EP2817541A1

EP2817541A1 - Butterfly valve

Info

Publication number: EP2817541A1
Application number: EP13711065.6A
Authority: EP
Inventors: Dominique Duboy
Original assignee: KSB SAS
Current assignee: KSB SAS
Priority date: 2012-02-21
Filing date: 2013-01-21
Publication date: 2014-12-31
Also published as: FR2987094B1; KR102020082B1; WO2013124546A1; FR2987094A1; KR20140126715A

Abstract

A valve wherein the static sealing section consists of two flexible side lips (28, 28'), so as to be able to move towards each other and together delimiting a space for receiving at least two strands (15) made of flexible material.

Description

Butterfly valve

The present invention relates to butterfly valves and seals for use in such valves. A butterfly valve comprises an annular body, a throttle integral with a maneuver shaft and freely pivotable about an axis respectively passing through diametrically opposite openings of the body and an annular elastomeric seal housed in a groove of the housing. one of the inner face of the body and the edge of the butterfly, the other of them coming into contact with the seal in a closed position of the valve. The seal includes a dynamic sealing section, preferably a hemi-toric seal, for sealing between the upstream and downstream of the butterfly valve by interposing between the body and the throttle valve in a closed position. It also includes a static sealing section housed in the groove. The seal can be held in place by a flange secured by the holding screws. This construction is criticized when the valves are used on ^'corrosive fluids could ^"charge, because deposits or corrosion causing over time a disassembly impossible screws and clamps, which makes replacement possible seal. To overcome this disadvantage, it has been proposed to insert gaskets into joints without screws or flanges, by acting on the shapes of the joints and grooves, examples of which will be found in EP05022089 and 1696157 and in US Pat. The mounting of the joint by means of a flange allows easy assembly, but makes it difficult to dismantle after use, while mounting in groove without flange, or screw, makes assembly and installation difficult or very difficult, and disassembly impossible without destroying the seal.

The aim of the invention is to provide a valve which retains the functional advantages of throat seal mounting solutions, but removes the disadvantages of indémontabilité, while guaranteeing easy installation and robust attachment.

According to the invention, the static sealing section consists of two flexible lateral lips, so as to be close to one another and delimiting between them a receiving space of at least two rods of flexible material, and said one of the body or the edge of the butterfly is pierced with passages, each rod being associated with a passage, each passage opening on the bottom of the groove, on the one hand, and, on the other hand, in a boss formed on an outer face of the body, and the conformations of the groove and the lips are such that the seal is retained in the groove, when the rods are in their reception space and are not retained there when they are not there . When the rods are not in place in the seal, the lips of the seal can get closer and the seal can be easily removed from the groove. When the rods are in place, the seal is well retained in the groove. Each ring is made of a flexural material, metal or plastic, of solid or hollow section. The flexible material ring also refers to a metal spring ring with contiguous turns. In order to facilitate the insertion of the rods in their reception space, it is better that the number of passages normally equal to the number of rods, between 3 and 6, the passages being preferably distributed regularly over the circumference of the body or the butterfly .

Each ring has a cross-sectional dimension large enough to keep the lips sufficiently apart from each other. A ring may have, in particular, a size just lower, or better, slightly less than that of the space intended to receive it. It is better that the shape of the rush marries that of the throat. It will be preferred that the ring be at least partly and preferably entirely toric. It may also be provided, to facilitate the insertion of the rod in the space defined by the lips, to form a ring in several sub-parallel rods, in particular two hemi-toric sub-cones attached to one another. By flexible, it is meant that the ring can deform in bending up to the radius of curvature of the groove. It is better, to facilitate the establishment of the reeds in the throat, that the passages there open tangentially.

The conformations of the groove and the lips may be such that the lateral faces of the lips turned towards the lateral faces of the groove are smooth, in the part of the lips on the outside side, and provide, in the part of the lips on the side from inside, two re-entrant shoulders and conjugates of two shoulders of the groove. According to another embodiment, the lateral faces of the lips turned towards the lateral faces of the groove are inclined at an angle α with the median axis (in transverse section) of the joint, the faces of the groove on the inner side being inclined and making an angle β with the median axis of the joint and α> β.

Particularly good seal retention is obtained when the lips are in the shape of a trapezium whose small base on the inner side is greater than the greater width of the dynamic sealing section of the seal and whose height is greater than small as the distance from the shoulders of the throat to the back of the throat. Preferably, the space defined between the lips for receiving the rods is torus-shaped.

According to one embodiment, the seal is in the form of a sleeve having tenons, with flexible lips, delimiting between them a space, housed in grooves on the inner annular face of the body, uniformly distributed passages on the periphery of the body and opening, preferably, tangentially in the grooves, on one side, and in the bosses of the outer face of the body, on the other side, and through which the rods are introduced to lodge in the free space left between the lips.

To facilitate the fixing of the ring, one of its ends is surrounded by a handle mounted so as to rotate without rotating the ring while ensuring its translation. The handle can thus be screwed into a boss until it comes into abutment, which ensures the position, the fixing of the ring and the sealing of the fluid stream towards the outside of the body in case of deterioration of the seal. The mounting of the handle can be done by means of a ring-shaped metal ring. The handle can be completed with a fixing plug at the free end remote from the threaded end. Preferably, each ring ^' ends at the end opposite the handle by a bevel, which comes to tangency to the ring that precedes when the rods are put in place.

The invention also relates to a method of mounting the valve seal, into which the static sealing section of the seal is introduced into the groove, until the conformations of the groove and the lips can be combined, and then inserted by the passages rushes in their space of reception and one screws the handles in the threadings of the bosses of the body to fix the rushes.

To disassemble the valve seal, unscrew the handles and remove all the rods from their reception area. The passages are closed except for some, preferably one of them, which are placed in communication with a source of fluid under pressure, until the seal is expelled from the throat .

The invention finally relates to a seal comprising an annular elastomer piece, having, in addition to a dynamic sealing section, a static sealing section, characterized in that the static sealing section comprises two flexible lips, so as to be able to approaching one another and defining between them a receiving space, and the seal comprises a flexible bending ring and cross section such that it prevents the lips from getting closer when it is placed in place. reception area.

Preferably, the seal is surrounded at one of its ends by a threaded handle and rotatably mounted without driving the ring in rotation and the other end of the ring is tapered. In the accompanying drawings, given solely by way of example: FIG. 1 is a plan view of a valve according to the invention with offset and eccentric butterfly;

- Figure 2 is a cross-sectional view of a seal according to the invention, which has not yet received a ring; - Figures 3 and 4 describe the assembly of the seal according to the invention, while

Figure 5 shows the seal according to the invention in the assembled state;

- Figure 6 is a partial sectional view of one end of a rod;

- Figure 7 shows a rod connecting tangentially to a rod which is in front of him;

- Figure 8 is an elevational view of a valve according to the invention; - Figure 9 illustrates the method of disassembly of the seal according to the invention;

- Figure 10 is a sectional view of another seal according to the invention;

- Figures 11 to 14 illustrate other variants of a seal according to the invention; and

- Figure 15 is a sectional view of another valve according to the invention. In the figures, the throat is formed in the body, but it could just as well be in the edge of the butterfly.

The valve according to the invention shown in Figure 1 comprises an annular body 1, a butterfly 2 secured to a shaft 3 for maneuvering and freely pivoting about an axis 3 'respectively passing through diametrically opposite openings of the body 1. A Elastomeric ring seal 4 is housed in a groove 13 of the inner face of the body 1. A ring-shaped elastomer seal 4 is housed in a groove 13 made on the inner face of the body (see FIG. ).

This groove 13 is made concentrically to the axis of the pipe in a plane perpendicular to this axis passing through the plane of contact and sealing between the seal 4 and the butterfly 2. This groove 13 is pierced by four passages 18-1 , 18-2, 18-3 and 18-4 opening tangentially to the bottom of the groove 13. The passages 18-1 and 18-3 are diametrically opposed and placed along the axis 3 'and the shaft 3 maneuver, while that the other two passages 18-2 and 18-4 are diametrically opposed and offset by an angle of 90 ° with respect to the first two passages. These four passages are all offset from each other by 90 °, the first of them coinciding with the shaft 3 maneuver. The seal 4, shown in FIG. 2, has a section enabling it to cooperate with the section of the groove 13.

The seal 4, shown in Figure 2, consists of a ring whose inner face 7, intended to come into contact with the butterfly, is shaped half-toroid. This half-torus is associated with a section rectangular defined by its sides axb and whose side faces are each provided with a half-ring groove 9 and 9 '. The volume of these two half-tori, depending on the two sections si and s2, is provided to absorb the over-compression of the elastomer, when compressed by the butterfly in the closed position.

At the dynamic section coming into contact with the butterfly, is associated a static section which ensures the fixing and locking of the seal by replacing the function of the heel of the joints of the prior art. This section has the shape of a trapezium, the small base L is greater than the dimension b of the dynamic section and forms with it two shoulders 11 and 11 ', which provide a positive mechanical locking of the seal in the body 1 .

The height h of the trapezium is less than the depth H of the groove 13 of the body 1, in which is housed the seal 4 (see Figure 3).

The outer face of the seal 4 forming the large base of the trapezoid is hollowed out with a circular section, delimiting a toric shape, with respect to the trapezium and opening out from the large base of the trapezium. It delimits, with the non-parallel sides of the trapezium, two lips 28 and 28 ', whose vertical angle δ ° with which it ensures that these lips will bear well on the lateral faces of the groove 13 of the body 1 with a contact pressure "p" (see Figure 4).

To ensure certainly the establishment of the seal 4 in the groove 13 of the body 1, the dimension h of the heel of the seal will be significantly less than the depth H of the groove 13. The groove 13 made on the inner face of the body 1 consists of two rectangular sections, the first inner one of width is b plus a functional clearance, so as to pass without friction the dynamic section of the seal b. This section opens into a wider section, L 'and height H sufficient for the seal, introduced into this groove and carrying in the bottom of the groove, it is guaranteed that the shoulders 11 and 11' of the seal 4 have exceeded the edges 12 and 12 'of this groove 13.

In this way (see Figure 4), the lips 28 and 28 'can come to press against the side faces of the groove and exert a slight pressure thereon, due to the value of the angular preload δ °. Compared to the joints of the prior art, whose sections are massive with lateral snaps making the establishment in the grooves very difficult, this new design has the advantage of allowing the introduction of the profiled seal in the groove effortlessly since it does not carry a massive part, it deforms, allowing that no mass exceeds the dimension of b.

The value of "H" is chosen, preferably, so that, when the shoulders 11 and 11 'are in agreement with the edges 12 and 12', the recessed circular shape of the seal is tangent to the bottom of the groove 13 (see FIG. 5). In this way, the gasket 4 protrudes from the groove 13 by a value necessary for sealing.

Once the seal 4 is fully inserted into the groove 13, four rods 15 are introduced into the passages 18-1, 18-2, 18-3 and 18-4 and come block the profile of the seal 4 in the groove 13 (see Figure 5).

According to Figure 6, these rods 15 are made of flexible material, ^metal or plastic, solid or hollow section, or by metal spring with contiguous turns. To allow easy assembly and disassembly, the rods 15 are surrounded at their outer end by a threaded handle 16 and mounted by a metal ring and of toric form, so as to be able to rotate without causing the ring 15 to rotate, and equipped with a fixing cap 17.

The handle 16 carries at its end a thread 20, which, when screwed abutting ^' in the threaded boss 21 of the body 1, ensures its position and its attachment. In order to ensure the best possible continuity in the maintenance of the seal 4, each rod 15 terminates, at its end opposite the handle, by a bevel 31, which. just make tangence to the ring that precedes it. One of the advantages of the invention consists in the ease of disassembly of the seal 4. This is achieved by unscrewing the handles 16 of the rods 15, which allows to remove the four rods 15. The seal profile 4 sealing is no longer blocked in position, three plugs 29 are placed in the threads 20 of the bosses 21 of the body 1 to close the passages 18-1, 18-2 and 18-3, while, by the fourth passage 18-4 is introduced fluid pressure by a pump 26 connected to the boss 21 by the thread 20 and equipped with a pressure gauge 25, to control the pressure, and a check valve 27, which maintains this pressure . The seal 4 is thus expelled by the pressure of the fluid out of the groove 13 by the inner face of the body 1.

The elastomer seal 4 above is provided with two flexible lips 28 and 28 'with shoulder 12 and 12'. All variants of shape of these lips with or without positioning shoulder and blocking can be envisaged. FIG. 10 shows an exemplary embodiment of a seal 4 with the lips 41 and 41 ', inclined and without shoulder, which are housed in this groove 13, the section of which is trapezoidal in shape with blanks 42 and 42' oriented an angle β °. This design requires that the angle a ° be greater than the angle β °.

Figures 11 to 14 are cross-sectional views of prior seals, in Figure 11 of that of EP16961157, Figure 12 of that of US6494466, Figure 13 of that of EP05022089 and Figure 14 of US55113674, improved by the arrangement of flexible lips and rods according to the invention.

According to one embodiment of the invention, this also applies to a seal for a centered valve and an enveloping sealing sleeve. This sleeve provides the three main sealing functions required of a valve, namely outward sealing to the pipe connection flanges, outward sealing to the pivot and maneuvering axis passages and the internal sealing from upstream to downstream of the medium conveyed.

In order to provide these sealing functions, a conventional sleeve is anchored in the body by shoulders or recesses for small diameter valves and T-shaped or harpoon-type tenons. cooperates with the shapes of the body grooves for large diameter faucets. A description of these constructions has already been made in the documents W093 / 22588, FR2572789, FR2260041, EP0156581 and GB1508283. Figure 15 shows a butterfly valve in section, the body 1 is provided with trapezoidal grooves 13 on its inner annular face and grooves 31 and 31 ', trapezoidal, on its side faces.

Each of the grooves 13 communicate with four passages 18-1, 18-2, 18-3 and 18-4 spaced 90 ° apart from each other and opening tangentially in said grooves 13 and passing through the bosses 21 opening on the outer face of the body 1 ending with a thread 20. The sealing sleeve 4 is designed so that the lugs facing each of the grooves 13 are provided with two flexible lips 28 and 28 'and a O-shaped space between said lips. This arrangement makes it easy to place the cuff effortlessly, while rods 15 passing through the passages 18-1, 18-2, 18-3 and 18-4 are inserted into the toric space between the lips. 28 and 28 ', to ensure the positive and definitive locking of the sleeve 4. The locking in position of the rods 15 is achieved by a screwing of the handles 16 in the threads 20 of the bosses 21.

As for the previous description, the disassembly is performed in the reverse order of operations by removing the rods 15, by plugging certain passages 18-1, 18-2 and 18-3 by plugs 29 and introducing pneumatic pressure or hydraulic behind the sealing ring 4 by connecting a pump 26 to a passage ^■ 18-4 remained free.

Claims

Valve comprising an annular body (1), a throttle (2) integral with a shaft (3) and freely pivotable about an axis (3 ') passing respectively in diametrically opposite openings of the body (1) and a annular elastomeric sealing gasket (4) housed in a groove (13) of one of the inner face of the body (1) and the edge of the butterfly, the other of which comes into contact with the gasket ( 4) in a closed position of the valve, the seal (4) comprising a dynamic sealing section and a static sealing section housed in the groove (13), characterized in that:

the static sealing section consists of two flexible lateral lips (28, 28 '), so as to be able to approach one another and delimiting between them a reception space of at least two rods (15 ) in flexible matter, and

said one of the body or the edge of the butterfly is pierced with passages, each onc (15) being associated with a passage (18-1, 18-2, 18-3, 18-4), each passage opening on the bottom of the groove, on the one hand, and, on the other hand, in a boss formed on an outer face of the body (1) and the conformations of the groove (13) and the lips (28, 28 ') are such that the seal (4) is retained in the groove (13), when the rods (15) are in their reception area, and is not retained, when they are not there.

2. Tap according to claim 1, characterized in that the number of rods is from 3 to 6 regularly distributed.

3. Tap according to claim 1 or 2, characterized in that the side faces of the lips (28, 28 ') facing the side faces of the groove (13) are smooth in the part of the lips on the outside. and provide, in the portion of the lips on the inner side, two shoulders recesses and conjugate two shoulders (11, 11 ') of the groove (13).

4. Tap according to claim 1 or 2, characterized in that the side faces of the lips (41, 41 ') facing the lateral faces of the groove (13) are inclined at an angle with the axis (in section transverse) of the joint, the faces of the groove (13), on the interior side, are inclined and make an angle β with the median axis of the joint and α> β.

5. Tap according to claim 3 or, characterized in that the lips together have the shape of a trapezium, whose small base, on the inside, is greater than the greater width of the dynamic seal section of the seal and whose height is smaller than the distance from the shoulders of the groove to the bottom of the groove (13).

6. Tap according to one of the preceding claims, characterized in that the passages (18-1, 18-2, 18-3, 18-4) open tangentially into the groove (13).

Valve according to one of the preceding claims, characterized in that one of the ends of a rod is surrounded by a handle (16) threaded and rotatably mounted without driving the ring in rotation.

Valve according to one of the preceding claims, characterized by a plug (17) of the passage (18-1, 18-2, 18-3, 18-4).

Method of mounting the valve seal according to one of the preceding claims, characterized in that:

the static sealing section of the seal is introduced into the groove (13) until the conformations of the groove and the lips can be combined, and

- Rods (15) are inserted into their reception space and the handles (16) are screwed into threads (20) of the bosses (21) of the body (1) to fix the jones (15).

Method of disassembling the valve seal according to one of Claims 1 to 8, characterized in that:

- Unscrewing the handles and remove all the rods (15) from their reception space, and

- the passages are closed except for some of them that are put in communication with a source of fluid under pressure until the seal is expelled from the groove.

Joint, in particular for a valve according to Claims 1 to 8, comprising an annular member made of elastomer, having further a dynamic sealing section, a static sealing section, ^'in which:

the static sealing section comprises two flexible lips (28, 28 ') so as to be close to one another and delimiting between them a receiving space, and

the joint comprises a ring (15) flexible in flexion and with a cross section such that it prevents the lips from getting closer when it is put in place in the reception space,

characterized in that the rod (15) is surrounded at one of its ends by a handle (16) threaded and mounted so as to rotate without causing ¹ the ring (15) in rotation.

12. Joint according to claim 11, characterized in that the other end of the rod (15) is tapered.