Diaphragm valve

Abstract

The invention relates to a diaphragm valve for controlling the flow of a medium in a pipeline, comprising an upper housing part, a lower housing part, an operating unit, a diaphragm and an inner housing pressing the diaphragm, the diaphragm being placed on a bearing region of the lower housing part and being pressed against a clamping region of the inner housing, wherein the diaphragm has a sealing strip on the lower side facing the medium and the inner housing has a strip extending in the clamping region, the strip being arranged vertically above the sealing strip.

Description

Technical Field

[0001] The invention relates to a diaphragm valve for controlling the flow of a medium in a pipeline, comprising an upper housing part, a lower housing part, an operating unit, a diaphragm and an inner housing for pressing the diaphragm, wherein the diaphragm is placed on a supporting area of the lower housing part and is pressed with a clamping area of the inner housing. Background Art

[0002] The commercially customary design of a diaphragm valve consists of a lower part connected to an upper part by means of screws and nuts and, if necessary, washers, and the diaphragm is arranged in between. By tightening the individual screw connections, the diaphragm is compressed and the minimum surface pressure required for tightness is thereby achieved.

[0003] A further development of this design results in a design with a central housing nut screw connection, such as the diaphragm valve disclosed in EP 2 236 874 A1.

[0004] A disadvantage of the prior art is that in the variant with a central housing nut screw connection, the axial force must be applied via this single screw connection / screw connection, which requires a higher tightening torque than a plurality of individual screws.

[0005] This is not a problem for small-sized diaphragm valves and can be achieved with auxiliary tools, such as a strap wrench, but is hardly feasible for large embodiments.

[0006] The formula F = P*A (force = pressure * area) shows that the pressure area (or the squeeze area on the diaphragm valve) has a linear coefficient for the axial force. In commercial conventional solutions, the squeeze area is large, which means that a higher force must be applied to obtain sufficient pressure or a high enough squeeze on the seal to ensure that the valve is sealed. This causes increased loads on the various components, which can lead to premature failure of the valve. Summary of the invention

[0007] The object of the present invention is to provide a diaphragm valve in which no large axial forces are required to achieve tightness, thereby reducing the load on the individual components of the valve and simplifying the installation of the valve.

[0008] This object is achieved according to the invention in that the diaphragm has a sealing strip on the underside facing the medium and the inner housing has a strip extending in the clamping region, wherein the strip is arranged vertically above the sealing strip.

[0009] A diaphragm valve for controlling the flow rate of a medium according to the present invention includes an upper housing part and a lower housing part, preferably made of plastic. The upper housing part and the lower housing part are preferably screwed together with 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 by means of which the diaphragm valve is operated. Preferably, the operating unit includes a spindle, a spindle nut and a diaphragm holder, the diaphragm holder is connected to the diaphragm by a connecting element and the diaphragm holder acts on the diaphragm, wherein the pressure is transmitted via a pressure block. In addition, the operating unit preferably has a plurality of spindle variants, whereby connection to a manual, electric or pneumatic drive mechanism is made possible. The diaphragm valve according to the present invention has a diaphragm for controlling the flow rate and divides the diaphragm valve into a medium flow region and a medium-free region. The diaphragm is squeezed or clamped between the inner housing that presses the diaphragm at the support region of the lower housing part in the housing. Preferably, the housing has a circular base surface in the interlocking region and is configured to be cylindrical. The support surface is preferably configured as an annular surface arranged in the lower housing part, wherein the diaphragm is squeezed at the lower housing part with the clamping region of the inner housing relative to the support surface. The inner housing is preferably configured to be cylindrical and has a circular base surface, whereby the clamping surface is configured to be annular. The diaphragm has a sealing strip on the lower side facing the medium and the inner housing has a strip extending in the clamping region, wherein the strip is arranged vertically above the sealing strip. The preferably circularly surrounded sealing strip is integrally arranged on the diaphragm. The sealing strip preferably forms a sealing lip protruding or projecting from the lower side of the diaphragm beyond the lower side. Preferably, the sealing strip may have a cross-section with a tapered or also rounded shape. The strip arranged on the clamping region of the inner housing preferably extends in a circularly surrounding manner. The strip is convex with respect to the surface of the clamping region, or with respect to the surrounding outer surface, whereby the clamping mainly occurs below the strip. Therefore, in order to achieve sealing, the squeezing of the diaphragm is concentrated in a specific and narrow area, which in turn requires less axial force and still introduces a high pressure on the diaphragm or on the sealing strip due to the small area. And, thereby only a smaller tightening torque of the outer shell is required, which makes installation and maintenance easier.

[0010] Advantageously, it has been shown that the strip has a horizontally extending surface, or is configured in the form of a platform.

[0011] Advantageously, it has been shown that the strip extends in a tapered manner.

[0012] Advantageously, it has been shown that the strip and the sealing strip are arranged concentrically with respect to each other. In addition to the sealing strip and the strip being arranged in a straight line in the axial direction, or vertically with respect to each other, the sealing strip and the strip are also arranged concentrically with respect to each other to ensure that the strip is squeezed vertically on the sealing strip of the diaphragm.

[0013] It has been shown to be advantageous that the strip has a surface extending obliquely for centering the inner housing relative to the lower housing part. The obliquely extending surface preferably adjoins the outer diameter of the strip. Through this obliquely extending surface or hypotenuse and the radially adjacent strip, the sealing and centering functions are decoupled from each other, whereby the two functions are more reliably satisfied.

[0014] As an advantageous embodiment, it has been shown that an annularly extending nose (Nase) is arranged on the bearing surface of the lower housing part. This nose is used to center the diaphragm on the bearing surface of the lower housing part. As previously noted, the clamping force acts almost only on the strip and thus on the sealing strip of the diaphragm, so that the area on which the axial force acts remains as small as possible as described above.

[0015] It has been shown to be advantageous that the nose has an obliquely extending plane, wherein the inclined plane is arranged parallel to the inclined surface of the strip and is used for centering. The inner housing is thus centered on the lower housing part.

[0016] Preferably, a bulge (Wulst) is arranged at the diaphragm and is used for centering the diaphragm in the inner housing. The bulge is preferably arranged on the upper side facing away from the medium. The bulge is centered in the circumferential angle formed between the inclined surface and the horizontally adjacent outer surface.

[0017] The diaphragm is preferably formed by a support diaphragm and a diaphragm shield. Preferably, the diaphragm shield is directly adjacent to the lower side of the support diaphragm. Of course, the diaphragm can also be integrally formed.

[0018] It has been shown to be advantageous that the diaphragm is circular, or has a circular basic shape. This enables uniform force distribution.

[0019] It has been shown to be advantageous that the diaphragm is made of the plastics EPDM (ethylene-propylene-diene rubber, Ethylen-Propylen-Dien-Kautschuk), FKM (fluororubber, Fluorkautschuk) or NBR (nitrile rubber, Nitrilkautschuk). Preferably, the diaphragm shield is made of the plastics PTFE (polytetrafluoroethylene, Polytetrafluorethylen), PFA (perfluoroalkoxy polymer, Perfluoralkoxy-Polymere) or PE (polyethylene, Polyethylen). In a further preferred embodiment, the support diaphragm is made of the plastics EPDM (ethylene-propylene-diene rubber, Ethylen-Propylen-Dien-Kautschuk) or FKM (fluororubber, Fluorkautschuk).

[0020] All design options can be freely combined with each other. Description of the Drawings

[0021] Embodiments of the present invention are described with the aid of the accompanying drawings, wherein the present invention is not limited to the embodiments. In the figures:

[0022] Figure 1 A partial cross-sectional view through the diaphragm valve is shown,

[0023] Figure 2 A cross-section of an exploded view of the clamping area is shown, and

[0024] Figure 3 A partial cross-section of an exploded view of the diaphragm valve is shown. Detailed Description

[0025] In Figure 1 the accompanying drawings shown is a diaphragm valve 1 for controlling the flow rate of a medium in a pipeline according to the present invention. The diaphragm valve 1 has an upper housing part 2 and a lower housing part 3. Preferably, the housing parts 2, 3 are made of plastic and have threads 14 for mutual locking. For operating the diaphragm valve 1, the diaphragm valve 1 has an operating unit. Preferably, the operating unit (4) includes a pressure piece 21, and the diaphragm 5 is connected to the pressure piece via a connecting element 22. In addition, advantageously, the operating unit (4) includes a spindle (23) and a spindle nut (28) with an overmolded threaded insert (27). The spindle (23) is preferably connected to the diaphragm holder (26) by means of a center groove pin (25). A hexagon nut (24) is arranged in the diaphragm holder (26). Preferably, a threaded pin / connecting element of the diaphragm (22) is installed in the hexagon nut (24). In the case of a pneumatically actuated diaphragm valve, instead of rotating, the spindle preferably moves linearly and is directly (form-locked) connected to the diaphragm holder, so that the spindle nut (28) and the center groove pin are not required. The pressure piece (21) presses the diaphragm against the lower housing part when closed and pulls it with the connecting element (22) when open. The spindle 23 of the operating unit (4) is preferably connected to a drive mechanism, wherein the drive mechanism can be configured as manual, electric or pneumatic. The diaphragm valve 1 according to the present invention has a diaphragm 5 for controlling the flow rate of the medium. In addition, the diaphragm 5 divides the diaphragm valve 1 into a medium-free area and a medium flow area (9). The diaphragm valve 1 has an inner housing 6, by means of which the diaphragm 5 is fastened and positioned in the housing. The diaphragm 5 is placed on the support area 7 of the lower housing part 3 and is pressed by the clamping area 8 of the inner housing 6. In order to be able to achieve a small axial force at a high surface pressure, the diaphragm has a sealing strip 10 and the inner housing 6 has a strip 11 in the clamping area. Therefore, the pressure on the diaphragm 5 is achieved almost only via the surfaces of the strip 11 and the sealing strip 10. For this purpose, the strip 11 and the sealing strip 10 are arranged vertically one above the other, which in Figures 1 to 3It can be clearly seen. Advantageously, the strip 11 and the sealing strip 10 are configured to be concentric. In addition, the diaphragm 5 has a preferably circular base shape. From Figure 2 and Figure 3 it is clearly shown that the strip 11 has an inclined extending surface 12 for centering. Thus, the inner housing 6 is centered on the lower housing part 3, which also has an inclined extending plane 13 that extends parallel to the inclined surface 12, thereby achieving optimal positioning. Advantageously, there is a nose 17 at the support region 7. At this nose, the inclined plane 13 is arranged, and at this time the nose 17 is also used for centering the diaphragm 5. Advantageously, it has been shown that a bulge 18 is arranged on the upper side of the diaphragm 5. This bulge is used for centering the diaphragm 5 relative to the inner housing 6. Preferably, the bulge 18 is centered in the surrounding angle 16 formed between the horizontally extending outer surface 15 and the inclined surface 12 in the inner housing 6. The diaphragm 5 preferably consists of a support diaphragm 19 and a diaphragm shield 20, where the diaphragm shield 20 preferably abuts against the lower side of the support diaphragm 19. Of course, although not shown in the drawings, the diaphragm 5 can also be configured as a single component and does not have to consist of a support diaphragm 19 and a diaphragm shield 20.

[0026] List of reference numerals

[0027] 1 Diaphragm valve

[0028] 2 Upper housing part

[0029] 3 Lower housing part

[0030] 4 Operating unit

[0031] 5 Diaphragm

[0032] 6 Inner housing

[0033] 7 Support region of the lower housing part

[0034] 8 Clamping region of the inner housing

[0035] 9 Lower side of the diaphragm

[0036] 10 Sealing strip

[0037] 11 Strip

[0038] 12 Inclined surface of the inner housing

[0039] 13 Inclined plane of the lower housing part

[0040] 14 Thread

[0041] 15 Horizontally adjacent outer surface

[0042] 16 Surrounding angle

[0043] 17 Nose

[0044] 18 Bulge

[0045] 19 Support diaphragm

[0046] 20 Diaphragm guard

[0047] 21 Compression block

[0048] 22 Connecting element

[0049] 23 Mandrel

[0050] 24 Hexagon nut

[0051] 25 Center grooved pin

[0052] 26 Diaphragm holder

[0053] 27 Threaded insert

[0054] 28 Mandrel nut

Claims

1. A diaphragm valve (1) for controlling 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, wherein the diaphragm is placed on a support area (7) of the lower housing part (3) and is squeezed by a clamping area (8) of the inner housing, characterized in that, The diaphragm (5) has a sealing strip (10) on its lower side (9) facing the medium, and the inner housing has a strip (11) extending in the clamping area (8), wherein the strip (11) is arranged vertically above the sealing strip (10).

2. The diaphragm valve (1) according to claim 1, characterized in that, The sealing strip (10) and the strip (11) are configured to be circularly surrounded.

3. The diaphragm valve (1) according to claim 1 or 2, characterized in that, The strip (11) and the sealing strip (10) are configured to be concentric.

4. The diaphragm valve (1) according to any one of claims 1 to 3, characterized in that, The strip (11) has an inclined surface (12) for centering the inner housing (6) relative to the lower housing part (3).

5. The diaphragm valve (1) according to any one of claims 1 to 4, characterized in that, A circularly surrounded nose (17) is arranged at the bearing surface (7) of the lower housing part (3).

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

7. The diaphragm valve (1) according to any one of claims 1 to 6, characterized in that, A raised portion (18) is arranged at the diaphragm (5) and is used for centering the diaphragm (5) in 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 of plastic EPDM, FKM or NBR.

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

10. The diaphragm valve (1) according to any one of claims 1 to 9, characterized in that, The sealing strip (10) is integrally arranged on the lower side of the diaphragm (5).

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

12. The diaphragm valve (1) according to claim 9, characterized in that, The diaphragm shield (20) is made of plastic PTFE, PFA or PE.

13. The diaphragm valve (1) according to claim 9, characterized in that, The support diaphragm (19) is made of plastic EPDM or FKM.

14. The diaphragm valve (1) according to any one of claims 1 to 13, characterized in that, The strip (11) has a horizontally extending surface or is configured in the form of a platform.

Images