GB2555514A

GB2555514A - Improved compressed fluid vessel

Info

Publication number: GB2555514A
Application number: GB1712180.7A
Authority: GB
Inventors: Nicholas Basford Adrian; Raymond Clinch Michael; Hepples Warren; Marie Pretty Claire; Bernd Joachim Wollschlaeger Thomas
Original assignee: Luxfer Gas Cylinders Ltd
Current assignee: Luxfer Gas Cylinders Ltd
Priority date: 2016-07-29
Filing date: 2017-07-28
Publication date: 2018-05-02
Also published as: GB201712180D0; WO2018020267A1; GB201613184D0

Abstract

A pressure regulating and fluid delivery system for use with a compressed fluid vessel 1, has a high pressure inlet, a regulated pressure outlet 4, a pressure reducer for reducing the pressure of fluid from the inlet to a regulated pressure, and an adjustable outlet flow control 51 incorporating a flow control cavity 52 and a flow control disk 54. The disk 54 is mounted for rotation in the cavity 52 in spaced relationship away from the walls of the cavity 52 and has a plurality of angularly spaced different sized holes 59. A flow control outlet 64 seals with the disk 54 to allow fluid flow only through an aligned one of the holes 59. Also provided is shut off valve including a valve seat and a drive. Further provided is a pressure regulating system including a main body machined from a single block.

Description

(54) Title of the Invention: Improved compressed fluid vessel Abstract Title: Compressed Fluid Vessel (57) A pressure regulating and fluid delivery system for use with a compressed fluid vessel 1, has a high pressure inlet, a regulated pressure outlet 4, a pressure reducer for reducing the pressure of fluid from the inlet to a regulated pressure, and an adjustable outlet flow control 51 incorporating a flow control cavity 52 and a flow control disk 54. The disk 54 is mounted for rotation in the cavity 52 in spaced relationship away from the walls of the cavity 52 and has a plurality of angularly spaced different sized holes 59. A flow control outlet 64 seals with the disk 54 to allow fluid flow only through an aligned one of the holes 59. Also provided is shut off valve including a valve seat and a drive. Further provided is a pressure regulating system including a main body machined from a single block.

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Field of the invention [0001] The present invention relates to an improved compressed fluid vessel. Preferably, but not exclusively, the present invention is suitable for use in delivering gases such as, but not limited to, air and pharmaceutical gases such as oxygen. The present invention is particularly suited, but not exclusively, to lightweight compressed gas cylinders which enable patients, reliant upon regular or continuous gas therapy, to remain ambulatory.

Description of the related art [0002] Some medical treatments involve the use of gases that are inhaled by the patient. In the case of patients having chronic but stable conditions requiring regular or continuous treatment, portable lightweight compressed gas cylinders enable such patients to receive the treatment they need outside of a treatment center, for example in the patient’s own home and elsewhere.

[0003] Chronic obstructive pulmonary disease, (COPD) is a disabling respiratory disease and oxygen therapy is one of the few effective therapies known to increase survival for people with COPD. However, survival is only improved in those who inhale oxygen regularly and as prescribed. It is known that many patients with COPD do not use their oxygen regularly and/or as prescribed and so do not receive fully the health benefits of this therapy. Easily portable oxygen vessels can play an important role in enabling patients prescribed oxygen long term to remain ambulatory whilst also adhering to their prescription. Currently, however, many patients remain housebound due to the size and weight of existing oxygen systems.

[0004] Pressurised fluid vessels are, of course, very well-known and have been used in the storage and supply of compressed (pressure > 1 bar) gases for many years. Typically a gas cylinder is a seamless, one-piece vessel which is symmetric about a longitudinal axis and is formed of a strong metallic material such as steel or an aluminium alloy. The walls of the vessel have a thickness sufficient to withstand cycling of pressures well in excess of atmospheric pressure e.g. 200 bar. Such cylinders are generally referred to as Type 1 cylinders.

[0005] Lighter weight alternatives to conventional steel cylinders have been developed in recent years. These are particularly of benefit where the gas cylinder is to be carried, for example by ambulatory patients and emergency services. Typically such lighter weight alternatives comprise a liner consisting of the same or similar types of strong metallic material used in Type I cylinders which is partially (Type II cylinders) or fully (Type III cylinders) encased in a composite material comprising, for example, carbon fibre filaments and an epoxy resin. The primary purpose of the liner is to contain the fluid and to transfer internal gas pressure to the fibres. This permits a significant reduction in the thickness of the metallic walls of the cylinder which has the effect of reducing the total weight of the gas cylinder. As with Type I cylinders, the liner walls in combination with the outer composite material encasement are sufficiently strong to withstand cycling of pressures well in excess of atmospheric pressure e.g. 300 bar, 500 bar and even higher (e.g. 700 bar in the case of hydrogen gas). Type IV and Type V cylinders can be used for the containment of non-oxidising gases. [0006] For all types of cylinder, the vessel has an open neck encircling and coaxial with the longitudinal axis of the cylinder. In the cylinder neck a valve is mounted via which gas is supplied to or from the vessel. The valve typically comprises a brass body with external screw threads which engage with cooperating female threads formed on the inside of the neck of the vessel. The valve is normally connected to a user operable handle or similar to control the discharge of gas from the cylinder. In view of the significant gas pressures within the cylinder, the valve is, of necessity, robust both in terms of containing the gas pressure within the cylinder and in terms of withstanding external abuse and impacts. Furthermore, in the case of pressurized gas cylinders the valve is usually accompanied by a pressure regulator, otherwise referred to as a pressure reducer. As gas is dispensed from the cylinder the primary pressure, namely the pressure within the cylinder, falls and the regulator is adapted to accommodate this fail in primary pressure in a force balance system.

[0007] A pressure reducing valve suitable for use in a pressurized fluid vessel is described in GB2298026 and W02006/067527 the contents of which is incorporated herein by reference. In each case, the valve comprises a poppet with a large-diameter valve seating surface in combination with a small effective valve member cross-section. The poppet has within it a piston and cylinder combination which, in turn, has a chamber exposed to the low pressure side of the valve.

Summary of the invention [0008] The present invention seeks to provide an improved compressed fluid vessel. The present invention further seeks to provide an improved compressed fluid delivery system for use with a compressed fluid container.

[0009]The present invention further seeks to provide a compressed fluid delivery system which is robust and suitable for control and use by patients without medical supervision.

[00010] According to the present invention there is provided a pressure regulating and fluid delivery system adapted for use with a compressed fluid vessel, the pressure regulating and fluid delivery system comprising: a high pressure inlet; a regulated pressure outlet; a pressure reducer in fluid communication with the high pressure inlet for reducing the pressure of fluid from the high pressure inlet to a predetermined regulated pressure; and an adjustable outlet flow control comprising: a flow control cavity in fluid communication with the pressure reducer and the regulated pressure outlet, a flow control disk mounted on an axle for rotational movement within the flow control cavity and including a plurality of angularly spaced radially equidistant flow control holes with each one of the plurality of flow control holes having a different hole diameter, the axle supporting the flow control disk in a spaced relationship away from the walls of the flow control cavity; and a flow control outlet pipe adapted to form a fluid seal with the surface of the flow control disk whereby fluid flow out from the flow control cavity is via a flow control hole when aligned with the flow control outlet pipe.

[00011] In a preferred embodiment the flow control disk further includes at least one pressure balancing hole positioned at a radial distance from the rotational axis of the flow control disk different to the radial distance of the plurality of flow control holes and in a particularly preferred embodiment the at least one pressure balancing hole is positioned radially inside of the plurality of flow control holes.

[00012] Also the flow control outlet pipe is preferably adapted to present negligible frictional contact with the surface of the flow control disk during rotational movement of the flow control disk.

[00013] Preferably the edge of the flow control outlet pipe for contact with the flow control disk comprises an O-ring.

[00014] In a further preferred embodiment the pressure regulating and fluid delivery system further comprises a position indexing mechanism for restricting stable rotational positions of the flow control disk to a plurality of predetermined angular positions. The angular spacing between adjacent flow control holes of increasing diameter in the flow control disk may be equal with the angular spacing between the smallest flow control hole and the largest flow control hole being a multiple x of the angular spacing between other adjacent flow control holes.

[00015] The flow control disk may include a zero flow setting and the pressure regulating and fluid delivery system may further comprise a pressure regulator in fluid communication with the high pressure inlet and the flow control cavity, the pressure regulator being adapted to reduce the pressure of fluid flowing from the high pressure inlet and for supplying fluid at a lower regulated pressure to the flow control cavity whereby the pressure regulator is further adapted to function as a secondary fluid flow isolator when the flow control disk is set to the zero flow setting.

[00016] In a particularly preferred embodiment a main body includes a cavity open to the exterior of the main body, the pressure reducer and the outlet flow control being mounted within the cavity. The pressure reducer is preferably stacked below the outlet flow control within the main body cavity.

[00017] In a second aspect the present invention provides a compressed fluid vessel comprising: a casing; a hollow fluid container adapted to contain fluid at pressures greater than 1 bar provided within the casing; a pressure regulating and fluid delivery system as described above mounted within the casing, the high pressure inlet of the pressure regulating and fluid delivery system being in fluid communication with the interior of the hollow fluid container and the regulated pressure outlet extending through the casing; and a manually operable flow control mounted in a first aperture in the casing and adapted for rotational movement relative to the casing, the manually operable flow control being connected to the axle of the flow control disk for manual adjustment of the rate of fluid flow from the regulated pressure outlet.

[00018] Preferably the manually operable flow control includes at least one abutment for maintaining rotational alignment of the manually operable flow control and the flow control spindle. The at least one abutment of the manually operable flow control may be a downwardly extending cylindrical wall encircling at least part of the position indexing mechanism of the pressure regulating and fluid delivery system.

[00019] In a preferred embodiment the casing includes indicia representative of different fluid flow rates at the regulated pressure outlet corresponding to different rotational positions of the manually operable flow control relative to the casing.

[00020] Also the compressed fluid vessel may further comprise a display mounted in a second aperture in the casing, the display being adapted to provide information relating to the amount of fluid within the hollow fluid container.

[00021] Ideally the compressed fluid vessel is manually portable. Also in a particularly preferred embodiment the hollow fluid container comprises a liner of a metallic material at least partially encased in a composite material.

[00022] In a third aspect the present invention provides a high pressure shut-off valve adapted for use in a compressed fluid vessel, the shut-off valve comprising: a valve chamber having a longitudinal axis and including a fluid inlet and a fluid outlet, the fluid inlet being adapted for fluid communication with a source of high pressure fluid; a valve spindle movable along the longitudinal axis ofthe valve chamber and having a sealing end portion for engagement with a rim ofthe fluid outlet; and a drive mechanism connected to the valve spindle, the drive mechanism being adapted for connection to a manually operable valve control, wherein the valve chamber includes a high pressure region encircling the fluid outlet, the high pressure region being in permanent fluid communication with the fluid inlet and wherein the surface area ofthe sealing end portion is greater than the area within the periphery of the fluid outlet whereby a portion of the sealing end portion is exposed to the high pressure region encircling the fluid outlet when the sealing end portion is in contact with the periphery of the fluid outlet.

[00023] Preferably the rim of the fluid outlet is provided at the free end of a projection into the valve chamber and the high pressure region ofthe valve chamber encircles the projection. In a particularly preferred embodiment the projection has a substantially frusto-conical or hyperbolic cross-section.

[00024] The sealing end portion preferably comprises a sealing insert having a minimum hardness of E25-45 (Rockwell).

[00025] The material of the sealing insert is preferably selected from either polyether ether ketone (PEEK) or Vespel™.

[00026] Preferably the drive mechanism converts manually applied rotational movement to axial movement ofthe valve spindle within the valve chamber towards and away from the fluid outlet.

[00027] Ideally the shut-off valve further comprises a limiter for restricting axial movement of the valve spindle within the valve chamber. The limiter may be adapted to restrict manually applied rotational movement ofthe drive mechanism.

[00028] In a fourth aspect the present invention provides a pressure regulating and fluid delivery system comprising; a high pressure inlet; a regulated pressure outlet; a shut-off valve as described above in fluid communication with the pressure inlet; a manually operable valve control connected to the drive mechanism ofthe shut-off valve; and a pressure regulator in fluid communication with the fluid outlet of the shut-off valve and the regulated pressure outlet, the pressure regulator being adapted to reduce the pressure of fluid flowing from the shut-off valve and for supplying fluid at a lower regulated pressure to the regulated pressure outlet.

[00029] The drive mechanism of the shut-off valve may be adapted to move the valve spindle from a fully closed position to a full flow position in response to no more than 180° rotation ofthe manually operable valve control.

[00030] Also fluid conduits may be provided which interconnect the hollow fluid container and the shut-off valve, the shut-off valve and the pressure regulator, and the pressure regulator and the regulated pressure outlet, the fluid conduits being provided in a main body being a unitary indivisible component. [00031] In a particularly preferred embodiment the main body includes a first cavity open to the exterior of the main body, the shut-off valve being mounted in the first cavity and a second cavity open to the exterior of the main body, the pressure regulator being mounted in the second cavity.

[00032] In a fifth aspect the present invention provides a compressed fluid vessel comprising: a casing; a hollow fluid container adapted to contain fluid at pressures greater than 1 bar provided within the casing; and a pressure regulating and fluid delivery system as described above wherein the compressed fluid vessel is manually portable.

[00033] Preferably the manually operable valve control is mounted on or in the casing and is capable of rotational movement relative to the casing.

[00034] In a particularly preferred embodiment the hollow fluid container comprises a liner of a metallic material at least partially encased in a composite strengthening material.

[00035] In a sixth aspect the present invention provides a pressure regulating and fluid delivery system adapted for use with a compressed fluid vessel, the pressure regulating and fluid delivery system comprising: a main body including at least first and second cavities each open to the exterior of the main body, a high pressure inlet and a regulated pressure outlet; a high pressure valve mounted in the first cavity; and a pressure reducer mounted in the second cavity, the pressure reducer being in fluid communication with the high pressure inlet for reducing the pressure of fluid from the high pressure inlet to a predetermined regulated pressure; wherein the main body is machined from a single block and has fluid conduits interconnecting the first and second cavities and interconnecting the high pressure inlet with the first cavity and the regulated pressure outlet with the second cavity.

[00036] The pressure regulating and fluid delivery system may further comprise a manually adjustable fluid flow control for adjustment of the flow rate of fluid out of the regulated pressure outlet. Ideally the manually adjustable fluid flow control is mounted in the second cavity above the pressure reducer.

[00037] The main body may include a third cavity and a fluid pressure monitor mounted in the third cavity, a fluid conduit machined through the main body providing fluid communication between the high pressure inlet and the third cavity.

[00038] Whilst the pressure regulating and fluid delivery system and the pressurised fluid vessel of the present invention is particularly suited for use in the delivery of therapeutic gases to ambulatory patients, the pressure regulating and fluid delivery system and the pressurised fluid vessel are not restricted to this manner of use. The pressure regulating and fluid delivery system and the pressurised fluid vessel described herein are also suitable for use by emergency services (EMS) and within hospitals; in self-contained breathing apparatus including SCBA; and for the storage and delivery of pressurised fluids generally.

In this regard, the pressure regulating and fluid delivery system and the pressurised fluid vessel are capable of both continuous and intermittent fluid delivery.

Brief description of the drawings [00039] An embodiment of the present invention will now be described by way of example only with reference to the accompanying drawings, in which:

Fig. 1 illustrates a compressed fluid vessel in accordance with the present invention;

Figs. 2A and 2B are perspective views of a pressure regulating and fluid delivery system for use with a pressurised gas cylinder according to the present invention;

Fig. 3 is a cross-sectional view of the high pressure side of the pressure regulating and fluid delivery system of Figs. 2A and 2B according to the present invention;

Fig. 4 is an enlarged sectional view of a high pressure shut-off valve of the pressure regulating and fluid delivery system according to the present invention;

Fig. 5 is a cross-sectional view of a high pressure outlet of the shut-off valve of Fig. 4;

Fig. 6 is a perspective view of a flow control spindle of a flow control mechanism in accordance with the present invention;

Fig. 7A is an enlarged sectional view of the regulated pressure side of the pressure regulating and fluid delivery system in accordance with the present invention;

Fig. 7B is further sectional view of Fig. 7A illustrating the physical relationship of the regulated pressure side with the high pressure side of the pressure regulating and fluid delivery system in accordance with the present invention;

Fig. 8 is a sectional view of the pressure regulator and flow control of Figs. 7A and 7B;

Fig. 9 is a sectional view of a flow control module in accordance with the present invention; and

Fig. 10 is a plan view of a flow control disk of the flow control module of Fig. 9.

Detailed description of an exemplary embodiment [00040] References herein to the singular are intended to also include the plural unless stated otherwise. Furthermore, references to relative spatial positions e.g. above, below, upper, lower, left or right etc. are references only to the relative positioning of components as illustrated in the figures. Such references to relative spatial positions are not intended to imply any restriction on orientation of the compressed fluid vessel or its components during use. To aid in understanding the component parts of the compressed fluid vessel are magnified in the figures but different figures are magnified to different degrees. Therefore, whilst the relative dimensions of parts within each figure are representative, the relative dimensions of parts between figures are not, in all cases, representative. Furthermore, whilst the pressurised fluid vessel of the exemplary embodiment described below is adapted for the delivery of a medical gas, it is to be understood that the pressurised fluid vessel described herein is not limited to therapeutic uses and is suitable for the storage and delivery of compressed fluids generally and irrespective of the intended purpose of those fluids.

[00041] A compressed fluid vessel in the form of a lightweight compressed gas cylinder 1 adapted for the delivery of a medical (otherwise referred to herein as a therapeutic) gas to a patient is shown in Fig. 1. The compressed gas cylinder 1 generally comprises a hollow main body 2 in which therapeutic gas is stored under pressure (>1 bar); a cylinder head 3; a gas outlet 4; a flow scale 5 indicating a plurality of different rates of gas flow out from the cylinder; and a display 6. The hollow main body 2 is preferably made of an aluminium alloy liner strengthened by being fully-wrapped in a bonded fibre on the outside. In a particularly preferred embodiment the liner is made using a 7xxx series aluminium alloy such as, but not limited to, the proprietary L7x material of the Luxfer Group of companies. To ensure that the gas cylinder is portable and can be carried easily by an ambulatory patient the illustrated cylinder has a gas capacity equivalent to 1 litre of water; a length preferably less than 50 cm, more preferably around 35 cm; a diameter preferably not more than 12 cm, more preferably below 10 cm, more preferably still between 7.5 cm and 9.5 cm; and weighs, when full, preferably not more than 2.5 Kg, more preferably not more than 2.2 Kg, and, when empty, preferably not more than 2 Kg, more preferably below 1.8 Kg, more preferably still around 1.6 Kg. The top hamper alone, which is described in greater detail below, preferably weighs around 0.8 Kg. Of course, the capacity and dimensions of the cylinder may be different to those set out above. In particular, a similar compressed fluid vessel with a gas capacity equivalent to 2 litres of water is slightly larger and heavier than the dimensions detailed above but is still manually portable.

[00042] A pressure regulating and fluid delivery system 10, for use in the gas cylinder described above, is described in greater detail below with reference to Figs. 2-10 and is used to control the pressure and rate of flow of gas from the cylinder main body 2. The pressure regulating and fluid delivery system 10 is mounted within the cylinder head 3 and includes the gas outlet 4 of the gas cylinder 1 and a manual flow control 3a forming an upper portion of the cylinder head 3. In the illustrated embodiment the gas outlet 4, which extends through the cylinder head casing, comprises a cannula connection which is adapted for fluid connection to conventional medical gas delivery systems used by patients. Alternative gas outlet connections such as, but not limited to, a Schrader connection are also envisaged. The manual flow control 3a is rotatable about the main longitudinal axis X of the cylinder and relative to the rest of the cylinder head 3 with the rate of flow of gas out from the cylinder 1 being changed by rotation of the manual flow control 3a. The flow scale 5 is mounted to or printed on a fixed lower section 3b of the cylinder head adjacent an outer rim of the manual flow control 3a. The rim of the manual flow control 3a includes a marker 5a so that as the rate of gas out-flow is adjusted through rotation of the manual flow control 3a the marker 5a moves relative to the flow scale 5. Thus the position of the marker 5a relative to the flow scale 5 at any moment in time indicates the rate of gas flow out of the cylinder 1 at that time.

[00043] The cylinder head 3 also includes a display 6 which provides information relating to the amount of gas remaining in the cylinder 1. The display 6 may additionally provide status information such as, but not limited to, usage time, battery status, gas pressure, gas temperature etc. The display 6 may be an analogue display (as illustrated in the figures) or a digital display or a combination of both analogue and digital. Where the display 6 includes a digital display, the digital display is controlled by a micro-controller as part of an electronic gauge 8 mounted within the cylinder head 3. An electronic gauge 8, such as that described in GB2519969, the contents of which is incorporated herein, may be used to determine the amount of time remaining before full depletion of the gas within the cylinder.

[00044] Turning to Figs. 2-10 the pressure regulating and gas delivery system, in the form of a top hamper 10, includes a main body 11 which has a cylinder neck mounting 12 and an inlet supply 13 at its lower end. In the illustrated embodiment the inlet supply 13 is in the form of a dip tube but alternative forms of fluid inlet supply are also envisaged. The cylinder neck mounting 12 is sized to fit within and form a fluid seal with the neck (not shown) of the gas cylinder 1 and is threaded 12a on its outer surface to form a threaded coupling with the inner surface of the neck of the gas cylinder in the conventional manner. The dip tube 13 extends downwardly away from the main body 11 and the cylinder neck mounting 12 along the longitudinal axis X of the gas cylinder and is conventional in design. The dip tube 13 has a dip tube bore 15 and one or more gas inlet apertures 14 in fluid communication with the dip tube bore 15 (two gas inlet apertures are shown in this specific embodiment but may be different). The gas inlet apertures 14 are provided at the end of the dip tube 13 remote from the cylinder neck mounting 12 and enable ingress of gas from the main body 2 of the gas cylinder 1 into the dip tube bore 15.

[00045] As shown in Fig. 3 the upper end of the dip tube bore 15 is threadedly connected to the main body 11 and is in open fluid communication with two high pressure fluid conduits 16a, 16b provided in the main body 11. The first high pressure conduit 16a leads to a pressure gauge or transducer 17 which generates and supplies pressure information to the display 6. This arrangement enables the pressure gauge 17 to remain constantly ‘on’ and monitoring fluid pressure within the cylinder even when the gas flow is turned off. This functionality is useful as it means the contents of the cylinder can be monitored constantly. The second high pressure conduit 16b leads to a high pressure shutoff valve 20.

[00046] The high pressure shut-off valve 20 shown in Fig. 4 comprises a cavity or manifold defined by generally cylindrical walls 21,22 which have a common longitudinal axis Y substantially orthogonal to the longitudinal axis X of the gas cylinder. The inner cylindrical wall 21 includes a recess 18 sized to receive a sealing member 19 in the form of an O-ring or similar conventional fluid sealing device (in the illustrated embodiment the O-ring 19 is accompanied in the recess 18 by an anti-extrusion ring). The outer cylindrical wall 22 is slightly larger in diameter than the inner wall 21 and may, as illustrated, be substantially equal in diameter to the diameter of the cavity into the recess 18. At least part of the outer cylindrical wall 22 includes threads 23.

[00047] Mounted in the shut-off valve cavity and extending along the longitudinal axis of the manifold is a shut-off spindle 24. The spindle 24 extends through the sealing member 19 mounted in the recess 18 and slidingly engages the inner cylindrical wall 21 of the cavity. In addition the spindle 24 has threads 25 over part of its outer surface for co-operable engagement with threads 23 provided on the internal surface of the outer cylindrical wall 22. The co-operable threaded engagement of the spindle 24 with the outer cylindrical wall 22, and the sliding engagement of the spindle 24 with the inner cylindrical wall 21 permits rotational movement of the spindle relative to the main body 11 but also enables the spindle 24 to be removed for maintenance of the shut-off valve 20.

[00048] The second high pressure conduit 16b feeds into the shut-off valve 20 at the inner cylindrical wall 21 of the manifold. In the illustrated embodiment, the junction of the high pressure conduit 16b with the shut-off valve 20 is an open junction and so the shut-off valve cavity is exposed to the high pressure within the gas cylinder at all times. Alternative embodiments (not illustrated) are envisaged in which the shut-off valve cavity can be isolated from the high pressure within the cylinder. The innermost end portion of the spindle 24, within the inner cylindrical wall 21, includes a shut-off sealing insert 26 formed of polyether ether ketone (PEEK), DuPont™ Vespel™ SP-21 or other materials with a Rockwell hardness of E25-45 or similar, which form surfaces that are relatively smooth and with low friction characteristics. It is preferred, but not essential, that the material of the seating insert 26 has a Vickers hardness using the Hv0.1 scale which is equal to or greater than 20.0, more preferably equal to or greater than 25.0. The sealing insert 26 is mounted within a cavity provided in the innermost end portion of the spindle 24 so that the end portion of the spindle 24 encircles the side walls of the sealing insert 26 and only the end face of the sealing insert 26 is exposed.

[00049] Facing the shut-off sealing insert 26 is a shaped shut-off valve fluid outlet aperture 27. The shut-off valve fluid outlet aperture 27 is shaped to project into the shut-off valve cavity away from the innermost end wall of the shut-off valve cavity thereby forming part of the boundary of a generally annular high pressure region 28 surrounding the fluid outlet aperture 27. In the preferred embodiment, illustrated in Fig. 5, the shut-off valve fluid outlet aperture 27 is concentric with the longitudinal axis Y of the cavity and has a narrow rim 27a in the form of a valve seat with a diameter approximately 1/10, more preferably 1/6 greater than the diameter of the opening of the aperture 27. The valve seat 27a is preferably beveled and is the apex of a wall of substantially conical or hyperbolic section that projects from the innermost end wall of the cavity approx.

0.6 mm, more preferably approx. 1.0 mm. The beveled rim of the fluid outlet aperture 27 has a diameter of 2.5 mm, more preferably 1.75 mm, for an outlet aperture opening diameter of 2 mm, more preferably 1.5 mm. The spindle 24, in contrast, has a diameter of 10 mm, more preferably 6 mm, and is thus at least two times, more preferably four times, larger than the diameter of the opening of the outlet aperture 27. The exposed substantially flat outer surface of the PEEK sealing insert 26 engages the valve seat 27a forming a small sealing contact area.

[00050] The end of the spindle 24 opposite to the end comprising the sealing insert 26 projects beyond the shut-off valve cavity and is mounted to the rear of a manual shut-off control in the form of a hand wheel 29. The spindle 24 is mounted to the hand wheel 29 in any conventional manner (e.g. a threaded connection) which ensures rotational movement of the hand wheel 29 causes a corresponding rotation of the spindle 24. The cylinder head casing 3 has a generally circular aperture (not shown) which accommodates the hand wheel 29 whereby the hand wheel 29 is manually accessible from the outside of the casing and is freely rotatable relative to the cylinder head casing 3.

[00051] With the sealing insert 26 in contact with the valve seat 27a and sealing the outlet aperture 27, manual rotation of the hand wheel 29 in a first direction the threaded engagement between the spindle 24 and the outer cylindrical wall 22 causes the sealing insert 26 to be moved away from sealing engagement with the valve seat 27a by means of rotational and axial translation of the spindle 24 within the shut-off valve cavity. This enables high pressure fluid flow from the second high pressure conduit 16b into the shut-off valve outlet aperture 27. With the sealing insert 26 separate from the outlet aperture 27, manual rotation of the hand wheel 29 in the opposition direction causes the sealing insert 26 to be moved towards and into sealing engagement with the valve seat 27a. This shuts off high pressure fluid flow through the shut-off valve outlet aperture 27.

[00052] The underside of the hand wheel 29 which faces towards the main body 11 is shaped (not illustrated) so as to restrict rotational movement of the hand wheel 29 relative to the main body 11. Preferably maximum rotation of the hand wheel 29 is restricted to 180° or less. As only a small rotational movement of the hand wheel 29 is required to fully open I shut-off the high pressure valve, the shut-off valve is easy to operate even for those with limited mobility and/or strength. In addition the construction of the shut-off valve 20 described herein ensures a lower torque is required to close the shut-off valve 20 in comparison to the torque necessary to close the high pressure shut-off valves of conventional pressurised gas cylinders. Thus the shut-off valve 20 described herein is particularly suited for use in the delivery of therapeutic gases where the patient may have restricted mobility and/or strength.

[00053] The shut-off valve outlet aperture 27 of the shut-off valve 20 is in fluid communication with a high pressure inlet 42 of the flow control valve and regulator assembly 30 (see Figs. 7 and 8). The flow control valve and regulator assembly 30 is located within a regulator chamber 31 of the main body 11 and the flow control valve and regulator assembly 30 is substantially circularly symmetric about an axis X which is coaxial with the longitudinal axis of the gas cylinder 1. The flow control valve and regulator assembly 30 have many features common to the balanced valves described in GB2298026, the contents of which is incorporated herein by reference. In a particularly preferred embodiment the size and weight of the components of the flow control valve and regulator assembly 30 are oxygen compatible and miniaturized in comparison to conventional top hamper regulator components.

[00054] A detailed description of the pressure regulating valve module is not provided herein as the structure and operation of the valve module is similar to that described in GB2298026. A moveable valve member or poppet 34 is mounted in the chamber of a valve housing 32 which includes a regulated pressure valve outlet 33. The valve housing 32 is in threaded engagement with a wall of the regulator cavity or chamber 31 of the main body 11 which prevents movement of the valve housing 32 relative to the regulator chamber 31. Also an O-ring 35 provides a fluid seal bridging the junction between the wall of the regulator chamber 31 and the valve housing 32.

[00055] The top of the valve housing 32 includes a through hole 36 which receives an upper stem portion 37 of the poppet 34. . The internal wall of the valve housing 32 includes an internal shoulder which functions as a valve seat

38. At the bottom of the upper stem portion 37 the poppet 34 includes an external annular shoulder 39 which faces towards the valve seat 38 and has a seating surface for engagement with the valve seat 38. In the illustrated embodiment the seating surface of the annular shoulder 39 is a ring or fillet of elastomeric material. The ring or fillet forming the seating surface may be a separate component securely fixed or bonded to the shoulder of the poppet or may be an integral part of and unitary with the poppet 34.

[00056] An upper pressure threshold piston 40 is mounted within and forms a sealing sliding fit within the poppet 34. The upper pressure threshold piston 40 is restrained from movement relative to the valve housing 32. In contrast the poppet 34 is capable of axial movement relative to the valve housing 32 and the upper pressure threshold piston 40 and is biased by means of a biasing member 41 towards the valve seat 38. In this way the pressure regulating valve module permits fluid flow through the valve at a predetermined pressure threshold P₂which is less than the high pressure Pt of the cylinder.

[00057] The flow control valve and regulator assembly 30 further comprises a lower pressure threshold piston 43 in sliding but fluid sealing engagement with the wall of the top hamper regulator chamber 31 (see Fig. 7A and Fig. 8). To enhance the fluid seal of the piston 43 with the wall of the top hamper regulator chamber 31, a sealing member such as, but not limited to, an O-ring or X-ring 46 is preferably provided in a recess in the side wall of the piston 43. A piston biasing member 44 is provided which acts upon the uppermost side of the piston

43. The piston biasing member 44 biases the piston 43 towards the bottom of the top hamper regulator chamber 31 and defines the permitted regulated fluid pressure. With this arrangement a residual positive pressure may be maintained in the regulator chamber 31 and any connected upstream components when the contents of a pressurized cylinder is close to becoming fully depleted. The biasing member 44 is preferably, but not exclusively, a conventional compression spring.

[00058] The underside of the piston 43 defines at least a part of a regulated pressure cavity 45 which is in fluid communication with the regulated pressure outlet of the valve module. Thus the regulated pressure cavity 45 is a middle section of the regulator chamber 31 with the valve housing 32 below and the flow control module 51 above (described in greater detail below). The underside of the piston 43 engages or acts on the upper stem portion 37 of the poppet 34 whereby downward movement of the piston 43 causes a corresponding downward movement of the poppet 34 which releases the seating surface 39 from the valve seat 38 and opens the valve module. From this position, upward movement of the piston 43 releases engagement of the underside of the piston with the stem portion 39 thereby exposing the poppet 34 to the biasing force of the valve biasing member 41. Thus upward movement of the piston 43 causes the valve module to close. With the gas pressure in the regulated pressure cavity at the required regulated pressure the force of the biasing force ofthe biasing member 44 is balanced by the gas pressure within the regulated pressure cavity 45 and the valve module is held closed.

[00059] At a lower corner of the regulated pressure cavity 45 an opening leads to regulated pressure supply conduit 47. The regulated pressure supply conduit 47 leads to a flow control cavity 52 which is described in greater detail below. The regulated pressure supply conduit 47 is additionally in communication with a relief valve 48. Fluid flow from the regulated pressure cavity 45 through the opening to the regulated supply conduit 47 is controlled by means of an O-ring 46a provided on the underside ofthe lower pressure threshold piston 43. The O-ring 46a closes the opening to the regulated supply conduit 47 when the piston 43 drops as a result of a fall in pressure. Thus, the piston 43 and O-ring 46a enforce a minimum pressure threshold in respect of fluid flow in the regulated supply conduit 47. This ensures that the regulated pressure cavity 45 is always at a positive pressure relative to atmosphere which in turn prevents ingress of moisture or other contaminants to the regulated pressure cavity 45 and upstream from the regulated pressure cavity.

[00060] The relief valve 48 is mounted at the intersection of the regulated pressure supply conduit 47 with a vent to atmosphere 49. The relief valve 48 includes a plug 50 which is threadedly secured to the main body 11 and is accessible from outside the main body permitting adjustment ofthe position of the plug 50 relative to the main body 11 and the regulated pressure supply conduit 47. The relief valve 48 additionally includes a fluid sealing component, such as but not limited to an O-ring, which is mounted on a stem and is provided to form a fluid seal with the regulated pressure supply conduit 47 isolating the vent to atmosphere 49 from the regulated pressure supply conduit 47. A biasing member extends between the stem and the adjustable plug 50 and acts to bias the O-ring(s) in the relief valve’s closed position. In the event of a failure of the flow control valve and regulator assembly 30 resulting in the regulated pressure conduit 47 being exposed to excessive pressure, the relief valve 48 acts to bleed the excess pressure via the vent to atmosphere 49.

[00061] As mentioned above and more clearly illustrated in Fig. 9, the regulated pressure supply conduit 47 is in open fluid communication with a flow control cavity 52 which is part of a flow control module 51. The flow control module 51 provides a plurality of different selectable rates of gas delivery via the gas outlet 4. The flow control module 51 includes the manual flow control 3a which is mounted for relative rotational movement in the top of the cylinder head casing 3. A perimeter region of the lower section 3b of the cylinder head casing overlaps the bottom rim of the manual flow control 3a and thus supports and centres the manual flow control 3a. In the illustrated embodiment the manual flow control 3a is mounted in an aperture in the casing 3 and includes a handle shaped to be grasped easily between the fingers of a user. It will be apparent that the handle may be omitted or replaced by a rim or a plurality of contact surfaces for a user’s fingers to enable the manually operable flow control 3a to be turned. Also, in an alternative embodiment the manual flow control 3a may be mounted on top of the casing 3 with an operable connection through the casing 3 to the flow control module 51.

[00062] A first end of a flow selector spindle 53 engages the manual flow control 3a by means of a threaded connection such that rotation of the manual flow control 3a induces corresponding rotation of the spindle. The opposite second end of the flow selector spindle 53 is connected to a flow control disk 54 mounted within the flow control cavity 52.

[00063] To ensure only a single rate of gas delivery can be selected from the plurality of different rates of gas delivery at any one time, the flow control module 51 additionally includes a positional indexing mechanism. The positional indexing mechanism is preferably provided by positive inter-engagement between two co-operable components at a plurality of different angular positions of the flow selector spindle 53. The positional indexing mechanism illustrated in Fig. 6 and 9 comprises a generally cylindrical section on the flow selector spindle 53 intermediate the first and second ends of the flow selector spindle. The cylindrical section is of larger diameter than the ends of the flow selector spindle and has on its outer surface a plurality of discrete indentations 55 each located at a separate angular position and collectively defining a circle on the surface ofthe cylindrical section. In the illustrated embodiment twelve radially spaced indentations 55 are provided on the surface of the cylindrical section of the flow selector spindle 53. However the positional indexing mechanism may utilize fewer or more indentations. The cylindrical section of the flow selector spindle 53 is located within a detent plate 56 which contains at least one positional indexing component in the form of a resiliently biased protrusion 57. The resiliently biased protrusion 57 projects towards the spindle 53 and is adapted to form positive engagement with any one of the plurality of indentations 55 in the surface of the cylindrical section. Two protrusions 57 are shown in Fig. 9 arranged 180° apart from each other. The protrusions 57 are each biased, for example by means of a compression spring (not shown), towards engagement with the flow selector spindle 53. The biasing of the protrusions 57 is sufficiently strong for the protrusions to urge the flow selector spindle 53 towards angular positions in which the protrusions 57 are positively engaged with a corresponding (and opposing) pair of indentations 55 in the cylindrical section whilst not so strong as to prevent manual rotation of the flow selector spindle 53 past the protrusions. In this way the interaction of the protrusions 57 and the indentations 55 define a plurality of predetermined stable rotational positions.

[00064] In the illustrated embodiment, the manually operable flow control 3a includes a generally cylindrical wall extending downwardly from the underside of the flow control 3a. The cylindrical wall is in sliding contact with and at least partially overlaps the detent plate 56 in the axial direction so as to maintain alignment between the manually operable flow control 3a and the flow selector spindle 53. It will, of course, be apparent that alternative component(s) functionally equivalent to the cylindrical wall may be employed, for example, a plurality of discrete downwardly extending flanges distributed around the periphery of the detent plate 56.

[00065] As may be more clearly seen in Fig. 10 the flow control disk 54 has a central non-symmetric aperture for fixed engagement to the end of the flow selector spindle 53 which functions as a disk axle and one or more pressure balancing apertures in the form of through holes 58 radially outside of the central aperture. As illustrated in Fig. 10 all of the plurality of pressure balancing apertures 58 are preferably equal in diameter and are evenly spaced around and encircling the central aperture. Although ten pressure balancing apertures 58 are illustrated in Fig. 10, different numbers of pressure balancing apertures 58 are envisaged preferably evenly distributed angularly about the flow control disk 54. [00066] Radially outside of the pressure balancing apertures 58 a plurality of flow selection holes 59 are provided (eleven flow selection holes are illustrated labelled A-L). Each flow selection hole 59 in the plurality of flow selection holes is of a different diameter but with the centre of each hole at the same radial distance from the centre of the disk 54. The centre of each of the flow selection holes 59 is angularly spaced from its neighbours by the same angular distance with the exception of the angular distance between the centres of the smallest flow control hole and the largest flow control hole. The angular separation of the smallest flow selection hole and the largest flow selection hole is equal to double the angular separation between the centres of all other adjacent flow selection holes. Where the total number of flow selection holes 59 is n, (n+1) equals the total number of indentations 55 in the surface of the cylindrical section of the flow selector spindle 53. In this way, the positional indexing mechanism provides positive engagement individually representative of each one of the flow selection holes 59 as well as the segment of the flow control disk 54 where there is no flow selection hole.

[00067] As illustrated in Figs. 8 and 9 a flow control housing 60, which contains the flow control cavity 52, is nested within the spiral of the regulator biasing member 44. This is a particularly preferred arrangement but it is to be understood that alternative arrangements are also envisaged not involving a nested arrangement and/or not involving a compression spring as the regulator biasing member 44.

[00068] The flow control housing 60 has a regulated pressure inlet port 61 which is in unrestricted fluid communication with the regulated pressure supply conduit 47 and a regulated pressure outlet port 62 which is similarly in unrestricted fluid communication with the gas outlet 4 via a gas outlet conduit 63. Both ports are provided in the top wall or ceiling of the flow control housing 60 with the centre of the regulated pressure outlet port 62 a radial distance away from the longitudinal axis X of the top hamper 10 equal to the radial distance of the centres of the flow selection holes 59 from the longitudinal axis X. In addition, a flow control outlet pipe 64 is provided coaxially aligned with the regulated pressure outlet port 62 within the flow control cavity 52. The flow selector spindle 53 extends through the flow control housing 60 into the flow control cavity 52 with the second end of the flow selector spindle 53 being the disk axle supporting the flow control disk 54 for rotation within the flow control cavity 52. The flow control disk 54 is supported by the flow selector spindle 53 separate from (i.e. spaced away from and therefore not in contact with) the surfaces of the walls defining the flow control cavity 52. In addition, the flow control disk 54 is held by the flow selector spindle 53 in contact and forming a fluid seal with an end of the flow control outlet pipe 64. In Fig. 9 the flow control outlet pipe 64 is an O-ring or equivalent so as to present negligible frictional contact to the surface of the flow control disk 54. In an alternative embodiment the flow control outlet pipe 64 may comprise a rigid conduit with an O-ring or equivalent at the end of the pipe 64 that is in contact with the flow control disk 54. Thus, outflow of gas from the flow control cavity 52 is only possible via one of the flow selection holes 59 in the flow control disk 54 and along the flow control outlet pipe 64 to the regulated pressure outlet port 62. The rate of gas outflow from the flow control cavity 52 is determined by the diameter of the flow selection hole 59 aligned with flow control outlet pipe 64 and the regulated pressure outlet port 62. [00069] As mentioned earlier, the separation of the smallest flow selection hole from the largest flow selection hole is equal to double the angular separation between the centres of all other adjacent flow selection holes, this provides a selectable segment of the flow control disk 54 which has no hole and corresponds to a user selection of no gas outflow.

[00070] As the flow control disk 54 is supported away from the surface of the inner walls of the flow control housing 60, frictional contact with the wall surface is avoided. Moreover, the pressure balancing aperture(s) 58 in the flow control disk 54 ensures that the regulated gas pressure within the cavity is equal on both sides of the disk 54 so that the disk ‘floats’ i.e. is not subjected to pressure gradients within the flow control cavity 52.

[00071] The gas cylinder 2 may be re-filled via a fill port 65 in the top hamper 10. The fill port 65 is conventional in design so as to be compatible with existing pressurised gas filling equipment. The fill port 65 is in fluid communication with the gas cylinder 2 via the high pressure shut-off valve 20. A high pressure plug 66 is provided in the high pressure conduit leading from the shut-off valve outlet 27 which provides access to the high pressure conduit for maintenance purposes. The high pressure plug 66 also enables the fitting of a sintered filter component in the high pressure line (not shown) to prevent potential contaminants getting into the flow of gas in the top hamper.

[00072] As clearly shown in the figures, the main body 11 is an indivisible unitary, i.e. one piece, component machined from a single block of metallic material, preferably brass or phosphor bronze. The main body 11 includes a plurality of cavities each of which is open to the outside of the main body 11 with each cavity containing a different one of the functional components described above. As shown in Figs. 2A, 2B and 7B the local axis of each cavity in the main body 11 (the local axis being orthogonal to the respective cavity opening) is at a different radial position with respect to the main axes X and Y of the top hamper whereby the plurality of cavities are arranged in a 3-dimensional array across the outer surface of the top hamper. The fluid conduits referred to above are machined through the single block of the main body so as to interconnect the cavities and the functional assemblies within the cavities. The flow control valve and regulator assembly 30 is mounted in the regulator cavity 31 with the regulator assembly stacked below the flow control module 51 at the closed bottom of the cavity 31. Similarly the shut-off valve 20, the relief valve 48 and the pressure transducer 17 are each mounted in separate respective cavities provided in the main body 11. In this way a top hamper including high pressure shut-off, pressure measurement, pressure regulation and fluid flow control is provided in a join-free, indivisible main body component 11 which avoids the weaknesses inherent in multi-component high pressure systems. Moreover, maintenance of the functional assemblies of the top hamper 10 is simplified as each functional assembly is separately accessible from the exterior of the main body 11 and individual access to each of the fluid conduits is also provided. [00073] In use, the high pressure shut-off valve 20 is opened allowing gas to flow from the pressurised cylinder 2 to the flow control and regulator valve 30. With the manual flow control 3a set to no flow, i.e. the gas flow marker 5a is aligned with Ό’ flow on the flow scale 5 and the regulated pressure outlet port 62 is aligned with the segment of the flow control disk 54 having no flow selection hole, the high pressure gas from the gas cylinder 2 flows to the flow control valve and regulator assembly 30 where it is reduced in pressure to the regulated gas pressure for example between 3 and 6 bar, more preferably 3.6 bar to 5.5 bar and ideally 4-5 bar and from there to the flow control cavity 52. When the manual flow control 3a is subsequently turned to a chosen non-zero gas flow rate, this causes the flow control disk 54 to be rotated until a flow selection hole 59 corresponding to the chosen gas flow rate is aligned with the flow control outlet pipe 64 and the regulated pressure outlet port 62. Correct alignment of the flow selection hole 59 with the regulated pressure outlet port 62 is ensured by the positional indexing mechanism described above. Gas then flows from the flow control cavity 52 via the flow selection hole 59, the flow control outlet pipe 64, the regulated pressure outlet port 62 to the gas outlet 4 and from there to the patient. The flow control valve and regulator assembly 30 responds to any gas outflow to maintain the pressure of the gas at the gas outlet 4 at the regulated gas pressure. To turn off the gas flow, the user turns the manual flow control 3a in the opposite direction until the marker 5a is aligned with the O' on the flow scale 5 and the regulated pressure outlet port 62 is aligned with the segment of the flow control disk 54 having no flow selection hole. In this position there is no flow from the flow control cavity 52 irrespective of the position of the shut-off valve 20. With the manual flow control 3a set to zero flow, pressure will rise in the valve chamber until it exceeds the upper pressure threshold at which point the valve of the regulator assembly closes providing a secondary pressure isolation function. Optionally, the high pressure shut-off valve 20 may additionally be closed when the manual flow control 31 is set to zero flow.

[00074] The gas cylinder and its components described herein are capable of operating within a temperature range of -20°C to 65°C and capable of operating at any level of humidity.

[00075] It is to be understood that the embodiment described above is only one preferred exemplary embodiment. Changes may be made to the compressed fluid vessel and to the pressure regulating and gas delivery system of the compressed fluid vessel described herein. As mentioned earlier the fluid inlet supply may be in a form other than a dip tube and where the fluid inlet supply is a dip tube it may have inlet apertures which differ in number to the two illustrated in the figures. In addition, although the illustrated embodiment shows a direct pressure feed to the pressure gauge via a high pressure conduit, an indirect pressure feed may alternatively be employed. Also, the profile of the outlet aperture of the high pressure shut-off valve may differ from the profile illustrated in the accompanying figures. The number and position of fluid seals including O-rings may be different to the number and arrangement illustrated. Also, alternative mechanisms may replace the positional indexing mechanism of the gas flow control illustrated herein. Furthermore, the illustrated direct connection between the manually operable flow control and the flow control spindle may be replaced by gearing to establish a rotational relationship between the manually operable flow control and the flow control spindle which is different to the 1:1 relationship of the direct connection. The pressure balancing holes may be omitted as the flow control holes are also functional as pressure balancing holes. In a further alternative, the flow control disk may include one or more regions of mesh with each region of mesh including a plurality of pressure balancing holes. Furthermore, although the specific embodiment described herein comprises a single indivisible main body 11 in which the various functional components are each mounted in cavities in the main body 11, the present invention also encompasses constructions in which the main body consists of a plurality of interconnected sections. These and other changes may be made to compressed fluid vessel and the pressure regulating and gas delivery system of the compressed fluid vessel without departing from the spirit and the scope of the invention as claimed in the accompanying claims.

Claims

1. A pressure regulating and fluid delivery system adapted for use with a compressed fluid vessel, the pressure regulating and fluid delivery system comprising:

a high pressure inlet; a regulated pressure outlet;

a pressure reducer in fluid communication with the high pressure inlet for reducing the pressure of fluid from the high pressure inlet to a predetermined regulated pressure; and an adjustable outlet flow control comprising:

a flow control cavity in fluid communication with the pressure reducer and the regulated pressure outlet, a flow control disk mounted on an axle for rotational movement within the flow control cavity and including a plurality of angularly spaced radially equidistant flow control holes with each one of the plurality of flow control holes having a different hole diameter, the axle supporting the flow control disk in a spaced relationship away from the walls of the flow control cavity; and a flow control outlet pipe adapted to form a fluid seal with the surface of the flow control disk whereby fluid flow out from the flow control cavity is via a flow control hole when aligned with the flow control outlet pipe.

2. A pressure regulating and fluid delivery system as claimed in claim 1, wherein the flow control disk further includes at least one pressure balancing hole positioned at a radial distance from the rotational axis of the flow control disk different to the radial distance of the plurality of flow control holes.

3. A pressure regulating and fluid delivery system as claimed in claim 2, wherein the at least one pressure balancing hole is positioned radially inside of the plurality of flow control holes.

4. A pressure regulating and fluid delivery system as claimed in claim 3, wherein the flow control disk includes a plurality of pressure balancing holes.

5. A pressure regulating and fluid delivery system as claimed in any one of the preceding claims, wherein the flow control outlet pipe is adapted to present negligible frictional contact with the surface of the flow control disk during rotational movement of the flow control disk.

6. A pressure regulating and fluid delivery system as claimed in any one of the preceding claims, wherein the edge of the flow control outlet pipe for contact with the flow control disk comprises an O-ring.

7. A pressure regulating and fluid delivery system as claimed in any one of the preceding claims, further comprising a position indexing mechanism for restricting stable rotational positions of the flow control disk to a plurality of predetermined angular positions.

8. A pressure regulating and fluid delivery system as claimed in any one of the preceding claims, wherein the angular spacing between adjacent flow control holes of increasing diameter in the flow control disk is equal and wherein the angular spacing between the smallest flow control hole and the largest flow control hole is a multiple x of the angular spacing between other adjacent flow control holes.

9. A pressure regulating and fluid delivery system as claimed in any one of the preceding claims, wherein flow control disk includes a zero flow setting and the pressure regulating and fluid delivery system further comprises a pressure regulator in fluid communication with the high pressure inlet and the flow control cavity, the pressure regulator being adapted to reduce the pressure of fluid flowing from the high pressure inlet and for supplying fluid at a lower regulated pressure to the flow control cavity wherein the pressure regulator is further adapted to function as a secondary fluid flow isolator when the flow control disk is set to the zero flow setting.

10. A pressure regulating fluid delivery system as claimed in claim 9, wherein a main body includes a cavity open to the exterior of the main body, the pressure reducer and the outlet flow control being mounted within the cavity.

11. A pressure regulating fluid delivery system as claimed in claim 10, wherein the pressure reducer is stacked below the outlet flow control within the main body cavity.

12. A compressed fluid vessel comprising: a casing;

a hollow fluid container adapted to contain fluid at pressures greater than 1 bar provided within the casing;

a pressure regulating and fluid delivery system as claimed in any one of claims 1 to 11 mounted within the casing, the high pressure inlet of the pressure regulating and fluid delivery system being in fluid communication with the interior of the hollow fluid container and the regulated pressure outlet extending through the casing; and a manually operable flow control mounted in a first aperture in the casing and adapted for rotational movement relative to the casing, the manually operable flow control being connected to the axle of the flow control disk for manual adjustment of the rate of fluid flow from the regulated pressure outlet.

13. The compressed fluid vessel of either of claim 12, wherein the manually operable flow control includes at least one abutment for maintaining rotational alignment of the manually operable flow control and the flow control spindle.

14. The compressed fluid vessel as claimed in claim 13, wherein the at least one abutment of the manually operable flow control is a downwardly extending cylindrical wall encircling at least part ofthe position indexing mechanism ofthe pressure regulating and fluid delivery system.

15. The compressed fluid vessel of any one of claims 12 to 14, wherein the casing includes indicia representative of different fluid flow rates at the regulated pressure outlet corresponding to different rotational positions of the manually operable flow control relative to the casing.

16. The compressed fluid vessel of any one of claims 12 to 15, further comprising a display mounted in a second aperture in the casing, the display being adapted to provide information relating to the amount of fluid within the hollow fluid container.

17. The compressed fluid vessel of any one of claims 12 to 16, wherein the compressed fluid vessel is manually portable.

18. The compressed fluid vessel of claim 17, wherein the hollow fluid container comprises a liner of a metallic material at least partially encased in a composite material.

19. A high pressure shut-off valve adapted for use in a compressed fluid vessel, the shut-off valve comprising:

a valve chamber having a longitudinal axis and including a fluid inlet and a fluid outlet, the fluid inlet being adapted for fluid communication with a source of high pressure fluid;

a valve spindle movable along the longitudinal axis ofthe valve chamber and having a sealing end portion for engagement with a rim ofthe fluid outlet; and a drive mechanism connected to the valve spindle, the drive mechanism being adapted for connection to a manually operable valve control, wherein the valve chamber includes a high pressure region encircling the fluid outlet, the high pressure region being in permanent fluid communication with the fluid inlet and wherein the surface area ofthe sealing end portion is greater than the area within the periphery ofthe fluid outlet whereby a portion ofthe sealing end portion is exposed to the high pressure region encircling the fluid outlet when the sealing end portion is in contact with the periphery of the fluid outlet.

20. The shut-off valve as claimed in claim 19, wherein the rim of the fluid outlet is provided at the free end of a projection into the valve chamber and the high pressure region ofthe valve chamber encircles the projection.

21. The shut-off valve as claimed in claim 20, wherein the projection has a substantially frusto-conical or hyperbolic cross-section.

22. The shut-off valve as claimed in any one of claims 19 to 21, wherein the sealing end portion comprises a sealing insert having a minimum hardness of E25-45 (Rockwell).

23. The shut-off valve as claimed in claim 22, wherein the material of the sealing insert is selected from either polyether ether ketone (PEEK) or Vespel™.

24. The shut-off valve as claimed in any one of claims 19 to 23, wherein the drive mechanism converts manually applied rotational movement to axial movement ofthe valve spindle within the valve chamber towards and away from the fluid outlet.

25. The shut-off valve as claimed in claim 24, further comprising a limiter for restricting axial movement of the valve spindle within the valve chamber.

26. The shut-off valve as claimed in claim 25, wherein the limiter is adapted to restrict manually applied rotational movement of the drive mechanism.

27. A pressure regulating and fluid delivery system comprising: a high pressure inlet;

a regulated pressure outlet;

a shut-off valve as claimed in any one of claims 19 to 26 in fluid communication with the high pressure inlet;

a manually operable valve control connected to the drive mechanism of the shut-off valve; and a pressure regulator in fluid communication with the fluid outlet of the shutoff valve and the regulated pressure outlet, the pressure regulator being adapted to reduce the pressure of fluid flowing from the shut-off valve and for supplying fluid at a lower regulated pressure to the regulated pressure outlet.

28. The pressure regulating and fluid delivery system as claimed in claim 27, wherein the drive mechanism of the shut-off valve is adapted to move the valve spindle from a fully closed position to a full flow position in response to no more than 180° rotation of the manually operable valve control.

29. The pressure regulating and fluid delivery system of any one of claims 27 or 28, further comprising fluid conduits interconnecting the hollow fluid container and the shut-off valve, the shut-off valve and the pressure regulator, and the pressure regulator and the regulated pressure outlet, the fluid conduits being provided in a main body being a unitary indivisible component.

30. The pressure regulating and fluid delivery system of claim 29, wherein the main body includes a first cavity open to the exterior of the main body, the shutoff valve being mounted in the first cavity and a second cavity open to the exterior of the main body, the pressure regulator being mounted in the second cavity.

31. A compressed fluid vessel comprising: a casing;

a hollow fluid container adapted to contain fluid at pressures greater than 1 bar provided within the casing; and a pressure regulating and fluid delivery system in accordance with any one of claims 27 to 30, wherein the compressed fluid vessel is manually portable.

32. The compressed fluid vessel of claim 31, wherein the manually operable valve control is mounted on or in the casing and is capable of rotational movement relative to the casing.

33. The compressed fluid vessel of claims 31 or 32, wherein the hollow fluid container comprises a liner of a metallic material at least partially encased in a composite strengthening material.

34. A pressure regulating and fluid delivery system adapted for use with a compressed fluid vessel, the pressure regulating and fluid delivery system comprising;

a main body including at least first and second cavities each open to the exterior of the main body, a high pressure inlet and a regulated pressure outlet;

a high pressure valve mounted in the first cavity; and a pressure reducer mounted in the second cavity, the pressure reducer being in fluid communication with the high pressure inlet for reducing the pressure of fluid from the high pressure inlet to a predetermined regulated pressure;

wherein the main body is machined from a single block and has fluid conduits interconnecting the first and second cavities and interconnecting the high pressure inlet with the first cavity and the regulated pressure outlet with the second cavity.

35. The pressure regulating and fluid delivery system as claimed in claim 34,

5 further comprising a manually adjustable fluid flow control for adjustment of the flow rate of fluid out of the regulated pressure outlet.

36. The pressure regulating and fluid delivery system as claimed in claim 35, wherein the manually adjustable fluid flow control is mounted in the second cavity

10 above the pressure reducer.

37. The pressure regulating and fluid delivery system as claimed in any one of claims 34 to 36, wherein the main body includes a third cavity and a fluid pressure monitor mounted in the third cavity, a fluid conduit machined through

15 the main body providing fluid communication between the high pressure inlet and the third cavity.