GB2584205A

GB2584205A - Cavity filler for a valve

Info

Publication number: GB2584205A
Application number: GB2006523.1A
Authority: GB
Inventors: Anwar Hawa Javed
Original assignee: Hawa Valves India Pvt Ltd
Current assignee: Hawa Valves India Pvt Ltd
Priority date: 2020-05-04
Filing date: 2020-05-04
Publication date: 2020-11-25
Anticipated expiration: 2040-05-04
Also published as: GB2584205B; GB2584205B8; GB202006523D0

Abstract

A valve 10 comprises a valve housing 12. The valve housing 12 has a valve cavity 14 in fluid communication with two bores 42, 38 defining a flow path through the housing 12, the valve cavity 14 defined by one or more walls (40, Fig. 2). A flushing fluid inlet and outlet 22, 24 are in fluid communication with the cavity 14 for passing a flushing fluid therethrough. The valve housing 12 further comprises a valve element 18 mounted within the valve cavity 14, the valve element 18 being selectively movable between open and closed positions for selectively allowing and inhibiting a flow of fluid along the flow path. First and second valve seats 20 provide a seal between the valve element 18 and the valve housing 12. A cavity filler (26, Fig. 2) is situated between at least one of the cavity walls 40 and the valve element 18 for blocking a flow of fluid. The cavity filler 26 defines one or more flushing pathways in fluid communication with the flushing fluid inlet 22 and flushing fluid outlet 24 for receiving a flow of flushing fluid.

Description

CAVITY FILLER FOR A VALVE

Background

Valves are well known in conduits for fluid management, to selectively enable or prevent flow through the conduit. Typically, this is achieved by having a valve element which is moveably mounted in a cavity formed in a valve housing. The movement may be via sliding such as in a gate valve, or rotation such as in a ball valve. In order to facilitate the manufacture of the valve gaps and voids are generally provided. These gaps and voids may allow assembly, greasing and/or thermal deformation of the components. As a result, these gaps and voids are typically present in the assembled valve.

In use, such as in industrial applications, the valve will be exposed to the fluid medium that flows through the conduits. This fluid medium may further include solid particles of varying size, either deliberately due to the nature of the medium, or dirt and debris inevitably picked-up in use. Due to the mechanical operation of the valve the medium may penetrate the valve components and enter the gaps and voids required for other purposes. The effect of the medium penetrating the valve components and residing within them can cause degradation and wear of the components. Particularly, the particles or debris in the medium may be deposited in these gaps and voids. This deposit can build up over time and may impact significantly on the performance of the valve.

Typically, the build-up of these particles and debris is handled with routine cleaning and/or maintenance of the valve and regular replacements. This requires down-time for the valve and hence the system in which the valve is fitted.

Alternatively, cavity fillers may be provided in the valve. These cavity fillers are inserted during assembly of the valve into the gaps and voids. The cavity fillers are generally impervious to the fluid medium such that it is not able to enter these regions and deposit the particles and/or debris, thereby preventing the build-up.

However, it is inherent that there will still be a level of deposit as the cavity fillers cannot be perfectly formed to completely occupy the volume of the gaps and voids. This is particularly important as the cavity filler may encourage build-up between the filler itself and the moving valve element. This build-up can significantly negatively affect the performance of the valve and increase the degradation of the valve element in use.

There is therefore a need for an improved valve.

Summary

The present disclosure provides a valve according to claim 1. This valve provides a more effective seal whilst providing an effective method of regular cleaning of the valve. The cavity filler fills the valve cavity which otherwise could have allowed particle deposition. This further ensures the valve components are lubricated and flushed with fluid through the pathways provided. This allows increased longevity of part life as well as increased time between regular maintenance of the valve.

The one or more flushing pathways may be defined between the cavity filler and the valve element. This is a convenient and effective way to flush the valve element between the valve element and the cavity filler. This further ensure the moving components, such as the valve element, are free of obstructions and particles are removed that could cause friction and risk of degradation of the moving components.

The one or more flushing pathways may each have a depth defined as a distance between the valve element and the cavity filler, wherein the depth of the flushing pathway may be between 1% to 10% of a depth of the cavity filler, preferably less than 5% of the depth of the cavity filler. These are suitable dimensions to provide a volume of a pathway for effectively removing particles and flush fluid through the valve.

The one or more flushing pathways may each have a depth defined as a distance between the valve element and the cavity filler, wherein the depth of the flushing pathway may be between 1 millimetres to 10 millimetres. These are suitable dimensions to provide a volume of a pathway for effectively removing particles and flush fluid through the valve.

The depth of the flushing pathway may be at a maximum at the centre of the cavity filler and decrease in a direction transverse to the fluid flow pathway. These are suitable dimensions to provide a volume of a pathway for effectively removing particles and flush fluid through the valve. This also encourages the removal of larger particles or debris.

One or more of the flushing pathways may be provided through a central portion of the cavity filler. This is a suitable arrangement to provide an appropriate position of the flushing pathways to allow for flushing fluid.

The cavity filler may comprise first and second cavity filler portions, each cavity filler portion on opposite sides of the valve element. This is a suitable arrangement to provide an appropriate position of the flushing pathways to allow for flushing fluid.

A volume may be defined between the cavity walls and the valve element, and the cavity filler may occupies at least 70% of the volume of between the cavity walls, preferably at least 70% of the volume of between the cavity walls, more preferably at least 80% of the volume of between the cavity walls, most preferably at least 90% of the volume of between the cavity walls. This is a suitable volume of the cavity filler to provide effective flushing fluid as well as a seal or block against the deposition of particles in the valve cavity.

The valve element may comprise a through bore, wherein the bore of the valve element may be selectively alignable with the housing bores to allow or inhibit a flow of fluid along the flow pathway. This is a convenient way to form the valve element compared to providing a valve element that will need to be fully removed from the conduit to allow a fully open position. This arrangement allows the through bore of the valve element to be aligned or misaligned with the housing bores to selectively move from the open position to the closed position respectively.

The valve may be a gate valve and the valve element may be movable between the open and closed positions in a first direction, and the cavity filler may be provided adjacent to the valve element and spaced therefrom in a second direction transverse to the first direction. This provides one arrangement of possible types of the valves that the cavity filler can be implemented in.

The valve may be a ball valve and the valve element may be rotatable around an axis to move between the open and closed positions wherein the cavity filler of the valve element is shaped to conform to the valve element. This provides one arrangement of possible types of the valves that the cavity filler can be implemented in.

The valve element may be substantially, or generally, spherical. This provides one type of valve element, to which the cavity filler may correspond in shape.

The valve may comprise a sacrificial anode formed of a metal of higher reactivity than the valve housing. This valve may help reduce galvanic corrosion of the valve components, in particular due to the different reactivity of the metals the sacrificial anode will corrode more readily than the valve components.

The cavity filler may be formed of the metal such that the cavity filler is the sacrificial anode. This valve may help to further reduce galvanic corrosion of the valve components, in particular due to the cavity filler having a larger surface area this will reduce the likelihood of galvanic corrosion.

The present disclosure further provides a method of flushing a valve according to claim 15.

The flushing fluid may be a grease or flushing compound. Such fluids may effectively remove particles that are deposited in the valve. This further provides lubrication to the valve and its components.

The present disclosure further provides a method of retro-fitting a cavity filler to a valve according to claim 17.

The valve housing may further comprises a flushing fluid inlet and a flushing fluid outlet in fluid communication with the cavity for passing a flushing fluid through the cavity, and the cavity filler may be inserted such that one or more flushing pathways are defined in fluid communication with the flushing fluid inlet and flushing fluid outlet for receiving a flow of flushing fluid. This valve more accurately provides a means for flushing the valve to remove particle deposition. Further, this can help to prevent degradation of the valve.

Brief Description of Drawings

The present disclosure will be described with reference to the accompanying Figures in which: Figure 1 is a cross-sectional view of a typical gate valve; Figure 2A is a cross-sectional view of a gate valve with a cavity filler; Figure 2B is an exploded view of the gate valve of Figure 2A.

Figure 2C is a partially cutaway view of the gate valve of Figure 2B; Figure 3A is a cross-sectional view of a ball valve with a cavity filler; Figure 3B is an exploded view of the ball valve of Figure 3A; and Figure 3C is a partially cutaway view of the ball valve of Figure 3A.

Detailed Description of the Drawings

Figure 1 shows a schematic view of a typical valve 10 for attaching to a flow conduit for a flow of fluid. The valve 10 of Figure 1 is an example of a gate valve, but the present disclosure can equally be applied to any other type of valve. The valve 10 comprises a valve housing 12. The valve housing 12 may be formed of a valve body 12a and at least one valve bonnet 12b attached thereto. The valve housing 12 may include an upper valve bonnet 12a attached to an first side of the valve 10 in use, and a lower valve bonnet 12b attached to an opposite side of the valve 10 in use. The valve housing 23 further comprises an inlet bore 42, and an outlet bore 38, with a fluid flow pathway through the valve 10 defined from the inlet bore 42 to the outlet bore 38. Of course, the valve 10 may be bi-directional such that the flow pathway can also be reversed (i.e. from the outlet bore 38 to the inlet bore 42). Typically the valve housing 12 will be formed of a metal. This metal may be more reactive than the conduits which are attached to the valve 10.

A valve cavity 14 is defined in the valve housing 12. This valve cavity 14 may be formed in only the valve body 12a. Alternatively, as shown in Figure 1 the valve cavity 14 may also extend into the valve bonnet 12b. The valve cavity 14 may be manufactured into the valve housing 12, such as by machining. Alternatively, the valve cavity 14 may be formed as the valve housing 12 is itself formed such as via casting or 3D printing. The valve cavity 14 is in fluid communication with the inlet and outlet bores 42, 38 such that the flow pathway includes at least a portion of the valve cavity 14.

A valve element 18 is mounted into the valve cavity 14. In the valve 10 of Figure 15 the valve element 18 is a gate valve element. The valve element 18 may be formed of a valve element body with a valve through bore 44 formed therein. The valve bore 44 may be the same or differently dimensioned to the inlet and outlet bores 42, 38. The valve cavity 14 is sized and shaped to allow for movement of the valve element 18 between an open position in which fluid can flow along the flow path through the valve 10 and a closed position in which fluid is inhibited from flowing along the flow path through the valve 10. In particular, the fluid may be stopped or prevented from flowing through the valve 10 along the flow path in the closed position. In order to facilitate assembly of the valve 10, the valve cavity 14 is generally larger than the volume occupied by the valve element 18 in use. This space between the cavity walls and the valve element 18 in use may be defined as a cavity gap.

The cavity may also be sized and shaped to permit the use of flushing fluid, such as grease or a flushing compound, to clean and/or service the valve 10. In particular, the flushing fluid may be primarily water or grease under pressure with corrosion-preventative additives. This may be by removing debris from the valve cavity 14, and/or by providing a lubricant effect for the movement of the valve element 18. The flushing fluid may be inlet into the valve cavity 14 via a flushing fluid inlet 22, to flow through the cavity 14, and out of a flushing fluid outlet 24. While Figure 1 shows the flushing fluid inlet 22 as formed in the valve bonnet 12b, this is not necessarily the case and the flushing fluid inlet 22 and outlet 24 may be reversed. Additionally, each of the flushing fluid inlet 22 and outlet 24 may be provided on either the valve bonnet 12b or valve body 12a.

In some examples a slip or a plurality of slips 36 are provided in the valve cavity 18. The slips 36 are positioned to direct a flushing fluid to the surface of valve element 18 to permit movement. This is particularly the case where the flushing fluid can act as a lubricant. The valve housing 12 may further comprise one or more valve seats 20 which provide a seal between valve housing 12 at a point aligned with the inlet and/or outlet bore 40, 38 and the valve element 18. The valve seats 20 may be provided either side of the valve element 18. The valve seats 20 are configured to provide a seal between the valve element 18 and the valve housing 12. The valve seats 20 may further positioning and guiding the valve element 18 when it is moved between the open and closed positions.

The valve element 18 can be selectively moved between an open position which allows fluid to flow along the flow path and a closed position for inhibiting flow of a fluid along the flow path. In the open position the fluid flows through the valve housing 12 along the fluid flow path. To move between these positions, the valve element 18 may move in the cavity 14. From Figure 1, the valve element 18 is moved upwards such that the bore 44 of the valve element 18 is selectively aligned with the inlet and outlet bores 40, 38. That is, in the open position the bore 44 of the valve element 18 is aligned with the inlet and outlet bores 40, 38 such that a flow path is defined from the inlet bore 40, through the first valve seat 20, through the bore of the valve element 18, through the second valve seat 20, and then through the outlet bore 38.

The valve element 18 may be moved from this open position to the closed position by moving in a direction transverse to the direction of the fluid flow pathway. This direction is preferably perpendicular to the direction of the fluid flow pathway. In the closed position, the solid body of the valve element 18 will seal to the valve seat 20 to inhibit or prevent fluid from flowing through the valve 10.

In use, the fluid will typically contains small to large particles and/or debris. As the fluid passes through the valve 10, the particles may become lodged or deposited in the valve 10, such as in the valve cavity 14. The particles may become deposited between components of the valve 10 such as the valve element 18 and the valve seats 20.These particles and debris can build-up in the valve 10 until they can cause a malfunction of the valve 10. For example this may be through erosion and/or jamming of the valve 10. As the valve element 18 moves between the open and closed positions, it will pass through an intermediate position in which the valve cavity 14 is in fluid communication with the inlet bore 40. As a result, the valve cavity 14 may fill with fluid and these particles and debris may be deposited in the valve cavity 14.

Figure 2A and 2C show a gate valve 10 incorporating the present disclosure. Unless otherwise expressly specified, the features described above in relation to Figure 1 are also applicable to Figures 2A and 2B. The valve 10 comprises a valve housing 12, with a valve cavity 14. The valve housing 12 may be formed of a central valve body 12a, with first and second valve bonnets 12b attached thereto. In particular, the valve bonnets 12b may be attached either side of the valve body 12a. Of course, other arrangements of the valve housing 12 may be used with the present disclosure, including a single valve bonnet 12b.

The valve cavity 14 is in communication with inlet and outlet bores 38, 42 which define a flow path through the valve housing 12. The valve cavity 14 is defined by one or more cavity walls 40. The cavity walls 40 may define a generally rectangular or cylindrical valve cavity 14, or any other suitable shape. The valve housing 12 further comprises a flushing fluid inlet 22 and a flushing fluid outlet 24. A flushing fluid pathway is defined from the flushing fluid inlet 22 to the flushing fluid outlet 24, for the flow of a flushing fluid through the valve 10. The flushing fluid inlet 22 and flushing fluid outlet 24 are in fluid communication with the valve cavity 14 for passing a flushing fluid through the valve housing 12.

The valve housing 12 further comprises a valve element 18, the valve element 18 is mounted in the valve cavity 14. The valve element 18 is selectively movable between an open position for allowing a flow of fluid along the flow path 40 and, a closed position for inhibiting a flow of fluid along the flow path. A use footprint of the valve element 18 may be defined as the total volume occupied by the valve element 18 as it moves between the open and closed positions. The valve cavity 14 defines a volume greater than this use footprint in order to allow the valve 10 to be assembled. The difference in volume between the valve cavity 14 and the use footprint may be referred to as a cavity gap, or void. That is, there is a gap or space formed between the valve element 18 and the cavity walls 40.

Valve seats 20 are provided, at least a first and a second valve seat 20, configured to provide a seal between the valve element 18 and the valve housing 12.

The valve housing 12 further comprises a cavity filler 26. The cavity filler 26 may be formed of any suitable material, such as a thermoplastic or a metal. The use of a metal cavity filler 26 is discussed in more detail below. The cavity filler 26 is provided between at least one of the cavity walls 40 and the valve element 18 for blocking a flow of fluid, such as the main fluid in the flow path and/or the flushing fluid. The valve element 18 may be moveable between the open and closed positions in a first direction, and the cavity filler 26 may be spaced from the valve element 18 in a second direction transverse, or perpendicular, to the first direction. A cavity gap volume is defined between the at least one cavity walls 40 and the valve element 18, and the cavity filler 26 may occupy at least 70% of the volume of between the cavity walls 40, preferably at least 70 %, more preferably at least 80%, most preferable at least 90%.

As shown in Figures 2A to 2C the cavity filler 26 may comprise first and second cavity filler portions. For example, each cavity filler portion may be provided on opposite sides of the valve element 18. This may be, for example, one cavity filler portion provided upstream of the valve element 18 and one cavity filler portion provided downstream of the valve element 18. Of course, more than two cavity filler portions may be provided as appropriate.

The cavity filler may in this sense substantially surround the valve element 18. In particular, a use footprint of the valve element 18 may be defined as the total volume occupied by the valve element 18 as it moves between the open and closed positions. The cavity filler 26 may substantially surround this use footprint, or at least one or more sides thereof.

Figure 2B shows the valve 10 in an exploded view, where it may be seen that the cavity filler 26 may comprise four cavity filler portions. The cavity filler portions may be shaped to engage the valve seats 20, such as to seal thereto. In order to assemble the valve 10, the central valve body 12a may be first provided. The valve seats 20 may be inserted therein, where present. The cavity filler 26 may then be inserted into the valve body 12a.

Alternatively, the cavity filler 26 and valve seats 20 may be inserted together.

The valve element 18 may then be inserted into the valve cavity 14. The valve bonnets 12b are then attached to the valve body 12a to compete the assembly of the valve 10. Of course, this method may be adjusted as appropriate based upon the particular combination of components used in a given valve 10.

The portions of the cavity filler 26 may be configured to interface with each other, such as to collectively form the cavity filler 26. For example, each cavity filler portions may be provided with surfaces or projections to interlock with each other.

The cavity filler 26 may be provided in the absence of one or more valve seats 20. That is, the cavity filler 26 itself may act to seal with between the valve housing 12 and the valve element 18. To achieve this, the cavity filler 26 may comprise projections to seal with the valve element 18. The cavity filler 26 in this arrangement may be configured to provide the characteristics of the valve seat 20.

The cavity filler 26 defines one or more flushing pathways 28. The flushing pathways 28 are in fluid communication with the flushing fluid inlet 22 and flushing fluid outlet 24 for receiving a flow of flushing fluid. In this sense, a flushing fluid flow path is defined from the flushing fluid inlet 22, through the one or more flushing pathways 28 and out via the flushing fluid outlet 24. The flushing fluid pathways 28 may be defined generally as regions in which there is a gap in the cavity filler 26. For example, there may be one or more bores formed in the cavity filler 26. These bores may be machined into a blank cavity filler 26.

Alternatively, the bores may be formed integrally with the cavity filler 26.

The flushing pathways 28 of the cavity filler 26 may be defined between the cavity filler 26 and the valve element 18. That is, there may be a space between an inner surface of the cavity filler 26 and the valve element 18. This may again be defined as one or more channels formed on this inner surface of the cavity filler 26. The channels may be shaped -10 -such that the flushing pathways 28 are widest in the centre of the cavity filler 26 when viewed in cross section from a plan, or above, view. That is, when viewed generally transverse or perpendicular to the direction of fluid flow in the flushing pathway 28. The flushing pathways 28 may occupy substantially all, if not the entire distance, of the inner surface of the cavity filler 26. In this sense, the cavity filler may be spaced from the valve element 18 by a distance to define the flushing pathways 28. Alternatively, the flushing pathways 28 may pass through a central portion of the cavity filler 26. For example, the cavity filler 26 may be generally porous or have one or more bores formed therethrough defining the flushing pathways 28.

The ball valve element 18 may be driven by a valve stem extending into the cavity 14, and the cavity filler 26 may be appropriately shaped to allow this valve stem to contact the valve element 18 and actuate it accordingly, by sliding between the open and closed positions.

The one or more flushing pathways 28 may each have a depth defined as a distance between the valve element 18 and the cavity filler 26. Alternatively, the depth may be defined as a reference dimension, such as a diameter or width of the flushing pathway 28. The depth is sufficient to allow particles of various sizes that may be present in the fluid to be flushed through the flushing pathway 28 to clean the valve 10. The cavity filler 26 itself may have a depth defined in the same direction. The depth of the flushing pathway 28 may be up to 50% of the depth of the cavity filler 26. Preferably, the depth of the flushing pathway 28 may be between 1% to 10% of the depth of the cavity filler 26, more preferably less than 5% of the depth of the cavity filler 26. For example, the depth of the flushing pathway 28 is between 1 millimetre to 10 millimetres. Of course, the dimensions will depend upon the dimensions of the valve 10 and its use conditions. Certain use conditions may result in larger particles or debris which requires flushing.

The depth of the flushing pathway 28 may be at a maximum at the centre of the cavity filler 26 and decreases in a direction transverse to the fluid flow pathway 42. That is, the shape of the flushing pathway 28 may be arcuate in at least one dimension. Of course, any other shape for the flushing pathways 28 which is effective for the removal of particles or debris with flushing fluid may be used. Further, the shape of one or more flushing pathway 28 may be selected to provide different amounts of flushing fluid to different regions of the cavity filler 26. A flushing pathway 28 of a larger depth may receive a large volume of flushing fluid. This may be used for areas of the valve 10 that are more prone to particle deposition. With a larger volume of flushing fluid the particles may be more readily removed.

The flushing fluid may pass through a portion of the valve cavity 14 prior to entering the flushing pathway 28 defined by the cavity filler 26. For example, the cavity filler 26 may not extend over the entirety of the valve cavity 14. As a result, the flushing fluid may contact other areas of the valve 10 such as to provide lubrication. This may be applied to mechanical operating components in the valve 10, particularly those which encounter metal-to-metal contact. This may prevent degradation to prolong component life and longevity between regular maintenance.

In Figure 2C the valve 10 is shown in a fully assembled configuration with a partially removed section. The valve element 18 is in a closed position with the valve element 18 sealing with the valve seats 20 to prevent a flow of fluid along the main flow pathway. The valve 10 may be provided with a flow of flushing fluid to clean and/or service the valve in this position. The flushing fluid flow 46 is shown in this Figure 2C as a series of dashed lines. The flushing fluid flows 46 from the flushing fluid inlet 22 into the flushing pathways 28 and to the flushing fluid outlet 24. The flushing fluid outlet 24 may be into the valve element 18 through bore 44 and into the fluid flow path 42.

As shown in Figure 2C, the flushing fluid may flows over an upper surface of the valve element 18, before entering the flushing fluid pathways 28. In the valve 10 of Figure 2C, the flushing fluid pathways 28 are defined between the cavity filler 26 and the valve element 18. This can be seen underneath the valve element 18 where the flushing fluid is flowing along an inner surface of the cavity filler 26 to the flushing fluid outlet 24.

The cavity filler 26 may comprises a sacrificial anode formed of a metal of higher reactivity than the valve housing 12. For example, the sacrificial anode made be formed of aluminium. The sacrificial anode is provided in the valve 10 to preferentially corrode compared to the valve components such as the valve body 12, or the valve element 18.

The greater reactivity of the sacrificial anode enables galvanic corrosion of the sacrificial anode before the valve components. A part or the entirety of the cavity filler 26 itself may be formed of the metal such that the cavity filler 26 is the sacrificial anode. For example, the cavity filler 26 may be formed of aluminium. Alternatively, the cavity filler 26 may receive a distinct sacrificial anode.

-12 -Following a period of use, the sacrificial anode will be depleted. The valve 10 may then be opened and the sacrificial anode replaced. This may involve merely replacing a distinct sacrificial anode received in the cavity filler 26. Alternatively, the entire cavity filler 26 itself may be replaced.

While the detailed description to this point has focused upon a valve 10 which is a gate valve, the present disclosure is not limited thereto. The cavity filler 26 with a flushing fluid pathway 28 may be used with a valve 10 that may suffer from a build-up of particles or debris. Another example valve 10 for use with the present disclosure is shown in Figures 3A to 3C. The valve 10 of these Figures 3A to 3C is a ball valve. Of course, the shape and movement of the valve element 18 differs to the gate valves 10 of Figures 1 and 2A to 2C. However, unless expressly specified otherwise or inherently technically incompatible, any description above in relation to Figures 1 and 2A to 2C may be equally applicable to the ball valve 10 of Figures 3A to 3C.

The ball valve 10 comprises a valve housing 12, which includes a valve cavity 14. Again, the valve housing 12 may be formed of a valve body 12a, which may be centrally located, and one or more valve bonnets 12a attached thereto. The valve housing 12 includes an inlet bore 42 and an outlet bore 38 for receiving a flow of fluid. As in the depicted ball valve 10, the valve bonnet(s) 12b may extend from the valve body 12a in the direction of the inlet and outlet bores 42, 38. This is in contrast to the gate valve of Figures 1 and 2A to 2C where the valve bonnet(s) 12b extend from the valve body 12a in a direction transverse, or perpendicular, to the inlet and outlet bores 42, 38. One or both of the inlet and outlet bores 42, 38, and/or the cavity 14, may extend in the valve bonnet(s) 12b. In a particular example, the valve cavity 14 may be formed in the valve body 12a, with the inlet bore 42 formed in a first valve bonnet 12b and the outlet bore 38 formed in a second valve bonnet 12b.

A valve element 18 is proved within the cavity 14. The valve element 18 is a ball valve element, such that it may be generally spherical or ball-shaped. This may include, for example, flattened portions on the valve element 18 which deviate from strictly spherical or ball-shaped.

-13 -The valve element 18 of this example is moveable between an open position where fluid is able to flow from the inlet bore 42, through the valve 10, to the outlet bore 38 and a closed position where fluid is inhibited, or prevented, from flowing along this path via rotation of the ball valve element 18. The ball valve element 18 may comprise a through bore 44 formed therein, which is selectively alignable with the inlet and outlet bores 42, 38. The rotation of the ball valve element 18 may be about any suitable axis. For example, the axis may be generally transverse or perpendicular to the flow path of fluid through the valve 10. Of course, the valve element 18 may be any suitable shape which allows the valve 10 to move between an open and closed position via rotation of the valve element 18.

The valve 10 may further include one or more valve seats 20 which seal between the valve housing 12 and the valve element 18. For example, these valve seats 20 may be provided in one or more recesses inside the valve housing 12. In a particular example, the valve 10 may include first and second valve bonnets 12b, each of which houses one of the inlet and outlet bores 42, 38. Each valve bonnet 12b may further include a recess for receiving a valve seat 20.

During manufacture, the valve element 18 may be inserted into the valve cavity 14 in a direction generally corresponding to the flow path of fluid through the valve 10, known as a side-entry valve 10. Alternatively, the valve element 18 may be inserted into the valve cavity 14 in a direction transverse or perpendicular to this direction, known as a top-entry ball valve 10. The present disclosure may equally apply to either type of valve 10, or a valve 10 assembled via any other method.

As with the other valves 10, the volume of the cavity 14 is greater than the volume occupied by the valve element 18 as it moves between the open and the closed positions. Again, this may be to allow for assembly of the valve 10. In accordance with the present disclosure, a cavity filler 26 is provided to occupy this otherwise empty space between the cavity walls 40 and the ball valve element 18. Again, one or more flushing fluid pathways 28 may be provided in the cavity filler 26 to allow for a flow of flushing fluid through the valve 10. The flushing fluid may be inserted into the valve 10 via one or more flushing fluid inlets 22, and exit from the valve with the debris via one or more flushing fluid outlets 24.

-14 -The ball valve 10 is shown in an exploded arrangement in Figure 3B, which shows this arrangement. The cavity filler 26 may be formed of two cavity filler portions as shown in this Figure. Each cavity filler portion may be inserted from opposite sides of the valve 10.

As the ball valve element 18 rotates between the open and closed positions, if it is generally rotationally symmetric it will occupy the same volume in the open and closed positions. As a result, the cavity filler 26 may generally completely occupy the remaining volume of the cavity 14, except for the flushing fluid pathways 28. The ball valve element 18 may be driven by a valve stem extending into the cavity 14, and the cavity filler 26 may be appropriately shaped to allow this valve stem to contact the valve element 18.

The cavity filler 26 of the valve element 18 may be shaped to conform to the spherical valve element 18. That is, an inner surface of the cavity filler 26 may be shaped to conform to an outer surface of the valve element 18. For example, the inner surface of the cavity filler may be a portion of a sphere of generally the same diameter as the sphere of the valve element 18. Further, the one or more flushing pathways 28 of the cavity filler 26 may also be shaped to conform to the spherical valve element 18.

Figure 3C shows the ball valve 10 in an assembled state with a partially removed section to expose the internal valve housing 12 components in the open configuration. The flushing fluid flow is shown. The flushing fluid is inlet via the flushing fluid inlet 22, for example as a fluid under pressure. The flushing fluid flows along the flushing fluid pathways 28 to remove the deposited particles and/or debris from the valve 10. For example, the flushing fluid may flow between the cavity filler 26 and the valve element 18 if the flushing fluid pathways 28 are defined in this space. The communication of the flushing fluid inlet 22 and the flushing fluid outlet 24 with the cavity filler 26 allows the flushing fluid to flow from the inlet 22, through the flushing pathways 28 and to the outlet 24, taking the deposited particles and/or debris therewith.

As with the valve 10 of Figures 2A to 2C, the valve may further include a sacrificial anode, which will perform as described above. Again, this may be disposed within the cavity filler 28, or a part or the entirety of the cavity filler 26 may act as such a sacrificial anode.

With the valve 10 including a cavity filler 26 including these flushing pathways 28, a method of flushing a valve is provided. A valve in accordance with the above disclosure is provided, -15 -and a flushing fluid is provided along the one or more flushing pathways 28. The flushing fluid may be input into the flushing fluid inlet 22, flow through the flushing pathway(s) 28, and out of the flushing fluid outlet 24.

The flushing fluid may be a flushing compound or a grease. In particular, the flushing fluid may be primarily water or grease under pressure with corrosion-preventative additives. The flushing fluid may be injected into the flushing fluid inlet 22 under pressure.

This method may be applied to any suitable valve 10, including a ball valve 10 or a gate valve 10.

A cavity filler may also be retro-fitted to an existing valve 10. That is, a valve 10 which is already installed in a conduit. The valve 10 may be temporarily removed and the cavity filler 26 installed therein. The method of retro-fitting a cavity filler 26 to a valve 10 comprises the initial step of providing a valve 10. This valve 10 includes a valve housing 12 with a valve cavity 14 defined therein. The valve cavity 14 is be fluid communication with an inlet bore 42 and an outlet bore 38. Together, these bores 42, 37 define a flow path through the valve housing 12. The valve cavity 14 is defined by one or more cavity walls 40. A valve element 18 is mounted within the valve cavity 14 defining a cavity gap between at least one of the cavity walls 40 and the valve element 18. The valve element 18 is selectively moveable between an open position for allowing a flow of fluid along the flow path and a closed position for inhibiting a flow of fluid along the flow path. The valve 10 may further include one or more valve seats 20, such as first and second valve seats 20. Each valve seat 20 may be configured to provide a seal between the valve element 18 and the valve housing 12. The valve 10 may generally be similar to any described above in relation to the Figures.

A cavity filler 26 that corresponds in shape and size to the cavity gap is then provided. This may be an off-the-shelf component, or may be specifically manufactured for the particular valve 10. For example, the cavity filler 26 may be shaped after the dimensions of the cavity gap have been measured. This cavity filler 26 is inserted into the valve 10 to retrofit it thereto. The inserted cavity filler 26 then substantially fill the cavity gap.

The valve housing 12 may further comprise a flushing fluid inlet 22 and a flushing fluid outlet 24 in fluid communication with the cavity 14 for passing a flushing fluid through the cavity 14, and the cavity filler 26 may be inserted such that one or more flushing pathways -16 - 28 are defined in fluid communication with the flushing fluid inlet 22 and flushing fluid outlet 24 for receiving a flow of flushing fluid. This results in a valve 10 generally similar to those described above in relation to Figures 2A to 3C.

Claims

-17 -CLAIMS: 1. A valve comprising: a valve housing comprising: a valve cavity in fluid communication with two bores which define a flow path through the housing, the valve cavity defined by one or more cavity walls: and a flushing fluid inlet and a flushing fluid outlet in fluid communication with the cavity for passing a flushing fluid through the cavity, a valve element mounted within the valve cavity, the valve element selectively moveable between an open position for allowing a flow of fluid along the flow path and a closed position for inhibiting a flow of fluid along the flow path; first and second valve seats, configured to provide a seal between the valve element and the valve housing; and a cavity filler provided between at least one of the cavity walls and the valve element for blocking a flow of fluid, the cavity filler defining one or more flushing pathways in fluid communication with the flushing fluid inlet and flushing fluid outlet for receiving a flow of flushing fluid.
2. The valve of claim 1, wherein the one or more flushing pathways are defined between the cavity filler and the valve element.
3. The valve of claim 2, wherein the one or more flushing pathways each have a depth defined as a distance between the valve element and the cavity filler, wherein the depth of the flushing pathway is between 1% to 10% of a depth of the cavity filler, preferably less than 5% of the depth of the cavity filler.
4. The valve of claim 2 or 3, wherein the one or more flushing pathways each have a depth defined as a distance between the valve element and the cavity filler, wherein the depth of the flushing pathway is between 1mm to 10mm.
5. The valve of claim 3 or 4, wherein the depth of the flushing pathway is at a maximum at the centre of the cavity filler and decreases in a direction transverse to the fluid flow pathway.
-18 - 6. The valve of any preceding claim, wherein one or more of the flushing pathways is provided through a central portion of the cavity filler.
7. The valve of any preceding claim, wherein the cavity filler comprises first and second cavity filler portions, each cavity filler portion on opposite sides of the valve element.
8. The valve of any preceding claim, wherein a volume is defined between the cavity walls and the valve element, and the cavity filler occupies at least 70% of the volume of between the cavity walls, preferably at least 70%, more preferably at least 80%, most preferably at least 90%.
9. The valve of any preceding claim, wherein the valve element comprises a through bore, wherein the bore of the valve element is selectively alignable with the housing bores to allow or inhibit a flow of fluid along the flow pathway.
10. The valve of any preceding claim, wherein the valve is a gate valve and the valve element is movable between the open and closed positions in a first direction, and the cavity filler is provided adjacent to the valve element and spaced therefrom in a second direction transverse to the first direction.
11. The valve of any of claims 1 to 9, wherein the valve is a ball valve and the valve element is rotatable around an axis to move between the open and closed positions wherein the cavity filler of the valve element is shaped to conform to the valve element.
12. The valve of claim 11, wherein the valve element is generally spherical.
13. The valve of any preceding claim, wherein the valve comprises a sacrificial anode formed of a metal of higher reactivity than the valve housing.
14. The valve of claim 13, wherein the cavity filler is formed of the metal such that the cavity filler is the sacrificial anode.
15. A method of flushing a valve, comprising the steps of: providing a valve according to any preceding claim; -19 -flowing a flushing fluid along the one or more flushing pathways between the flushing fluid inlet and flushing fluid outlet to remove debris in the cavity.
16. The method of claim 15, wherein the flushing fluid is a grease or flushing compound. 5
17. A method of retro-fitting a cavity filler to a valve comprising the steps of: providing a valve comprising: a valve housing comprising: a valve cavity in fluid communication with two bores which define a flow path through the housing, the valve cavity defined by one or more cavity walls: a valve element mounted within the valve cavity defining a cavity gap between at least one of the cavity walls and the valve element, the valve element selectively moveable between an open position for allowing a flow of fluid along the flow path and a closed position for inhibiting a flow of fluid along the flow path; first and second valve seats, configured to provide a seal between the valve element and the valve housing; providing a cavity filler that corresponds in shape and size to the cavity gap; and inserting the cavity filler to fill the cavity gap.
18. The method of claim 17, wherein the valve housing further comprises a flushing fluid inlet and a flushing fluid outlet in fluid communication with the cavity for passing a flushing fluid through the cavity, and the cavity filler is inserted such that one or more flushing pathways are defined in fluid communication with the flushing fluid inlet and flushing fluid outlet for receiving a flow of flushing fluid.