DE102009055343A1 - Pinch valve for temporary or complete throttling of e.g. material or product flow, has housing provided with input and outlet openings and control opening connected with medium, where housing has section-wise not-circular cross section - Google Patents

Abstract

The valve (1) has a housing (5) provided with an input opening (2) and an outlet opening, and a tubular valve sleeve connected with the input opening and the outlet opening within the housing to form a valve channel between the input opening and the outlet opening. The housing and valve sleeve are arranged such that a control chamber is formed between the housing and the valve sleeve. The housing has a control opening (4) connected with a pressurizing medium e.g. compressed air. The housing has a section-wise non-circular cross section. An independent claim is also included for a method for producing a pinch valve.

Description

The present invention relates to a pinch valve. Valves generally serve to temporarily shut off or restrict a flow of material or product. In principle, all gases, dusts, liquids, solids and suspensions and other materials are suitable as the product stream. In contrast to most other types of valves can with the help of a pinch valve and a perfect seal when shutting off a product stream with solid components such. As granules, powders or pastes can be achieved. In other words, a valve is an actuator.

Pinch valves generally have a housing having an inlet opening and an outlet opening, wherein inside the housing a tubular valve collar is connected to the inlet and outlet openings and arranged to form a valve channel between the inlet and outlet openings, the housing and valve collar being such are arranged, that between the housing and the valve sleeve, a control chamber is formed, and the housing has a control port for connection to a pressure medium, so that upon application of the control port with a pressure medium, the valve sleeve moves such that the channel cross-section between the input and output ports is reduced and / or closed.

In other words, the valve sleeve by applying a pressure medium, for. As compressed air, neutral gases or a neutral fluid, eg. As water, are compressed to the control port in such a way that the valve sleeve cross-section preferably closes lip-shaped or at least reduced, so that the product flow is prevented by the valve channel or at least throttled. If the control opening is then relieved again, the valve channel opens again due to the rebound resilience of the valve sleeve and the pressure of the product flow back to the full cross-section.

Often, the housing consists of a housing main body and at least one sleeve cover in which the input or output port is formed.

The sleeve cover usually has an essentially tubular element, which is designed such that the tubular element projects into the interior of the housing main body when the socket cover is fitted on the housing main body and the valve sleeve is clamped between the housing main body on the one hand and the outer surface of the tubular element on the other hand.

The passage formed by the housing main body generally has at least two sections of different cross-section. This has the advantage that, in a pressureless state, a completely free passage of the pinch valve can be formed, so that virtually no pressure loss occurs due to the use of a pinch valve.

The passage section with a larger passage cross section forms outside the valve sleeve a control chamber which can be pressurized to close or throttle the valve via the control port. In addition, the larger passage cross section serves to allow the valve sleeve to expand freely and to fold like a lip. If the larger passage cross-section is not made sufficiently large, this leads to an S-shaped deformation or a three-sided closing of the valve sleeve, which in turn causes sealing problems during shut-off and requires a higher pressure for closing the valve sleeve, which has a negative effect on the service life of the valve sleeve Valve sleeve affects. It is understood that the passage cross-section does not necessarily have to be circular. If, in the context of this application, a larger or smaller passage cross-section is mentioned, this basically means the passage cross-sectional area.

The previously known with a pressure medium operated pinch valves made of stainless steel (stainless steels) were produced by machining of semi-finished products (tube profiles) or welded version of various cold pressed, lasered or stamped sheet metal parts. Due to the very limited design options, due to the manufacturing process, these Edelstahlquetschventile have been produced in heavy and voluminous or non-compact variants. These Edelstahlquetschventile were usually offered only with standard flange or female threaded connections. Aseptic connections, such as clamp connections or pipe fittings for the food and beverage industry, both chemical and pharmaceutical, have rarely been offered as an alternative to standard flange or female threaded connections in conjunction with stainless steel pinch valves. Such aseptic connections have hitherto been used as separate components to the sleeves or flanges z. B. attached by welding or bolted together via an internal and external thread. It is easy to understand that this type of implementation is very complicated and therefore associated with very high production costs.

Based on the described prior art, it is therefore an object of the present invention, pinch valves always reliably seal even with extreme product properties and at the same time have a low weight, are compact, and allow a simple valve sleeve change, and further provide a method for the cost-effective production of pinch valves. Furthermore, it is an object of the present invention to provide an aseptic squeeze valve, ie a pinch valve without dead spaces, edges or corners.

This object is achieved in that the housing in the control space forming region at least partially has a non-circular cross-section.

Between the valve sleeve and the inner wall of the housing portion, a control chamber is formed, which can be pressurized by acting on the control port with a pressure medium and compresses the valve sleeve so that the valve channel cross-section closes and / or at least reduced.

Due to the non-circular design of the control or functional space is a reliable, reproducible, given two-sided z. B. lip-shaped closing function of the valve sleeve ensured by the pressurization. In particular, it is prevented that the valve sleeve closes from three sides, whereby under certain circumstances - depending on the product properties - a tight closing would not always be guaranteed.

In a preferred embodiment, the housing has a substantially elliptical cross-section in the area forming the control space, wherein preferably the major axis of the elliptical cross-section is longer than the minor axis by more than 10%, preferably by more than 20%.

Alternatively, the housing may have a substantially rhombic cross-section in the area forming the control space, the diagonals of the rhomboidal cross-section being of different lengths, preferably one diagonal of the rhomboidal cross-section being longer than 10%, preferably more than 20% the other diagonal of the rhombic cross-section is.

Experiments have shown that this form of the control chamber not only ensures extremely reliable closing even under the most difficult product properties, but also the pressure / closing volume of the valve cuff compared to a circular control or functional space is greatly minimized, which in the operation of the pinch valve considerable Energy savings brings with it.

It is particularly preferred that the housing in cross-section at least partially has a non-circular, preferably elliptical, outer contour. A housing having a non-circular, preferably elliptical, outer contour is advantageous since the housing can be made as compact as possible and material can be saved. In this case, the outer contour substantially corresponds to the shape of the inner contour of the housing. If the housing in the area forming the control chamber has a rhombus shape with rounded corners, then the outer contour should also be rhombus-shaped with rounded corners, so that the housing wall thickness is substantially constant, which not only saves material, but also reliable closure be achieved in extreme product temperature fluctuations, as the housing wall heats evenly and thus thermal stresses are minimized.

The rhombic shape has the advantage that the outer contour has flat surfaces which are arranged on opposite sides. These can be realized for example as anti-rotation during assembly of the pinch valve. Furthermore, it is possible to use the flat surfaces as engagement surfaces in the screwing of the pinch valve with female thread connection to a pipe outer thread, which simplifies the assembly. Advantageously, the housing has a rhombus-shaped cross section with rounded corners in the area forming the control space, wherein preferably the radii of curvature of the opposite rounded corners are equal.

In a further embodiment it is provided that the housing has at least one housing main body and a socket cover in which the input or output opening is formed, wherein the socket cover is preferably screwed by means of screws with the housing main body.

The sleeve cover may have a substantially tubular member which is formed so that protrudes with mounted on the housing main body sleeve cover the tubular member into the interior of the housing main body and the valve sleeve between the housing main body on the one hand and outer surface of the tubular member on the other hand is clamped, wherein the tubular member preferably has a cone-shaped outer surface.

Furthermore, the housing main body in the area opposite to the cone-shaped outer surface of the tubular element with an attached sleeve cover may also be formed conical, whereby the clamping surface between tubular element and housing main body is increased.

It is understood that the conical inner surface and / or the conical outer surface also formed stepped, d. H. can consist of several sections with different inner and outer diameters. Furthermore, the preferred cylindrical valve collar may alternatively be replaced by a molding collar with beads at both ends.

The valve channel is thus formed in a preferred embodiment of the inner contour of the tubular elements of the sleeve cover and the inner contour of the valve sleeve. Since the valve sleeve is clamped between socket cover and housing, formed in the known pinch valves in the valve channel a shoulder at the transition between the tubular member and the valve sleeve, so that the inner diameter of the valve channel changes more or less abruptly in the flow direction. However, such paragraphs are undesirable in particular in the life and pharmaceutical industry, since at these points inhomogeneous flow rates develop and product or cleaning agent residues can permanently settle and therefore the growth of microorganisms is favored. For this reason, pinch valves are often avoided in the food industry.

According to a particularly preferred embodiment, the substantially tubular element of the sleeve cover and the valve sleeve are configured such that a shoulder is formed between the tubular element and the valve sleeve, wherein the shoulder, i. H. the maximum change in the inner diameter in the region of a transition of the valve collar and sleeve cover is less than 1 mm, preferably less than 0.2 mm and particularly preferably less than 0.5 mm. If the heel is smaller than 1 mm, preferably smaller than 0.2 mm and particularly preferably smaller than 0.5 mm, this has the advantage that deposits from the product stream or from germs and bacteria on the small heel are prevented and, in addition, cleaning measures are facilitated.

In order to prevent that when installing the substantially tubular element of the socket cover, the valve sleeve is damaged and / or compressed and thus forms a bead, the socket cover and / or the housing main body may have a stop. The stop may be arranged such that the relative position between sleeve cover and housing is fixed in the axial direction.

In operation, the inlet and outlet openings of the pinch valve according to the invention with a product flow leading element, such as a hose or a pipe connected. Frequently, the product flow leading element is connected by means of a flange with the pinch valve. In this case, both the produkstrom leading element and the pinch valve on a flange which - are pressed together - with the interposition of a seal - for attachment. The circular flanges have on the one hand a sealing function, but also serve to provide a certain stability. Therefore, the - generally circular - flanges are made with relatively large diameters. In this case, the desired stability of the compound, for. As the resistance to tilting, the factor that determines the size of the diameter of the flanges, since the necessary tightness can be ensured with significantly smaller flange diameters.

In a preferred embodiment it is therefore provided that the pinch valve has a non-circular flange. Thereby, the pinch valve can be made of less material, since it is not necessary for the stabilizing function to provide a circular bearing surface. For example, it is possible that the flange surface has recesses. Also, the flange can provide a rectangular or rhombic bearing surface.

In a further preferred embodiment, the sleeve cover closes in the transverse direction, i. H. perpendicular to the imaginary connecting line between the inlet and outlet opening with the outer contour of the housing flush.

Particularly preferably, the housing and / or the sleeve cover made of metal, preferably made of stainless steel and best of all made of a cast stainless steel. It has proven to be particularly advantageous if the housing made of CF8M or AISI 316 and the sleeve cover made of CF4m or AISI316L is made.

With regard to the method, the object mentioned is achieved by a method for producing a pinch valve having a housing which has at least one sleeve cover, an inlet opening, an outlet opening and a control opening for connection to a pressure medium, wherein the inlet and outlet openings via a Passage are connected to each other, and a valve sleeve which is connected to the input and output ports and arranged so that it forms a valve passage between the input and output ports, characterized in that the sleeve cover and / or the housing are produced by investment casting.

All parts of the pinch valve, except the valve sleeve and any existing screws, can be manufactured in the so-called precision casting process from stainless steel (stainless steel) or alternative high-grade metals. The process is used to obtain castings with the highest dimensional accuracy and best surface quality. Investment casting enables the production of very complex shaped parts by casting technology and also permits production with very small wall thicknesses and tolerances. With this method, castings with a mass of a few grams up to several hundred kilograms can be manufactured. The tolerances are approximately ± 0.4 to ± 0.7% of the nominal size. Thus, the possibly necessary further machining can be greatly reduced in comparison to other casting methods or it may possibly be completely dispensed with, which thus brings significant cost advantages in the production with it.

The raw model is usually made from special waxes by injection molding. The raw model making tools are made of either aluminum or steel. In order to realize undercuts in the contour of the raw model, preformed water-soluble or ceramic cores are needed with another tool.

In a further step, the raw models are assembled into so-called model grapes either from many small raw models or from a few large raw models. The constellation of the raw models on the model grape depends on the melt volume of the melting pot. This individually finished model grape is then dipped into a slurry. The slip is a ceramic mass for producing a shell mold made of fine refractory flour as a molding material and z. B. ethyl silicate as a binder.

The model grape coated with the slurry is then wetted with sand directly afterwards. The dipping and sanding is usually repeated four to seven times, until the shell mold receives the necessary stability for casting. The waxing of the wax models is carried out with a special Ausschmelzofen at about 150 ° C.

Following the melting, the thin-walled molds are fired at about 750 to 1200 ° C in an oven and thus ideally preheated for the immediate subsequent casting of the molds. As a rule, casting is always done in hot molds so that even narrow cross-sections and fine contours run well. After casting and complete solidification of the melt, the casting is removed by sawing or vibration. Subsequently, the castings are given their final appearance by means of grinding and / or blasting as well as heat treatments, straightening, surface treatments (electropolishing) and then, if necessary, with a minimum of necessary post-machining by means of CNC or milling machines.

Further advantages, features and applications of the present invention will become apparent from the following description of a preferred embodiment and the accompanying figures. Show it:

1 a perspective view of a pinch valve according to the invention with female thread connection and / or flange,

2 a perspective view of a pinch valve according to the invention with clamping sleeve and / or Rohranschweißende,

3 a perspective view of a pinch valve according to the invention with pipe fitting and / or hose fitting,

4 an exploded perspective view of the pinch valve of 1 .

5 a longitudinal sectional view of the pinch valve of the invention 1 .

6 a longitudinal sectional view as in 5 , but with inserted valve sleeve,

7 a cross-sectional view of the pinch valve of 1 .

8th Bottom and top of a socket cap with internal thread design,

9 Bottom and top of a socket cover with clamp connection design,

10 Bottom and top of a socket cover with pipe-weld end design,

11 Bottom and top of a flange-mounted socket cover,

12 Bottom and top of a socket cover with hose fitting design,

13 Bottom and top of a socket cover with tube fitting design,

14 Bottom and top of a sleeve cover with a substantially rhomboid flange design.

In 1 is a perspective view of a pinch valve 1 shown in accordance with the present invention. The pinch valve 1 has an entrance opening 2 and an exit port 3 and a control port 4 , The entrance opening 2 and the exit port 3 (only in 5 shown) are connected to each other via a valve sleeve 13 (only in 4 and 6 shown). Will the control terminal 4 pressurized with a pressure medium, for example in the form of compressed air, so the valve sleeve 13 compressed and the channel cross-section between the inlet opening 2 and exit port 3 closed or at least reduced.

The pinch valve 1 of the 1 has a housing 5 , a socket cap with female thread connection 14 and a sleeve cover with flange 15 on. The pinch valve 1 of the 2 has a housing 5 , a socket cover with clamp connection 16 and a sleeve cover with pipe weld end connection 17 on.

In 3 is a pinch valve 1 with a housing 5 shown, with a sleeve cover with pipe fitting connection 19 and external thread 29 , as well as a sleeve cover with hose fitting connection 18 is available. The hose fitting connection 18 here has two tubular elements 27 and two beads 28 on.

The individual components of the pinch valve 1 are in the exploded view in 4 to recognize more clearly. The pinch valve 1 consists of a preferably substantially elliptical shaped housing 5 with an elliptical annulus as control or functional space 6 ,

The housing 5 also has a total of four flat surfaces 21 on, which serve as an assembly aid. By providing the flat surfaces 21 the outer contour deviates somewhat from the elliptical shape. Alternatively, this shape can also be regarded as a rhombus with rounded corners.

Next is in 4 to realize that the socket covers 14 . 15 with screws 7 on the housing 5 are screwed.

The different socket covers 14 . 15 . 16 . 17 . 18 . 19 . 20 all have a lid base surface and a tubular member extending inwardly therefrom 11 with conical outer surface.

In the lid base of the sleeve cover 14 to 20 holes are introduced through which the screws 7 into the corresponding threaded holes 8th (please refer 5 ) in the housing 5 intervention. This embodiment of the housing 5 and all sleeve cover 14 to 20 has the advantage that the pinch valve 1 in three parts or including the valve sleeve 13 four parts can be executed and thus can be dispensed with other items.

The investment casting process allows the housing 5 with the help of a lost core in one piece in a preferably elliptical control or functional space 6 can be made without the housing section with a larger passage cross-section 10 very time-consuming and costly machining nachzubearbeiten, with the housing portion of the housing 5 with smaller passage cross-section 9 (please refer 6 ) in each case in the direction of the housing section with a larger passage cross-section 10 and in the direction of the entrance or exit opening 2 . 3 extended. In this case, the widening inner surface corresponds to the input or output opening 2 . 3 essentially the conical outer surface of the tubular element 11 the sleeve cover 14 to 20 so that the valve cuff 13 (please refer 6 ) between the outer surface of the tubular elements 11 the sleeve cover 14 to 20 on the one hand and on the other hand, the conically widening inner surface 12 of the housing 5 can be trapped.

It is understood that the conical surfaces can also be formed stepped, as in 5 the example of the flared inner surface of the housing 12 is shown.

It is only essential that the two surfaces are formed such that when mounted sleeve cover 14 to 20 the valve sleeve 13 safe between housing 5 and sleeve cover 14 to 20 is held. The illustrated stepped embodiment has the advantage that the valve sleeve 13 can be held very well even when acted upon by higher pressures. Basically, could also be the outer surface of the conical extension 11 be formed stepped, but it has been shown that in the assembly of the pinch valve is advantageous if the conical extension 11 has no steps, because then the sleeve cover 14 to 20 easier in the valve sleeve 13 and the case 5 can be used.

In 5 It can also be seen that, in the embodiment shown, the housing section has a smaller passage cross-section 9 in the direction of the housing section with a larger passage cross-section 10 gradually expanded. This has the advantage that, if in the depressurized state, ie when the control port is not pressurized, the valve sleeve 13 due to the product flow, it does not damage the valve boot 13 comes. In 6 is clearly seen that the pinch valve 1 a housing section with a larger passage cross-section 10 and two housing sections with a smaller one Passage section 9 Has. This measure ensures that the valve sleeve 13 can be mounted such that a valve channel is formed, which has a constant channel cross-section substantially.

In 6 is another longitudinal section through the pinch valve 1 shown. This figure is different from 5 only by the additional fact that the valve sleeve 13 is shown. In this illustration it becomes clear that there is between the valve cuff 13 and inner wall of the housing section with a larger passage cross-section 10 a control or function room 6 located.

In 7 is a cross section of the pinch valve 1 where clearly the approximately elliptical functional or control room 6 can be seen.

The bottom and top of sleeve covers of various embodiments is in the 8th to 14 shown. The 8th shows a top (right half) and a bottom (left half) of a sleeve cover 14 female threaded version, wherein the internal thread for connection with a product-carrying component in the inwardly extending tubular member 11 is trained.

In 9 is the top (right half of the picture) and the bottom (left half of the picture) of a sleeve cover 15 shown with clamp connection. While on the bottom, the inwardly extending tubular member 11 is shown, the top has a clamping piece.

An in 10 shown embodiment of a sleeve cover 16 with Rohranschweißenden has on the top (right half of the picture) a pipe end 26 for welding with a material-supplying line, z. B. with an aseptic compound, on. On the bottom (left half of the picture) is the tubular element 11 visible, noticeable.

11 shows the bottom (left half of the picture) with a tubular element 11 and the top (right half of the picture) of a sleeve cover 20 with a flange connection. Well recognizable are the holes 22 for fixing the socket cover to the housing 5 , as well as the holes 23 for fixing the circular flange disc 24 , Will be a first flange 24 attached to a corresponding counterpart, for example, a second flange, so creates a product current-tight connection. To increase the stability, in particular the tilting rigidity, of such a connection, the socket cover has an annular bearing surface 25 on.

It is particularly advantageous that material can be saved by the spatial separation of the flange and the support surface in the production. It is understood that in addition to a circular flange and other flange and socket cover geometries, such as rectangular or rhombus-shaped configurations, are conceivable. So is in 14 the upper (right half of the picture) and lower side (left half of the picture) of a substantially diamond-shaped sleeve cover 20 shown.

A top (right half of the picture) and a bottom (left half of the picture) of a sleeve cover 18 with hose fitting version is in 12 shown. On the bottom well recognizable is the tubular element 11 In contrast, the upper side is an outwardly extending tubular element 27 having, which in two segments, each with a bead 28 is divided. For commissioning, a product-carrying hose may be drawn onto the outwardly extending tubular member, through the bead portions 28 with a larger diameter the hose is fixed.

In 13 is a sleeve cover 19 shown with pipe fitting version. The top (right half) has an outwardly extending tubular member 27 which expands and an external thread 29 having. It is also conceivable that the tubular element 27 a union nut 29 having. With the external thread 29 or the union nut 29 For example, it is possible to have a product-carrying element on the tubular element 27 to fix. On the bottom (left half of the picture) of the socket cover is the inwardly extending tubular element 11 seen with the valve sleeve between the tubular element 11 and the housing 5 is trapped.

LIST OF REFERENCE NUMBERS

1

pinch

2

entrance opening

3

output port

4

control port

5

casing

6

control room

7

screw

8th

threaded hole

9

Housing section with smaller passage cross-section

10

Housing section with a larger passage cross-section

11

tubular element

12

conical expanding inner surface of the housing

13

valve sleeve

14

Sleeve cover with female thread connection

15

Sleeve cover with flange

16

Sleeve cover with clamp connection

17

Sleeve cover with pipe weld end connection

18

Sleeve cover with hose fitting connection

19

Sleeve cover with pipe fitting connection

20

Sleeve cover with flange and rhombic design

21

flat surfaces for mounting aid

22

drilling

23

drilling

24

circular flange disc

25

support surfaces

26

pipe end

27

tubular element

28

bead

29

External thread or union nut

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited non-patent literature

• AISI 316 [0028]
• AISI316L [0028]

Claims (13)

Pinch valve ( 1 ) with a housing having an entrance opening ( 2 ) and an exit opening ( 3 ), wherein within the housing a tubular valve sleeve ( 13 ) with the input ( 2 ) and exit opening ( 3 ) and arranged such that they are arranged between input ( 2 ) and exit opening ( 3 ) forms a valve channel, wherein housing and valve sleeve are arranged such that between the housing and the valve sleeve a control chamber is formed, and the housing has a control port ( 4 ) for connection to a pressure medium, so that when the control opening ( 4 ) with a pressure medium, the valve sleeve moves such that the channel cross section between input ( 2 ) and exit opening ( 3 ) is reduced and / or closed, characterized in that the housing in the control space forming region at least in sections has a non-circular cross-section. Pinch valve ( 1 ) according to claim 1, characterized in that the housing ( 1 ) in the control space forming region has a substantially elliptical cross section, wherein preferably the major axis of the elliptical cross section is greater than 10%, preferably more than 20%, longer than the minor axis. Pinch valve ( 1 ) according to claim 1 or 2, characterized in that the housing ( 1 ) in the control space forming region has a substantially rhombus-shaped cross-section, wherein preferably one diagonal of the rhomboidal cross-section by more than 10%, preferably more than 20%, longer than the other diagonal of the rhomboidal cross-section. Pinch valve according to claim 3, characterized in that the housing in the control space forming region has a rhombus-shaped cross section with rounded corners, wherein preferably the radii of curvature of the opposite rounded corners are equal. Pinch valve ( 1 ) according to one of claims 1 to 4, characterized in that the housing in cross-section at least partially has a non-circular, preferably substantially elliptical or rhombus-shaped outer contour. Pinch valve ( 1 ) according to one of claims 1 to 5, characterized in that the housing at least one housing main body and a sleeve cover ( 14 - 20 ), in which the input or output opening is formed, wherein the socket cover preferably by means of screws ( 7 ) with the housing main body ( 5 ) is screwed. Pinch valve ( 1 ) according to claim 6, characterized in that the sleeve cover ( 14 - 20 ) has a substantially tubular element, which is formed such that when mounted on the housing main body socket cover the tubular element into the interior of the housing main body ( 1 ) and the valve sleeve is clamped between the housing main body on the one hand and the outer surface of the tubular element on the other hand, wherein the tubular element preferably has a conical outer surface. Pinch valve according to claim 6 or 7, characterized in that the substantially tubular element of the socket cover ( 14 - 20 ) and the valve sleeve are configured such that the shoulder formed between the tubular element and the valve sleeve in the valve channel is less than 1 mm, preferably less than 0.2 mm and particularly preferably less than 0.1 mm. Pinch valve according to one of claims 6 to 8, characterized in that the socket cover ( 14 - 20 ) with the outer contour of the housing ( 5 ) flush. Pinch valve according to one of claims 6 to 9, characterized in that the socket cover has a flange, wherein the Flanschauflagefläche is not circular. Pinch valve according to one of claims 1 to 10, characterized in that the housing and / or the sleeve cover made of metal, preferably made of stainless steel and best of a cast stainless steel CF8M or AISI 316 is made. Method for producing a pinch valve with a housing, which has at least one sleeve ( 14 - 20 ), an entrance opening ( 2 ), an exit opening ( 3 ) and a control port ( 4 ) for connection to a printing medium, wherein input ( 2 ) and exit opening ( 3 ) are interconnected via a passage, and a valve sleeve ( 13 ) connected to the input ( 2 ) and exit opening ( 3 ) and arranged such that they are arranged between input ( 2 ) and exit opening ( 3 ) forms a valve channel, characterized in that the socket cover ( 14 - 20 ) and / or the housing are made by investment casting. A method according to claim 12, characterized in that a pinch valve according to one of claims 1 to 11 is produced.

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