DE1675982C2 - Sealing device for gate valves - Google Patents

Description

The invention relates to a sealing device for gate valves having a flow passage versebenen housing, one arranged in the housing and between an open position and a closed position movable valve member, wherein the housing or the valve member has a valve seat surface and wherein the sealing device surrounds a flow passage, in the closed position of the valve between the housing and the valve parts a medium-tight Creates closure and the at least one cooperating with the valve seat surface, made of elastic Has material existing sealing ring.

Elastic material, such as natural and synthetic, is usually used for the splicing devices Rubber, neoprene, polytetrafluoroethylene, Viton.

Polyamide or the like. Used. If the elastic material is relatively soft, such as. B. more synthetic Rubber with a durometer hardness of 6tl to 80, it is difficult to make a simple execution create that at high working pressures, such. E. at Pressures on the order of 14 kg / cm * or higher, works flawlessly. However, such are soft elastic materials are advantageous in that they provide an effective seal on valve seat surfaces

ίο create even if this is not particularly smooth are. Also, the softer materials can seal regardless of its presence create solid foreign matter, and they have a desirable wiping effect when the valve member

is moved between the open and closed positions.

The harder materials, such as B. polyamides, are more wear-resistant than the softer materials, and they are advantageous for higher working pressures, however they require, in order to produce a tight seal, smoother valve seat surfaces. Therefore, they are generally affected by the presence of solid foreign matter adversely affected, and they do not have as good a wiping effect as the softer materials.

»5 It's also a valve (USA.Patent 2 955 392) known, in which the elastic closure sealing ring of non-elastic metal Holding flanges is surrounded, the side facing the valve seat surface with sharp edges

is that sealing ring material, which is not in the operation when closing the valve in the Sealing ring groove is pressed within the retaining ring, is cut off from the sharp edges. In one embodiment the sealing ring is

formed between two converging flanges in a channel-shaped holder, the valve seat surface of which facing end if formed from brass or similar fast-wearing material is how the sharp edges of the first embodiment acts. If the holder is stainless steel or other wear-resistant material, a small amount of the Material of the sealing ring pressed in the direction against the valve seat surface.

It is a rubber sealing ring for taps, especially taps in the food industry (German Patent specification 855 184), known, which is composed of two different hard building materials. The softer building material takes on the sealing on the stationary housing, while the harder one Component takes over the sliding seal on the cock plug.

The object of the invention is to provide a valve of the introductory to create said type, the sealing devices of which the advantageous properties of both the relatively hard elastic materials as well as the relatively soft elastic materials exhibit. This object is achieved according to the invention by the combination of the following features

solved that the sealing device is a

! has relatively hard, non-metallic elastic material existing sealing ring, which is provided in its end face facing the valve seat surface with a recess, which consists of a softer elastic material ^! set is filled, which has an annular surface which, together with an adjacent annular surface of the sealing ring with the valve seat

surface engages sealingly and that the protruding Uppen-like adjacent to the insert recess Parts of the sealing ring designed to be deformable for compressing the insert id

When using a valve with a sealing device according to the invention, the first occurs Annular surface of the insert made of the softer elastic material with the valve seat surface engaged. When the pressure is increased, the relatively hard elastic also comes out Material existing sealing ring with the valve seat surface in engagement. Such a sealing device generally has the characteristics of both hard and relatively soft elastic vision Materials. If in normal operation the soft elastic insert is compressed and in Contact with the valve seat surface is pressed, a good medium-tight seal is obtained, even if the valve seat surface has undergone a surface treatment, dL usually in use a seal made of hard elastic material, such as. B. a polyamide, not sufficient results in a medium-tight seal. In addition, the soft elastic material makes a seal un- * 5 depending on the presence of foreign matter, and it exerts the desired wiping effect the valve seat surface when the valve member is moved. It is also capable of deformability the lip-like parts of the soft elastic insert 3 "withstand relatively high medium pressures, because it is pressed together in the sealing ring made of hard elastic material is.

A valve is known (US Pat. No. 2,810,543) in which the sealing devices each have an O-ring which is arranged in a recess, which is formed by a part ring and a seat ring, both of which are made of metal, or by two Metal inserts is formed. The 40 ^; Wounds of the recess run obliquely on the side facing the valve seat surface in such a way that the opening of the recess towards the valve seat surface is reduced in order to prevent the O-ring from being squeezed out of the recess. The sealing function is performed by the O-ring. Only in the event of failure of the O-ring should the metal rings act as an emergency seal until repair.

Hs are also valves with wedge or flat slide (British patent specification 724 578 or USA.-Patent 3 006 599), in which the sealing devices consist of a sealing ring have elastic material which is permanently arranged in a metal retaining ring. The sealing function is only exercised by the sealing ring made of elastic material.

Finally, a method for producing a seat and sealing surface, for example for valves and slides, is known (German patent specification ⁶ ^ 543 507), which is mounted in a recess in the housing and held in this by a metal inner ring of variable shape . During the manufacture of the seat and sealing surface, the inner ring is permanently expanded outwards and thereby brought into pressure connection with the elastic ring mounted in the housing casing, so that it is securely held in the housing recess. The exposed end face of the elastic ring performs the sealing function.

All of these known designs have no sealing devices, in which the advantageous Properties of hard elastic sealing material and soft elastic sealing material are or can be combined with one another.

A preferred embodiment of the invention is characterized in that the sealing ring extending from the insert recess to its outer circumference and its inner circumference Has small channels for anchoring the insert at least on part of their Length contain some of the softer, elastic material that anchoring extensions of the Use forms.

In another preferred embodiment of the invention the sealing ring is on a concentric one Support ring firmly arranged. In addition, the sealing ring can preferably be made with reference to a cylindrical surface formed on the housing slidably disposed leg.

The invention is explained below with reference to the drawing, for example.

F i g. 1 is a sectional view of a valve fitted with a sealing device according to the invention is provided;

F i g. Fig. 2 is a fragmentary sectional view, on an enlarged scale, showing one of the assembled Figure 3 shows sealing devices used in the valve of Figure 1;

F i g. 3 is a further enlarged sectional view of the portion used in the sealing device of FIG. 2 provided composite sealing ring;

F i g. 4 is a fragmentary sectional view, on an enlarged scale, of one end of the one shown in FIG reproduced sealing ring;

F i g. 5 is one of the F i g. 4, similar sectional view, in which the sealing ring in contact with the Valve seat surface of a valve part, for example a valve slide, is shown;

F i g. 6 is a partial sectional view of a ring body made of a material such as a polyamide; which is prepared for the production of two sealing rings of the type shown in Figure 3;

FIG. 7 is an end view of the FIG. (S reproduced Ring body;

F i g. 8 is a sectional view showing the process of molding and curing the softer elastic Materials illustrated;

F i g. 9 is one of the F i g. f> similar view which illustrates the machining operations to be performed after the molding process;

Fig. 10 is a partial sectional view *. a sealing ring, after the in F i g. 9 machining operations indicated by dashed lines have been executed;

F i g. 11 is a partial sectional view of the seal ring according to FIG. 10, which is based on a metal Carrier ring is applied;

Figure 12 is a partial cross-sectional view of a wedge rail for a valve according to the invention.

The slide valve shown in Fig. I consists from a housing 10 and a movable slide 11. The housing 10 can be in various ways be made, and in the illustrated example, it is made of metal plates. The rope walls

12 of the housing are machined to receive 13 welded fittings. The slide 11 is usually connected to an operating rod (not shown) which is; outwardly through a suitable cap or hood (not shown).

The operating device (not shown) connected to the operating rod can be a be of various types, for example a handwheel, a gearbox or a remote-controlled pneumatic, hydraulic or electric actuator.

Between the inner end portions of the hubs

13 and the slide 11 are each an annular sealing device composed of several parts 14 arranged. As will be described below, these devices 14 include Sealed with respect to the housing 10, and they are in sealing contact with the side valve seat surfaces of the slide 11.

The Schieberll can be in different versions have different shape, and he is in the example shown as a flat plate with a Flow opening 16 shown, which in the open position of the valve with the flow openings of the Nozzle 13 is in alignment.

The design of each sealing device 14 is shown in FIG. It has a retaining ring 17, one end portion of which is machined to be inserted into a machined bore 18 to fit in the valve housing 10. A gap between these matching ones Surfaces is prevented by an elastic O-sealing ring 19. The other end part of the retaining ring 17 is provided with a bore 20 in which an elastic sealing ring 21 is received. In the embodiment shown, the sealing ring 21 is arranged on a support ring 22. He is made of a relatively hard, wear-resistant material such as polyamide. A majority of helical compression springs 23 arranged at a distance from one another in the circumferential direction stand with the inner end of the sealing ring 21 and thus press it as shown in FIG. 2 to the right. A protection 24 against deposits is provided, which is located between the retaining ring 17 and the support ring 22 extends. This protection 24 can have the shape of a slotted ring, which is in an annular Recess 26 of the retaining ring 17 is used and a cylindrical surface 27 of the adjacent Slidably overlapped portion of the support ring 22.

The sealing ring 21 is sealed with respect to the retaining ring 17 by an O-sealing ring 28. The sealing ring 21 is in the in F i g. 2 reproduced position held by a projecting flange 29 which engages a shoulder 31 on the retaining ring 17 in engagement

That end of the sealing ring 21 which contacts the adjacent slide is provided with an annular insert 32 which, as described below, is made of a material which is relatively softer than the material used for the sealing ring 21

The sealing ring 21 is shown in FIG. 3 shown separately His outer run is with a groove 33 to Receipt of the elastic O-ring 28 is provided. Its inner circumference is provided with a groove 34 which

a rib 36 (FIG. 2) formed on the outer circumference of the support ring 22 can suitably receive.

The preferred shape of the end part of the sealing ring which touches the adjacent slide 16 21 is as follows. The insert 32 made of elastic material is in a recess which is delimited by a bottom surface 38 and side surfaces 39. The side faces 39 of the recess converge towards the end of the sealing ring 21, and they create lip-like parts 41 both next to the outer circumference and next to the inner circumference of the elastic Insert 32. The outer surface 42 of the insert 32 can usually be somewhat domed, such as it in Fig. 3 is indicated, but it becomes flat when pressed into contact with the valve seat surface will. The outer surfaces 43 of the lip-like parts 41 are, as shown in FIG. 3 can be seen, machined so that they each make an angle with respect to the plane of an adjacent valve seat surface on the order of 15 °. The outer and inner corner edges are beveled like this at 44 and 45 is indicated. It should be noted that the surfaces 43 are formed such that when this End of the sealing ring ^! is brought into contact with a flat valve seat surface, the initial contact takes place on the outer surface 42 of the elastic insert 32, and that afterwards when this Surface 42 is pressed a little flat, a contact on the lip-like parts 41 is made. In In other words, the surfaces 43 which are adjacent to the elastic insert 32 are machined somewhat free with respect to the non-flattened outer surface 42 of the insert 32.

The embodiment described above is shown in FIG. 4 reproduced as an enlarged detail. As can be seen, the surface 42 of the elastic insert 32 protrudes somewhat with respect to the adjacent surfaces of the lip-like parts 41. In Fig. FIG. 5 illustrates what occurs when the sealing ring 21 is brought into contact with a valve seat surface 46 of the slide 16. As stated above, the initial force exerted by the springs 23 (FIG. 2), with which the sealing ring 21 is pressed against the slide 16, serves to compress the elastic insert 32 enough to permit direct contact with the lip-like parts 41 to bring about with the slide 16. When the force with which the sealing ring 21 is pressed against the slide 16 increases, it bends the lip-like parts 41 against the insert 32, whereby the pressure acting on the insert and thus the contact pressure of the surface 42 of the projection 32 on the valve seat surface 46 is increased. This pressure effect maintains a good, medium-tight seal between the elastic insert 32 and the valve seat surface 46. At the same time, the soft, elastic insert 32 is able to withstand relatively high medial pressures, since it is mounted in the ring 21 which makes use of the harder elastic material

In general, the sealing device described above has the characteristics of both the hard as well as the relatively soft elastic material. If the soft resilient insert 32 compressed and pressed into contact with valve seat surface 46 is a good medium-tight seal cr-

Io

hold even if the valve seat surface 46 has a surface treatment has experienced, which is usually insufficient with such a material as polyamide results in a medium-tight seal. In addition, the soft elastic material provides a seal regardless of the presence of foreign stains, and it exerts the desired wiping effect on the valve seat surface when the slide is moved. If the slider is between the OH'enstcllung and the closed position moved m is, a part of the sealing ring 21 is out of contact with the valve seat surface 46. Auf this part of the sealing ring, the pressing effect on the insert 32 is canceled. However, as soon as the When the slide reaches the fully oiled or fully closed position, the pressing action becomes restored in the manner described above.

When the sealing device 14 is fully assembled, the insert 32 provides a seal on a diameter that is slightly smaller than the diameter of the bore 20, with softens the O-ring 28 is in sealing contact (FIG. 2). Therefore, on the upstream side of the valve 10, there is a Medium pressure zone present, which causes the LettungsdifTerenttaldruck the sealing ring 21 against pushes the slide 16. Under such conditions is the force with which the sealing ring 21 is pressed against the slide 16, both by the pressing force of the springs 23 and by the Line pressure dependent.

When the valve is assembled, each sealing ring 21 becomes with respect to its retaining ring 17 printed inside for a limited amount. The dimensions are such that between the Sides of the slide 16 and the end faces of the Hall crest 17 there is some play. If the Valve is closed, it is pushed by the line pressure against the downstream ropes of the valve, so that the downstream sealing ring 21 is essentially up to the limit of its possible movement is pressed. The upstream flange 29 is then located nearly in contact with the holding shoulder 31. It is believed that it is desirable to be on the downstream j side to maintain a seal, the dimensions can be such that the pressure of the slide 16 on the downstream sealing ring 21 a sufficient force between the sealing ring and supplies the slide to maintain the desired seal.

As stated above, the purpose of the flange is 29 in holding the sealing ring 21 in its retaining ring 17. At the time when the sealing ring 21 is installed in the retaining ring 17, it is pressed into the bore 20, thereby deforming it to a sufficient extent to enable the flange 29 passes through the bore 20. As soon as the sealing ring 21 is sufficiently far into the bore 20 is pressed in, the flange 29 snaps into the position shown in FIG. 2 position shown.

The support ring 22 reinforces the sealing ring 21 and helps ensure that it is in the desired shape remains. It preferably has a relatively tight fit in the sealing ring 21. This can thereby be achieved that the sealing ring 21 is immersed in boiling water before practicing the support ring22 is forced. When the seal

21 then cools, a tight shrink fit is obtained.

Another purpose of the support ring 22 is to provide a sufficient secondary seal or Lock in the event of sounding, the sealing ring 21 is destroyed, for example by fire.

The F i g. 6 through 11 illustrate a method for producing the sealing ring 21. As shown in FIG. 6, an annular body 51 created. This can be cut or shaped from a pipe. Polyamide is according to his physical properties that enable subsequent machining is a suitable one Material for use as a sealing ring. The ring body 51 is dimensioned such that it after two separate sealing rings 21 for certain operations to be described below forms. Two annular recesses 38 from the one shown in FIG. 3 reproduced cross-sectional shape made in the ends of the ring body 51 by suitable machining. In addition, a A plurality of small channels 52 spaced from one another in the circumferential direction are provided (Fig. 7). These channels 52 provide a connection between the inner corner edges of the recesses 38 and the outer peripheral surface and the inner peripheral surface of the ring body 51.

After the annular body 51 has been formed, a suitable elastic material, such as Viton, is formed in the recesses 38. This molding process is preferably carried out in the manner shown in FIG. S illustrated way. In this example two heated plates 53 and 54 are used which are supported by suitable means so that they can be moved towards and away from one another. After a suitable supply has been introduced into the recesses 38, the ring body 51 is arranged between the plates 53, 54 together with a concentric metal sheath ring 56 which has a width which is slightly smaller than the width of the ring body 51. By applying a clamping pressure, the plates 53 and 54 are moved into a position in which they come into engagement with the ends of the spacer ring 56, whereby they compress the ring body 51 by a predetermined amount. When the plates 53 and 54 are heated to a suitable curing temperature, the end parts of the ring body 51 are also heated together with the Viton material, whereby the Viton is cured and bonded to the adjacent, the recesses 38 delimiting surfaces. During this hardening or VUI kanisierungsvorganges the Viton is UNU · \ a pressure sufficient to I.uf trapped and excess material through the small Ka ducts 52 through skip. The presence of pressed out material at the end of the curing process is an indication of a correct molding process, in which air inclusions or empty spaces in the recesses 38 are avoided. In addition, the material pressed into the channels 52 serves as additional anchoring for the inserts 32 formed in this way in the recesses 38.

After the hardening process has ended, d. Ring body 51 of a series of machine ren subject to processing operations through which he cm Shaping is obtained that is shown in FIG. > »By gcstrichcli

309 638/41

These machining operations serve to form the flanges 2, the grooves 33 receiving the o-rings 28 (FIG. 2), the end faces 43, the beveled corner edges 44 and the grooves 34. Finally, by means of a suitable tool, the ring body 51 is separated into two identical parts, the doors in FIG. 9 is indicated by the double dashed line 57. After the separation, each part has the appearance shown in Fig. K) in cross section. Either before or after the separation, the two parts are machined at their ends in such a way that the outer surface 42 of the Viton insert 32 protrudes somewhat over the adjacent end diameters 43 of the lip-like parts 41. Thereafter, the support ring 22 is combined with the sealing ring 21 in the manner described above.

In some cases, the sealing ring 21 may constitute the sealing device 14 without the others Parts are built into a valve. So is in Fig. 12 a slide valve with a wedge-shaped slide reproduced in which some features of the invention are present. The wedge-shaped valve slide 61 has lateral valve seat surfaces 62. The valve housing is provided with a recess that has a Sealing ring 63 receives, which is similar in its design to the sealing ring 21 described above and can be made of polyamide. Each of the two sealing rings 63 can in the Geliäuse held by a screw connection 64

ίο and with reference to the housing by means of a elastic O-ring65 must be sealed. Each seal ring 63 is in the manner described above with a recess for receiving an insert 66 made of soft elastic material, such as

“5 Viton, provided. When the slide 61 is in the completely the closed position is moved, the valve seat surfaces become on the last part of the closing movement pressed against the lip-like parts of the sealing ring 63, thereby causing

ao these parts compress the elastic insert 66 and thus into tight final contact with it push the slide 61.

For this purpose 2 sheets of drawings

Claims (4)

ϊ 675,982 patent claims: 1. Sealing device for gate valves with a one provided with flow passages Housing, one arranged in the housing and between an open position and a Closing position movable valve member, wherein the housing or the valve member has a valve seat surface and wherein the sealing device surrounds a flow passage formed in the Closed position of the valve between the housing and the valve parts a medium-tight seal creates and at least one cooperating with the valve seat surface of elastic Has material existing sealing ring, characterized by the combination the following characteristics that the sealing device is made of a relatively hard, not metallic elastic material existing sealing ring (21 or 63) in his the end face facing the valve seat face (46) is provided with a recess (38, 39) which is filled by a made of softer elastic material insert (32), the one has annular surface (42) which, together with an adjacent annular surface (43) of the sealing ring with the valve seat surface (46) sealingly engages, and that of the insert recess (38, 39) adjacent protruding lip-like parts (41) of the sealing ring (21 or 63) for pressing the insert together (32) are designed to be deformable. 2. Sealing device according to claim 1, characterized in that the sealing ring (21) from the insert recess (38, 39) to its outer circumference and its inner circumference has extending small channels (52) for anchoring the insert (32) at least part of their length contain some of the softer, resilient material that anchor extensions of the insert (32) forms. 3. Sealing device according to one of claims 1 and 2, characterized in that the Sealing ring (21) is fixedly arranged on a concentric support ring (22). 4. Sealing device according to one of claims 1 to 3, characterized in that the Sealing ring (21) displaceable with respect to a cylindrical surface formed on the housing (10) is arranged.