Shut-off valve

Abstract

The invention relates to a shut-off valve (1) for pipes, having a housing (2) in which a through-passage (3) is formed, having a shut-off unit (4) with a shut-off slide (5) for releasing and shutting off the through-passage (3), having at least a first connection flange (6) which is arranged on the housing (2), is connected to the through-passage (3) and is intended for connecting to a first pipe end, and having at least a second connection flange (7) which is arranged on the housing (2), is connected to the through-passage (3) and is intended for connecting to a second pipe end, wherein the connection flanges (6, 7) are fastened on the housing (2) via releasable screw connections (8) and the connection flanges (6, 7) have welding surfaces (9, 10) for weldable connection to the pipe ends, wherein exchangeable seat bushes (13, 14) line the through-passage (3) in the housing (2), wherein the connection flanges (6, 7) bear against the seat bushes (13, 14), which protrude into the housing (2), wherein a respective sealing ring (15), in particular a graphite sealing ring, provides a force shunt connection between the connection flange (13, 14) and the housing (2), wherein the clamping force on the sealing ring (15) is limited by the force shunt connection.

Description

[0001] WRZR0093

[0002] February 6, 2026

[0003] BD-AY

[0004] Drainage valve

[0005] The invention relates to a shut-off valve for pipes, comprising a housing in which a passage is formed, a shut-off unit with a gate valve for opening and closing the passage, at least one first connecting flange arranged on the housing and connected to the passage for connection to a first pipe end, and at least one second connecting flange arranged on the housing and connected to the passage for connection to a second pipe end, wherein the connecting flanges are attached to the housing via detachable screw connections and the connecting flanges have welding surfaces for weldable connection to the pipe ends, wherein replaceable seat bushings line the passage in the housing, and wherein the connecting flanges bear against the seat bushings projecting into the housing.

[0006] Such a shut-off valve is known from WO 2020 / 144303 A1. The shut-off valve described here has a passage formed in a housing, which can be opened and closed by a gate valve. The passage is connected to two connection flanges formed on the housing, which can be used to connect the valve to flanged pipe ends. Because the connection flanges are attached to the housing via detachable screw connections and have welding surfaces for welding to the pipe ends, the housing of the shut-off valve can be very easily installed in a pipe assembly between two pipe ends. For this purpose, the shut-off valve, with the connection flanges screwed to the housing, is simply inserted between the pipe ends and welded tightly to the pipe ends via the welding surfaces.The housing can also be easily removed from the pipe assembly by loosening the screw connections, without having to detach the connection flanges from the pipe ends at the welded joints. This ensures that the connection flanges remain optimally aligned within the pipe assembly for reinstallation of the housing, allowing for quick restoration of a high level of leak tightness. During maintenance, the connection flanges remain within the pipe assembly, simplifying access to the components located inside the housing for replacement. By lining the passage with the seat bushings, cavitation-induced wear on the seat bushings can be easily remedied by replacing the seat bushings, possibly along with the connection flanges. Lining the passage with the seat bushings prevents cavitation from occurring on the housing itself, thus effectively preventing wear on the housing caused by the lining.The way the connection flanges fit against the seat bushings projecting into the housing ensures a secure hold for the seat bushings. Furthermore, removing the housing from the connection flanges makes the seat bushings more easily accessible for replacement. However, a disadvantage of this type of shut-off valve is that the revealed sealing arrangements of the seat bushings offer only limited sealing against the housing and the connection flanges and are subject to faster wear due to vibrations in the pipework.

[0007] It is therefore an object of the invention to provide an improved shut-off valve that enables easy maintenance and repair, easy installation and offers high tightness with low wear of the seals.

[0008] This problem is solved by a shut-off valve with the features of claim 1. Such an improved shut-off valve enables easy maintenance and repair, easy installation, and offers higher tightness and low wear of the seals.

[0009] By positioning a sealing ring, particularly a graphite sealing ring, in a force-fit connection between a connection flange and the housing, with the clamping force on the sealing ring limited by this force-fit connection, an improved shut-off valve can be achieved. This valve offers easier maintenance and repair, simpler installation, higher tightness, and reduced seal wear. The single sealing ring in the force-fit connection between one of the connection flanges and the housing simultaneously seals between the housing, a seat bushing, and the connection flange. The clamping force on the single sealing ring between the housing, a seat bushing, and the connection flange is limited by the force-fit connection between the connection flange and the housing. This reduces the stress on the sealing ring caused by vibrations in the pipe assembly.A sealing ring, especially 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 during the service life of the shut-off valve.

[0010] Advantageous embodiments and further developments of the invention are set forth in 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 meaningful way, thus revealing further embodiments of the invention.

[0011] According to an advantageous embodiment of the invention, the passage runs straight through the housing. A straight passage avoids wear that can occur with a non-straight passage, for example due to cavitation.

[0012] A particularly preferred embodiment provides that the connection flanges are arranged on opposite sides of the housing. This arrangement of the connection flanges on opposite sides allows for easy alignment of the housing between the flanges. Furthermore, the opposite arrangement of the connection flanges simplifies the installation of the valve. A particularly advantageous embodiment of the invention provides that the gate valve is contacted by the replaceable seat bushings when the passage is closed. With the arrangement or use of replaceable seat bushings, wear-related damage at the contact point between the gate valve and the seat bushings during closure can be remedied, in particular, by simply replacing the seat bushings. Thus, continuous tightness of the shut-off valve can be achieved through simple replacement of the seat bushings.

[0013] A particularly advantageous embodiment provides that the seat bushings are positioned in seat bushing receptacles formed on the housing. Positioning the seat bushings in these receptacles allows for easy alignment, ensuring a high level of sealing against the gate valve.

[0014] According to an advantageous embodiment of the invention, the seat bushings each have a radially outwardly projecting collar, wherein the inner surface of the collar of each seat bushing bears against an annular outer support surface of the housing. This design is particularly practical and allows for easy and quick replacement of the seat bushings. Preferably, the annular outer support surface is formed within the seat bushing receptacle in the housing. The forces acting on the seat bushings can be effectively absorbed by the outer support surface.

[0015] A particularly preferred embodiment provides that each sealing ring rests on the radially outwardly projecting collar of the respective seat bushing and is held clamped between one of the seat bushings and one of the connecting flanges. Clamping the sealing ring between the seat bushing and the connecting flange allows it to be held in the housing without any additional elements. Thus, the sealing ring can be easily removed during maintenance and replaced if necessary. A particularly advantageous embodiment of the invention relates to the fact that the seat bushings each have a cylindrical axial section, which is received in an inner receiving section of the connecting flanges, following the radially outwardly projecting collars.The cylindrical axial section extends telescopically into the connecting flanges, with the connecting flanges and the seat bushings being guided and centered relative to each other and exhibiting axial movement relative to one another. This design allows, in particular, the edge of the connecting flanges, which radially overlaps the seat bushings in the cylindrical area, to exert an axial clamping force on the sealing ring resting on the radially outwardly projecting collar. The force transmitted via the sealing ring to the collar simultaneously holds the seat bushing in its position on the annular support surface in the seat bushing receptacle.

[0016] A particularly advantageous embodiment of the invention provides that each sealing ring, in its uncompressed state, has a volume larger than its compressed volume clamped against the housing at the respective cylindrical axial section and the respective radially outwardly projecting collar between one of the seat bushings and one of the connecting flanges. The larger volume of the sealing ring in its uncompressed state causes it to be pressed into the smaller volume between the seat bushing and the connecting flange when axial clamping forces generated by the connecting flanges are applied, thus creating a tight seal. The sealing ring remains in an uncompressed state as long as its volume is not compressed by the application of such forces (clamping forces).is in a state of elastic or plastic deformation, depending on the material of the ring and the strength of the acting forces.

[0017] An advantageous embodiment of the invention provides that the connecting flanges project radially beyond at least part of the cylindrical axial section of the seat bushings, so that each sealing ring is clamped between a seat bushing and a connecting flange, with the clamping force on each sealing ring being limited by the force bypass. The contact area of ​​the connecting flanges, over which the clamping force is applied, is determined and limited by the shape of the seat bushings. Preferably, the axial clamping forces act uniformly over an axial sealing surface of the sealing ring to achieve optimal force transmission. Thus, the sealing ring is subjected to less stress with improved sealing, resulting in reduced wear on the sealing ring.

[0018] A particularly advantageous embodiment provides that the seat bushings, viewed in an axial longitudinal section, have a radius of curvature in a transition area between the cylindrical axial section and the radially outwardly projecting collar. This radius of curvature causes the sealing ring, held between the connecting flange and the outwardly projecting collar, to flow radially outward when an axial clamping force is applied. The deflection of the clamping force outward by the radius of curvature, in conjunction with the flowability of the sealing ring, achieves excellent sealing of the seat bushings against the inner wall of the housing surrounding them. By arranging the sealing ring in a force-by-force configuration, as described above, the clamping force is limited, ensuring that the maximum clamping force is precisely dimensioned to guarantee a very good seal without overloading the sealing ring.Overloading the sealing ring could damage it and impair its sealing function. The described design prevents this.

[0019] According to a preferred embodiment of the invention, the gate valve is replaceable. Wear-related damage that impairs the tightness of the shut-off valve can be easily remedied by replacing the gate valve.

[0020] A particularly advantageous embodiment provides that the gate valve has a through-opening whose geometry can be varied by replacing the gate valve. By geometrically varying the through-opening of the gate valve, the valve assembly can be used as a shut-off valve, a control valve, or for throttling. Further features, details, and advantages of the invention will become apparent from the following description and the drawings, which show exemplary embodiments of the invention. Corresponding objects or elements are designated with the same reference numerals in all figures. The figures show:

[0021] Figure 1 Shut-off valve,

[0022] Figure 2 Sectional view through the shut-off valve,

[0023] Figure 3 Sectional view through seat bushing and connection flange,

[0024] Figure 4 Top view of the seat bushing and

[0025] Figures 5 and 5a show top views of gate valve variants.

[0026] Figure 1, designated by reference numeral 1, shows a shut-off valve according to the invention. The shut-off valve 1 has a housing 2 in which a straight passage 3 (Fig. 2) is formed. This passage 3 (Fig. 2) can be opened and closed via a gate valve 5 (Fig. 2) by actuating a shut-off unit 4. For this purpose, the shut-off unit 4 includes a handwheel 17, which actuates a spindle 18 (Fig. 2) with which the gate valve 5 (Fig. 2) can be moved within the passage 3 (Fig. 2). Two connection flanges 6, 7 are arranged on opposite sides 11, 12 (Fig. 2) of the housing 2 and are connected to the passage 3 (Fig. 2). A first connection flange 6 serves for connection to a first pipe end, while a second connection flange 7 serves for connection to a second pipe end. The connection flanges 6, 7 are attached to the housing 2 via screw connections 8.This allows the connection flanges 6, 7 to be easily detached from the housing 2 for maintenance work without having to disconnect them from the welded connections at the pipe ends. This ensures that the connection flanges 6, 7 are still optimally aligned within the pipe assembly when the housing 2 is reinstalled, allowing for quick restoration of a tight seal. The connection flanges 6, 7 have welding surfaces 9, 10, which are used to create a welded connection with the pipe ends to be joined (not shown). This allows the shut-off valve 1 to be easily connected to a pipe assembly via the connection flanges 6, 7. For this purpose, the shut-off valve 1, with the connection flanges 6, 7 screwed onto the housing 2, is inserted directly between the pipe ends and welded tightly to the pipe ends via the welding surfaces 9, 10.

[0027] Figure 2 shows a sectional view through the shut-off valve according to Figure 1. In this view, the straight passage 3 formed in the housing 2 between the two connection flanges 6, 7 arranged on opposite sides 11, 12 is visible. The connection flanges 6, 7 are fastened to the housing 2 by means of screw bolts 19. The screw connections 8 can be loosened for maintenance work, so that the connection flanges 6, 7 can be separated from the housing 2 for maintenance purposes. During maintenance, the connection flanges 6, 7 thus remain in the pipe assembly, which simplifies access to the components 5, 13, 14 arranged in the housing 2 for replacement. The connection flanges 6, 7 are preferably multi-part and comprise a connection stub 28, which forms the weld surfaces 9, 10 and the passage 3, and a flange plate 29, which receives the screw connections 8 and is arranged on the connection stub 28.The connecting flanges 6, 7 rest against seat bushings 13, 14, which project far enough into the housing 2 that, when the passage 3 is closed by the gate valve 5, they contact it, as shown in Figure 2. The contact between the seat bushings 13, 14 and the gate valve 5 ensures a tight seal of the pipe connection in the passage 3. The seat bushings 13, 14 can be easily replaced when worn. Because the seat bushings 13, 14 project into the housing 2 and line the passage 3 within the housing 2, wear occurs only on the seat bushings 13, 14 and not on the housing 2 itself. Wear on the shut-off valve 1 can therefore be remedied by replacing the seat bushings 13, 14.By screwing the connection flanges 6, 7 to the housing 2, the seat bushings 13, 14, which rest against the connection flanges 6, 7, are fixed in the housing 2 and thus optimally secured. The gate valve 5 is a separate component from the spindle 18 of the shut-off unit 4, so that it can also be easily replaced during maintenance work. Wear on the gate valve 5 can therefore also be easily remedied. Replacing the gate valve 5 also allows the geometric shape of the passage opening 16 (Figs. 5, 5a) formed in the gate valve 5 to be varied. Figures 5 and 5a show different geometric configurations of the passage openings 16 (Figs. 5, 5a). The passage opening shown in Fig. 5 is particularly suitable for selectively opening and closing the passage 3 completely. With the one shown in Fig.In contrast, with the geometry of the passage opening shown in 5a, flow control is possible, since the cross-section of the passage opening left open depending on the position of the gate valve varies more or less linearly in the direction of movement of the gate valve.

[0028] Figure 3 shows a sectional view through a seat bushing 13, 14, which lines the passage 3 in the housing 2. One of the connecting flanges 6, 7 rests against the seat bushing 13, 14 projecting into the housing 2. Advantageously, two such connecting flanges 6, 7 with such seat bushings 13, 14 are arranged on opposite sides 11, 12 (Fig. 2) of the housing 2. Thus, the connecting flanges 6, 7 (Fig. 2) have opposing weld surfaces 9, 10 (Fig. 2) on the housing 2. The seat bushings 13, 14 each have a radially outwardly projecting collar 23. The seat bushings 13, 14 bear against an annular outer support surface 24 of the housing 2 with an inner surface of the collar 23. Preferably, the annular outer support surface 2 is formed as a base in the seat bushing receptacle 22 in the housing 2. This allows the forces acting on the seat bushings 13, 14 to be effectively absorbed by the outer support surface 24.The sealing ring 15, used individually for sealing, rests on the radially outwardly projecting collar 23 of the respective seat bushing 13, 14. The sealing ring 15 is held clamped between one of the seat bushings 13, 14 and one of the connecting flanges 6, 7. The clamped, individual sealing ring 15 between the seat bushing 13, 14 and the connecting flange 6, 7 is held in the housing 2 without any further elements. The seat bushings 13, 14 each have a cylindrical axial section 26 extending from the radially outwardly projecting collar 23. This section is received in an inner receiving section 25 of the connecting flanges 6, 7. Since the cylindrical axial section 26 telescopically extends into the connecting flanges 6, 7 when the flanges 6, 7 are fitted, the connecting flanges 6, 7 and the seat bushings 13, 14 are guided and centered relative to each other. They possess a degree of axial movement relative to each other to facilitate fitting.This design enables, in particular, the inner edge of the connecting flanges 6, 7, which radially overlaps the seat bushings 13, 14 at the axial section 25, to exert an axial clamping force on the sealing ring 15 resting on the outwardly projecting collar 23. The sealing ring 15 simultaneously holds the seat bushings 13, 14 in their position on the annular support surface 24 in the seat bushing receptacle 22. In its uncompressed state, the sealing ring 15 has a volume that is greater than its volume when compressed against the housing 2 at the respective cylindrical axial section 26 and the respective radially outwardly projecting collar 23 between one of the seat bushings 13, 14 and one of the connecting flanges 6, 7.The larger volume of the sealing ring 15 in its uncompressed state ensures that, when axial clamping forces are applied, it is pressed into the smaller volume between the seat bushing 13, 14 and the connecting flange 6, 7 by means of the connecting flanges 6, 7. This ensures a tight seal for the individual sealing ring 15. Therefore, a single sealing ring 15 can be used to seal between the housing 2 and the respective connecting flange 6, 7. The connecting flanges 6, 7 project radially beyond the cylindrical axial section 26 of the seat bushings 13, 14. The sealing ring 15 is clamped between a seat bushing 13, 14 and a connecting flange 6, 7 by means of these projections. The clamping force on each individual sealing ring 15 is limited by the force bypass. At the seat bushings 13, 14 a transition area 27 is provided between the cylindrical axial section 26 and the radially outwardly projecting collar 23, which has a radius of curvature.This radius of curvature 27 causes the sealing ring 15, which is held between the connecting flange 6, 7 and the outwardly projecting collar 23, to flow radially outwards when an axial clamping force is applied. The deflection of the clamping force outwards by the radius of curvature 27, in combination with the flowability of the sealing ring 15, results in an excellent seal between the seat bushings 13, 14 and the inner wall of the housing 2 surrounding the seat bushings 13, 14. The present design of the sealing ring 15 in the force-by-shutoff configuration, as described above, aims to limit the clamping force and ensure optimal sealing without overloading the sealing ring 15. Overloading the sealing ring 15 could lead to damage and impair its sealing effect. The described design helps to prevent such overloading.As shown in Figure 3, the screw bolts 19 are screwed into blind holes 30 in the housing 2. To optimally position the seat bushings 13, 14 with the connecting flanges 6, 7 in the housing 2, the housing 2 has seat bushing receptacles 22 which secure the seat bushings 13, 14 between the connecting flanges 6, 7 and the housing 2.

[0029] Figure 4 shows a top view of a seat bushing 13, 14, which can be used as an alternative to the seat bushings 13, 14 shown in Figures 2 and 3. This seat bushing 13, 14 has a passage 3 reduced to several small openings 20. With such a reduced passage 3, throttling can be achieved via the alternatively usable seat bushing 13, 14. In Figure 4, it can be clearly seen that the openings 20 in the passage 3 (Figure 3) are evenly distributed, so that a uniform, throttled flow can be achieved in the passage 3 (Figure 3) when the gate valve 5 (Figure 2) opens.

[0030] Figures 5 and 5a show different geometric configurations of the passage openings 16 (Figs. 5, 5a). The passage opening shown in Fig. 5 is particularly suitable for selectively opening and closing the passage 3 completely. In contrast, the geometry of the passage opening shown in Fig. 5a allows for flow control, since the cross-section of the passage opening left open varies more or less linearly in the direction of movement of the gate valve, depending on the position of the gate valve.

[0031] The gate valves 5 shown in Figures 5 and 5a have a mounting geometry 21, which is clearly visible in the figures. This mounting geometry 21 allows the gate valves 5 to be easily attached to the spindle 18 (Fig. 2) during replacement.

[0032] List of references

[0033] I Shut-off valve

[0034] 2 cases

[0035] 3rd round

[0036] 4 shut-off unit

[0037] 5 gate valves

[0038] 6 First connection flange

[0039] 7 Second connection flange

[0040] 8 screw connections

[0041] 9 First welding surface

[0042] 10 Second welding surface

[0043] II First page

[0044] 12 Second page

[0045] 13 First seat bushing

[0046] 14 Second seat bushing 15 Sealing ring

[0047] 16 Passage opening

[0048] 17 Handwheel

[0049] 18 spindles

[0050] 19 screw bolts

[0051] 20 passage openings

[0052] 21 Mounting geometry

[0053] 22 Seat bushing mount

[0054] 23 collars

[0055] 24 external support surface

[0056] 25 Recording section

[0057] 26 Axial section

[0058] 27 Transition area

[0059] 28 connection spigots

[0060] 29 Flange plate

[0061] 30 blind holes

[0062] - Claims -

Claims

Claims 1. Shut-off valve (1 ) for pipes, with a housing (2) in which a passage (3) is formed, a shut-off unit (4) with a gate valve (5) for releasing and shutting off the passage (3), at least one first connection flange (6) arranged on the housing (2) and connected to the passage (3) for connection to a first pipe end, and at least a second connecting flange (7) arranged on the housing (2) and connected to the passage (3) for connection to a second pipe end, wherein the connecting flanges (6, 7) are attached to the housing (2) via detachable screw connections (8) and the connecting flanges (6, 7) have welding surfaces (9, 10) for weldable connection to the pipe ends, wherein replaceable seat bushings (13, 14) line the passage (3) in the housing (2), wherein the connecting flanges (6, 7) bear against the seat bushings (13, 14) projecting into the housing (2), characterized in that that a sealing ring (15), in particular a graphite sealing ring, is located in a force bypass between connection flange (13, 14) and housing (2), wherein the clamping force on the sealing ring (15) is limited by the force bypass.

2. Shut-off valve (1) according to one of the preceding claims, characterized in that the passage (3) runs straight through the housing (2).

3. Shut-off valve (1) according to one of the preceding claims, characterized in that the connection flanges (6, 7) are arranged on opposite sides (11, 12) of the housing (2).

4. Shut-off valve (1) according to one of the preceding claims, characterized in that the shut-off valve (5) is contacted by the replaceable seat bushings (13, 14) when the passage (3) is shut off.

5. Shut-off valve (1) according to one of the preceding claims, characterized in that the seat bushings (13, 14) are positioned in seat bushing receptacles (22) formed on the housing (2).

6. Shut-off valve (1) according to one of the preceding claims, characterized in that the seat bushings (13, 14) each have a radially outwardly projecting collar (23), wherein the seat bushings (13, 14) are supported with an inner side of the collar (23) on an annular outer support surface (24) of the housing (2).

7. Shut-off valve (1) according to claim 6, characterized in that each sealing ring (15) rests on the radially outwardly projecting collar (23) of the respective seat bushing (13, 14) and is clamped between one of the seat bushings (13, 14) and one of the connecting flanges (6, 7).

8. Shut-off valve (1) according to claim 6 or 7, characterized in that the seat bushings (13, 14) each have a cylindrical axial section (26) received in an inner receiving section (25) of the connecting flanges (6, 7) following the radially outwardly projecting collars (23).

9. Shut-off valve (1) according to claim 8, characterized in that each sealing ring (15) in an uncompressed state has a volume which is larger than its volume compressed clamped against the housing (2) at the respective cylindrical axial section (26) and the respective radially outwardly projecting collar (23) between one of the seat bushings (3, 14) and one of the connecting flanges (6, 7).

10. Shut-off valve (1) according to claim 8 or 9 characterized in that the connecting flanges (6, 7) project radially at least partially beyond the cylindrical axial section (25) of the seat bushings (13, 14), so that each sealing ring (15) is clamped between a seat bushing (13, 14) and a connecting flange (6, 7), wherein the clamping force on each sealing ring (15) is limited by the force bypass.

11. Shut-off valve (1) according to one of claims 8 to 10, characterized in that the seat bushings (13, 14), viewed in an axial longitudinal section, have a radius of curvature in a transition area (27) between the cylindrical axial section (26) and the radially outwardly projecting collar (23), which causes the sealing ring (15) held between the connecting flange (6, 7) and the outwardly projecting collar (23) to flow radially outwards when an axial clamping force is applied.

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