Valve

Abstract

The invention relates to a valve (1), in particular a ball valve, comprising a housing with at least two connection openings (5) and a closure body (15) arranged inside the housing, and a valve stem (41). Furthermore, the valve has a seal with two sealing half-shells (21), which are fixed to the housing, bear against a surface of the closure body and surround some regions of said closure body in a shell-like manner, as well as an elastic intermediate shell (25) for each sealing half-shell. Said elastic intermediate shell is produced from an elastically compressible material having a higher elasticity than a material of the sealing half-shells and is located between the housing and the respective sealing half-shells.

Description

[0001] FAUCET

[0002] The invention relates to a tap, in particular a ball tap.

[0003] Ball valves have a shut-off element in the form of a perforated sphere. The orientation around an axis generally perpendicular to the flow direction determines the flow characteristics.

[0004] Ball valves are sometimes also called "ball valves," but they should not be confused with those ball valves where a movable ball creates a directional effect, e.g., to achieve a check valve effect (ball check valve). To avoid misunderstandings, the term "ball valve" is generally used in this text, but this is not intended to restrict it to specific applications; rather, it refers to ball valves in general, including ball valves used as valves (i.e., ball valves in the sense of "ball valves").

[0005] Commercially available ball valves feature a seal, generally made of PTFE, which partially contacts the ball and rotates relative to it when the flow direction needs to be changed. These seals are typically ring-shaped or cup-shaped and create a seal against the ball, preventing fluid from passing through the valve when it is closed. However, ensuring that the seal remains reliably effective over time and independent of fluctuations in external influences is a challenge that is not always satisfactorily resolved in practice (first problem). External forces, such as thermal expansion or wear, often cause leaks or the ball to jam.

[0006] A further, second problem concerns cleaning. Depending on the application, it is more or less important that no residues from the fluid flowing through or surrounding the ball valve can form in the area of ​​the ball valve, which cannot be removed at least by a reliable cleaning process.

[0007] Several approaches have already been proposed in the context of these challenges. DE 10 2021 117 563 A1 proposes equipping the sealing half-shells, located between the metallic housing half-shells on the one hand and the metallic locking body (ball) on the other, with an enlarged collar. Sealing rings are arranged between the housing half-shells and the sealing half-shells, sealing the sealing half-shells against the housing half-shells. While the enlarged collar may improve the area around the switching shaft, it does not solve the problems described above.DE102006015173A1 and CN 218670713 U each disclose a ball valve with a seal comprising two sealing elements. The first sealing element, which rests directly against the ball, may be made of PTFE, while the second is more elastic than the first and exerts a pressing force towards the ball, particularly in the axial direction, on the first sealing element, analogous to a spring arranged between the housing and the first sealing element. The first sealing element has a partially concave surface adapted to the surface of the ball, but is pressed against the surface of the ball in a ring-like manner, which is why the problems discussed above are not solved. Furthermore, dead spaces are created behind the ring-like first sealing elements in which residues can accumulate over time, which is particularly disadvantageous with regard to the second problem.

[0008] EP 0985 863 addresses this second problem and shows a pneumatically actuated ball valve in which a thin gap exists between the ball and its seat. For cleaning, fluid flows through this gap, allowing the ball to be pivoted back and forth. For normal operation, an inflatable sealing element is pressed against the surface of the ball, thus separating the gap from the flow area. This solution is disadvantageous with regard to the first problem.

[0009] It is an object of the present invention to overcome problems of the prior art and to provide an improved valve, in particular a ball valve, which remains reliable even under fluctuations in external influences and / or brings improvements in cleanability.

[0010] This text describes a valve comprising a housing with at least two connection openings (outlets), a closure element located inside the housing, and a control shaft. The closure element is rotatable about an axis defined by the control shaft to change the flow state (in the simplest case, "on" and "off"; more complex configurations with multiple outlets or adjustable flow cross-sections and thus adjustable flow rates are also possible) between the connection openings, in particular by being rotationally fixed to the control shaft. In many embodiments, the closure element has an outer surface that corresponds in some areas to the surface of a sphere, interrupted by bores. It can, as is known per se, have the shape of a hollow sphere with, for example,It can have two opposing bores and possibly at least one further bore, or, in the case of a 2-way valve, it can be designed as a solid sphere with a central bore, thus taking the form of a so-called spherical ring. A design as a C-shaped closure body with a surface that partially follows a sphere is also possible. In principle, other external shapes besides the spherical shape would be conceivable, i.e., other bodies of revolution rotating around the axis of the switching shaft, e.g., cylindrical or conical bodies or ellipsoids of revolution with an axis of rotation corresponding to the axis of the switching shaft. However, the spherical basic shape—like the cylindrical basic shape—has manufacturing advantages.

[0011] Furthermore, the valve features a seal with (at least) two sealing shells, for example, sealing half-shells, which are fixed to the housing (i.e., not rotating with the valve body), rest against a surface of the valve body, and partially surround it in a shell-like manner; that is, an inner surface of the sealing shells is concave, continuously curved, and fits precisely against a region of the convex outer surface of the valve body. The sealing shells can be made of PTFE, for example.

[0012] If the sealing body is convexly curved in two directions – for example, especially if the valve is a ball valve – then the inner surface of the sealing shells is correspondingly concavely curved in two directions.

[0013] According to one aspect of the invention, the valve has an elastic intermediate shell for each sealing shell. This intermediate shell is made of an elastically compressible material with a higher elasticity than the material of the sealing shells and is located between the housing and the respective sealing shell. The housing forms a receptacle for each intermediate shell, with a continuously concave surface portion into which the intermediate shell is received. The surface portions of the receptacles for the intermediate shells in the housing are concave in the sense that they are continuously concave (if the valve is a ball valve, then continuously concave in two spatial directions, i.e., biaxially concave, meaning not only planar concave but also concave with respect to movements in both the zenith and azimuth directions; similar to a concave mirror).They follow, in particular, the outer contour of the closure body, with a radius of curvature that is larger than the cumulative thickness of the intermediate shell and sealing shell. That is, for example, if the closure body is spherical (spherical, with functional bores), the receptacles are spherically concave.

[0014] The elastic intermediate shells can, in particular, have a consistently constant thickness in certain areas. For example, the thickness can be essentially constant across the entire intermediate shell, or at least across a large part of its surface, e.g., over at least 50% or at least 70% of its surface.

[0015] The intermediate shells are, in particular, shell-like, comparatively planar structures, which distinguishes them from mere rings. They can extend from an outer collar of the sealing shells to essentially the connection opening; in particular, they can substantially fill the space between an outer surface of the associated sealing shell and an inner surface of the receptacle in the housing. They can, for example, encompass a solid angle of at least π / 4 sr, or at least 3π / 8 sr, or at least π / 2 sr, or 3π / 4 sr, or more (an upper limit for the solid angle is the hemisphere with a solid angle of 2π sr minus the solid angle of the connection opening).

[0016] The material of the elastic intermediate shells is more elastic than the material of the sealing shells (e.g., PTFE) and than the material of the housing (a metal, e.g., stainless steel or aluminum). In one example, the intermediate shells are made of a thermoplastic polyurethane (TPU), specifically a TPU grid. More generally, the intermediate shells can be made of a homogeneous or structured—in the latter case, for example, a grid-like structure or one with other regular structures, such as a grid of recesses or through-holes, etc.—elastically deformable material, such as a polymer-based material.

[0017] The thickness of the intermediate shells is, for example, at least 1% and at most 8% of the radius of curvature, e.g., between 2% and 6% or between 2.5% and 4% of the radius of curvature. For a spherical closure body with a diameter of 200 mm (radius of curvature 100 mm), the thickness of the intermediate shells is, for example, between 2 mm and 6 mm.

[0018] The valve can be free of cavities, except for the areas through which the fluid flows. In particular, the valve can be free of cavities in the area between the sealing shells and the housing. This proves advantageous because, if cavities are present, contaminants can accumulate there over time, which should be avoided. If the valve body is a sphere (with bores designed according to function), the intermediate shells can have the approximate shape of a so-called spherical zone (the lateral surface of a spherical layer), i.e., a spherical surface area bounded by two circles running in parallel planes. In versions with a third and possibly a fourth connection opening, the intermediate shells, deviating from the spherical zone shape, also have lateral cutouts for the corresponding connection opening(s).

[0019] In various designs, the sealing shell rests against the housing on both sides of the associated intermediate shell, so that without the intermediate shells there would be a closed cavity surrounding the longitudinal axis, which cavity is completely filled by the intermediate shell, leaving no cavity between the housing and the sealing shells.

[0020] While it is known in the art to press a seal, e.g., made of PTFE, against the outer surface of the closure body by an elastic force, whereby the elastic force is exerted by spring elements or by an elastic medium in the form of an elastic ring, as shown, for example, in DE102006015173A1, these solutions have the disadvantage that the pressure is only applied at specific points or along a line, so that the seal is not pressed evenly across its entire surface. Where it is not pressed directly or with reduced pressure, the fluid transported in the piping system can undesirably penetrate into an intermediate area between the closure body and the seal, which can also cause problems for cleaning.However, if, in the prior art, the contact pressure is chosen to be too high in order to prevent such ingress, this can lead to problems with operation and excessive wear. By providing an intermediate shell according to the invention, which is inserted into a continuously concavely curved recess, these problems are avoided: the intermediate shell can, in particular, have a homogeneous or approximately homogeneous thickness, whereby the seal is pressed uniformly against the closure body along the entire extent of the intermediate shell, in a radial direction, i.e., towards the center of the closure body. Regardless of the thermal state of the closure body or the fluid pressure applied to it, a defined contact pressure is always present over the entire sealing shell.Especially during the switching process of the ball, the sealing behavior is important, and the flow / creep of fluid between the ball and the sealing shell must be avoided.

[0021] The seal comprises exactly two sealing half-shells, and the ball valve has two corresponding intermediate shells, each adapted to the sealing half-shells. The sealing half-shells and the intermediate shells can each have approximately the shape of a so-called spherical zone, i.e., the shape of a portion of a spherical surface between two parallel planes intersecting the sphere. However, depending on the shape of the valve body, they can also have a cylindrical, conical, or other shape adapted to the surface of a body of revolution. The housing can also be two-part, with the two housing halves being attachable to one another, for example, by screws.

[0022] In particular, and in contrast to the prior art, it can be provided that the housing components (e.g., housing halves) together with the sealing shells, the intermediate shells, and the closure body form a single unit which does not need to be disassembled for connection to a pipe system, but which, unlike the prior art, can be integrated into a pipe system as a whole, further increasing reliability and tightness. For this purpose, sealing contours adapted to flanges (e.g., with standard dimensions and / or belonging to the pipe valve) can be provided in the vicinity of the connection openings. These flanges can be screwed onto the housing halves and attached to the pipe system, e.g., by welding.

[0023] The housing can be solid and cylindrical as a whole, e.g. with blind holes for attaching screws to the aforementioned flanges and with a sealing contour for sealing against the flanges.

[0024] The number of connection openings can vary depending on the design. In the simplest case, where the tap is a 2-way tap or 2-way valve, there are exactly two connection openings – or "outlets". However, if the tap is a 3-way valve, there can be three or even more than three, for example, four, connection openings.

[0025] In embodiments with three or more connection openings (three or more outlets, i.e., particularly in embodiments as a 3-way valve), exactly two housing halves, exactly two sealing half-shells, and exactly two intermediate shells can also be present, wherein the sealing half-shells and intermediate shells are located opposite each other and each has approximately the shape of spherical zones, with lateral incisions for the third connection opening (and optionally further connection openings). The seal against the third connection opening (and optionally further connection openings) can be achieved in a manner known per se by a sealing contour on which an O-ring is used for sealing. Embodiments of the present invention combine the aforementioned approach with an electronically controlled drive of the switching shaft. Depending on the fluid, there are fundamentally different drives for valves, e.g.Ball valves, including manual, pneumatic, and electric actuators. Electronically controlled actuators allow operation based on an electronic control signal. With an electric actuator, the electronic control signal activates the electric drive; with a pneumatic actuator, the electronic control signal causes the pneumatic system to actuate. This can be achieved via one or more actuators that generate a pneumatic pulse, which in turn actuates the pneumatic drive and thus rotates the shaft. A simpler version with so-called 3-position actuators, capable of moving to the 0°, 45°, and 90° positions, also exists and is suitable for the invention and the cleaning method described below.

[0026] The inventive method is particularly advantageous in conjunction with an electric drive and programming that enables a special cleaning process. This cleaning process provides that the valve body is subjected to defined rotations about its axis of rotation (corresponding to the axis of the switching shaft) by an electrical drive, and that the valve is permeated by a fluid, in particular a cleaning fluid, during and / or between the defined rotations.

[0027] The provision of elastic intermediate shells results, firstly, in a particularly good suitability for an electric or pneumatic actuator of the sealing body, since the elastic intermediate shells ensure that a defined contact pressure is always present on the entire sealing half-shells, regardless of the thermal state. Furthermore, this approach avoids- 11 -

[0028] The sealing shells and intermediate shells could create dead spaces between the housing or sealing shells on the one hand and the valve body on the other, in areas where the flow is not direct. Therefore, it is advisable and effective to use a cleaning method in conjunction with the design using sealing shells and intermediate shells. This method exposes only the outer surface of the valve body to the fluid flow that removes contaminants. This is achieved by electrically driven, defined rotations around the axis of rotation of the valve body. During and / or between these defined rotations, the valve is circulated with a fluid, particularly a cleaning fluid.

[0029] In its various forms, the defined rotations stipulate that the closure body is rotated successively (e.g.) from a neutral position, in which the valve is open with respect to one flow direction, in two opposite directions (swivel movements), by an angle that is substantially greater than 0° and substantially less than 90°, for example approximately 45°.

[0030] Following these potentially repeated pivoting movements in opposite directions from the neutral position, the closure body can be rotated 180° and the process of pivoting movements in opposite directions can then be repeated. Alternative procedures are conceivable; depending on the fluid properties, various interconnection options exist.

[0031] In addition to a tap that can be programmed to perform the described cleaning process, a tap cleaning process of the described type is also part of the present invention. In various embodiments, a sealing element, e.g., an O-ring, is used to seal the connection to the switching shaft. This element sits over the joint (e.g., weld seam) between the switching shaft and the valve body, achieving a defined contact pressure. This seal prevents any fluid that might get between the valve body and the seal from escaping along the switching shaft. An additional seal, which would require a material-weakening indentation, is not necessary. If special applications require it, further sealing elements can be installed around the switching shaft in addition to the regular seal.

[0032] In its 3-way configuration, the valve, particularly a ball valve, can have a fourth port in addition to a third port, which is closed with a blind flange – allowing for use as a 4-way valve. This provides greater flexibility, enabling applications where the fourth port can be utilized. Furthermore, with certain ball valve designs, additional external pressure can be applied to the sealing surfaces via the fourth port. This pressure can be particularly advantageous in thermally stressed applications and at high pressures, ensuring valve tightness.

[0033] Another aspect of the present invention—which is particularly advantageous when implemented together with the first aspect—elastic intermediate shells—but which can also be implemented independently, concerns a C-shaped locking element, i.e., a sphere milled to form a C-shaped hemisphere. Such a shape can, of course, also be produced by a non-ablative process. Such C-shaped locking elements are known per se. They have certain advantages, for example, regarding cleanability. According to this further aspect, the C-shaped locking element (the C-sphere) has an additional bearing on the side opposite the insertion of the switching shaft. This bearing can be constructed similarly to the switching shaft but is shorter and lacks a drive mechanism. This results in a particularly stable guide.It has been found that, particularly when an elastic force is applied where the surface of the valve body follows the contour of the ball surface, or when other substantial forces are applied to the valve body, for example, in the closed state under high fluid pressure, this guide improves the seal. The seemingly simple measure of adding another bearing on the opposite side therefore results in a significant improvement in the properties of the ball valve with a C-type valve body (i.e., the C-type ball valve).

[0034] The invention according to the second aspect also relates to a ball valve, in particular according to the first aspect, comprising a housing with at least two connection openings, a valve body, and a control shaft connected to the valve body, wherein the valve body is rotatable in the housing about an axis defined by the control shaft in order to change the flow state between the connection openings, and a seal, which is fixedly arranged between the valve body and the housing, bears against a surface of the valve body and surrounds it in a certain area. The valve body has the shape of a C-shaped ball valve valve body, i.e., it is C-shaped as a whole with a spherical outer surface.The insertion of the switching shaft is located on the outside of one side of the arc defined by the C-shape. The arc spans an area of ​​over 180° (with respect to the center of the sphere), such that a point diametrically opposite the insertion of the switching shaft also lies within the area of ​​the spherical outer surface. At this point, essentially diametrically opposite the insertion of the switching shaft, a bearing coaxial with the switching shaft is provided. This bearing can be implemented, for example, by a bearing shaft that is coaxially mounted with the switching shaft in the housing and that is connected to the locking body at the aforementioned point (the bearing shaft connection point), wherein the bearing shaft is rotatable about its axis and / or the locking body is rotatable relative to the bearing shaft about its axis.The bearing shaft can be designed similarly to the shift shaft, but in comparison it can be shorter and, in particular, unlike the shift shaft, it does not have to completely penetrate the housing, i.e., it does not have to protrude radially outwards from the housing, since, unlike the shift shaft, it can be purely passive and no drive needs to be attached to it.

[0035] Examples of embodiments of the invention are described below with reference to the drawings. In the drawings, identical reference numerals denote identical or analogous elements. The drawings partially show corresponding elements in different sizes from figure to figure. They show:

[0036] Fig. 1 shows a view of a ball valve;

[0037] Fig. 2 shows a view of the ball valve according to Fig. 1 with electric drive module;

[0038] Fig. 3 shows an exploded view of the ball valve according to Fig. 1;

[0039] Fig. 4 shows a variant of the ball valve according to Fig. 1, cut along a vertical plane through the longitudinal axis;

[0040] Fig. 5 shows a detail from Fig. 4;

[0041] Fig. 6 shows a diagram of the drive;

[0042] Fig. 7 a diagram (angle as a function of time); Figs. 8 and 9 each a view of a ball valve with a third and fourth outlet;

[0043] Fig. 10 shows an exploded view of a variant of the ball valve according to Fig.

[0044] 8 and 9 without a fourth connection opening;

[0045] Fig. 11 shows another ball valve - depicted with an electric drive module - in a view;

[0046] Fig. 12 is an exploded view of the ball valve according to Fig. 11, without the electrical drive module; and

[0047] Figs. 13-15 show sectional views of the ball valve according to Figs. 11 and 12 in different switching states.

[0048] An example of a ball valve in a 2-way configuration is shown in Figure 1. Figure 2 shows the ball valve according to Figure 1 with an actuator module 51 with an electric actuator, and Figure 3 shows an exploded view of the components of the ball valve from Figure 1, omitting some elements (namely, fasteners: screws, washers). The ball valve 1 has a generally cylindrical housing with two housing halves 2, which are screwed together. For this purpose, one housing half has 2 through holes for the housing screws 3, and the other housing half has 2 threaded blind holes. The housing has sealing contours 7 around the opposing connection openings 5 ​​and flange threaded blind holes 9 to allow the attachment of flanges 11 to the housing. These flanges 11 can be welded to pipe ends.The procedure using reversibly attachable flanges 11 to the housing and sealable against the housing (flange O-ring 12, sealing contour 7) has, in contrast to prior art ball valve housings, the important advantage that the housing halves 2 with the elements arranged therein can be pre-assembled and embedded as a unit in the pipe system. According to the prior art, however, the housing halves were each welded to the pipe system and only then, already integrated into the pipe system, attached to each other, which, depending on the precision of the pipe system, could lead to leakage problems due to shear forces or the like.

[0049] Inside the housing is the sphere, i.e., the valve body 15. In the illustrated embodiment, the valve body 15 is a hollow sphere with three bores 16 and a connection point 17 on the upper side for the switching shaft 41. However, in configurations as a 2-way valve, it would also be conceivable that the valve body, as a hollow sphere, has only two opposing bores 16 or is designed entirely as a spherical ring, i.e., as a solid sphere with a continuous cylindrical bore.

[0050] Two housing-mounted sealing half-shells 21, for example made of PTFE, with an inner sealing surface 22 adapted in shape to the spherical surface of the closure body and with a collar 23, serve to seal against the closure body 15.

[0051] The housing halves each form a receptacle for the sealing half-shells 21. These receptacles are recesses and, in certain areas on the inside around the connection openings 5, have a spherically concave curved surface section 28. Between this spherically concave curved surface section 28 and an outer surface of the sealing half-shells, there is an intermediate shell 25 made of an elastic material, for example, thermoplastic polyurethane (TPU), in particular a TPU grid. The intermediate shells 25 have a spherically convex outer surface whose contour corresponds to the spherically concave curved surface section 28 of the housing halves. They also form a spherically concave inner surface whose contour follows the contour of the corresponding section of the outer surface of the sealing half-shell.The thickness of the intermediate shells 25 is homogeneous in that the outer contour of the closure body (and thus the inner contour of the sealing half-shells), the outer contour of the sealing half-shells (and thus the inner contour of the intermediate shells) and the inner contour of the spherically concave curved surface part 28 (and thus the outer contour of the intermediate shells) correspond to each other, with radii of curvature that differ according to the thickness of the sealing half-shells or the intermediate shells - with reference to the assembled state.

[0052] However, in their unloaded, unassembled state, the sealing half-shells 25 are slightly thicker than the space between the sealing half-shells and the spherically concave curved surface section 28. Therefore, due to their elastic compression, they press the sealing half-shells against the surface of the closure body with a constant external pressure. This pressure force acts radially, meaning it is uniformly distributed across the entire surface, regardless of the curvature of the closure body, unlike prior art solutions where a ring or spring elements are compressed.

[0053] Outside the spherically concave curved surface area 28, but still within the receptacle for the sealing half-shells, the housing halves 2 in the illustrated embodiment form a shoulder 29. This shoulder forms a stop with an outer surface 30 of the collar 23 of the sealing half-shells 21, thus fixing the orientation of the sealing half-shells 21 in the face of the frictional forces occurring on the inner sealing surfaces when the valve body 15 rotates. To seal the sealing half-shells 21 to the housing halves 2, the ball valve has an O-ring seal with a sealing contour 31 (e.g., according to DIN 11864; version: January 1, 2025; aseptic and hygienic applications) and a (second) O-ring 32. The standardized sealing contour (aseptic seal) may already have a centering feature as well as a defined metallic stop. The sealing type can be the same as the one used in the flange connection.Therefore, the latter (with sealing contours 7 and (first) O-ring 12) can optionally be designed according to DIN 11864; version: 1.1.2025.

[0054] In the sectional view according to Figure 4 and the detail shown in Figure 5 from area V of Fig. 4, it can be seen particularly well that the concavely curved surface part 28 runs parallel to the surface of the closure body 15 and accordingly also to the sealing surface 22 of the sealing shells 21, in the sense that it has the same curvature, with a radius of curvature larger by the cumulative thickness of the sealing shell and the (slightly compressed) intermediate shell.It can also be seen that on both sides of the intermediate shell 25 there is physical contact between the sealing shell 21 on the one hand and the corresponding housing half-shell 2 on the other, towards the transverse central plane of the ball valve by means of the collar 23, and towards the respective connection opening (outwards) by means of a projecting portion 27 of the sealing shell with a radially outwardly convex curved surface area. Between the projecting portion 27 and the collar 23, a seat for the intermediate shell 25 is thus formed on the outside of the sealing shell 21.

[0055] To rotate the valve body 15 relative to the housing, sealing halves 21, and intermediate shells 25, the ball valve 1 has a switching shaft 41, which is rotatable about a switching shaft axis 40 perpendicular to the longitudinal axis 10 (flow axis; see Fig. 1) and which is rotationally fixed to the valve body 15. In certain embodiments, there is a positive-locking connection between the switching shaft 41 and the connection point 17, in the sense that the switching shaft 41 is not circularly symmetrical in cross-section at its end, and the connection point 17, for example, which is milled, has a corresponding cross-sectional shape. The switching shaft is welded to the ball, for example, by laser welding (or another welding process or by brazing). Therefore, there is also, for example, a fillet weld circumferentially around the switching shaft 41 between the switching shaft 41 and the valve body.

[0056] Fig. 3 also shows a switching shaft O-ring for the inner seal towards the housing halves, a guide sleeve 44 which passes through the housing in the assembled state, a guide sleeve retainer 46 which can be screwed onto the outside of the housing and a console 47, for example for attaching an electric drive of the switching shaft 41.

[0057] If required for specific applications, additional sealing elements can be installed around the shift shaft in addition to the regular seal. In such applications, the guide sleeve 44 can be replaced by these additional sealing elements.

[0058] In some embodiments, the switching shaft is driven electrically or pneumatically and electronically. Besides the advantage of enabling automated operation within a system, synergies also arise with the previously described design of the seal between the housing and the closure element by facilitating a cleaning process that improves cleaning efficiency and reliability compared to the prior art. Figure 6 schematically shows an electronic control unit 53 that controls an electric motor 52 driving the switching shaft 41. The electronic control unit 53—which can optionally be fully or partially integrated into an electric motor control unit, i.e., the electric motor can optionally be a servo motor—can be configured to provide a rotary drive for the switching shaft 41 with a range of 360°, at least 180°, or at least 90° rotation, and can enable the shaft to be moved to any desired rotational position.Furthermore, it is designed to ensure continuous monitoring of the rotation position.

[0059] As an alternative to an electric drive, a pneumatic actuator can also be used, which can also be electronically controlled and which can allow for easier readjustment after a replacement of the drive.

[0060] The electronic control unit 53 is specifically designed to perform an automatic cleaning procedure. This procedure involves moving the closure body into defined positions while a fluid, in particular a cleaning fluid, flows through the ball valve.

[0061] Figure 7 shows one possible embodiment of the cleaning process. The deflection angle a (rotational position of the switching shaft 41 about the switching shaft axis 40) is shown as a function of time t, where a deflection angle a = 0° corresponds to the position "ball valve = fully open; Fig. 3". The illustrated cleaning process involves first rotating the valve body 45° in one direction and remaining in this position for a period of time while cleaning fluid flows through the ball valve. Then, the valve body is rotated past the zero position to a position deflected 45° in the other direction and remains there for another period of time. This process is repeated (in Fig.

[0062] Figure 7 shows a repetition). The flow in the positions shown, combined with the rotational movements between assuming these positions and the even contact pressure, results in particularly good cleaning. Depending on the configuration, the closure body 15 can be rotated further, e.g., by 135° and then by 225°, to be exposed to the flow from all sides. The closure body can stop at defined positions, analogous to Figure 7, and steps can be repeated.

[0063] The method shown in Fig. 7 achieves very good cleaning results. However, other procedures with different angle settings and cycles are also conceivable. A characteristic feature of this cleaning method is that the valve body is automatically and controllably moved into different positions while a fluid flows through the ball valve.

[0064] While Figures 1-3 show an embodiment of the ball valve as a 2-way valve, 3-way valve versions are also possible. Figures 8 and 9 show a view of a corresponding embodiment with a total of four connection ports from two different perspectives. Figure 10 shows a variant without the fourth connection port in an exploded view (omitting individual elements, e.g., screws; orientation as per Figure 8). The elements analogous to the embodiment described above as a 2-way valve have the same reference numerals and are not described again.

[0065] In addition to the first and second connection openings 5 ​​arranged on opposite sides, the 3-way valve embodiment has a third connection opening 61 and, optionally (Figs. 8 and 9), a fourth connection opening opposite the third. The third connection opening 61 and, optionally, the fourth connection opening are formed by each housing half 2 having a semicircular incision 67 on a lateral portion 66; that is, the third connection opening 61 and, optionally, the fourth connection opening is / are formed between the housing halves 2. The sealing half-shells 21 and the intermediate shells 25 also have corresponding incisions, which can be seen particularly well in Fig. 10. The function of the intermediate shells 25 is analogous to that of the 2-way valve embodiment.The sealing of the third connection opening is achieved via a sealing ring 62, a sealing shell sealing contour 65 and sealing ring O-rings 63, 64, one of which is pressed against the sealing shell sealing contour 65.

[0066] A third flange 61 (collar flange) assigned to the third connection opening can be screwed onto the housing analogously to the (first and second) flanges 11 (groove flanges) described above and can therefore be attached to the housing after welding with the pipe system, just like the first and second flanges.

[0067] The optional fourth connection opening is closed, for example, by a blind flange 71, whereby a blind flange intermediate shell in the area of ​​the collar can support a uniform contact pressure between sealing half shells 21 and closure body 15.

[0068] The optional fourth port allows the ball valve to be used as a 4-way valve. This opens up applications where this design with four outlets is used. Alternatively, this fourth port, particularly with certain ball valve designs, can be used to apply additional external pressure to the sealing halves, especially by means of a blind flange intermediate shell between an inner surface of the blind flange and the corresponding portion of the sealing half-shell 21. In thermally stressed applications and / or at high pressures, this pressure-adjustment option can be advantageous to ensure valve tightness. A further advantage of the fourth port is the flexibility it provides when redesigning an entire system, as either of the side ports can be used as the third port.

[0069] Figures 11 and 12 show – with and without drive module 51 with electric drive – a further embodiment of a ball valve 1, specifically in a 2-way valve configuration. The embodiment according to Fig.

[0070] Figures 11 and 12 differ from the embodiments described above in that the locking body 15 is a C-sphere, i.e., it has a C-shape by forming an arc, and has a spherically extending (i.e., forming part of a sphere) outer surface 91. The connection point for the switching shaft 41 is located on the upper and outer side of the C-sphere, and on the lower side, diametrically opposite (not visible in Figure 12 due to the chosen perspective), is a bearing shaft connection point for a bearing shaft 81 coaxial with the switching shaft 41. This bearing shaft is sealed against the housing by a bearing shaft O-ring 83 and is guided in a housing-fixed bearing shaft guide sleeve 84, which lies in a seat 85 formed in the housing and is held there by an underside end 86 – which essentially corresponds in its function to the retainer 46.

[0071] The two-sided support provided by the switching shaft 41 and bearing shaft 81 ensures that the valve body is always pressed against the seal formed by the sealing half-shells 21 with a uniform force in all directions, even when, for example, it is under high fluid pressure. In Figures 13-15, the ball valve 1 according to Figures 11 and 12 is shown in section along a horizontal plane through the longitudinal axis 10, with the figures showing different positions of the valve body 15. Figure 13 shows the ball valve in the open position, Figure 14 in the closed position, and Figure 15 in a position where the valve body is rotated by approximately 45° relative to the closed position, as is the case, for example, during the cleaning process.

Claims

PATENT CLAIMS 1.A valve (1) comprising a housing with at least two connection openings (5, 61), a closure body (15) and a switching shaft (41) connected to the closure body, wherein the closure body (15) is rotatable in the housing about an axis (40) defined by the switching shaft (41) in order to change a flow state between the connection openings (5, 61), and a seal with a plurality of sealing shells (21) which are fixedly arranged between the closure body (15) and the housing, bear against a surface of the closure body (15) and surround it in a shell-like manner in certain areas, characterized by, for each sealing shell (21), an elastic intermediate shell (25) made of an elastically compressible material with a higher elasticity than a material of the sealing shells (1), wherein the housing forms a receptacle for each intermediate shell (25) with a continuously concave curved surface section (28) into which the intermediate shell (25) is received.

2. Valve according to claim 1, wherein the valve is a ball valve and the concave curved surface portion (28) of the housing is biaxially concave, in particular spherically concave.

3. Tap according to claim 1 or 2, wherein the elastic intermediate shells (25) have a constant thickness, 4. Tap according to any one of the preceding claims, wherein the elastic intermediate shells (25) each comprise a solid angle of at least π / 4 sr.

5. Tap according to any one of the preceding claims, wherein the elastic intermediate shells are made of a thermoplastic polyurethane.

6. Tap according to one of the preceding claims, wherein the housing is composed of two housing halves (2) which can be screwed together, each of the housing halves (2) having a fastening point, with sealing contour (7), for a reversibly attachable flange (11).

7. Tap according to claim 6, wherein a first of the connection openings (5) is provided in a first of the housing halves (2) and a second of the connection openings is provided in a second of the housing halves (2).

8. Tap according to one of the preceding claims, comprising a third connection opening (61) arranged between the first and second housing half (2), and a fourth connection opening arranged opposite the third connection opening between the first and second housing half (2), and closed with a blind flange (71) to form a 3-way valve.

9. Tap according to claim 8, comprising an elastic blind flange intermediate shell (73) for exerting a lateral contact pressure on the closure body (15) from one side of the blind flange (71), 10. Tap according to any of the preceding claims, comprising an electric drive for the switching shaft (41) and an electronic control unit (53) for controlling the electric drive.

11. Tap according to claim 10, wherein the electronic control unit (53) is programmed to perform an automated cleaning process.

12. Tap according to claim 11, wherein the automated cleaning method includes defined rotary movements of the closure body (15) about the axis (40), wherein the tap is supplied with fluid during the rotary movements and / or between the rotary movements.

13. Tap according to claim 12, wherein the defined rotational movements include pivoting the closure body from a zero position in which the tap is open with respect to a flow direction successively in two opposite directions, by an angle greater than 0° and less than 90°.

14. Tap according to claim 13, wherein, following pivoting in two opposite directions, the closure body is rotated by 180° and then pivoted again in two opposite directions by an angle greater than 0° and less than 90°.

15. Tap according to one of the preceding claims, wherein the closure body (15) is C-shaped with a spherical outer surface, and wherein the closure body (15) is additionally mounted on a side opposite the switching shaft (41).

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