized, once the adapter10is engaged with the cylinder4, and the release valve12is engaged with the adapter10. The pressurization may be with nitrogen or other gases commonly used for fire extinguishers.

With reference toFIG.7, a method of charging a fire extinguisher2with an extinguishing agent88includes providing a cylinder4with a neck8that defines a passage20through which the internal volume22inside of the cylinder4may be accessed. The cylinder4is selected for its ability to withstand the pressures and use conditions required of the fire extinguisher2.

An adapter10is provided on which the first and second portions42,46carry first and second indexing marks84,86respectively.

Also provided is a dip tube50which includes one or more entry holes68, in which the dip tube50is so configured that the one or more entry holes68may be located in the vertically lowest part of the cylinder4when the fire extinguisher2is orientated for use. The vertically lowest part of the cylinder4when the fire extinguisher2is orientated for use can be determined by reference to the position of the mounting brackets6on the cylinder4and a knowledge of where the fire extinguisher2is to be mounted, for example onto the underside of a ceiling5(seeFIG.1).

Before a first end54of the dip tube50is engaged with the second mouth44of the through bore36of the adapter10, the adapter10is engaged with the neck8of the cylinder4. The engagement is tightened to the level of torque that will be employed when the fire extinguisher is constructed ready for use. The orientation of the release valve12relative to the determined vertically lowest part of the cylinder4is noted using the first indexing elements84on the first portion42.

The adapter10is next disengaged from the cylinder4.

The first end54of the dip tube50is engaged with the second mouth44of the through bore36of the adapter10and the second indexing elements86located on the second portion46of the adapter10are used to orientate the dip tube50. Once the dip tube50is correctly orientated the grub screw58is tightened in the threaded bore56to fix the orientation of the dip tube50. The orientation is determined by the previously measured orientation of the adapter10relative to the cylinder4and has the effect that once the adapter10(with which the dip tube50is engaged) is engaged with the neck8of the cylinder4the entry holes68are in the determined vertically lowest part of the cylinder4when the fire extinguisher2is orientated for use.

The second end90of the dip tube50is inserted through the passage20in the neck8until the cylinder engagement element30of the adapter10and the adapter engagement element26of the cylinder4are in a position to engage with each other. The cylinder engagement element30and adapter engagement element26are then caused to engage with each other so that a pressure tight engagement is achieved.

A funnel (not shown) is engaged with the valve engagement element48of the first mouth40of the adapter10and a predetermined amount of extinguishing agent88is introduced into the cylinder4. The extinguishing agent88will flow from the funnel into the through bore36. The extinguishing agent88will then, pass out of the through bore36and into the passage20/internal volume22through the filling holes62. Depending on the nature of the extinguishing agent88, some extinguishing agent88may flow along the dip pipe50and out of the entry holes68therein but the dip tube50may become blocked because of the low pressures used to charge the cylinder4with the extinguishing agent88.

Once the cylinder4is fully charged with extinguishing agent88, the funnel is disengaged from the valve engagement element48.

The release valve12is next engaged with the valve engagement element48of the adapter10. The engagement of the release valve12with the valve engagement element48causes the filling holes62to be closed or blocked with the result that when the fire extinguisher2is discharged the extinguishing agent88and any propellent gas cannot pass through the filling holes62forcing the extinguishing agent88and any propelling gas to enter the dip tube50through the entry holes68and travel along the dip tube50.

Once the release valve12is engaged with the adapter10the cylinder4may be pressurized by a known technique. For example, for a fire extinguisher2that contains a dry powder extinguishing agent88, pressurized nitrogen is introduced into the cylinder4.

The release valve12may be so configured that it is possible to release the pressurized gas within the cylinder4without operating the valve element82so as to cause the discharge of the extinguishing agent88. This is particularly useful if the fire extinguisher2needs to be serviced. Once the pressurized gas is released from the cylinder4the extinguishing agent88can be poured out of the cylinder4through the filling holes62. Thereafter the adapter10can be disengaged from the cylinder4. It is noted that where the extinguishing agent88is a dry powder and the dip tube50is not is not a linear dip tube this is co-axial with central axis A when the adaptor10is engaged with the cylinder4, it is likely not to be possible to disengage the adapter10from the cylinder4without damage to at least the dip tube50whilst the extinguishing agent88is in the cylinder4.

The above description is meant to be exemplary only, and one skilled in the art will recognize that changes may be made to the embodiments described without departing from the scope of the disclosure. Still other modifications which fall within the scope of the present disclosure will be apparent to those skilled in the art, in light of a review of this disclosure.