GB2642514A

GB2642514A - Valve assembly

Info

Publication number: GB2642514A
Application number: GB2410133.9A
Authority: GB
Inventors: Parra Paños Jaume
Original assignee: Phinia Delphi Luxembourg SARL
Current assignee: Phinia Delphi Luxembourg SARL
Priority date: 2024-07-11
Filing date: 2024-07-11
Publication date: 2026-01-14
Also published as: GB202410133D0; WO2026013126A1

Abstract

A check valve assembly for a gaseous fuel system, the valve assembly 110 comprising; a valve member 136 moveable between an open position in which a gaseous fuel flow, such as hydrogen, is permitted through the valve assembly and a closed position in which the flow is prevented, the valve member 136 defining a valve seating surface 90; a valve seat 92 defined by a valve housing assembly 112 with which the valve seating surface is engageable when in the closed position, wherein the valve seat comprises an annular recess 102; and an annular seal member 100 provided within the annular recess. Wherein both the valve seating surface 90 and the valve seat 92 are configured to be perpendicular to an axis of movement (A-A) of the valve member 136 between the open and closed positions. The valve allows for increased durability of the seal. Also claimed is a gaseous fuel system with a primary fuel source (70, fig.2).

Description

[0001] VALVE ASSEMBLY

[0002] FIELD OF THE INVENTION

[0003] This invention relates to a valve assembly for use in a gaseous fuel system. In particular, the invention relates to a valve assembly for use in a fuel system for delivering gaseous fuel such as hydrogen to an internal combustion engine.

[0004] BACKGROUND

[0005] In hydrogen fuel supply systems, there is a need to provide a check valve between a tank storing hydrogen gas and a secondary storage vessel for gaseous fuel. For example, the delivery plant may have a tanker for transporting the hydrogen gas to remote sites (e.g. filling stations). Within the transportation system or the filling station itself there may also be a need for a check valve for a hydrogen gas supply. A movable check valve member is biased by means of a closing spring towards a valve seat to close off the supply of gaseous fuel to the secondary storage vessel. The check valve is operable in response to the difference in gas pressure across the check valve member, so that as the pressure in the inlet supply from the tank overcomes the force due to gaseous fuel in the secondary storage vessel in combination with the spring, the check valve member is caused to lift away from the valve seat, against the spring force, to open the flow from the tank to the secondary storage vessel.

[0006] In the known check valve assembly, the valve member is provided with frustoconical end surface which engages with a frusto-conical valve seat of the housing. An annular seal is arranged in an annular recess provided in the frusto-conical end surface. However, one problem with the sealing arrangement is that seal durability is found to be compromised and as a consequence the service life of the check valve is not optimum.

[0007] It is against this background that the invention has been devised.

[0008] SUMMARY OF THE INVENTION

[0009] According to a first aspect of the invention, there is provided a valve assembly (for a gaseous fuel system), the valve assembly comprising; a valve member which is moveable between an open position in which a gaseous fuel flow is permitted through the valve assembly and a closed position in which the gaseous fuel flow is prevented through the valve assembly, the valve member defining a valve seating surface; a valve seat defined by a valve housing assembly with which the valve seating surface is engageable when in the closed position, wherein the valve seat comprises an annular recess; and an annular seal member provided within the annular recess; wherein both the valve seating surface and the valve seat are configured to be perpendicular to an axis of movement of the valve member between the open and closed positions.

[0010] The valve assembly may therefore take the form of a check valve or other shut off valve in a gaseous fuel system.

[0011] The valve assembly may further comprise an inlet flow passage for gaseous fuel, wherein the inlet flow passage defines an inlet flow direction which is parallel to the 15 axis of movement of the valve member between the open and closed positions.

[0012] The inlet flow passage may be defined by the valve housing assembly.

[0013] The valve member may define a valve flow passage for gaseous fuel through the 20 valve member, and wherein the valve flow passage defines a flow direction through the valve member which is parallel to the axis of movement of the valve member.

[0014] The valve member may be provided with a plurality of cross drillings which allow the passage of fuel into the valve flow passage, from a chamber defined by the 25 valve bore when the valve member is moved away from the valve seat.

[0015] The annular seal member may, for example, define an inner annulus boundary which surrounds the inlet flow passage.

[0016] According to a second aspect of the invention, there is provided a gaseous fuel system comprising a primary fuel source for delivering gaseous fuel to a fuel tank via the valve assembly of the first aspect.

[0017] It will be appreciated that preferred and/or optional features of the first aspect of 35 the invention may be incorporated alone or in appropriate combination within the second aspect of the invention also.

[0018] BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order that the invention may be more readily understood, preferred non-limiting embodiments thereof will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a cross section view of a known check valve for use in a gaseous fuel 10 system; Figure 2 is a schematic view of a fuel system to illustrate the position of the check valve in Figure 1; Figure 3 is a cross section view of a check valve assembly of an embodiment of the invention; and Figure 4 is a force diagram to illustrate the forces acting on a seal assembly of the check valve in Figure 3.

[0020] In the drawings, as well as in the following description, like features are assigned like reference signs.

[0021] DETAILED DESCRIPTION OF THE INVENTION

[0022] Throughout this description, it will be appreciated that directional references are not limiting and that valve assemblies according to the invention can be used in any orientation.

[0023] By way of background to the invention, Figure 1 shows a known check or shut off valve assembly 10 for a gaseous fuel supply system (e.g. hydrogen). The check valve assembly 10 includes a valve housing assembly comprising a main housing part 12 adjacent to a secondary housing part 14. The main housing part 12 is received within an outer housing such as a cap nut 16 and is engaged with the cap by means of a screw thread. The main housing part 12 comprises an inlet 18 which communicates with a primary storage vessel (not shown in Figure 1) which is a source of hydrogen gas, such as a fuel tank in a supply station. The inlet 18 delivers hydrogen gas to an inlet flow passage 20 defined by a bore within the main housing part 12.

[0024] The secondary housing part 14 is provided with an outlet passage 24 having an outlet end 26 which communicates with a downstream storage vessel (not shown), such as a transportation tank on a transportation vehicle.

[0025] The bore in the main housing part 12 further comprises a defines a central flow chamber 30 and an outlet guide portion 32. The bore through the main housing part 12 has a stepped diameter along its length, with the central flow chamber 30 having a relatively larger diameter compared to the diameter of the outlet guide portion 32. The inlet flow passage 20 is of relatively small diameter, compared to the central flow chamber 30. At an end remote from the outlet end 26, the secondary housing part 22 has an end region which is received within the outlet guide portion 32 of the main housing part 12.

[0026] The bore in the main housing part 12 further defines a valve seat 34 between the inlet flow passage 20 and the central flow chamber 30, the valve seat 34 tapering from the relatively smaller diameter of the inlet flow passage 20 to the relatively larger diameter of the central flow chamber 30. The valve seat 34 is of frustoconical form and defines a valve seating surface for a piston or check valve member, referring to generally as 36. The check valve member 36 is movable within the bore defined within the main housing part 12 and is guided for movement within the outlet guide portion 32 The check valve member 36 takes the form of a hollow tubular member which itself defines an internal flow passage 38. The check valve member 36 includes a closed end region 40 which defines an external valve seating surface 42 for the valve member 36. The external seat 42 is of frusto-conical form. The diameter of the internal passage 38 is stepped to define a shoulder 44 part-way along the length of the check valve member 36 for engagement with one end of a valve spring 46 which applies a biasing force to the check valve member 36. The other end of the spring 46 is engaged with a step 52 in the end of the secondary housing part 22 where it is received within the main housing part 12. A seal 50 is located between the main housing part 12 and the secondary housing part 14 to prevent leakage between these parts and, hence, from the check valve assembly as a whole.

[0027] The inlet end of the check valve member 36 is provided with a plurality of cross-5 drillings 48a, 48b which communicate, at their radially outermost ends, with the central flow chamber 30 and, at their radially innermost ends, with the internal passage 38 of the check valve member 36. The cross-drillings are comprised of two pairs of opposed drillings; one pair 48a is shown in the cross section of Figure 1 and for the other pair only one cross drilling 48b is visible. Any number of cross 10 drillings may be included, and the four cross drillings in this embodiment are just exemplary.

[0028] The biasing spring 46 is received in the internal passage 32 of the check valve member 36. The biasing spring 46, sandwiched between the shoulder 44 in the check valve member 36 and the step 52 on the second housing part 22, serves to bias the check valve member 36 towards the valve seat 34 defined by the main housing part 12. This is the closed position of the check valve member 36 in which the valve seating surface 42 is engaged with the frusto-conical valve seat 34. Depending on the difference in fuel pressure across the check valve member 36, the check valve member 36 can be caused to move away from the valve seat 34, opening communication between the inlet passage 20 and the central flow chamber 30. This is the open position of the check valve member 36.

[0029] In more detail, the frusto-conical surface 42 of the check valve member 36 is provided with an annular recess 60 within which an annular seal 62 is accommodated. When the biasing spring 46 urges the check valve member 36 towards the valve seat 34, the seal 62 is compressed into the annular recess 60 and ensures a fluid-tight seal to prevent fuel flow past the engaged surfaces in these circumstances. In use, gaseous fuel is introduced into the inlet end 18 of the inlet passage 20. If the force due to fuel pressure acting on the end surface of the check valve member 36 exceeds the force of the spring (acting in combination with fuel pressure within the outlet passage 24), the check valve member 36 is caused to lift away from the valve seating surface 34 to allow fuel to flow past the valve seating surface 34 and into the central flow chamber 30. From here, fuel is able to flow through the cross drillings 48a, 48b and into the internal flow passage 38 for onward delivery to the outlet passage 24. The flow of fuel through the inlet flow passage 20, towards the open valve seat 34, flows in a direction parallel to the axis of movement of the check valve member 36. The flow into the inlet end 18 of the inlet passage 20 approaches the open valve seat 34 along an axis parallel to a central axis of the annular seal 62. The central axis of the annular seal 62 is aligned with and parallel to the axis of movement of the check valve member 36.

[0030] Figure 2 shows the location of the check valve assembly 10 between a fuel source 70 (for example a fuel tank) and a secondary storage vessel 80 (for example a transportation vehicle). When the check valve assembly 10 is open, gaseous fuel from the fuel source 70 is able to flow through the assembly to the secondary storage vessel 80 and when the check valve assembly 10 is closed the flow of gaseous fuel is prevented. The check valve assembly 10 may be located in any fuel supply system between the primary storage vessel 70 (i.e. the source of hydrogen gas) and a secondary storage vessel 80.

[0031] It has been found with the conventional arrangement of Figure 1, with the annular seal 62 located within the frusto-conical surface 34, suffers in that the relative movement between the engaging surfaces, at an angle which is oblique relative to the direction of movement of the check valve member 36, leads to undesirable wear of the seal 62 so that the lifetime of the seal is compromised. A further problem exists because the annular seal 62 is located within a movable part (the check valve member 36), which leads to instability and a less than optimum seal when the parts are brought together.

[0032] The present invention addresses this problem by configuring the sealing interface between the check valve member 36 and the valve seat 34 in a different way. The check valve assembly 110 of embodiments of the invention includes a similar configuration of passages to that shown in Figure 1, so only the differences around the sealing surfaces will be described in detail. Referring to Figures 3 and 4, the check valve member 136 is modified at the inlet end so that the end region has a flat end face to define the valve seating surface 90. The valve seating surface 90 is engageable with a correspondingly shaped flat surface valve seat 92 defined by the main housing part 112. Importantly, the engageable surfaces 90, 92 are both arranged to be perpendicular to the direction of movement of the check valve member 136, along axis A-A, as it moves between open and closed positions. Therefore, as the valve seating surface 90 of the check valve member 136 moves into engagement with the valve seat 92, along axis A-A, it does so whilst avoiding tangential movement between the engaging surfaces 90, 92, as best illustrated in Figure 4. The inlet flow is introduced past the open valve seat 92 through an inlet flow passage 120 which is aligned with the axis of movement A-A of the check valve member 136 and which is defined within the inner annulus boundary of the annular seal 100. On exiting the inlet passage 120, the inlet flow then flows radially outwards, tangentially across the surface of the valve seat 92 and over the annular seal 92, into the central flow chamber 130 defined within the valve housing bore. From the central flow chamber 130, fuel flows through the cross drillings 148 into an internal valve flow passage 138 defined within the check valve member 136. The fuel flow then exits the valve assembly 110 through an outlet passage (not shown in Figure 3) of the type described with reference to Figure 1.

[0033] In an alternative embodiment to that shown in Figure 3, the end surface 90 need not be entirely flat, but only flat in the region of the seal (the region which engages with the flat surface of the main housing part 112). For example, the outer edge of the end surface 90 may be chamfered or otherwise shaped. Also, or alternatively, the central portion, inside the inner annulus boundary of the seal 100, may have an alternative form to the flattened region of the surface shown in the figure, providing there is flat surface to surface contact between the surfaces 90,92 around the seal 100. The inlet passage 120 may take any shape or form.

[0034] Another modification of the check valve member 136 compared to that shown in Figure 1 is that the valve seating surface 92 defined by the main housing part 112 is provided with an annular groove 102 or recess within which an annular seal 100 is arranged, rather than the annular seal being located within a surface of the moving check valve member (as in Figure 1). A combination of the engaging, sealing surfaces 90, 92 coming together perpendicular to the movement direction of the check valve member 136, and the annular seal 100 being received within the annular groove 102 in the static housing part 112, provides a more robust and reliable seal arrangement which is not prone to wear. One reason for this is that the valve seat and the valve seating surface approach each other tangentially in the prior art (i.e. there is relative tangential movement between the surfaces), which subjects the annular seal 100 to shear forces. In embodiments of the invention, the annular seal 100 is only subject to compression forces as the facing sealing surfaces 90, 92 are brought together perpendicular to the direction of movement along axis A-A, with no shear force component acting on the annular seal 100.

[0035] In alternative embodiments to those described previously, the valve housing assembly may be of a different form, comprising any number of housing parts. For example, the main housing part 112 defining the inlet passage 120 and the valve seat 92 need not be the same housing part as defines the outlet guide portion 132 of the bore for the check valve member 136, but could be the same part.

[0036] It will be appreciated that modifications to the invention may be made without departing from the scope of the invention set out in the appended claims.

Claims

1. CLAIMS: 1. A valve assembly (110) for a gaseous fuel system, the valve assembly (110) comprising; a valve member (136) which is moveable within a valve bore (132) between an open position in which a gaseous fuel flow is permitted through the valve assembly (110) and a closed position in which the gaseous fuel flow is prevented through the valve assembly (110), the valve member (136) defining a valve seating surface (90); a valve seat (92) defined by a valve housing assembly (112) with which the valve seating surface (90) is engageable when in the closed position, wherein the valve seat (92) comprises an annular recess (102); and an annular seal member (100) provided within the annular recess (102); wherein both the valve seating surface (90) and the valve seat (92) are configured to be perpendicular to an axis of movement (A-A) of the valve member (136) between the open and closed positions.

2. The valve assembly (110) as claimed in claim 1, wherein the valve member (136) defines a valve flow passage (138) for gaseous fuel through the valve member (136), and wherein the valve flow passage (138) defines a flow direction through the valve member (136) which is parallel to the axis of movement (A-A) of the valve member (136).

3. The valve assembly (110) as claimed in claim 1 or claim 2, comprising an inlet flow passage (120) for gaseous fuel, wherein the inlet flow passage (120) defines an inlet flow direction which is parallel to the axis of movement (A-A) of the valve member (136) between the open and closed positions.

4.

5.

6.

7.The valve assembly (110) as claimed in claim 3, wherein the annular seal member (100) surrounds the inlet flow passage (120) The valve assembly (110) as claimed in claim 3 or claim 4, wherein the inlet flow passage (120) is defined by the valve housing assembly (112) The valve assembly (110) as claimed in any of claims 3 to 5, wherein the valve member (136) is provided with a plurality of cross drillings (148) which allow the passage of fuel into the valve flow passage (138), from a chamber (130) defined by the valve bore (132), when the valve member (136) is moved away from the valve seat (92).A gaseous fuel system comprising a primary fuel source (70) for delivering gaseous fuel to a fuel tank (80) via the valve assembly (110) as claimed in any of claims 1 to 6.