Seal web for diaphragm valve

Abstract

To provide a diaphragm valve achieving sealing without the need for high axial forces, thereby reducing the load on individual components of the valve, and facilitating assembly of the valve.SOLUTION: A diaphragm valve 1 for controlling a flow of a medium in a pipeline comprises a housing upper part 2, a housing lower part 3, an actuation unit 4, a diaphragm 5, and an inner housing 6 which presses against the diaphragm 5. The diaphragm 5 lies on a bearing region of the housing lower part 3 and is compressed by means of a clamping region 8 of the inner housing 6, where the diaphragm 5 has a seal web 10 on the bottom side facing the medium, and the inner housing 6 has a web 11 extending in the clamping region 8, where the web 11 is arranged vertically above the seal web 10.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a diaphragm valve for regulating the flow rate of a medium in a pipeline, which has an upper housing portion, a lower housing portion, an operating unit, a diaphragm, and an inner housing for pressing the diaphragm. The diaphragm is mounted on the mounting area of the lower housing portion and is pressed by the clamping area of the inner housing.

Background Art

[0002] The design of commercially available diaphragm valves is such that the lower portion is coupled to the upper portion using bolts and nuts and in some cases washers, and the diaphragm is disposed between the lower and upper portions. By tightening the individual bolt joints, the diaphragm is pressed, thereby obtaining the minimum surface pressure required for sealing. An improved form of this design is a design with a central housing nut screw fastening, such as the diaphragm valve disclosed in European Patent Application Publication No. 2236874.

[0003] The disadvantage of the known prior art is that in the case of a form with a central housing nut screw fastening, an axial force must be applied through this single screw fastening / bolt joint, which requires a higher tightening torque compared to the case of a plurality of individual bolts.

[0004] This is not a problem for small-sized diaphragm valves and can be achieved by an auxiliary tool such as a strap wrench, but it is almost impossible for large embodiments.

[0005] From the formula F = P × A (force = pressure × area), it can be seen that the area to be pressed (or the pressing area against the diaphragm) is the primary coefficient with respect to the axial force. In commercially available diaphragm valves, the pressing area is large, which means that a large force must be applied to obtain sufficient pressure or a sufficiently high pressing force against the sealing member to make the valve airtight. Since the load on the individual components increases, there is a risk that the valve will fail prematurely.

Summary of the Invention

Problems to be Solved by the Invention

[0006] The problem of the present invention is to propose a diaphragm valve that does not require a large axial force to obtain sealing performance, thereby reducing the load on the individual components of the valve and facilitating the assembly of the valve.

Means for Solving the Problems

[0007] According to the present invention, this problem is solved in that the diaphragm has a sealing web on the lower surface facing the medium, and the inner housing has a web extending within the clamping region, and the web is disposed vertically above the sealing web.

[0008] The diaphragm valve according to the present invention for regulating the flow rate of a medium in a pipeline preferably has an upper housing part and a lower housing part made of plastic. The upper housing part and the lower housing part are preferably screwed to each other via threads arranged on the upper housing part and the lower housing part. The diaphragm valve according to the present invention has an operating unit for operating the diaphragm valve. Preferably, the operating unit has a spindle, a spindle nut, and a diaphragm holder. The diaphragm holder is connected to the diaphragm by a connecting element and acts on the diaphragm, in which case the pressing force is transmitted via a pressing member. Furthermore, the operating unit preferably has a plurality of different forms of spindles. This enables connection with manual, electric or pneumatic drive devices. The diaphragm valve according to the present invention has a diaphragm for regulating the flow rate, which separates the diaphragm valve into a region through which the medium flows and a region without the medium. The diaphragm is pressed against the mounting region of the lower housing part by an inner housing pressing the diaphragm within the housing, or is clamped between the inner housing and the mounting region. Preferably, the housing and the inner housing have circular bottom surfaces in regions that engage with each other inside and outside, and both are formed in a cylindrical shape. The mounting surface is preferably formed as an annular surface arranged on the lower housing part. In this case, the diaphragm is pressed against the mounting surface of the lower housing part by the clamping region of the inner housing. Since the inner housing is preferably formed in a cylindrical shape with a circular bottom surface, the clamping surface is formed in an annular shape. The diaphragm has a sealing web on the lower surface facing the medium, and the inner housing has a web extending within the clamping region, and the web is arranged vertically above the sealing web. The sealing web, preferably extending circularly over the entire circumference, is integrally arranged on the diaphragm. The sealing web preferably forms a sealing lip that projects or protrudes from the lower surface of the diaphragm and rises from this lower surface. Preferably, the sealing web may have a cross-section that tapers or has a rounded shape.The web disposed in the clamping region of the inner housing preferably extends circularly over the entire circumference. Since the web is raised with respect to the surface of the clamping region or the outer surface extending over the entire circumference, the clamping mainly takes place below the web. As a result, the pressing of the diaphragm for obtaining sealing performance is concentrated in a specific narrow region, so that the required axial force is still small, and moreover, a high pressure is applied to the diaphragm or the sealing web based on a small area. Therefore, only a very small tightening torque of the housing is required, and thus simple assembly and maintenance are possible.

[0009] It has been found to be advantageous if the web has a surface extending in the horizontal direction or is formed as a flat part.

[0010] It has been found that it is a preferred embodiment if the web tapers.

[0011] It has been found to be advantageous if the web and the sealing web are concentrically arranged with respect to each other. In addition to the sealing web and the web being arranged axially in a row, one above the other or perpendicular to each other, the sealing web and the web are also concentrically arranged with respect to each other in order to ensure that the web presses the sealing web provided on the diaphragm in the vertical direction.

[0012] It has been found to be advantageous if the web has an inclined surface for centering the inner housing with respect to the lower part of the housing. The inclined surface preferably connects to the outer diameter of the web. The inclined surface or chamfer and the radially connected web separate the sealing function and the centering function from each other, so that both functions can be performed more reliably and better.

[0013] It has been found that a preferred embodiment is one in which a protrusion extending over the entire circumference is arranged on the mounting surface of the lower part of the housing. This protrusion is used for centering the diaphragm on the mounting surface of the lower part of the housing. As described above, it should be noted that in order to minimize the area on which the axial force acts, the pressing force acts only on the web, and ultimately only on the sealing web of the diaphragm.

[0014] It has been found to be advantageous if the protrusion has a plane that extends obliquely, and this inclined plane is arranged parallel to the inclined surface of the web and is used for centering. This centers the inner housing in the lower part of the housing.

[0015] Preferably, a raised portion is arranged on the diaphragm and is used for centering the diaphragm within the inner housing. The raised portion is preferably arranged on the upper surface that does not face the medium. The raised portion is centered within a corner portion that is formed between the inclined surface and the outer surface that is horizontally connected and extends over the entire circumference.

[0016] The diaphragm is preferably formed from a support diaphragm and a diaphragm shield. Preferably, the diaphragm shield is in direct contact with the lower surface of the support diaphragm. Of course, the diaphragm may also be formed as a one-piece.

[0017] It has been found to be advantageous if the diaphragm is formed circularly or has a basic circular shape. This enables an even force distribution.

[0018] All possible configurations can be freely combined with each other. Although an embodiment of the present invention will be described based on the drawings, the present invention is not limited to this embodiment only.

Brief Description of the Drawings

[0019]

Figure 1

Figure 2

Figure 3

Embodiments for Carrying Out the Invention

[0020] The drawing shown in FIG. 1 shows a diaphragm valve 1 according to the present invention for regulating the flow rate of a medium in a pipeline. The diaphragm valve 1 has an upper housing part 2 and a lower housing part 3. Preferably, both housing parts 2, 3 are made of plastic and have threads 14 for closing against each other. To operate the diaphragm valve 1, the diaphragm valve 1 has an operating unit. Preferably, the operating unit (4) includes a pressing member 21, and a diaphragm 5 is coupled to this pressing member 21 via a coupling element 22. Further, it is advantageous if the operating unit (4) includes a spindle (23) and a spindle nut (28) with a threaded insert (27) surrounded by injection molding. The spindle (23) is preferably coupled to a diaphragm holder (26) by a grooved pin (25). A hex nut (24) is arranged on the diaphragm holder (26). Preferably, a threaded pin / coupling element (22) of the diaphragm is assembled within this hex nut (24). In a pneumatically actuated diaphragm valve, the spindle preferably moves linearly rather than rotates and is directly (in a form-fitting manner) coupled to the diaphragm holder. In this case, the spindle nut (28) and the grooved pin are unnecessary. The pressing member (21) presses the diaphragm against the lower housing part during closing and is pulled at the coupling element (22) during opening. The spindle 23 of the operating unit (4) is preferably coupled to a drive device, which may be formed manually, electrically or pneumatically. The diaphragm valve 1 according to the present invention has a diaphragm 5, and this diaphragm 5 regulates the flow rate of the medium. Further, the diaphragm 5 divides the diaphragm valve 1 into a region without the medium and a region (9) through which the medium flows. The diaphragm valve 1 has an inner housing 6, and by means of this inner housing 6, the diaphragm 5 is mounted and positioned within the housing. The diaphragm 5 is placed on a mounting region 7 of the lower housing part 3 and is pressed by a clamping region 8 of the inner housing 6.In order to be able to achieve a high surface pressure and at the same time a small axial force, the diaphragm has a sealing web 10, and the inner housing 6 has a web 11 within the clamping region. As a result, the pressing of the diaphragm 5 is achieved substantially only via the areas of the web 11 and the sealing web 10. For this purpose, as can be well recognized in FIGS. 1 to 3, the web 11 and the sealing web 10 are arranged vertically above and below each other in the vertical direction. It is advantageous if the web 11 and the sealing web 10 are formed concentrically. Furthermore, the diaphragm 5 preferably has a circular basic shape. In FIGS. 2 and 3, it can be well recognized that the web 11 has an inclined extending surface 12 for centering. As a result, the inner housing 6 is centered in the lower housing part 3. Similarly, the lower housing part 3 also has an inclined extending plane 13, and since this plane 13 extends parallel to the inclined surface 12, optimal positioning is achieved. It is advantageous if the lower housing part has a projection 17 in the mounting region 7. The inclined plane 13 is arranged on this projection 17, and the projection 17 is also used for centering the diaphragm 5. It has been found to be advantageous if a raised portion 18 is arranged on the upper surface of the diaphragm 5. The raised portion 18 is used for centering the diaphragm 5 with respect to the inner housing 6. Preferably, the raised portion 18 is centered at the corner portion 16 formed between the horizontally extending outer surface 15 and the inclined surface 12 within the inner housing 6 and extending over the entire circumference. The diaphragm 5 preferably consists of a support diaphragm 19 and a diaphragm shield 20, and the diaphragm shield 20 preferably abuts against the support diaphragm 19. Of course, even if it cannot be recognized in each drawing, the diaphragm 5 may be formed as one member, and it is not necessary to consist of the support diaphragm 19 and the diaphragm shield 20.

Explanation of Signs

[0021] 1 Diaphragm valve 2 Upper housing part 3 Lower housing part 4 Operating unit 5 Diaphragm 6 Inner housing 7 Placing area, lower part of housing 8 Clamping area, inner housing 9 Bottom surface, diaphragm 10 Seal web 11 Web 12 Inclined surface, inner housing 13 Inclined flat surface, lower part of housing 14 Thread 15 Outer surface connected horizontally 16 Corner extending over the entire circumference 17 Protrusion 18 Raised portion 19 Support diaphragm 20 Diaphragm shield 21 Pressing member 22 Coupling element 23 Spindle 24 Hexagon nut 25 Grooved pin (Knebelkerbstift) 26 Diaphragm holder 27 Threaded insert 28 Spindle nut

Claims

1. A diaphragm valve (1) for regulating the flow rate of a medium in a pipeline, comprising an upper housing part (2), a lower housing part (3), an operating unit (4), a diaphragm (5), and an inner housing (6) for pressing the diaphragm, the diaphragm being mounted on a mounting area (7) of the lower housing part (3) and being pressed by a clamping area (8) of the inner housing, The diaphragm valve (1) is characterized in that the diaphragm (5) has a sealing web (10) on its lower surface (9) facing the medium, and the inner housing has a web (11) extending into the clamping area (8), the web (11) being arranged vertically above the sealing web (10).

2. 2. The diaphragm valve (1) according to claim 1, wherein the sealing web (10) and the web (11) are formed so as to extend over the entire circumference in a circular shape.

3. 3. The diaphragm valve (1) according to claim 1 or 2, characterized in that the web (11) and the sealing web (10) are arranged concentrically.

4. 4. The diaphragm valve (1) according to claim 1, wherein the web (11) has an inclined surface (12) for centering the inner housing (6) relative to the lower housing part (3).

5. 5. The diaphragm valve (1) according to claim 1, wherein a circular projection (17) is arranged on the support surface (7) of the lower housing part (3) and extends over the entire circumference.

6. 6. The diaphragm valve (1) according to claim 5, characterized in that the protrusion (17) has an inclined plane (13) which is arranged parallel to the inclined surface (12) of the web (11) and is used for centering.

7. 7. The diaphragm valve (1) according to claim 1, wherein a protrusion (18) is arranged on the diaphragm (5) and is used for centering the diaphragm (5) within the inner housing (6).

8. The diaphragm valve (1) according to any one of claims 1 to 7, characterized in that the diaphragm (5) is made from one of the following plastics: EPDM, FKM or NBR.

9. The diaphragm valve (1) according to any one of claims 1 to 8, characterized in that the diaphragm (5) comprises a support diaphragm (19) and a diaphragm shield (20).

10. 10. The diaphragm valve (1) according to any one of claims 1 to 9, characterized in that the sealing web (10) is arranged integrally with the underside of the diaphragm (5).

11. 11. Diaphragm valve (1) according to any one of claims 1 to 10, characterized in that the diaphragm (5) is circular or has a circular basic shape.

12. 10. The diaphragm valve (1) according to claim 9, characterized in that the diaphragm shield (20) is made from any one of the plastics PTFE, PFA or PE.

13. 10. The diaphragm valve (1) according to claim 9, characterized in that the support diaphragm (19) is made from one of the following plastics: EPDM or FKM.

14. 14. The diaphragm valve (1) according to any one of claims 1 to 13, characterized in that the web (11) has a horizontally extending surface or is formed as a flat portion.

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