WO2020216692A1

WO2020216692A1 - Gate valve member

Info

Publication number: WO2020216692A1
Application number: PCT/EP2020/060922
Authority: WO
Inventors: Owen ROBB; Gary Smart
Original assignee: Unity Well Integrity Limited
Priority date: 2019-04-24
Filing date: 2020-04-17
Publication date: 2020-10-29
Also published as: GB2583355A8; GB2583355B; GB2583355B8; GB201905739D0; GB2583355A

Abstract

Described is a gate valve member for use in a gate valve. The gate valve member comprises a lattice structure and an outer shell at least partially surrounding the lattice structure. The outer shell surface includes a sealing surface configured to sealingly engage a valve seat in a gate valve, and the lattice structure and the outer shell are integrally formed.

Description

Gate Valve Member

FIELD

Some examples relate to a gate valve member for use in a gate valve, and a method of manufacture of a gate valve member.

BACKGROUND

Gate valves are typically used to either permit or prevent the flow of fluids. Generally, gate valves have both an open configuration, in which flow of a fluid is permitted, and a closed configuration, in which the flow of a fluid is prevented.

A gate valve typically consists of a moveable gate valve member which is located adjacent to a valve seat. The valve seat may incorporate an aperture or port therein which permits the flow of a fluid through the gate valve when the moveable gate valve member is in the open configuration i.e. not or minimally obstructing the port in the valve seat. In the closed position, the moveable gate valve member is positioned so as to occlude the port in the valve seat, thereby preventing fluid from flowing through the gate valve, and closing the valve. A gate valve may be positioned, for example, between two adjacent sections of pipe or tubing. The moveable gate valve member can be optionally positioned in a flow of fluid in the pipe or tubing thereby assisting to control the flow of fluid through the pipe or tubing.

Under normal operating conditions, when the gate valve is closed, flow of fluid is prevented which causes pressure in the pipe or tubing to act on the area of the moveable gate valve member exposed to the fluid flow, leading to a differential pressure acting over the gate valve member of the gate valve. This causes an axially directed force to act on the moveable gate valve member, causing it to be pressed against the seat member adjacent to which it is positioned. As such, this gate valve member effectively acts as a valve seat, or part of a valve seat. The moveable gate valve member being pressed against a seat member assists the gate valve to provide an effective fluid seal.

It has been observed that, in cases where the pressure in the pipe or tubing is relatively low, leakage past the closed gate valve member can occur. Traditional methods of overcoming this problem have involved injecting grease into the valve in an attempt to improve the seal on the seat and stop the leakage. However due to, for example, migration of grease with the use of the valve, this method may become less reliable over time, which is undesirable.

SUMMARY

One aspect relates to a gate valve member for use in a gate valve, the gate valve member comprising:

a lattice structure; and

an outer shell at least partially surrounding the lattice structure, wherein the outer shell includes a sealing surface configured to sealingly engage a valve seat in a gate valve;

the lattice structure and the outer shell being integrally formed.

In use, the gate valve member may be able to be moved between an open and a closed position such that, when in the closed position, the sealing surface of the gate valve member is able to engage a valve seat in a gate valve.

The present inventors have discovered that the weight of the gate valve member has a bearing on sealing capabilities, especially when exposed to low pressures, which result in a low pressure differential acting across the gate valve member. In particular, when the gate valve member is oriented such that its longitudinal axis is not vertical, the effect of gravity on the gate valve member may urge the gate valve member away from the valve seat, creating a leak path. In this instance, the weight of the gate valve member is of importance, because a heavier gate valve member requires a larger force and therefore a larger pressure differential acting thereacross to overcome the downwards force associated with gravity and create a seal against the valve seat. In this respect, the present inventors have understood that reducing the weight of the gate valve member may alleviate this issue, and that therefore a more lightweight gate valve member is likely to produce a more reliable seal, particularly where there is a low pressure differential involved.

Having a gate valve member in the form of a lattice structure having an outer shell may assist to provide a gate valve member that is both lightweight and has sufficient rigidity and structural integrity to resist any deformation of the gate member, for example, as a result of a differential pressure acting thereon. When installed in a gate valve, having a lightweight gate valve member may permit a reduced fluid pressure to act on the gate valve member to force the gate valve member against the valve seat in the gate valve. As such, a lightweight gate valve member is able to provide a seal against the valve seat at lower differential pressures acting across the gate valve. This is particularly useful where the longitudinal axis of the gate valve member is not vertically oriented, as in this case the effect of gravity is a factor, and the weight of the gate valve member must be overcome in order to establish a seal between the gate valve member and a valve seat.

At least part of the gate valve member may be manufactured or constructed through use of an additive manufacturing process. Such additive manufacturing may facilitate integrally forming of the lattice structure to the outer shell. The construction of at least part of the gate valve member (e.g. the lattice and/or the outer shell) may comprise sintering and/or melting. The construction of at least part of the gate valve member (e.g. the lattice and/or the outer shell) may comprise a laser-based powder bed melting process. The construction of at least part of the gate valve member (e.g. the lattice and/or the outer shell) may comprise at least one of selective laser melting (SLM), direct metal laser sintering (DMLS) and electron beam melting (EBM). Producing the gate valve member using additive manufacturing may be particularly suitable as it may allow an intricate structure (e.g. an intricate lattice structure) to be produced.

The additive manufacturing process may comprise constructing the gate valve member as a monolithic structure. The additive manufacturing process may comprise constructing the gate valve member using a single material or material type, or a combination of two or more material or material types.

The lattice structure may be provided as a structural feature of the gate valve member. The lattice structure and the outer shell being integrally formed may further assist to increase a property of the gate valve member. For example, may increase at least one of the strength, rigidity and toughness of the gate valve member.

The lattice structure may have a particular configuration depending on the design requirements of the gate valve member. For example, the lattice structure may have a configuration to particularly enhance (e.g. to optimise) the rigidity of the gate valve member. Additionally or alternatively, the lattice structure may be configured to enhance the strength or resistance to deformation of the gate valve member.

The lattice structure may be configured to have a cellular structure comprising a plurality of cells. The cell structure may comprise closed cells (i.e. cells that are sealed and/or self-contained relative to another cell). The cell structure may comprise open cells (e.g. cells that are open relative to another cell). Such a cellular structure may assist to improve a quality of the gate valve member, for example the rigidity or the strength of the gate valve member. Such a cellular structure may assist in to provide a structure that provides ease of manufacture of the gate valve member. As will be described in more detail later, such a structure may enable the properties of the gate valve member to be altered after the initial manufacture of the gate valve member (e.g. initial manufacture of the structure of the gate valve member).

The lattice structure may be uniform throughout the gate valve member. Alternatively, a variable lattice structure (e.g., variable geometry of the lattice structure) may be provided. Such variability may provide localised variations in a property of the gate valve member, such as a mechanical property, for example strength, weight etc.

The shape of the gate valve member may be constrained depending on the geometry of the gate valve in which the gate valve member is intended to be used. The gate valve member may generally comprise the shape of a rectangular prism. The gate valve member may comprise at least one planar surface. In one example, the gate valve member may comprise two planar surfaces. The at least one planar surface may be defined by, or form part of, the outer shell. The at least one planar surface may assist to provide a fluid-tight seal between the gate valve member and a seat in the gate valve. The at least one planar surface may be defined by or located upon the outer shell of the gate valve member. For example the sealing surface may be defined by or located upon a planar surface of the gate valve member.

The gate valve member may comprise a through bore. The through bore may function to allow a fluid to pass through the gate valve member, for example when the gate valve member is in the open configuration. The through bore may be defined by a gap in the lattice structure of the gate valve member, and as such the lattice structure may extend to the periphery of the through bore. Such a design may permit the gate valve member to comprise a through bore without significantly compromising a quality of the gate valve member, for example the strength of the gate valve member.

The outer shell may completely surround (e.g. envelop) the lattice structure. In this way, the outer shell may be provided as a single structure. Having an outer shell that completely surrounds the lattice structure may provide a complete outer shell with an internal lattice structure. Having a complete outer shell may provide the lattice structure with further structural reinforcement.

The outer shell may cover a single surface of the lattice structure, for example, a single planar surface of the lattice structure. In this case, the outer shell may assist to provide a sealing surface, for example, while permitting a gate valve member comprising a minimum volume of material and therefore having a minimum weight.

The outer shell may comprise or be provided in a plurality of parts, for example two parts. The outer shell may be provided as two layers on the gate valve member. In this case, the outer shell may provide the lattice structure with two planar surfaces, for example two parallel planar surfaces. Such a configuration may permit the gate valve member to provide a sealing surface on each of the parts of the outer shell, thus permitting the gate valve member to have multiple (e.g. two) sealing surfaces. Where two sealing surfaces are provided, each of the sealing surfaces may be opposing sealing surfaces. Such a gate valve member may be useable with a gate valve to provide, for example, sealing capability for fluid flow in two directions, for example a forward and a reverse direction.

The lattice may be constructed from a lattice material. The lattice material may be a single solid material. The lattice material may be a mixture of at least two materials. The lattice material may be a foam and/or porous material. The lattice material may comprise interstices. Such interstices may be able to be filled with a secondary material, which may enable a user to alter the structural properties of the lattice material.

The lattice material may be a metal or metal alloy. The lattice material may be a composite material, for example a material that is a mixture of a metal and a non-metal. The selection of the lattice material may be dependent on the manufacturing process intended to be used to form the lattice. For example, use of a metallic lattice material may be beneficial where this material is capable of being used in an additive manufacturing process, for example a three-dimensional printing process.

The lattice structure (e.g. the lattice material forming the lattice) may be arranged in the form of a beam, or an arrangement of beams (for example, an arrangement of truss like members such as struts and ties). The beams may be solid beams, or may be hollow, e.g. in the form of hollow tubes. Forming the lattice structure in this way may provide the lattice with a preferential property (e.g. stiffness or strength), while reducing the overall volume of material required to form the lattice. The beam or beams may have any suitable cross-sectional shape, or a mixture of suitable cross-sectional shapes, such as a circular, triangular, square, rectangular, pentagonal and/or hexagonal cross-sectional shape.

The lattice structure (e.g. the lattice material forming the lattice) may be arranged in the form of at least one wall or panel, for example a plurality of two-dimensional walls or panels arranged into a three dimensional structure. Such an arrangement of lattice material may assist to provide the lattice with, for example, improved strength or resistance to deformation in a particular dimension, such as improved resistance to lateral deformation.

The lattice may define or comprise a cellular structure (e.g. the lattice material may be arranged to form a cell or cells).

For example, the lattice may define or comprise an open cellular structure. In such a structure, the lattice may define or comprise cells (e.g. voids) surrounded by a lattice material comprising areas of open space through which the void of one cell is connected to the void of an adjacent cell. A lattice comprised of an open cellular structure may permit the properties of the lattice to be altered after manufacture, for example by allowing for the introduction of a substance into the open cells after initial manufacture of the cells. Where the lattice defines or comprises an open cellular structure, the cells may be able to hold a filler material (e.g. at least a part of the open cellular structure may be at least partially filled with a filler material). For example, where the lattice defines or comprises an open cellular structure, the cells may be able to be filled with a liquid, a gas, a foam and/or a gel. The filler material may provide the lattice with beneficial properties, e.g. the filler material may improve the strength, toughness, rigidity or resistance to deformation of the gate valve member. As such, where the lattice comprises an open cell structure, it may be possible to alter a quality or property of the lattice structure after the initial manufacture of the lattice structure. For example, the weight and/or strength of the gate valve member may be altered post manufacture.

The outer shell may comprise or define at least one aperture, and may be located on the gate valve member to facilitate the introduction of a filler material into the lattice. For example, the outer shell may contain a plurality of apertures to facilitate the introduction of a selected filler material into the lattice, where the lattice comprises an open cellular structure. The outer shell may contain at least one aperture to facilitate the injection of a filler material into the lattice, or a part of the lattice comprising an open cellular structure. As such, the geometry of the outer shell may assist to permit filling of an open cell structure in a simple and quick manner.

Alternatively or additionally, the lattice may define or comprise a closed cellular structure. In such a structure the lattice may define or comprise cells (e.g. voids) completely surrounded (e.g. encased) in a lattice material such that the void of each cell is sealed off from the void of each adjacent cell. Where the lattice defines a closed cellular structure, the closed cells may be able to hold a filler material (e.g. be at least partially filled, as defined previously) during the initial manufacture of the lattice material. The filler material may then be sealed in the lattice structure upon completion of the manufacture of the lattice structure.

The lattice may define or comprise a mixture of open cells and closed cells.

The form of the cells in the lattice structure may be at least partially defined by the geometry of the gate valve member. The lattice structure may comprise at least one of a triangular prism or pyramidal shaped cell, a rectangular prism shaped cell, a pentagonal prism shaped cell and a hexagonal prism or honeycomb shaped cell.

The lattice may comprise or define a uniform distribution of cells, wherein the size and/or shape of cells may be uniform throughout the lattice. This may provide a simpler manufacturing process for the lattice. The lattice may comprise or define a non-uniform distribution of cells, wherein the size and/or shape of cells may differ throughout the lattice. For example, in portions of the lattice where there may be expected to be a high stress concentration, the lattice may comprise smaller cells, differently shaped cells, or cells with a greater wall thickness. Having differing size and/or shape of cells may allow a lattice to be constructed having differing properties throughout the volume of the lattice, for example enhanced strength under compression in a volume that is expected to experience high compressive stresses in use.

The lattice structure may comprise a plurality of repeating geometric structures. For example the lattice structure may comprise a plurality of repeating triangular prism structures, for example repeating triangular prism shaped cells. The lattice structure may comprise a plurality of rectangular prism structures, for example a plurality of repeating rectangular prism shaped cells. The lattice structure may comprise a plurality of honeycomb structures, for example a plurality of repeating honeycomb cells.

The gate valve member may be a single part, or may comprise multiple parts, e.g. two parts (e.g. may have a modular construction). At least one module may comprise a shell structure and a lattice structure. Where the gate valve member comprises multiple parts, the gate valve member may be considered a split gate valve member. Each part of the multi-part (i.e. modular) gate valve member may be able to move independently of some or each of the other parts of the multi-part gate valve member (e.g. moved independently relative to the gate valve). The multi-part gate valve member may comprise multiple parts of identical or similar size. Alternatively, the gate valve member may comprise multiple parts some or each of which differ in size. A modular part gate valve member may facilitate to provide an enhanced seal relative to a single part gate valve member, and/or may function to reduce sliding friction or reduction in wear and/or flow induced erosion of the gate valve member. A multi-part gate valve member may additionally be more easily installed, and/or be more tolerant of installation relative to a single part gate valve member.

The modular gate valve member may comprise a connecting member that connects at least two parts of the modular gate valve member. For example, the modular gate valve member may comprise a sleeve that connects at least two part of the modular gate valve member. The sleeve may assist to seal a leak path between the modules of the gate valve member. At least one part, or each part, of the multi-part gate valve member may be manufactured through use of additive manufacturing, as previously described. For example, each part of the multi-part gate valve member may comprise an outer shell and a lattice. By producing at least a part of the multi-part gate valve member using additive manufacturing, this may enable more complex and/or non-conventional part geometries to be produced that would otherwise not be possible using other manufacturing techniques. For example, a complex and/or non-conventional geometry may enable the multiple parts of the multi-part gate valve member to fit together in a way that enhances sealing of the gate valve member or reduces flow induced erosion and/or wear of the gate valve member, or facilitates installation of the gate valve member.

The gate valve member may comprise at least one connector (e.g. a number of connectors corresponding to the number of parts of the gate valve member) for connection to a driveable member. The driveable member may assist to permit the gate valve member to move between the open and closed position when located in a gate valve. The driveable member may be a stem or shaft. The driveable member may be connected to a motor or the like to enable axial movement of the driveable member.

The connector may comprise a pivotal connector, such that a pivotable connection is possible between the driveable member and the gate valve member. The pivotable connection may permit lateral movement of the gate valve member when located in the gate valve. Such lateral movement may permit the gate valve member to seat against a valve seat in the gate valve, and may permit the gate valve member to“float” relative to the gate valve. In this way, a pivotal connection between the driveable member and the gate valve member may permit enhanced sealing on a valve seat of the gate valve member.

The gate valve member may comprise a secondary material. The secondary material may be to improve a property of the gate valve member, for example for the purpose of increasing the hardness and/or toughness of the gate valve member, for example for the purposes of increasing the level of wear the gate valve member is able to endure while still being able to function correctly. The secondary material may be in the form of a wireframe or mesh. The secondary material may be flexible (e.g. sufficiently flexible to conform to the shape of the gate valve member). In one example, a secondary material may be integrated into the material of the gate valve member, such as being integrated into the outer shell of the gate valve member (e.g. intertwined, woven through or integrally formed with the material of the gate valve member). Additionally or alternatively, the secondary material may be connected (e.g. welded) to an outer surface of the gate valve member. Where the gate valve member is constructed via an additive manufacturing process, the gate valve member may be constructed around the secondary material. Such a process of comprising a secondary material in the gate valve member for the purpose of increasing the overall hardness and/or toughness of the gate valve member may be known as hardfacing.

One aspect relates to a gate valve comprising a gate valve member as previously described.

The gate valve member may move relative to the gate valve, between an open position in which a fluid is permitted to flow through the gate valve, and a closed position in which the gate valve member prevents and/or restricts fluid flow through the gate valve.

The gate valve may comprise a first seat member. The gate valve may additionally comprise a second seat member. The first seat member may comprise a seat surface. The second seat member may comprise a seat surface. In use, when the gate valve member is in the closed position, a pressure (e.g. a pressure from a fluid flow) may act upon an area of the gate valve member such that it experiences a force in the direction of the seat of the first seat member or the second seat member. Such a force may assist to provide a seal between the first and/or second seat member and may assist to provide a seal between the gate valve member and the first and/or second seat member.

The first and second seat members may be located parallel to one another. The gate valve member may be located in a gap or void between the first and second seat members.

One aspect relates to a method for manufacturing a gate valve member, comprising: producing a three dimensional model of the gate valve member comprising a lattice structure and an outer shell; and forming a gate valve member according to the three dimensional model such that the lattice structure and the outer shell are integrally formed.

The method for manufacturing the gate valve member may comprise forming a gate valve member according to the three dimensional model using an additive manufacturing process. The method for manufacturing the gate valve member may comprise a sintering process. The method for manufacturing the gate valve may comprise an ablation process (e.g. a laser ablation process). The method for manufacturing the gate valve may comprise a combination of a sintering process and an ablation process. The method for manufacturing the gate valve member may comprise a laser-based powder bed melting process. The method for manufacturing the gate valve member may comprise at least one of selective laser melting (SLM), direct metal laser sintering (DMLS) and electron beam melting (EBM).

The method of manufacturing the gate valve member may comprise constructing the integrally formed lattice structure and outer shell in a plurality of layers. The method of manufacturing the gate valve member may comprise forming the gate valve member in a plurality of layers formed of a single material or material type.

The method of manufacturing may comprise applying a design optimisation process to the three dimensional model of the gate valve member. The optimisation process may produce a gate valve member with preferential characteristics or properties, for example by keeping the weight of the gate valve member to a minimum while minimally affecting or reducing the overall strength of the gate valve member. In similar words, the design optimisation process may be configured to maximise a property of the design of the gate valve member (e.g. strength, toughness, stiffness, or the like) while minimising the volume of material required to construct the gate valve member.

The design optimisation process may be or comprise a topology optimisation process, for example involving removal of materials which have little or no effect on the overall strength, rigidity, toughness etc. of the gate valve member.

The design optimisation process may comprise the forming of a lattice or lattice structure as at least a part of the gate valve member. The design optimisation process may comprise the forming of an outer shell as at least a part of the gate valve member. The design optimisation process may comprise the forming of a lattice or lattice structure and an outer shell, forming a monolithic structure.

The method of manufacturing the gate valve may comprise the selection of a cell shape or type (e.g. a pyramidal or honeycomb shaped cell) and repeating the geometry of the selected cell type to form the lattice. The method of manufacturing the gate valve may comprise selecting a geometry of the lattice material. For example, where the lattice material is arranged in a truss-like structure, the method may comprise selecting a cross sectional shape or area of a support of the truss-like structure, for example a circular, triangular or square cross section. Where the lattice material is arranged as a plurality of walls or panels arranged in lattice structure, the method may comprise selecting a thickness of the walls or panels, for example 0.5mm, 1 mm, 1.5mm or the like.

The method may comprise stress-testing the gate valve member, for example the lattice material of the gate valve member, to ensure fitness for purpose.

The above described gate valve member and associated gate valve may have applications in many industries. One such industry is the oil and gas industry, where the gate valve may find application in an oil and gas well. In such an application, the gate valve may be oriented such that the longitudinal axis of the gate valve is horizontal. In this particular application, the gate valve may be used to seal or cap part of the well. Any leakage past the gate valve member could potentially allow hydrocarbons to escape to the surface of a well, creating a safety issue in the well. This is particularly relevant in depleted wells, where well fluids may have a lower pressure, which may not provide a seal against the valve seat in a gate valve if the gate valve member is too heavy. Having a lightweight gate valve member may therefore be particularly beneficial in the oil and gas industry.

A further aspect may relate to a gate valve member for use in a gate valve, the gate valve member comprising:

a lattice structure; and

an outer shell at least partially surrounding the lattice structure, wherein the outer shell includes a sealing surface configured to sealingly engage a valve seat in a gate valve. The gate valve may be constructed through use of additive manufacturing. The gate valve may be integrally formed through use of additive manufacturing. The gate valve may be formed as a monolithic structure through use of additive manufacturing.

A further aspect relates to a gate valve member for use in a gate valve, the gate valve member comprising:

a lattice structure; and

an outer shell at least partially surrounding the lattice structure, wherein the outer shell includes a sealing surface configured to sealingly engage a valve seat in a gate valve; and

the lattice structure and the outer shell being integrally formed at least in part by additive manufacturing.

a first component assembled relative to a second component, each of the first and second components comprising:

a lattice structure; and

an outer shell at least partially surrounding the lattice structure, wherein the outer shell includes a sealing surface configured to sealingly engage a valve seat in a gate valve.

The gate valve member may comprise further components, for example a third component and optionally a fourth component.

One or each of the components may be integrally formed, such that one or each forms a monolithic structure.

The gate valve member may comprise a sleeve that extends between the first and second components. The sleeve may bridge a gap between the first and second components. The sleeve may therefore assist to seal a leak path in the gate valve member. The gate valve member may comprise a biasing member. The biasing member may be positioned between the first component and the second component, and may urge the first component away from the second component. The biasing member may be in the form of a spring, for example a helical spring or a leaf spring.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1A is an isometric view of a gate valve member.

Figure 1 B is the isometric view of Figure 1A with a cutaway portion showing internal detail.

Figure 2A is a schematic illustration of a gate valve in the open position.

Figure 2B is a schematic illustration of a gate valve in the closed position.

Figures 3A-C are isometric views showing detail of a multi-part gate valve member. Figure 4A is a schematic illustration of a gate valve in the open position.

Figure 4B is a schematic illustration of a gate valve in the closed position.

Figure 5 is a flow chart showing the steps involved in a manufacturing process.

DETAILED DESCRIPTION OF THE DRAWINGS

Figure 1A is an isometric view of a gate valve member 10. The gate valve member 10 generally has a shape of a rectangular prism having a through bore 14 extending laterally through the gate vale member 10 and located towards one axial end of the gate valve member 10. In this illustration, the gate valve member 10 comprises an outer shell 12 which extends completely around the exterior of the gate valve member 10. The outer shell 12 comprises a flat upper surface 15 that, when incorporated into a gate valve, forms a sealing surface for sealing against a valve seat.

For reasons of clarity, a longitudinally extending axis 17 and a laterally extending axis 19 is shown on the gate valve member 10. Figure 1 B illustrates the same gate valve member 10 as shown in Figure 1A, but shows a cutaway portion revealing a part of the internal structure of the gate valve member 10. In this illustration, the thickness of the outer shell 12 can be seen, as well as a lattice structure 16 located inside the gate valve member 10. As is the case in this illustration, the outer shell 12 and lattice structure 16 are made from a single integrally formed structure, which may be known as a monolithic structure. The skilled person will appreciate that the gate valve member 10 may be formed in a monolithic structure from a single material, or from a mixture of materials.

In this illustration, the lattice structure 16 has a honeycomb form, which is constructed from a plurality of walls or panels 18 extending in a lateral direction relative to the gate valve member 10, and arranged in a repeating hexagonal pattern, to create a plurality of closed cells of a hexagonal prism shape. While a closed cell construction is shown here, the skilled person would understand that an open cell structure could be created by including channels or apertures in the panels 18. Equally, while the outer shell 12 is shown extending completely around the lattice 16, the skilled person would understand that it would be possible to have gaps in the outer shell 12.

In this example, a honeycomb shaped lattice is provided. However, other shapes of lattice may also be possible, for example a lattice comprising cells of a triangular prism or pyramidal shape. A uniform lattice is provided in this example, although the skilled person would appreciate that it would be possible to have a lattice of a non-uniform construction.

Shown in Figure 1A is an optional port 11 (although the skilled person would understand that multiple ports may be possible). The port may be used to permit the filling of a filler material internal to the gate valve member 10, for example into interstices or cells in the lattice structure 16. Although not explicitly shown in Figure 1 B, the skilled person would understand that the gaps in the lattice structure 16 could be filled with a filler material, such as a fluid, a foam or a gel, which may have the effect of preferentially altering properties of the gate valve member such as strength or rigidity. Further, although not explicitly shown in Figure 2B, the cells of the lattice structure 18 may be closed, or may be open such that each cell of the lattice structure 18 is connected to each adjacent cell by an open space. Where the cells are open, a filler material may be injected into a single cell, and subsequently flowed to the other cells in the lattice structure 18.

The gate valve member 10 also comprises a connector portion 20. The connector portion 20 comprises a T-shaped profile (a dovetail-shaped profile may also be acceptable) to enable connection with a valve stem (not shown) so as to enable movement of the gate valve member 10 within a gate valve. Although not shown, the connector 20 may enable a degree of rotational movement, such that the gate valve member 10 is able to pivot relative to a valve stem.

In the case of the gate valve member 10 shown, its construction may be by the process of additive manufacturing. Such a process may involve the construction of the gate valve member 10 in individual layers which together form the gate valve member 10. Processes of additive manufacturing that could be used for the construction of the gate valve member 10 will be described later in more detail.

Figures 2A and 2B are schematic illustrations of a gate valve 130 in an open and a closed position. The gate valve comprises a gate valve member 110, as is illustrated in Figures 1A and 1 B.

The gate valve 130 comprises a seat member 134, which are located on either side of the gate valve member 110, such that the gate valve member 110 is able to seat against the seat member 134 to form a seal against the seat member 134. A seal arrangement 136 is provided on an upper surface of the seat member 134 to assist in the sealing of the gate valve member 110 against the seat member 134. In particular, the seal arrangement 136 is provided such that, when the gate valve member 110 is in the closed position, fluid pressure acting from below the gate valve member 110 would press the gate valve member 110 against the seal arrangement 136, thereby enhancing the efficacy of the seal arrangement 136.

The gate valve member 110 is located in a space provided in the seat member 134, and the movement of the gate valve member can be controlled by movement of a valve stem 140 inserted through an opening 132 located on the seat member 134. The valve stem 140 is coupled to the gate valve member 110 (best shown in Figure 2B) by a connector 120 (which may be a T-shaped connector as described relative to figures 1A and 1 B) to enable axial movement of the gate valve member 110 within the space in the seat member 134, thus enabling the gate valve member 110 to be configured between the open position as shown in Figure 2A and the closed position as shown in Figure 2B. A seal member 138 is provided between the seat member 134 and the valve stem 140 to prevent unwanted fluid leakage from the gate valve 130. In this example, the valve stem 132 is controlled by an actuator arrangement 135 (which in this case is a piston arrangement), which enables movement of the gate valve member 110. The skilled person will appreciate that other arrangements enabling the movement of the gate valve member 110 may be possible.

In both Figure 2A and 2B, the gate valve 130 is connected to a pipe structure 142, which may comprise a flow of fluid. When the gate valve member 110 is in the open position, the flow of fluid is able to flow through laterally-extending apertures 144, 146 in the seat member 134, and through a laterally extending through bore 114 in the gate valve member 110, which is aligned with the apertures 144, 146. As such, in the open position, the gate valve member 110 permits flow of a fluid therethrough.

When in the closed position, the gate valve member 110 creates an obstruction to fluid flow through the gate valve 130. In this instance, the pressure of the fluid flowing in the pipe structure 142 acts through either aperture 144, 146 (depending on the direction of fluid flow through the pipe structure 142) on an exposed portion of the gate valve member 110, resulting in a laterally directed force on the gate valve member 110. This laterally directed force pushes the gate valve member 110 against the seat member 134 thereby enhancing the seal between the gate valve member 110. To enhance sealing, it may be possible to provide, for example, a seal member between the gate valve member 110 and the seat member 134, although this is not shown in this example.

Figures 3A to 3C illustrate a multi-part gate valve member 210. Many of the features of the multi-part gate valve member 210 are consistent with those shown in Figures 1A and 1 B, and for conciseness an in-depth description of these features will not be repeated. The multi-part gate valve member 210 comprises an upper part 213a and a lower part 213b, with Figure 3C showing only the lower part 213b. Each of the upper part 213a and the lower part 213b comprise a through bore 214a, 214b, both of which are aligned. As a fluid is intended to be flowed through the through bores 214a, 214b, an inner sleeve 222 is provided that bridges the through bores 214a, 214b to prevent leakage of a fluid between the upper and lower part 213a, 213b of the gate valve member 210. As with the illustration of Figure 1 , in this example each of the upper and lower parts 213a, 213b comprises an outer shell 212 and an inner lattice structure 216, as shown in Figure 3B.

Located between the upper and lower parts 213a, 213b is a biasing arrangement, which in this example is shown as four helical springs 224, located at each corner of the gate valve member 210. In this example, the biasing arrangement functions to separate the upper and lower parts 213a, 213b so that, when incorporated into a gate valve, at least one of the upper and lower parts 213a, 213b is pushed against a valve seat and thereby assists to provide an effective seal in the gate valve member.

Figures 4A and 4B illustrate a multi-part valve member 330 shown in the context of a gate valve. Figure 4A illustrates the valve member 330 in the open position, while Figure 4B illustrates the valve in the closed position. Many of the features of the multi part gate valve 330 are consistent with those shown in Figures 2A and 2B, and for conciseness an in-depth description of these features will not be repeated.

Figure 4A illustrates a gate valve 330 member comprising a gate valve member having an upper part 310a and a lower part 310b in the open configuration. The upper part 310a, and the lower part 310b are aligned to form a through bore 314 extending through the gate valve member 310a, 310b. Positioned around the circumference of the through bore is a sleeve 340 which seals off the through bore 314 from a gap that is between the upper part 310a and the lower part 310b.

In this example, biasing members 342 (in the form of helical springs) are located between the upper part 310a and the lower part 310b of the gate valve member to force each of the upper part 310a and lower part 310b apart and against a seat member 334. As such, the biasing members 342 may enhance the seal provided by the multi-part gate valve member 310a, 310b. In this example, a sealing arrangement 336 is provided on both sides of the gate valve member 310a, 310b. As such, this valve member 310a, 301 b may be used to prevent a flow of fluid in both directions through the gate valve. Figure 5 illustrates a basic process for producing a gate valve member using additive manufacturing. The steps involved in the production of a gate valve member include the initial design of the gate valve member 401 using 3D CAD. A 3D CAD programme incorporating Finite Element Analysis (FEA) capabilities may be particularly suitable for the design of the gate valve member. The initial design may be constrained by the requirements of the gate valve into which the gate valve member is to be incorporated. For example, the initial design may involve selecting a thickness of gate valve member, to enable an appropriate fit between seat members of a gate valve.

The initial step of designing the gate valve member 401 may optionally comprise selecting a design of a lattice 401a, for example to form the internal structure of the gate valve member. The step of selecting the design for the lattice 401a may comprise selecting a cell structure for the lattice, and repeating the cell structure on a 3D CAD programme to provide a complete lattice structure.

The following step in the production of the gate valve member is the optimisation of the original 3D CAD design 403. The optimisation process may be performed, for example, as an in-built function of the 3D CAD programme used to produce the original 3D CAD design. The optimisation may comprise use of Finite Element Analysis (FEA). In this case, the optimisation process may be to reduce the overall weight of the gate valve member, whilst providing a gate valve member that is able to withstand a minimum force, for example a minimum lateral force, applied to the gate valve member. Such an optimisation process may result in a reduction in weight of the gate valve member by 30-80% when compared to typical gate valve members. The optimisation process may comprise a topology optimisation process, and may involve the removal of material from the original CAD design of the gate valve. Additionally or alternatively, the optimisation process may comprise reshaping or resizing of the cell structure of the lattice, and/or may comprise a reduction of or addition to the thickness of an outer shell of the gate valve member.

The optimisation process may also involve the step of providing constraints to the optimisation process 403a, for example based on certain design requirements of the gate valve member. In one example, the gate valve member may be required to have a certain thickness in order that it can be incorporated into a specific gate valve. Further, where the gate valve is required to provide a seal to a high pressure source, a design constraint may be that the gate valve member is required to withstand a certain magnitude of lateral force without significant deformation. Such constraints should be taken into account during the optimisation process to ensure that the gate valve member is fit for purpose.

The final step in the production of the gate valve member is the use of the optimised gate valve member design to construct a gate valve member using additive manufacturing 405. Any appropriate additive manufacturing process may be used, for example a three dimensional printing process. The additive manufacturing process may comprise the construction of the gate valve member in layers, for example from a powder. Such a process may require sintering and/or melting of the powder in layers to build the gate valve member, and the sintering/melting may be performed using a laser sintering/melting technique. One technique for constructing the gate valve member may be a laser-based powder bed melting process.

An alternative technique that may be suitable for the construction of the gate valve member may be an additive manufacturing process comprising laser ablation. Such a technique may comprise providing material from which the gate valve member is to be produced, and using a laser to remove unwanted material so as to form the gate valve.

Producing the gate valve member using additive manufacturing may be particularly suitable as it may allow an intricate structure (e.g. an intricate lattice structure) to be produced, while also permitting the use of a wide range of building materials. For example, using the above-described additive manufacturing processes, gate valves in materials in all the API 6A classes can be produced.

The construction of the gate valve through additive manufacturing permits both the lattice and the outer shell of the gate valve to be produced.

Once produced by additive manufacturing, further finishing processes may optionally be applied to the gate valve member 407. An example of an optional finishing process is the application of a corrosion resistant alloy, for example to the exterior surface of the gate valve member.

Claims

CLAIMS:

1. A gate valve member for use in a gate valve, the gate valve member comprising:

a lattice structure; and

an outer shell at least partially surrounding the lattice structure, wherein the outer shell surface includes a sealing surface configured to sealingly engage a valve seat in a gate valve,

the lattice structure and the outer shell being integrally formed.

2. A gate valve member according to claim 1 , wherein at least part of the gate valve member is constructed through use of an additive manufacturing process.

3. A gate valve member according to claim 1 or 2, wherein the construction of at least part of the gate valve member comprises sintering.

4. A gate valve according to any preceding claim, wherein the lattice structure has a cellular structure comprising a plurality of cells.

5. A gate valve according to claim 4, where the cellular structure is a closed cellular structure.

6. A gate valve according to claim 5, wherein at least a part of the closed cellular structure comprises a filler material.

7. A gate valve according to claim 4, where the cellular structure is an open cellular structure.

8. A gate valve according to claim 7, wherein at least a part of the open cellular structure is filled with a filler material.

9. A gate valve according to claim 8, wherein the outer shell comprises at least one aperture to facilitate introduction of the filler material into the open cellular structure.

10. A gate valve according to any preceding claim, wherein the outer shell comprises at least one planar surface for seating against a valve seat in a gate valve.

11. A gate valve according to any preceding claim, comprising a through bore defined by a gap in the lattice structure.

12. A gate valve according to any preceding claim, wherein the outer shell completely surrounds the lattice structure.

13. A gate valve according to any preceding claim, wherein the lattice structure comprises a metal.

14. A gate valve according to any preceding claim, wherein the lattice structure is arranged in the form of a plurality of panels arranged into a three dimensional structure.

15. A gate valve according to any preceding claim, wherein the lattice structure comprises a honeycomb-shaped cellular structure.

16. A gate valve according to any preceding claim, wherein the lattice structure comprises a uniform distribution of cells.

17. A gate valve according to any of claims 1 to 15, wherein the lattice structure comprises a non-uniform distribution of cells.

18. A gate valve member according to any preceding claim, wherein the gate valve member comprises multiple parts.

19. A gate valve comprising a gate valve member according to claims 1 to 18.

20. A method for manufacturing a gate valve member, comprising:

producing a three dimensional model of the gate valve member comprising a lattice structure and an outer shell; and

forming a gate valve member according to the three dimensional model such that the lattice structure and the outer shell are integrally formed.

21. A method according to claim 20, wherein the forming step comprises use of an additive manufacturing process.

22. A method according to claim 20 or 21 , comprising forming the gate valve member using a sintering process.

23. A method according to any of claims 20 to 22, comprising forming the lattice structure and outer shell in a plurality of layers.

24. A method according to any of claims 20 to 23, comprising applying a design optimisation process to the three dimensional model of the gate valve member.

25. A method according to claim 24, wherein the design optimisation process is or comprises a topology optimisation process.