An inlet stem and pressure regulator for a pressure vessel

Abstract

NOT VISIBLE DUE TO STATUS OF PATENT

Description

[0001] An Inlet Stem and Pressure Regulator for a Pressure Vessel

[0002] FIELD OF INVENTION

[0003] The invention relates to a pressure vessels (e.g., gas cylinders) and specifically to an inlet stem and a pressure regulator for a pressure vessel, having a safety feature (or features) responsive to impact.

[0004] BACKGROUND OF INVENTION

[0005] A pressure vessel, often in the form of a gas cylinder, usually has a pressure regulator (or valve assembly) connected to its outlet to permit and regulate dispensing of fluid (usually gas) from within the pressure vessel (just “vessel”, for short). Given that such pressure vessels are often cylindrical and relatively tall compared to their width, they are prone to falling over, or handling mishaps in general.

[0006] The pressure regulator (just “regulator”, for short) projects upwardly and / or laterally from a top of the vessel. For this reason, it is at an extremity of the vessel. Depending on how the vessel falls, or what bumps it, the regulator may receive the impact first. Whilst the vessel itself is usually very strong, the regulator is often a point of failure, or the connection between the vessel and the regulator may be the point of failure.

[0007] The Applicant is aware broadly of two regulator configurations, classified as a traditional regulator (FIG. 1 ) and a modem regulator (FIG. 2). A classic regulator projects laterally from a top of the vessel and its gauges (usually pressure indicator gauges) are separate from a main housing of the regulator. This means that an overall length of the regulator is reduced, but the gauges project outwardly from the housing, creating more points of impact. Further, the gauges may be fragile components.

[0008] Conversely, the modem regulator integrates the gauges into the main housing to protect them, but this means that the regulator projects further away from a centre of the vessel than a traditional regulator due to the position of the pressure adjustment knob.

[0009] If the vessel topples over, the modem regulator has the advantage of reducing the risk of impact on the gauges, but the disadvantage of increasing the risk of a purely compressive load acting on the knob and being transferred to an inlet stem of the regulator. The stem is the most likely component to fail on a modem regulator.

[0010] The inlet stem has two functions:

[0011] 1 . Serve as the conduit for high pressure gas from the cylinder to the regulator manifold.

[0012] 2. Serve as the structural / mechanical connection between the cylinder and the regulator manifold.

[0013] The high-pressure gas flowing through the inlet stem is reduced to a lower pressure inside the regulator (this is the function of the regulator). As this happens, the gas cools; this causes the entire regulator and stem to become very cold. As the temperature of the material (usually a brass stem) decreases, it becomes increasingly brittle (that is, impact resistance decreases with temperature). Any loads incident on the regulator are transferred via the inlet stem to the cylinder. If these loads are high and / or applied quickly, they can cause the stem to fracture.

[0014] The exact position of the fracture point varies, but the most common fracture location is the threaded connection - this is because the threads cause a stress concentration. If the stem fractures, high pressure gas (up to 300 bar) is allowed to escape from the cylinder directly into the atmosphere. This is dangerous for numerous reasons - most notably, it turns the cylinder into a “rocket”.

[0015] FIGS 3-5 illustrate an existing (Prior Art) apparatus to improve the safety of the inlet stem in the event of impact. The apparatus has a stress riser, in the form of a horizontal or circumferential V notch, in a known location. This makes the failure point of the stem predictable. Once the failure point is predictable, a spring-loaded valve can be positioned inside the stem. This valve closes off the conduit in the stem in the event of stem fracture and prevents gas from escaping.

[0016] This solution is not without its own problems, though:

[0017] 1 . All load is transferred to the stem via the threads, meaning there is still a risk of failure at the threads.

[0018] 2. The stem is tightened into the regulator housing using a hexagon upstream of the V notch Failure point. Hence, if too much torque is applied to the hex, it can promote premature failure in the notch.

[0019] 3. The rubber seal is bonded to the piston — there is no positive mechanical connection. It therefore has a risk of separating and blocking the stem if the bond fails.

[0020] 4. The current stem with the V notch is only really used - to the Applicant’s knowledge - in Australia, and it is intended for low pressure applications with flammable gas (up to about 15 bar).

[0021] 5. When the stem snaps, it ejects the wedge as shrapnel. This is not a problem for low pressure applications, but, at high pressure (300 bar), the shrapnel is a safety hazard.

[0022] 6. Most notably, the stem is primarily intended to fracture under bending stress - the reason for this is that vertical entry cylinders are primarily used in Australia, whereas horizontal entry cylinders are common worldwide. If a vertical entry cylinder falls over, a shear force and bending moment is most likely to be induced on the stem, but a compression force on the stem is very unlikely (the cylinder would need to fall completely upside down). If a horizontal entry cylinder falls over, a pure or partial compression load is very likely to be induced on the stem, and the V notch may be less useful in this scenario.

[0023] The Applicant wishes to overcome or at least ameliorate these drawbacks. The Applicant wishes to increase the safety of vessels should impacts occur.

[0024] SUMMARY OF INVENTION

[0025] Accordingly, the invention provides an inlet stem for use with a pressure regulator, the inlet stem having a longitudinal stem axis and including: a vessel connection at one end for connection to a pressure vessel; and a manifold connection at the other end for connection to an inlet manifold of the regulator, the inlet stem being configured to interconnect fluidically the vessel and the inlet manifold, wherein the inlet stem further includes: at least one oblique notch defined in or on an exterior surface of the inlet stem between the vessel connection and the manifold connection, the oblique notch being inclined relative to the stem axis.

[0026] The invention extends to a pressure regulator for use with a pressure vessel, the regulator including: the inlet stem as defined above; and at least an inlet manifold, wherein the manifold connection of the inlet stem is connected to an inlet port of the inlet manifold.

[0027] The invention extends further to a pressure vessel assembly comprising: a pressure vessel; and the pressure regulator as defined above connected to an outlet of the vessel. The notch may have a V-shaped profile. The notch may be a groove or furrow machined into the surface. The notch may be considered a stress riser in that it may focus stresses or loads transmitted along the inlet stem.

[0028] The vessel connection may include a standard tightening hex.

[0029] The manifold connection may include a standard threaded spigot.

[0030] “Inclined” in the context of this specification may include extending a plane which is inclined relative to a point of reference.

[0031] The oblique notch may be (or may extend in a plane which is) inclined by 30°-60° relative to the stem axis. The oblique notch may be inclined 45° ± 5% relative to the stem axis. (The % tolerance may be relative to a full 360° rotation.)

[0032] There may be two oblique notches, namely a first oblique notch and a second oblique notch. The notches may be oppositely inclined relative to the stem axis; that is, a first notch may be inclined in one direction, or positively inclined, and the second notch may be inclined in the other direction, or negatively inclined. The oblique notches may be transverse (e.g., 90°) relative to each other.

[0033] There may also be a circumferential notch defined in the exterior surface of the inlet stem, the circumferential notch extending circumferentially around the inlet stem. The circumferential notch may be transverse to, or angled at 90° ± 5%, relative to the stem axis (that is, in a plane which is transverse to, or normal to, the stem axis).

[0034] There may also be one or more parallel notches defined in the exterior surface of the inlet stem, the one or more parallel notches extending linearly along the inlet stem. The one or more parallel notches may be parallel to, or angled at 0° ± 5%, relative to the stem axis.

[0035] The notch may function as a zone (e.g., a point or line) of weakness, increasing the chances of breakage or fracture at or in the region of the notch. The notch, or the zone defining the notch, may divide the inlet stem into two sections on either side of the notch, namely a proximal section adjacent the vessel connection and a distal section adjacent the manifold connection. Should the inlet stem break at the notch, the proximal section may remain attached to the vessel while the distal section may detach therefrom.

[0036] The inlet stem may have a sleeve provided over the notch or the zone. The sleeve may be of, or may include, Kevlar™ or similar aramid fibre composition. The sleeve may be configured to catch or contain shrapnel in the event of failure of the inlet stem. The sleeve may be perforated.

[0037] The sleeve may be anchored or attached to the inlet stem at opposite ends of the sleeve. One end of the sleeve may be provided on the distal section while the other end may be provided on the proximal section. The ends of the sleeve may be attached by respective retaining rings, e.g., being swaged onto the respective sections.

[0038] The inlet stem may include a valve assembly. The valve assembly may be configured to deploy or plug part of the inlet stem automatically upon breakage of the inlet stem. The valve assembly may include a seal. The seal may be configured to engage a seat defined in the inlet stem. The seat may be defined in the proximal section of the inlet stem. The valve assembly may include a bias arrangement to urge the seal against the seat. The bias arrangement may include a spring, e.g., a coil spring.

[0039] The valve assembly may include a pin or similar protuberance. The pin may be connected (directly or indirectly) to the seal. The pin may be orientated towards the distal section. The distal section may define a bearing surface configured to bear against the pin. The bearing surface may be configured to displace the pin, and thus the seal, against the bias of the bias arrangement.

[0040] The displacement of the pin against the bias may cause the seal to be displaced away from the seat and accordingly cause the valve assembly to be in an open configuration, e.g., permitting through flow of gas. If the bearing surface is removed, e.g., if the inlet stem fractures and the distal section separates from the proximal section, the bias arrangement may urge the seal against the seat, causing the valve assembly to be in a closed configuration, thereby preventing or at least inhibiting flow of gas through the inlet stem (or at least the remaining proximal section thereof). Accordingly, the valve assembly may serve to seal the vessel automatically in the event of inlet stem breakage or failure.

[0041] The distal section of the stem may define one or more flat parts. For example, the distal section may define two diametrically opposed flat parts. The flat part(s) may provide that portion of the distal section with an at least partially polygonal profile. The flat part(s) may enable gripping by a tool, e.g., pliers, spanner, wrench, etc., for applying a torque to tighten (or loosen) the inlet stem to (or from) the inlet manifold. As the notch is not between the flat part(s) and the inlet manifold, a torque applied via, or relative to, the flat part(s) may be transmitted directly to the connection interface and not via the notch. In this fashion, the zone with the notch may not be stressed or strained during routine installation or maintenance of the inlet stem and / or regulator.

[0042] A proximal end of the proximal section may define a portion with a polygonal outer profile (e.g., hexagonal shaped) to receive a tool to apply a torque to the proximal section for tightening or loosening the inlet stem or the regulator to or from the vessel.

[0043] The inlet manifold may include or may be connected to one or more gauges having at least one gauge body. If the gauge body receives a knock or other impact, this impact may be transferred to the inlet stem via the manifold connection (e.g., threads thereof) which may then be considered a primary load path. The regulator may include a support bracket attached between the inlet stem (e.g., the distal section of the inlet stem) and the gauge body. The support bracket may create a secondary load path between the gauge body and the inlet stem to reduce load on the manifold connection and thus reduce a risk of failure of the manifold connection. The support bracket may also provide additional strength to the manifold connection.

[0044] BRIEF DESCRIPTION OF DRAWINGS

[0045] The invention will now be further described, by way of example, with reference to the accompanying diagrammatic drawings.

[0046] In the drawings:

[0047] FIG. 1 shows a schematic side view of a Prior Art pressure vessel and traditional regulator;

[0048] FIG. 2 shows a schematic side view of a Prior Art pressure vessel and modem regulator;

[0049] FIG. 3 shows an axial sectional view of a Prior Art regulator having a horizontal V-shaped notch;

[0050] FIG. 4 shows an axial sectional view of a Prior Art inlet stem of the regulator of FIG. 3;

[0051] FIG. 5 shows an axial sectional view of the Prior Art inlet stem of FIG. 4 in a broken configuration;

[0052] FIG. 6 shows an axial sectional view of an inlet stem in accordance with the invention, connected between a vessel and an inlet manifold;

[0053] FIG. 7 shows an enlarged axial sectional view of the inlet stem of FIG. 6;

[0054] FIG. 8 shows an enlarged axial sectional exploded view of the inlet stem of FIG.

[0055] 6;

[0056] FIG. 9 shows top and side views of the inlet stem of FIG. 6; FIGS 10-15 show top and side views of different embodiments of the inlet stem of FIG. 6;

[0057] FIGS 16-17 show various views of a regulator including the inlet stem of FIG. 6 and a support bracket;

[0058] FIG. 18 shows the inlet stem of FIG. 6 with the support bracket of FIGS 16-17; and

[0059] FIG. 19 shows side and tops views (with an enlargement) of the inlet stem of FIG. 6 with an alternative oblique notch.

[0060] DETAILED DESCRIPTION OF EXAMPLE EMBODIMENT

[0061] The following description of an example embodiment of the invention is provided as an enabling teaching of the invention. Those skilled in the relevant art will recognise that changes can be made to the example embodiment described, while still attaining the beneficial results of the present invention. It will also be apparent that some of the desired benefits of the present invention can be attained by selecting some of the features of the example embodiment without utilising other features. Accordingly, those skilled in the art will recognise that modifications and adaptations to the example embodiment are possible and can even be desirable in certain circumstances and are a part of the present invention. Thus, the following description of the example embodiment is provided as illustrative of the principles of the present invention and not a limitation thereof.

[0062] FIGS 1-5 illustrate Prior Art apparatus and therefore do not fall within the scope of the present invention.

[0063] FIGS 6 onwards illustrate apparatus (e.g., inlet stem or regulator) in accordance with the present invention. FIGS 6-8 illustrate an inlet stem 100 in accordance with the invention. In FIG. 6, the inlet stem 100 is connected via its vessel connection 102 at one end to a pressure vessel 10. This vessel connection 102 is a standard configuration which mates with a socket defined in the vessel 10. At its other end, the inlet stem 100 has a manifold connection 104 and is connected to an inlet manifold 12 of a pressure regulator. Again, this manifold connection 104 is a standard threaded spigot which mates with a corresponding threaded socket defined in the inlet manifold 12. The inlet stem 100 thus performs the conventional functions of fluidically and mechanically interconnecting the vessel 10 and the inlet manifold 12.

[0064] FIG. 7 shows the inlet stem 100 only (without parts of the vessel 10 or inlet manifold 12). The inlet stem 100 defines at least one oblique notch 110, 112 in its exterior surface between the vessel connection 102 and the inlet manifold 104, roughly halfway along its length. In this example, there are two oblique notches 110, 112, namely a first oblique notch 110 and a second oblique notch 112.

[0065] The oblique notches 110, 112 is “oblique” in that it is inclined relative to a stem axis 100.1 (which is a longitudinal axis centrally aligned with a longitudinal orientation of the inlet stem 100). As points of reference, a section of the inlet stem 100 between the vessel connection 102 and the notches 110, 112 is a proximal section 106, while a section of the inlet stem 100 between the notches 110, 112 and the manifold connection 104 is a distal section 108.

[0066] More particularly, this inlet stem 100 defines at least three notches, namely the two oblique notches 110, 112 and one circumferential notch 114. The oblique notches 110, 112 may be diagonal notches, e.g., inclined at +45° and -45° relative to the stem axis 100.1 . The circumferential notch 114 may be arranged at 90° relative to the stem axis 100.1. At least the oblique notches 110, 112 are novel, while the circumferential notch 114 in itself may be similar to or the same as the Prior Art notch of FIGS 3-5. The notches 110, 112, 114 form a zone of weakness where the inlet stem 100 is more likely to break or fracture in response to impacts past a point that can simply be absorbed (e.g., by elastic deformation) by the inlet stem 100. The notches 110, 112, 114 may have a V-shaped profile, e.g., being referred to as V notches. While other profile shapes may be practicable, the Applicant believes that the V shape localises stress effectively, e.g., with an apex of the V concentrating the stress. A depth or size of the notch 110, 112, 114 is calculated and balanced so that it does not significantly weaken an overall rigidity or integrity of the inlet stem 100, but so that if the inlet stem 100 is going to be broken, it breaks at a predictable location, that is, at one of the notches 110, 112, 114. The notches 110, 112, 114 may therefore be considered stress risers.

[0067] The Prior Art circumferential notch may work satisfactorily - that is, may break - when a shear force or bending moment is applied to the regulator, e.g., from a transverse or lateral impact. However, the Applicant has found that the circumferential notch did not work satisfactorily - that is, did not break, and therefore transmitted full impact - in response to a compressive or axial force, e.g. , from an axially inward impact on a distal end of the regulator. This means that, depending on a direction of the impact, the circumferential notch may work or may not.

[0068] The diagonal notch 110, 112 addresses this drawback. It is responsive to both transverse and axial impacts. Further, the use of plural notches 110, 112, 114 at different inclinations, as in the illustrated embodiment, further enhances or widens the direction of impacts to which the notches 110, 112, 114 will be responsive. The Applicant notes that it may not be essential to have all three of the notches precisely as illustrated in FIG. 7 — refer to FIGS 10-15 for notch options in different embodiments. The regulator of the present invention may have the “modem” configuration, that is, gauge(s) may be contained in a gauge body and the regulator projects laterally, not upwardly, from the vessel 10.

[0069] FIG. 8 illustrates the inlet stem 100 axially exploded at the three notches 110,1 12, 114. This may provide insight into the functioning of the notches 110, 112, 114 by showing how the proximal and distal sections 106, 108 can break apart, and also helps illustrate functioning of the sleeve 200 and valve assembly 210 (see further below). The inlet stem 100 includes additional safety features complemental to the notches 110, 112, 114 to increase the effectiveness of the notches 110, 112, 114 or to enhance safety in response to a break or fracture.

[0070] First, a sleeve 200 is provided around the zone of weakness, that is, around all of the notches 110, 112, 114. The sleeve 200 may be of a strong functional material, e.g., Kevlar or similar fibrous and flexible but strong composition. In the non-broken condition of the inlet stem 100, the sleeve 200 is slack or even bunched up, thus having space to flatten out. The sleeve 200 may be deformable but not readily elastically stretchable. The sleeve 200 is attached at opposite ends to respective sections of the inlet stem 100. More specifically, one end of the sleeve 200 - a proximal end - is attached to the proximal section 106 while the other end of the sleeve 200 - a distal end - is attached to the distal section 108.

[0071] As failures or breakages of the inlet stem 100 may be catastrophic (given potential high pressures) or at least energetic, the sleeve 200 may need to be very well attached. In this embodiment, the sleeve 200 is attached to the respective sections 106, 108 by means of respective swaged metal rings 202 to clamp or crimp the ends of the sleeve 200 firmly to the inlet stem 100.

[0072] In FIG. 8, with the inlet stem 100 broken at one or more of the notches 110, 112, 114, the distal section 108 will tend to separate from the proximal section 106. Accordingly, the sleeve 200 will be pulled tight in an attempt to keep the sections 106, 108 together. This may be advantageous in that it both stops of the distal section 108 (and attached components like the manifold, etc.) being forcefully propelled from the proximal section 106, the sleeve 200 thus acting as a tether, and it can also catch any ejected debris or shrapnel (should there be any), thus also acting as a safety net.

[0073] The sleeve 200 may be perforated at allow gas easily to escape therefrom, should this be needed during a stem failure. A second safety feature is the provision of an internal valve assembly 210 inside the proximal section 106 of the inlet stem 100. The valve assembly 210 is configured to deploy or plug the proximal section 106 automatically upon breakage of the inlet stem 100. While the Prior Art assembly of which the Applicant is aware also included a valve assembly, that Prior Art valve assembly was potentially dangerous in higher pressure applications, with potential for a part to be ejected, thus acting like shrapnel. This is why the Prior Art apparatus of FIGS 3-5 was used in lower pressure applications only.

[0074] The valve assembly 210 in accordance with the invention aims to improve upon this. The valve assembly 210 is mainly accommodated in a channel or conduit 212 defined in the proximal section 106 of the inlet stem 100. The valve assembly 210 includes a piston 214 having a seal 216 attached to a distal end of the piston 214, the seal 216 being configured to engage a seat 218 defined at a distal end of the channel 212 in the inlet stem 100. The valve assembly 210 includes a bias arrangement in the form of a spring 220 to urge the seal 216 against the seat 218, thereby blocking the channel 212 and making it fluid tight (or at least inhibiting fluid flow). FIG. 7 shows the channel 212 unblocked, while FIG. 8 shows the channel 212 blocked.

[0075] Further, the valve assembly 210 includes a pin 222 or similar protuberance connected to the piston 214. The pin 222 is connected by means of a positive mechanical connection like mating screw threads. The pin 222 is orientated towards the distal section 108. Correspondingly, the distal section 108 has a bearing surface 224 provided at a proximal end thereof. In the intact condition (FIG. 7), the bearing surface 224 urges the pin 222 inwardly against the bias of the spring 220, displacing the seal 216 away from the seat 218 and opening up the channel 212 for uninhibited fluid flow. This is the open configuration of the valve assembly 210.

[0076] If the inlet stem breaks (as in FIG. 8), the bearing surface 224 is removed (or at least is further back). Accordingly, the pin 222 is no longer inwardly held, and the spring 220 urges the piston 214 and hence the seal 216 outwardly, such that the seal 218 engages the seat 218. This is the closed configuration of the valve assembly 210, preventing or reducing gas flow. Therefore, the valve assembly 210 serves to seal the proximal section 106 of the inlet stem 100, and hence the vessel 10, automatically in the event of inlet stem breakage or failure. However, in significant contrast with the Prior Art, the pin 222 remains positively mechanically fixed to the piston 216 inside the channel 212 of the proximal section 106. Accordingly, it is not ejected, or not intended to be ejected, as shrapnel out of the broken inlet stem.

[0077] FIG. 9 illustrates the various notches 110, 112, 114 of the inlet stem 110 in further detail. In addition to the diagonal and the circumferential notches 110, 112, 114, a vertical notch 115 (parallel to the stem axis 100.1 ) may be included.

[0078] Further, FIGS 10-15 illustrate various combinations of notches, as follows:

[0079] • FIG. 10: 2 diagonal, 1 horizontal (configuration 250);

[0080] • FIG. 11 : 2 diagonal, 1 horizontal, 2 vertical (configuration 252);

[0081] • FIG. 12: 2 diagonal, 1 horizontal, 4 vertical (configuration 254);

[0082] • FIG. 13: 2 diagonal (configuration 256);

[0083] • FIG. 14: 1 diagonal, 1 horizontal (configuration 258); and

[0084] • FIG. 15: 1 diagonal (configuration 260);

[0085] The combinations are not exhaustive, but merely illustrative of different options. Some combinations may work better than others, or some combinations may be chosen based on design preferences.

[0086] The Applicant believes that the notch configuration 250 of FIG. 10 is 1.8 times more likely to fail in the intended zone of weakness than the single horizontal notch of the Prior Art inlet stem of FIGS 3-5. Further, the notch configuration 250 of FIG. 10 may fail, as intended, in response to a wider range of incident impacts, including purely axial impacts. A further safety feature is the inclusion of flat sections 260 on the distal section 108 of the inlet stem — see FIGS 7-9. These flat sections 260 - or tightening flats - assist with tightening the inlet manifold 12 onto the manifold connection 104. Without the flats 260, when the manifold 12 is attached to the manifold connection 104 of the distal section 108, the manifold 12 is usually turned while the tightening hex at the proximal end of the proximal section 106 is held fast (e.g., by a tool like pliers or a spanner). As these two sections 106, 108 are either side of the notches 100, 112, 114 and the created zone of weakness, tightening may increase stress or loading on the notches 100, 112, 114 between the two torque points, potentially leading to premature or unintended failure at one of the notches 100, 112, 114.

[0087] With the flats 260, the tightening hex on the proximal section 106 is no longer used when fastening the manifold 12. Instead, the distal section 106 is held rotationally in place (e.g., by the same or similar tool like pliers or a spanner) while the manifold 12 is turned and tightened onto the adjacent manifold connection 104. As the zone of weakness is not between the flats 260 and the manifold connection 104, no stress is transmitted to the notches 100, 112, 114 during tightening.

[0088] FIGS 16-17 illustrate an additional safety component in the form of a support bracket 270, e.g., a removable bracket. This bracket 270 (illustrated in red in FIGS 16-17) is attached between part of the manifold 12 or a gauge 14 (more specifically, a gauge body using fastening points) and the distal end, more specifically, the tightening flats 260. The bracket 270 may therefore be fitted after tightening. The bracket 270 creates a secondary load path (with an existing, primary load path being the threads of the manifold connection) between the gauge body, or regulator as a whole, and the inlet stem 100, further reducing the likelihood of thread failure of the manifold connection 104 in the event of an impact.

[0089] FIG. 18 shows the inlet stem 100 and support bracket 270 only, to provide a holistic view of the inlet stem 100 in accordance with the invention, with all disclosed safety features included. FIG. 19 shows the inlet stem 100 with a slightly differently configured oblique notch 111. The notch 111 is still generally inclined at 45°, but it now also “coils” around the stem 100. The oblique notch 111 may be considered a thread which changes direction halfway through its diameter and has a pitch equal to its root diameter. The benefits of the specific notch 111 are that:

[0090] • It allows the inlet stem 100 to be made using a modified threading op on a normal CNC lathe (reduces manufacturing cost).

[0091] • It ensures constant wall thickness.

[0092] The Applicant believes that the invention as exemplified has various benefits and improved advantages, including:

[0093] • The inclined notch 110, 112 (alone or in combination with other notches 114, 115) creates a failure zone response to a wider range of impact angles, and thus more effective, than the Prior Art circumferential notch. This makes the inlet stem 100 suitable for laterally projecting regulators or modem regulators.

[0094] • The internal valve assembly 210 has been configured to eliminate the ejected wedge and positively fastens the seal 216 to the piston 214 with an additional threaded connection.

[0095] • Tightening flats 260 have been added downstream from the notches 110, 112, 114 to reduce premature failure.

[0096] • A removeable bracket 270 can be attached around the inlet stem 100 at the flats 260 to create a secondary load path (other than the threads) between the regulator and the stem 100, further reducing the likelihood of thread failure.

[0097] • A flexible and perforated sleeve 200 can be added around the failure point to catch any ejected shrapnel.

[0098] • Due to the sleeve 200, the inlet stem 100 can be customised to fail preferentially in various given loading type using a combination of vertical, horizontal, and diagonal notches 110, 112, 114,115 without concern about ejected shrapnel.

[0099] • In the current application, the notch 110, 112, 114 has been configured to fail in a primarily compressive loading. Technically, this is achieved by increasing the value of the local stress concentration factor (K) in both bending and compression at the failure point, compared to the value of the stress concentration factor at the thread.

[0100] • The inclined notch 110, 111 , 112 may improve the fatigue safety factor of the inlet stem 100 relative to the prior art notch in bending in that it makes it less likely for the inlet stem 100 to fail in fatigue when subjected to repeated small bending loads.

Claims

AMENDED CLAIMS received by the International Bureau on 22 April 2025 (22.04.2025)What is claimed is:

1. A pressure regulator for use with a pressure vessel, the pressure regulator including: an inlet stem having a longitudinal stem axis and including: a vessel connection at one end for connection to the pressure vessel; a manifold connection at the other end for connection to an inlet manifold of the pressure regulator, the inlet stem being configured to interconnect fluidically the vessel and the inlet manifold; and at least one oblique notch defined in or on an exterior surface of the inlet stem between the vessel connection and the manifold connection, the oblique notch being inclined relative to the stem axis; and an inlet manifold, wherein the manifold connection of the inlet stem is connected to an inlet port of the inlet manifold, wherein the inlet manifold includes or is connected to one or more gauges having at least one gauge body; and a support bracket attached between the inlet stem and the gauge body, the support bracket configured to create a secondary load path between the gauge body and the inlet stem to reduce load on the manifold connection and thus reduce a risk of failure of the manifold connection.

2. The pressure regulator as claimed in claim 1 , in which the oblique notch has a V- shaped profile and is a groove or furrow machined into the surface, the oblique notch being a stress riser in that it focuses stresses or loads transmitted along the inlet stem.

3. The pressure regulator as claimed in claim 1 , in which the oblique notch is, or extends in a plane, inclined by 30°-60° relative to the stem axis.

4. The pressure regulator as claimed in claim 3, in which the oblique notch is inclined 45°±5% relative to the stem axis.

5. The pressure regulator as claimed in claim 1 , in which the oblique notch is a first oblique notch and there are two oblique notches, namely the first oblique notch and a second oblique notch.

6. The pressure regulator as claimed in claim 5, in which the oblique notches are oppositely inclined relative to the stem axis in that the first oblique notch is inclined in one direction and the second oblique notch is inclined in the other direction.

7. The pressure regulator as claimed in claim 6, in which the oblique notches are transverse relative to each other.

8. The pressure regulator as claimed in claim 1 , in which there is also a circumferential notch defined in the exterior surface, the circumferential notch extending circumferentially around the inlet stem and being transverse to, or angled at 90°±5%, relative to the stem axis.

9. The pressure regulator as claimed in claim 1 , in which there are also one or more parallel notches defined in the exterior surface of the inlet stem, the one or more parallel notches extending linearly along the inlet stem and being parallel to, or angled at 0°±5% relative to, the stem axis.

10. The pressure regulator as claimed in claim 1 , wherein: the oblique notch functions as a zone of weakness, increasing the chances of breakage or fracture at or in the region of the oblique notch;the oblique notch divides the inlet stem into two sections on either side of the oblique notch, namely a proximal section adjacent the vessel connection and a distal section adjacent the manifold connection; and the inlet stem is configured such that, should the inlet stem break at the oblique notch, the proximal section remains attached to the vessel while the distal section detaches therefrom.

11. The pressure regulator as claimed in claim 10, which has a sleeve provided over the oblique notch, the sleeve configured to catch or contain shrapnel in the event of failure of the inlet stem.

12. The pressure regulator as claimed in claim 11 , in which the sleeve is anchored or attached to the inlet stem at opposite ends of the sleeve by respective retaining rings.

13. The pressure regulator as claimed in claim 10, which includes a valve assembly configured to deploy or plug part of the inlet stem automatically upon breakage of the inlet stem.

14. The pressure regulator as claimed in claim 13, in which the valve assembly includes: a seal configured to engage a seat defined in the inlet stem; and a bias arrangement to urge the seal against the seat.

15. The pressure regulator as claimed in claim 14, in which: the valve assembly includes a pin or similar protuberance connected to the seal, the pin being orientated towards the distal section; the distal section defines a bearing surface configured to bear against the pin; andthe bearing surface is configured to displace the pin, and thus the seal, against the bias of the bias arrangement.

16. The pressure regulator of claim 15, in which: the displacement of the pin against the bias causes the seal to be displaced away from the seat and accordingly cause the valve assembly to be in an open configuration, permitting through flow of gas; and if the bearing surface is removed when the inlet stem fractures and the distal section separates from the proximal section, the bias arrangement urges the seal against the seat, causing the valve assembly to be in a closed configuration, thereby preventing or at least inhibiting flow of gas through the proximal section of the inlet stem.

17. The pressure regulator of claim 10, wherein the distal section of the stem defines one or more flat parts which provide that portion of the distal section with an at least partially polygonal profile configured to enable gripping by a tool for applying a torque to tighten or loosen the inlet stem to or from the inlet manifold, such that the torque applied via, or relative to, the one or more flat parts is transmitted directly to the manifold connection and not via the notch.

18. The pressure regulator as claimed in claim 10, in which a proximal end of the proximal section defines a portion with a polygonal outer profile configured to receive a tool to apply a torque to the proximal section for tightening or loosening the inlet stem to or from the vessel.

19. A pressure vessel assembly comprising: a pressure vessel; and the pressure regulator as claimed in claim 1 connected to an outlet of the pressure vessel.