Valve, modular system, valve seat, valve spindle, and production method

Abstract

The aim of the invention is to provide an improved valve which allows a simple maintenance and operability. For this purpose, the invention proposes a valve (1) with a housing (2), wherein the housing (2) has a housing lower part (3) and a housing upper part (4) which are reversibly secured to each other. A valve spindle (5) is guided on the housing upper (3) and / or lower part (4) in an axially movable manner, and the valve spindle (5) has a conical seal surface (6) on one end. The housing lower part (3) is equipped with a valve seat (7) in a replaceable manner, said valve seat having a conical seat surface (8). By axially moving the valve spindle (5), the valve (1) can be converted from an open position into a closed position, in which the conical seal surface (6) of the valve spindle (5) contacts the conical seat surface (8) of the valve seat (7) in order to sealingly close a fluid channel (11) running from an inlet connection (9) to an outlet connection (10) in the housing lower part (3). The invention additionally relates to a valve seat (7), to a valve spindle (5) for such a valve (1), to a modular system (24) comprising such a valve (1), and to a method for producing such a modular system (24).

Description

[0001] Valve, modular system, valve seat, valve stem and a method for manufacturing

[0002] The invention relates to a valve, a valve seat, a valve spindle, a modular system with such a valve, and a method for producing such a modular system.

[0003] Conventional valves, also called fittings, use a shut-off body with a sealing surface which can be lifted from a corresponding valve seat primarily by a lifting movement within a valve housing, thereby opening up a cross-section of the fluid channel and allowing a medium to flow through the fluid channel. The shut-off body can be part of an element which causes the shut-off body to move within the valve. This element can be, for example, a valve stem or a valve spindle which can be axially displaced, for example, by a rotating movement via a thread. Additional seals are typically provided in the housing to seal the moving parts against the fluid channel and / or against the environment.

[0004] Conventional valves contain wearing parts, particularly the valve seat and the seals used. A disadvantage of conventional valves is that replacing such wearing parts is very complex. During maintenance or repair of such parts, the entire valve must be regularly removed from the connected piping system, for example, to replace the seals and / or valve seat due to wear, as these components are arranged more or less inaccessibly within the housing. Furthermore, a full-surface contact seal between the valve seat and the shut-off body requires a high level of force when operating the valve.

[0005] It is therefore an object of the invention to provide an improved valve which enables easy maintenance and operation.

[0006] This object is achieved by a valve having the features of claim 1.

[0007] Because the valve spindle has a conical sealing surface at one end and the valve seat has a conical seating surface, only a small amount of force is required to move the valve from the open position to the closed position.

[0008] The valve housing consists of two parts, an upper housing section and a lower housing section, which are reversibly attached to one another. Reversible means that the two housing sections are attached to one another in such a way that the connection can be easily and damage-free removed and reconnected, e.g. for maintenance purposes. This allows good accessibility to the valve components, in particular the valve seat, during maintenance without the need to remove the entire valve from an existing assembly with conduit pipes that are firmly connected (e.g. welded) to the inlet and outlet connections of the valve. The valve seat, as a component particularly subject to wear, is replaceable and can therefore be replaced easily and without problem in order to restore function and tightness.

[0009] Based on such a valve, the invention proposes, according to a further aspect, a modular system, wherein the inlet connection, outlet connection and fluid channel of the lower housing part are designed for a first nominal diameter, with a further lower housing part, wherein the inlet connection, outlet connection and fluid channel of the further lower housing part are designed for a second nominal diameter that differs from the first nominal diameter, wherein the upper housing part can be reversibly connected to either of the two lower housing parts. Modular means that the modules of the system, i.e. the lower housing parts and the upper housing part, are designed such that they can be easily removed and replaced with other parts of the same type. This interchangeability does not affect the functionality of the overall system, in particular not the reversible connection of the housing parts.The modularity of the system facilitates maintenance and repair work, as well as adapting the system to different requirements. The modular system of the invention reduces the number of parts to be manufactured, allowing valves to be provided for different nominal sizes and / or pressure ratings.

[0010] In relation to a further aspect, the invention proposes a valve seat for such a valve, comprising a cylindrical section, a collar projecting radially outwardly beyond the cylindrical section, wherein the valve seat has an annular support surface on its axial underside of the projecting collar, and having a conical seat surface in the cylindrical section, wherein the valve seat consists essentially of a stellite.

[0011] The valve seat described here is characterized by particularly high wear resistance, while allowing easy assembly and disassembly. The valve seat is intended for use in the valve described here.

[0012] The invention further proposes a valve spindle having a conical sealing surface, the conical sealing surface consisting essentially of stellite. This type of sealing surface, consisting of stellite, offers high resistance to wear, such as corrosion or abrasion, while maintaining these properties even at high temperatures. The valve spindle is intended for use in a valve described herein.

[0013] According to a further aspect, the invention proposes a method for producing a valve from a modular system, which comprises the following steps: i) selection of an upper housing part, ii) selection of a lower housing part, iii) machining of the lower housing part comprising the following steps: a) machining the inner radius of an inlet connection, an outlet connection and a fluid channel of the lower housing part, wherein the inner radius is dimensioned in each case corresponding to a required nominal diameter, b) machining contact surfaces of the inlet connection and the outlet connection, iiii) connecting the machined lower housing part to the upper housing part.

[0014] The lower housing section comprises the part of the valve that will be used for later application, for example, in piping systems for conveying a medium. Machining the lower housing section allows for simple machining methods, both to adjust the inner radius to the required nominal diameter and to adapt the contact surfaces used to connect the valve to a piping system to the relevant environmental specifications.

[0015] Advantageous embodiments and further developments of the invention emerge from the dependent claims. It should be noted that the features listed individually in the claims can also be combined with one another in any technologically expedient manner, thus revealing further embodiments of the invention.

[0016] According to an advantageous embodiment of the valve, the cone angle of the sealing surface deviates from the cone angle of the seat surface, preferably by at least 2 degrees, more preferably by at least 10 degrees, in order to obtain a linear, annular contact surface between the sealing surface and the seat surface. Due to the deviating cone angles of the surfaces, in particular, no complete, flat contact of the sealing and seat surfaces is formed. The smallest possible contact surface ensures a high surface pressure with, at the same time, low operating force of the valve spindle. The high surface pressure results in good sealing of the valve in the blocking position with, at the same time, low force expenditure when closing and opening the valve. According to another advantageous embodiment of the valve, the sealing surface and / or the seat surface, viewed in an axial longitudinal section with respect to the valve spindle, have a curvature (e.g.a radius of curvature or some other spherical or convex shape), so that in the closed position, the sealing surface of the valve spindle rests against the valve seat surface in a linear, annular manner. Advantages of this design are the improved sealing and the low force required when moving the valve into the closed or open position. In this design, the shape of the sealing surface of the valve spindle or the valve seat surface deviates from the conical shape in the strictly mathematical sense.

[0017] The valve seat is preferably made of stellite or hardened steel, especially hardened chromium steel. Stellite is a cobalt-chromium-based alloy. This type of alloy, also known as a hard alloy, offers high resistance to abrasion and corrosion, while retaining these properties even at high temperatures. These wear-protective properties ensure a longer residence time of the valve seat within the valve, thus extending the maintenance cycle. The ferrous content of the valve seat is preferably less than 3%. The hot hardness of the valve seat is preferably 43-46 HRC. This minimizes wear and significantly increases service life.

[0018] The conical sealing surface of the valve is preferably made of Stellite or hardened steel, particularly hardened chromium steel. The wear-resistant properties of these materials ensure that the conical sealing surface remains in the valve for a longer time, thus extending the maintenance cycle. Advantageously, the hardened chromium steels are selected in a configuration that offers high resistance to the deposition of contaminants, i.e., substances that accumulate on the conical sealing surface of the valve and shorten the maintenance cycle and / or complicate the replacement of the conical sealing surface. Hardened chromium steels are particularly suitable for use in nuclear power plants because they are less prone to iridium deposition than cobalt-chromium-based hard alloys. The ferrous content of the sealing surface is preferably less than 3%. The hot hardness of the sealing surface is preferably 43-46 HRC.One embodiment of the valve provides that the valve spindle is formed by a valve shaft and a valve cone arranged at one end thereof, wherein the valve shaft and the valve cone are made of materials of different hardness, the valve cone having the conical sealing surface. This has the advantage that the material of the valve cone can be selected so that it has a high resistance to corrosion and abrasion, particularly at high temperatures. The conical sealing surface of the valve cone advantageously deviates from the cone angle of the seat surface in order, in particular, to avoid a flat, complete contact between the sealing and seat surfaces. The material of the valve shaft, which has no contact with the flowing medium, can accordingly be selected so that simple production and machining of the valve shaft is enabled.The valve allows for quick and easy replacement of wearing parts, such as the valve cone and valve seat, without having to completely remove the valve.

[0019] An advantageous design of the valve provides for the valve cone to be attached to the valve shaft by means of a press fit. This ensures that the valve cone is firmly connected to the valve shaft. For this purpose, the valve cone and the valve shaft are subjected to heat and / or cold treatment. In this design, the valve shaft is cooled, while the valve cone, which is made of a harder material than the valve shaft, is heated. The two differently temperature-controlled parts of the valve spindle are then put together. Upon cooling, the valve cone presses itself into the valve shaft. A press fit produced in this way ensures a strong and temperature-resistant connection between the valve cone and the valve shaft, without the surface structure of the materials being impaired by further chemical stress.Such stress can arise, for example, from welding the components, which causes iron nitride to form on the surface and thus reduces the ductility of the materials.

[0020] According to a preferred embodiment of the valve, the lower housing part and the upper housing part are reversibly fastened to one another with a bayonet lock. A bayonet lock ensures quick assembly and / or disassembly of the housing parts, resulting in simplified maintenance of the valve. The advantage here is that bayonet locks do not require any additional tools to operate them. One embodiment of the valve provides that the bayonet lock is designed to be fixed by means of a locking screw that connects the lower housing part to the upper housing part. This makes it possible to easily secure the housing parts to one another so that the connection does not loosen accidentally, e.g. due to vibrations or pressure loads. The forces acting on the housing parts due to the fluid pressure are fully absorbed by the bayonet lock. The locking screw serves only as a securing device.The locking screw can be dimensioned accordingly small and can be easily removed using standard tools for valve maintenance.

[0021] According to an advantageous embodiment of the valve, the valve seat has a radially outwardly projecting collar, via which the valve seat rests with its underside on an annular support surface formed in the fluid channel. This design is particularly practical and allows for easy and quick replacement of the valve seat. The forces acting on the valve seat can be well absorbed by the support surface.

[0022] A further embodiment of the valve provides that the lower housing section has an axial blind bore, the lower section of which, in which the annular support surface is formed, forms a partial section of the fluid channel, wherein the valve spindle is guided in an axially movable and sealing manner in a stuffing box packing received in the blind bore. The stuffing box packing provides an effective seal with low friction to prevent a medium present in the fluid channel from escaping along the valve spindle without impairing the movement of the valve spindle. The stuffing box packing can be removed through the blind bore when the housing parts of the valve are separated from one another. In the event of leaks, the stuffing box packing as a whole or individual seals thereof can be replaced with little effort.

[0023] According to an advantageous embodiment of the valve, the valve spindle extends at least partially through a cage structure arranged between the stuffing box packing and the valve seat, with a section of the fluid channel connected to the outlet port opening into a lateral opening in the cage structure. The opening (or openings) in the cage structure, through which the valve spindle passes, allow fluid to flow through the valve. At the same time, the cage structure serves to transmit an axial force from the stuffing box packing via the cage structure to the valve seat in order to fix it in its installed position.

[0024] It can be advantageous for the stuffing box packing to be formed as a single piece with the cage structure. Reducing the number of components simplifies maintenance and reduces manufacturing costs. Typically, however, the stuffing box packing consists of several annular elements arranged axially one above the other in the blind bore, with sealing rings between them.

[0025] One design of the valve provides for a sealing ring, in particular a graphite sealing ring, to rest on the outwardly projecting collar of the valve seat and to be clamped between the valve seat and the cage structure. A sealing ring, in particular a graphite sealing ring, offers excellent gas and water tightness, effectively preventing leaks. Sealing rings are wear parts that require frequent maintenance or complete replacement over the valve's service life. Clamping the sealing ring between the valve seat and the cage structure allows the sealing ring to be held in the housing without the need for additional elements. This allows the sealing ring to be easily removed during maintenance and replaced as needed.

[0026] According to a further embodiment of the valve, the valve seat above the outwardly projecting collar has a cylindrical section received in a lower section of the cage structure. The cylindrical section extends telescopically into the cage structure, wherein the cage structure and the valve seat are guided against one another and centered relative to one another and have axial mobility relative to one another. This embodiment enables, in particular, the lower edge of the cage structure, which radially overlaps the valve seat in the cylindrical region, to exert an axial clamping force on the sealing ring resting on the outwardly projecting collar. The force transmitted further to the collar via the sealing ring simultaneously holds the valve seat in its position on the annular support surface in the fluid channel.

[0027] A further embodiment of the valve provides that the sealing ring in an uncompressed state has a volume that is greater than its volume when compressed by clamping it against the housing base at the cylindrical section and the outwardly projecting collar between the valve seat and the cage structure. The larger volume of the sealing ring in the uncompressed state means that when axial clamping forces generated by the cage structure are applied, it is pressed into the smaller volume between the valve seat and the cage structure, creating a tight fit there. The sealing ring is in an uncompressed state as long as its volume is not compressed by the application of corresponding forces (clamping forces), i.e. it is in a state of elastic or plastic deformation, depending on the ring material and the strength of the acting forces.

[0028] According to an advantageous embodiment of the valve, the cage structure protrudes at least partially radially beyond the cylindrical section of the valve seat, so that the sealing ring is in a force shunt, wherein the clamping force acting axially on the sealing ring through the cage structure is limited by the force shunt. The compression distance of the cage structure, over which the clamping force is applied, is determined and limited by the shape of the valve seat. Preferably, the axial clamping forces act evenly across an upper sealing surface of the sealing ring in order to achieve optimal force transmission. Thus, the sealing ring is subjected to less stress with an improved seal, resulting in less wear on the sealing ring.

[0029] Preferably, the valve seat, viewed in an axial longitudinal section (relative to the valve spindle), has a radius of curvature in a transition region between the cylindrical section and the outwardly projecting collar, which causes the sealing ring held between the cage structure and the outwardly projecting collar to flow radially outwards when an axial clamping force is applied. By deflecting the clamping force outwards by the radius of curvature, in conjunction with the flowability of the sealing ring, an excellent seal between the valve seat and the inner wall of the fluid channel surrounding the valve seat is achieved. By arranging the sealing ring in the force shunt, as described above, the clamping force is limited and it is ensured that the maximum clamping force is precisely dimensioned to ensure very good sealing without overloading the sealing ring.If the sealing ring is overloaded, it could be damaged, and the sealing effect could be impaired. This is prevented by the design described.

[0030] A particularly preferred design of the valve provides that the assembly comprising the valve spindle, stuffing box packing, cage structure, and valve seat can be removed upwards after separating the upper and lower housing sections from the axial blind bore. Removing the assembly comprising the valve spindle, stuffing box packing, cage structure, and valve seat upwards after separating the upper and lower housing sections from the axial blind bore enables very simple inspection and maintenance of the individual parts without having to separate the entire valve from the piping system.

[0031] According to an advantageous embodiment of the valve, the assembly comprising the stuffing box packing, cage structure, and valve seat can be reversibly secured to the upper housing section by means of at least one clamping screw, applying a downward axial clamping force, i.e., in the direction of the valve seat. Advantageously, only a single clamping screw (or several clamping screws) is required to hold the assembly comprising the stuffing box packing, cage structure, and valve seat and simultaneously apply the axial clamping force. This can be removed with minimal effort for disassembly and maintenance.

[0032] One design of the valve provides for the housing upper section to be made entirely of one material, in particular a heat-resistant steel, preferably 16Mo3 steel. Heat-resistant steels offer the advantage that they can be used in environments with high temperatures in the range of over 500 °C.

[0033] A further embodiment of the valve provides an actuating means designed to control the axial movement of the valve spindle. The actuating means can be controlled manually. A handwheel can be used as the actuating means, the rotary movement of which moves the valve spindle. In addition to or as an alternative to manual control, an external (motor) drive is also possible as the actuating means. Depending on the requirements of the valve, the actuating means can be designed to move the valve spindle into two different positions (open position, closed position); alternatively, the actuating means can also be designed to move the valve spindle to intermediate positions, for example to variably throttle the fluid flow through the valve. The valve according to the invention is particularly suitable as a so-called small valve (nominal diameter up to approx.DN200), namely as a shut-off valve for water and steam circuits and other non-aggressive media, such as oil and gas.

[0034] A preferred design of the modular system provides for the upper housing section to be reversibly connected to the two lower housing sections using a bayonet lock or a connecting flange. The bayonet lock allows for quick assembly and / or disassembly of the housing sections, which simplifies valve maintenance. Another advantage of the bayonet lock is that no additional tools are required to operate it.

[0035] According to a further embodiment of the modular system, the actuating element is modularly interchangeable. Modular interchangeability means that the actuating element is designed so that it can be easily removed and replaced with other actuating elements of the same type without compromising functionality. This interchangeability facilitates maintenance and repair work, as well as adapting the system to different requirements. The replaced actuating elements are standardized to such an extent that they are compatible with the other components of the valve.

[0036] One design of the modular system provides that the upper housing section is suitable for use in valves with a nominal pressure rating of up to PN 500, whereby the nominal pressure rating of the lower housing sections depends on the respective designed nominal diameter.

[0037] Preferably, the upper housing section of the modular system has the same external dimensions regardless of the optionally reversibly connectable lower housing section. The upper housing section can thus be combined with a variety of lower housing sections designed for different nominal pressure levels (up to PN 500), nominal diameters and / or external dimensions. According to a further embodiment of the modular system, the lower housing sections each have an identical, i.e. corresponding, identical arrangement of installed components (stuffing box packing, cage structure, valve seat). An identical arrangement of the components, regardless of the designed nominal pressure level, the nominal diameter and / or the external dimensions of the respective lower housing section, simplifies the connection between the upper and lower housing sections. This improves the manageability and cost-effectiveness of the modular system by reducing the existing combination options.Consequently, a user can put together a modular system with the smallest possible number of individual components and combinations based on the required nominal pressure rating of the nominal diameter and / or the external dimensions of the housing base.

[0038] One design of the valve seat provides for a hot hardness of at least 43 HRC, with the ferrous metal content in the valve seat material being a maximum of 3% and / or the tungsten content being 4%. The material composition optimizes the wear resistance of the valve seat, for example, with regard to wear effects such as corrosion or abrasion, and thus extends its service life in the valve. Replacement of the valve seat within a valve is only necessary after its service life has expired. A longer service life therefore extends the valve's maintenance cycle.

[0039] According to one embodiment of the valve spindle, the hot hardness of the conical sealing surface of the valve spindle corresponds to at least 43 HRC, with the ferrous metal content in the valve spindle material being a maximum of 3% and / or the tungsten content being 4%. The material composition optimizes the wear resistance of the valve spindle, for example with regard to wear effects such as corrosion or abrasion, and thus extends its service life in the valve. The valve spindle within a valve only needs to be replaced after its service life has expired. A longer service life therefore extends the valve's maintenance cycle. It is conceivable that in the valve spindle, consisting of the valve shaft and valve cone, only the valve cone with the corresponding conical sealing surface needs to be replaced.

[0040] Further features, details, and advantages of the invention will become apparent from the following description and from the drawings, which show exemplary embodiments of the invention. Corresponding objects or elements are provided with the same reference numerals in all figures. They show:

[0041] Figure 1 Representation of the valve,

[0042] Figure 2 View of the valve in an axial

[0043] Longitudinal section,

[0044] Figure 3 Detailed view of the valve’s locking position,

[0045] Figure 3a Detailed view of the conical sealing surface and the conical seating surface with different cone angles,

[0046] Figure 3b Detailed view of the conical sealing surface and the conical seat surface with curvature,

[0047] Figure 3c Detailed view of the transition area between the cylindrical section and the outwardly projecting collar,

[0048] Figure 4 Representation of the modular system with a

[0049] lower housing part,

[0050] Figure 4a Representation of the modular system with an additional housing base,

[0051] Figure 5 Illustration of the valve shaft with the

[0052] valve cone,

[0053] Figure 5a Detailed view of the press fit of the valve shaft with the valve cone.

[0054] In the following description of the figures, the same reference numerals and the same terms are used for the same elements. The figures show a valve 1 according to the invention. The valve 1 has a housing 2, wherein the housing 2 has a lower housing part 3 and a higher housing part 4, which are reversibly fastened to one another. The figures specifically show an exemplary embodiment in which the housing parts 3, 4 are reversibly fastened to one another with a bayonet lock 12. The bayonet lock 12 is advantageously designed so that it can be operated without tools. Figure 1 further shows a bore 13 on the bayonet lock 12, via which the connected lower housing part 3 can be fixed to the upper housing part 4 by means of a locking screw. The lower housing part 3 each has contact surfaces 29 which are designed to receive corresponding connection surfaces 30 (Fig. 4) of a conduit system 31 (Fig. 4).

[0055] An arrangement comprising stuffing box packing 16, cage structure 17 and valve seat 7 (see Figure 2) can be reversibly fixed to the upper housing part 4 by means of one or more (here two) clamping screws 22 by applying an axial clamping force acting downwards in the direction of the valve seat 7 (Figure 2).

[0056] In the housing 2, comprising the lower housing part 3 and the upper housing part 4, there is an axially movable valve spindle 5, which has a conical sealing surface 6 (Figure 2) at one end. In the illustrated embodiment, the axial movement of the valve spindle 5 is possible via a handwheel. The valve 1 can be moved from an open position to a closed position by the axial movement of the valve spindle 5. When the valve 1 is in the open position, a medium located in the fluid channel 11 can flow freely through it from an inlet connection 9 to an outlet connection 10.If the valve 1 is moved from the open position to the closed position by the axial movement of the valve spindle 5, in which a conical sealing surface 6 (Figure 2) of the valve spindle 5 rests against a conical seating surface 8 (Figure 2) of the valve seat 7 (Figure 2), the fluid channel 11 in the lower housing section 3, which runs between the inlet connection 9 and the outlet connection 10, is sealed. The fluid flow is interrupted. The axial movement of the valve spindle 5 is controlled by an actuating means 23. The figures specifically show an embodiment in which the actuating means 23 is designed as a handwheel.

[0057] Figure 2 shows an axial longitudinal section through the valve shown in Figure 1. Figure 2 clearly shows an axial blind bore in the lower housing section 3, the lower section of which forms an annular support surface 15. The valve spindle 5 is axially movable within the blind bore and is sealed by the gland packing 16 located in the blind bore. The gland packing 16 contains additional seals to prevent fluid from escaping along the valve spindle 5.

[0058] A cage structure 17 is located beneath the stuffing box packing 16, with a section of the fluid channel 11 connected to the outlet port 10 opening into a lateral opening 18 of the cage structure 17. The valve seat 7 is located beneath the cage structure 17.

[0059] In the embodiment shown in Figure 2, the valve seat 7 has a radially outwardly projecting collar 14, wherein the valve seat 7 has an annular support surface 32 (Figure 3) on its axial underside of the projecting collar 14, via which the sealing ring 19, in the embodiment shown, is supported on the annular support surface 15 formed in the fluid channel 11. The valve seat 7 is preferably a valve seat 7 made of stellite. Between the valve seat 7 and the cage structure 17, a sealing ring 19 is held in a clamped manner on the outwardly projecting collar 14 of the valve seat 7. A graphite sealing ring is preferably used. In Figure 2, the valve seat 7 has, above the outwardly projecting collar 14, a cylindrical section 20 (Figure 3) received in a lower section of the cage structure 17.

[0060] Figure 2 shows the valve 1 in the blocking position. The conical sealing surface 6 rests against the conical seat surface 8 of the valve seat 7, whereby the fluid channel running from the inlet connection 9 to an outlet connection 10 is sealed.

[0061] Figure 3 shows a detailed view of the valve in the closed position. The contact of the conical sealing surface 6 of the valve spindle 5 with the conical seating surface 8 of the valve seat 7 is highlighted. Also visible is the sealing ring 19 clamped between the collar 14 and the lower edge of the cage structure 17. The cylindrical section 20 of the valve seat 7 dips into the cage structure from below. The clamping force can thus be transmitted via the cage structure 17 to the sealing ring 19 and from there further to the collar 14 of the valve seat 7. In an uncompressed state, the sealing ring 19 has a volume that is greater than its volume when clamped against the lower housing part 3 by the cylindrical section 20 and the outwardly projecting collar 14 between the valve seat 7 and the cage structure 17.

[0062] Figure 3 shows a design in which the cage structure 17 partially projects radially beyond the cylindrical section 20 of the valve seat 7, such that the sealing ring 19 is in a force shunt, wherein the transmission of a clamping force acting axially through the cage structure 17 to the sealing ring 19 is limited by a force shunt between the cage structure 17 and the cylindrical section 20 of the valve seat 7. The pressing path for applying the clamping force is limited by this design. The cylindrical section 20 of the valve seat 7 only penetrates into the cage structure 17 on its underside until the inner section of the cage structure 17 strikes the top side of the cylindrical section 20. This limits the deformation of the sealing ring 19 located in the force shunt. This prevents excessive deformation that would impair the sealing effect or even damage to the sealing ring 19.

[0063] Figures 3a and 3b show details of the engagement of the conical sealing surface 6 with the conical seat surface 8 in the locking position.

[0064] In Figure 3a, the cone angle of the sealing surface 6 deviates from the cone angle of the seat surface 8. In the locked position, a linear, annular contact surface results between the sealing surface 6 and the seat surface 8. This results in low force when actuating the valve and a high surface pressure, thus ensuring good sealing.

[0065] Figure 3b shows an alternative design in which the sealing surface 6 and / or the seating surface 8 are convexly curved. In the illustrated embodiment, for example, the sealing surface 6, in contrast to the seating surface 8, has a spherical shape in the contact area. This variant also creates a linear, annular contact surface.

[0066] Figure 3c shows a detailed view of the transition area 21 between the cylindrical section 20 and the outwardly projecting collar 14 of the valve seat 7. This collar has a radius of curvature. The sealing ring 19 is held axially clamped between the valve seat 7 and the overlying cage structure 17. The effect of the axial clamping force ensures that the sealing ring 19 flows radially outward due to the radius of curvature, thus creating an excellent seal.

[0067] Figures 4 and 4b show a modular system 24 with a valve 1, as shown in Figure 1. The embodiment according to Figure 4 shows that the upper housing part 4 is connected to a lower housing part 3, wherein the inlet connection 9, outlet connection 10 and fluid channel 11 of the lower housing part 3 are designed for a first nominal diameter 25. Figure 4b shows that the upper housing part 4 is connected to a further lower housing part 3', wherein the inlet connection 9, outlet connection 10 and fluid channel 11 of the further lower housing part 3' are designed for a second nominal diameter 26 which differs from the first nominal diameter 25. The upper housing part 4 can be reversibly connected to either of the two lower housing parts 3, 3'. The upper housing part 4 is suitable for use in valves 1 with a nominal pressure rating (PN) of up to PN 500, whereby the nominal pressure rating (PN) of the lower housing parts 3 depends on the respective designed nominal diameter (DN) 25, 26.The housing lower parts 3 of the modular system 24 each have an identical arrangement of inserted components comprising stuffing box packing 16, cage structure 17 and valve seat 7.

[0068] Figures 4 and 4b specifically show an embodiment in which the housing parts 3 and 4 are reversibly fastened to one another with a bayonet lock 12. The bayonet lock 12 is advantageously designed so that it can be operated without tools. The figures show that the respective lower housing parts 3 have a bore 13 in the bayonet lock 12, via which the connected lower housing parts 3 can be fixed to the upper housing part 4 by means of a locking screw (not shown here). Furthermore, the upper housing part 4 has the same external dimensions as the reversibly connectable lower housing part 3 in the embodiment shown.

[0069] Figure 5 shows a representation of the valve spindle 5, wherein the valve spindle 5 is formed from a valve shaft 27 and a valve cone 28 arranged at one end of the valve spindle 5. The valve shaft 27 and the valve cone 28 can be made of materials of different hardnesses. The hardnesses of the materials for the valve shaft 27 and the valve cone 28 can therefore differ from one another. The valve shaft 27 is preferably made of a material that allows for easy machining and adaptation to the other components of the valve 1. The valve cone 28 is preferably made of a harder material than the valve shaft 27, whereby the valve cone 28 is more resistant to corrosion and abrasion.

[0070] Figure 5a shows a detailed view of the interference fit between the valve shaft 27 and the valve cone 28. To achieve the interference fit between the valve shaft 27 and the valve cone 28, both components are subjected to a heat or cold treatment. In the illustrated embodiment, the valve cone 28 is heated and the valve shaft 27 is cooled. The valve cone 28 is then pulled onto the valve shaft 27. During the subsequent cooling, the valve cone 28 is pressed firmly into the valve shaft 27. The contact of the conical sealing surface 6 with the conical seating surface 8 in the locked position is similar to the embodiments shown in Figures 3 to 3c.

[0071] Figure 5a shows a detailed view of the interference fit between the valve shaft 27 and the valve cone 28. To achieve the interference fit between the valve shaft 27 and the valve cone 28, the two components 27, 28 are each heat-treated or cold-treated. In the illustrated embodiment, the valve cone 28 is heated and the valve shaft 27 is cooled. After the valve cone 28, which here is made of a harder material than the valve shaft 27, has been pulled onto the valve shaft 27, it is pressed into the valve shaft 27 after appropriate cooling. The contact of the conical sealing surface 6 with the conical seating surface 8 in the locked position is similar to the embodiments shown in Figures 3 to 3c.

Claims

Patent claims 1. Valve (1) with a housing (2), wherein the housing (2) has a lower housing part (3) and a housing upper part (4) which are reversibly fastened to one another, a valve spindle (5) which is guided axially movably on the upper (3) and / or lower housing part (4), wherein the valve spindle (5) has a conical sealing surface (6) at one end, and a valve seat (7) which is exchangeably received in the lower housing part (3) and which has a seating surface (8).

2. Valve (1) according to claim 1, wherein the valve seat (7) has a conical seating surface (8), wherein the valve (1) can be transferred from an open position into a blocking position by axial movement of the valve spindle (5), in which blocking position the conical sealing surface (6) of the valve spindle (5) comes into contact with the conical seating surface (8) of the valve seat (7) in order to sealingly close a fluid channel (11) running in the lower housing part (3) from an inlet connection (9) to an outlet connection (10).

3. Valve (1) according to claim 2, wherein the cone angle of the sealing surface (6) deviates from the cone angle of the seat surface (8), preferably by at least 2 degrees, more preferably by at least 10 degrees.

4. Valve (1) according to claim 1 or 2, wherein the sealing surface (6) and / or the seating surface (8) have a curvature when viewed in an axial longitudinal section, so that in the blocking position there is a linear contact of the sealing surface (6) of the valve spindle (5) on the seating surface (8) of the valve seat (7).

5. Valve (1) according to one of claims 1 to 4, wherein the valve seat (7) consists of stellite or hardened steel, in particular hardened chromium steel.

6. Valve (1) according to one of the preceding claims, wherein the conical sealing surface (6) of the valve (1) consists of stellite or hardened steel, in particular hardened chromium steel.

7. Valve (1) according to one of the preceding claims, wherein the valve spindle (5) is formed by a valve shaft (27) and a valve cone (28) arranged at one end thereof, wherein the valve shaft (27) and the valve cone (28) are made of materials of different hardness, wherein the valve cone (28) has the conical sealing surface (6).

8. Valve (1) according to claim 7, wherein the valve cone (28) is fastened to the valve shaft (27) by means of a press fit.

9. Valve (1) according to one of claims 1 to 8, wherein the lower housing part (3) and the upper housing part (4) are reversibly fastened to one another by a bayonet lock (12).

10. Valve (1) according to claim 9, wherein the bayonet closure (12) is designed to be fixed by means of a locking screw (13) which connects the lower housing part (3) to the upper housing part (4).

11. Valve (1) according to claim 10, wherein the locking screw (13) is aligned in the tangential direction to the rotational closing direction of the bayonet closure (12), wherein the locking screw (13) bears against a support surface of the housing upper part (4).

12. Valve (1) according to one of claims 1 to 11, wherein the valve seat (7) has a radially outwardly projecting collar (14), via which the valve seat (7) is supported with its underside on an annular support surface (15) formed in the fluid channel (11).

13. Valve (1) according to claim 12, wherein the housing lower part (3) has an axial blind bore, the lower section of which, in which the annular support surface (15) is formed, forms a partial section of the fluid channel (11), wherein the valve spindle (5) is accommodated in a stuffing box packing in the blind bore (16) is axially movable and sealed.

14. Valve (1) according to claim 13, wherein the valve spindle (5) extends at least partially through a cage structure (17) which is arranged between the stuffing box packing (16) and the valve seat (7), wherein a section of the fluid channel (11) connected to the outlet connection (10) opens into a lateral opening (18) of the cage structure.

15. Valve (1) according to claim 14, wherein the stuffing box packing (16) is formed integrally with the cage structure (17).

16. Valve (1) according to claim 14 or 15, wherein a sealing ring (19), in particular a graphite sealing ring, rests on the outwardly projecting collar (14) of the valve seat (7) and is held in a clamping manner between the valve seat (7) and the cage structure (17).

17. Valve (1) according to claim 16, wherein the valve seat (7) above the outwardly projecting collar (14) has a cylindrical portion (20) received in a lower portion of the cage structure (17).

18. Valve (1) according to one of claims 16 or 17, wherein the sealing ring (19) in an uncompressed state has a volume which is greater than its volume when clamped against the housing lower part (3) at the cylindrical section (20) and the outwardly projecting collar (14) between the valve seat (7) and the cage structure (17).

19. Valve (1) according to one of claims 17 or 18, wherein the cage structure (17) projects at least partially radially beyond the cylindrical portion (20) of the valve seat (7), so that the sealing ring (19) is in a force shunt, wherein the clamping force on the sealing ring (19) is limited by the force shunt.

20. Valve (1) according to one of claims 17 to 19, wherein the valve seat (7), seen in an axial longitudinal section, has a radius of curvature in a transition region (21) between the cylindrical section (20) and the outwardly projecting collar (14) which causes the sealing ring (19) held between the cage structure (17) and the outwardly projecting collar (14) to flow radially outwards when an axial clamping force is applied.

21. Valve (1) according to one of claims 14 to 20, wherein the arrangement comprising valve spindle (5), stuffing box packing (16), cage structure (17) and valve seat (7) can be removed upwards from the axial blind bore after separation of the upper housing part (4) and lower housing part (3).

22. Valve (1) according to claim 21, wherein the arrangement of stuffing box packing (16), cage structure (17) and valve seat (7) can be reversibly fixed to the upper housing part (4) by means of at least one clamping screw (22) by applying an axial clamping force acting downwards, ie in the direction of the valve seat (7).

23. Valve (1) according to one of claims 1 to 22, wherein the valve (1) has an actuating means (23) designed to control the axial movement of the valve spindle (6).

24. Valve (1) according to one of the preceding claims, wherein the upper housing part (4) consists entirely of one material, in particular a heat-resistant steel, preferably of steel 16Mo3.

25. Modular system (24), with a valve (1) according to one of the preceding claims, wherein the inlet connection (9), outlet connection (10) and fluid channel (11) of the lower housing part (3) are designed for a first nominal width (25), with a further lower housing part (3'), wherein the inlet connection (9), outlet connection (10) and fluid channel (11) of the further lower housing part (3') are designed for a second nominal width (26) which differs from the first nominal width (25), wherein the upper housing part (4) is selectively reversibly connectable to each of the two lower housing parts (3, 3').

26. Modular system (24) according to claim 25, wherein the upper housing part (4) can be reversibly connected to the two lower housing parts (3, 3') by means of a bayonet lock (12) or by means of a connecting flange.

27. Modular system (24) according to claim 25 or 26, wherein the actuating means (23) is modularly interchangeable.

28. Modular system (24) according to one of claims 25 to 27, wherein the upper housing part (4) is suitable for use in valves (1) with a nominal pressure rating of up to PN 500, wherein the nominal pressure rating (PN) of the lower housing parts () depends on the respective designed nominal diameter (DN, 25, 26).

29. Modular system (24) according to one of claims 25 to 28, wherein the housing upper part (4) has the same external dimensions independently of the optionally reversibly connectable housing lower part (3, 3').

30. Modular system (24) according to one of claims 25 to 29, wherein the housing lower parts (3, 3') each have contact surfaces (29) which correspond to the connection surfaces (30) of a conduit system (31) in order to accommodate the modular system (24).

31. Modular system (24) according to one of claims 25 to 30, wherein the housing lower parts (3, 3') each have an identically constructed arrangement of inserted components, comprising stuffing box packing (16), cage structure (17) and valve seat.

32. Valve seat (7) for a valve (1) according to one of claims 1 to 24, with a cylindrical section (20), a collar (14) projecting radially outwards beyond the cylindrical section (20), the valve seat (7) having an annular support surface (32) on its axial underside of the projecting collar (14), and with a conical seat surface (8) in the cylindrical section (20), the valve seat (7) consisting essentially of a stellite.

33. Valve seat (7) according to claim 32, wherein the hot hardness of the valve seat (7) corresponds to at least 43 HRC, wherein the FE content in the material of the valve seat (7) is at most 3% and / or the tungsten content is 4%.

34. Valve seat (7) according to claim 32 or 33, wherein the valve seat (7) can be used in a valve (1) according to one of claims 1 to 24.

35. Valve spindle (5) for a valve (1) according to one of claims 1 to 24, wherein the valve spindle (5) has a conical sealing surface (6), wherein the conical sealing surface (6) consists essentially of a stellite.

36. Valve spindle (5) according to claim 35, wherein the hot hardness of the conical sealing surface (6) corresponds to at least 43 HRC, wherein the FE content in the material of the valve spindle (5) is at most 3% and / or the tungsten content is 4%.

37. Valve spindle (5) according to claim 35 or 36, wherein the valve spindle (5) can be used in a valve (1) according to one of claims 1 to 24.

38. A method for producing a valve (1) from a modular system (24) according to one of claims 25 to 31, comprising the following steps: i) selecting an upper housing part (4), ii) selecting a lower housing part (3), iii) machining the lower housing part (3), comprising the following steps: a) machining the inner radius of an inlet connection (9), an outlet connection (10) and a fluid channel (11) of the lower housing part (3), wherein the inner radius is dimensioned in each case corresponding to a required nominal diameter (DN, 25, 26), b) machining contact surfaces (29) of the inlet connection (9) and the outlet connection (10), iiii) connecting the machined housing lower part (3) to the housing upper part (4).

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