Valve

Abstract

The present invention relates to a valve (1), wherein the valve (1) has an axially movable piston (2), wherein the piston (2) is arranged in a valve seat (3), wherein the piston (2) has a circumferential groove (6) with a groove base (7) in which a sealing ring (12) is arranged. According to the invention, at least in an axial sectional plane, a distance between a piston axis (10) and the groove base (7) in an axial region (21) around a contact point (13) between the sealing ring (12) and the groove base (7) has at least two different values.

Description

[0001] valve

[0002] The invention relates to a valve, wherein the valve has an axially movable piston, wherein the piston is arranged in a valve seat, wherein the piston has a circumferential groove with a groove base, in which a sealing ring is arranged. Such a valve is widely used in practice.

[0003] The invention is based on the object of creating a valve with improved performance and sealing properties. This object is achieved by the features of the independent claims. Advantageous embodiments are described in the subclaims.

[0004] It should be noted that the features listed individually in the dependent claims can be combined with one another in any technologically expedient manner and define further embodiments of the invention. Furthermore, the features listed in the claims are further specified and explained in the description, with further preferred embodiments of the invention being presented.

[0005] To achieve the stated object, the features of claim 1 are provided according to the invention. In particular, to achieve the stated object, in a valve of the type described at the outset, it is proposed according to the invention that, at least in one axial sectional plane, a distance between a piston axis and the groove base takes on at least two different values ​​in an axial region around a contact point formed between the sealing ring and the groove base. The sealing properties of the valve can thus be improved. This also makes it possible to avoid an indi f ferent equilibrium position of the sealing ring at the groove base, which allows a number of equal positionings of the sealing ring. In particular, this makes it possible to avoid very small local displacements of the sealing ring, which would result in a reduction in tightness.

[0006] The valve is preferably designed as a sanitary valve and is used in the sanitary area, for example in a kitchen, a toilet and / or a bathroom.

[0007] In an advantageous embodiment of the invention, it can be provided that the two different values ​​lie on different sides of the contact point. This can increase the service life of the sealing ring, as contact between the groove base and possible defects in the sealing ring is minimized. The two different values ​​can alternatively lie on the same side of the contact point. Such defects can occur, for example, at an equator, particularly when the sealing ring is designed as an O-ring. It has been found that at the equator, which often coincides with a tool parting line, parts or pieces can break off when removing excess material. Such breakouts can reduce the sealing effect. The design makes it possible for the sealing ring to rest on the other side of its equator. This ensures that defects have little or no effect on sealing.

[0008] In a valve of the type described at the outset, as an alternative or in addition to the preceding solution, the invention can provide for the stated object to be achieved by a contour of the groove base defining a clear rest position of the sealing ring on the groove base in an axial region, for example the one already mentioned. The reliability of the sealing performance of the sealing ring can thus be increased. The axial region is preferably a second contact point. The axial region can be understood, for example, as a region which is spanned in the axial direction around a contact point, for example the one already mentioned, between the sealing ring and the groove base.

[0009] Preferably, the rest position is formed along a complete circumference of the sealing ring around the piston. This allows the mechanical production of the piston and groove to be improved.

[0010] In a valve of the type described at the outset, as an alternative or in addition to the preceding solutions, the invention can provide for the stated object to be achieved by providing, at least in an axial sectional plane, a connecting line between a contact point, for example the one already mentioned, and a contact point, wherein the contact point is formed between the groove base and the sealing ring and the contact point is formed between the sealing ring and the valve seat, forming a straight line which runs through a center of a cord of the sealing ring. Thus, the positioning of the sealing ring under static or dynamic stress can be improved, and the sealing performance can be increased.

[0011] In this case the centre can be characterised, for example, by an area which extends around a cord centre point of the sealing ring with a radius of no more than 10%, in particular no more than 5%, of a cord thickness of the sealing ring and / or with a radius of at most five times, in particular at most twice, a manufacturing tolerance of the sealing ring. Such a design of the centre and arrangement of the contact point and the point of contact has proven particularly advantageous for the sealing performance of the sealing ring. It is therefore also possible to guide a line of force between the points at which the sealing ring is clamped during sealing, close to the centre point or through the centre point. This can improve support.

[0012] In an advantageous embodiment of the invention, it can be provided that the sealing ring has an axial play in the groove.

[0013] In the prior art, it is typically the case that the sealing ring is gripped on both sides of the groove in contact or even with preload so that there is no axial play.

[0014] The creation of a clearance has the advantage of providing additional freedom for positioning the sealing ring, allowing it to be positioned very precisely to match manufacturing tolerances. By creating an axial clearance, the sealing ring and the valve seat can align more easily, and geometric overdetermination is avoided.

[0015] In practice, when the valve is closed, a point-like contact is created between the sealing ring and the valve seat, which expands into a linear and partially flat contact in the circumference of the sealing ring as the piston is inserted further.

[0016] The axial clearance design allows the sealing ring to deflect in such a way that a circumferential seal between the sealing ring and the valve seat is possible.

[0017] Preferably, the clearance is dimensioned at least large enough to exceed a manufacturing tolerance of a groove dimension. Thus, an axially unloaded mounting is achievable.

[0018] In an advantageous embodiment of the invention, it can be provided that the axial region is no larger than a quarter of the axial extent of the sealing ring and, additionally or alternatively, that the axial region can be selected as small as desired. Preferably, the axial region is no larger than an eighth of the axial extent of the sealing ring. This allows preloads on the sealing ring to be better controlled and adjusted. Thus, sufficiently small structures can also be provided that define a position of the sealing ring.

[0019] In an advantageous embodiment of the invention, it can be provided that a return element acts on the piston. The return element is preferably a spring. The valve can therefore be used as a backflow preventer, for example as an RV cartridge. Backflow preventers are used to prevent unwanted backflow, for example of used water, or to protect pressure-sensitive systems in the event of fluctuating system pressure. The opening and closing direction of the piston can run along a piston axis. The piston axis can run parallel to flow lines of a water flow, in particular the flow direction.

[0020] In an advantageous embodiment of the invention, the valve seat can be provided with a mating contact surface against which the sealing ring rests. Preferably, the sealing ring rests tightly against the mating contact surface. This can increase the sealing performance of the sealing ring.

[0021] In an advantageous embodiment of the invention, the counter-contact surface can be arranged at an angle and, additionally or alternatively, curved relative to the piston axis. This reduces mechanical stress on the sealing ring and increases its service life.

[0022] In an advantageous embodiment of the invention, it can be provided that the groove base has a zone which encloses an angle of no greater than 20° with the mating contact surface. The angle is preferably no greater than 10°. The angle is particularly preferably no greater than 5°. The positioning of the sealing ring can thus be adjusted. The invention has here for the first time recognized that such a design of the angle is particularly advantageous. The sealing ring can therefore also be clamped between parallel or almost parallel surfaces. This can be gentle on the material.

[0023] In an advantageous embodiment of the invention, it can be provided that the groove base has a recess so that an equator of the cord of the sealing ring remains free of contact. The cord of the sealing ring can be referred to as the round or oval cross section of the sealing ring. The recess can, for example, be designed as a contact between two planes, wherein the normal vectors of the planes converge at an obtuse or an acute angle. An acute angle is defined as an angle between 0 ° and 90 °. An obtuse angle is defined as an angle between 90 ° and 180 °. Alternatively, the recess can be designed as a groove, wherein the groove depth is constant. Alternatively, the recess can be designed as a groove, wherein the groove depth is non-constant, in particular variable.Thus, the structural design of the recess ensures that the equator of the sealing ring's cord remains contact-free and that no stress is exerted on any defects in the sealing ring. In fact, in the prior art, it is often the case that defects or areas of reduced mechanical stability arise in the region of the equator of the sealing ring's cord during the manufacturing process. The design proposed here is intended to reduce or completely prevent the stress on such defects.

[0024] In an advantageous embodiment of the invention, the groove base can be provided with at least one step that contacts the sealing ring. Preferably, the step is rounded. This allows for improved positioning of the sealing ring within the groove.

[0025] The step can be formed at one of the two contact points between a groove wall and the groove base. The groove wall is the area of ​​the groove that is orthogonal to the piston axis defined above. The groove base is defined as the area of ​​the groove that is delimited by the groove walls. The groove walls are the last contour section before the exterior of the piston.

[0026] In an advantageous embodiment of the invention, the groove base can have a radius of curvature that is greater than the radius of curvature of the sealing ring's cord. This allows the sealing ring to roll or slide along the groove base with minimal stress.

[0027] In an advantageous embodiment of the invention, the groove base can be provided with a slope that forms an angle of less than 45° with the piston axis and, additionally or alternatively, an angle greater than 0°. Preferably, the angle is greater than 5°. Thus, the mechanical load on the sealing ring can be reduced.

[0028] In an advantageous embodiment of the invention, it can be provided that the piston is driven via a drive device. The drive device is preferably a screw drive and, additionally or alternatively, a hydraulic drive. This provides a reliable and low-maintenance drive for the piston.

[0029] In an advantageous embodiment of the invention, the recess can be trough-shaped or tapered at an angle, in particular with an angle of less than 180°. Preferably, the angle is less than 175°. Thus, a mechanical construction can be provided that is simple and inexpensive to manufacture.

[0030] In an advantageous embodiment of the invention, the sealing ring can be designed as a round ring and, additionally or alternatively, as an oval cord ring. The sealing ring is preferably designed as an O-ring. Thus, a sealing ring can be provided that can be manufactured cost-effectively.

[0031] In an advantageous embodiment of the invention, it can be provided that the sealing ring remains contact-free on at least one groove wall. The groove wall is preferably arranged orthogonally to the piston axis. The groove wall can be considered the last contour section before the outer region of the groove. This allows for improved sealing performance, particularly in dynamic applications.

[0032] In a valve of the type described above, as an alternative or in addition to the preceding solutions, the invention can provide for the stated object to be achieved by arranging a contact point between the sealing ring and the groove base at a distance from an equator of the sealing ring, at least when the valve is closed. The equator is the line of the sealing ring's cord that runs through the center of the sealing ring's cord and is arranged orthogonally to the piston axis of the piston. In this way, the load on possible defects in the sealing ring, which are caused by the manufacturing process and often occur at the equator, can be reduced.

[0033] The invention will now be explained using a few

[0034] The invention is described in more detail in exemplary embodiments, but is not limited to these few exemplary embodiments. Further variants of the invention and exemplary embodiments arise from combining the features of individual or multiple claims with one another and / or with individual or multiple features of the exemplary embodiments and / or the previously described variants of inventive devices.

[0035] It shows :

[0036] Fig. 1 a valve in a perspective view and

[0037] Fig. 2 shows a valve from the prior art in a sectional view and

[0038] Fig. 3 shows a valve according to the invention in a sectional view and the corresponding enlarged detail view and

[0039] Fig. 4 shows the valve from Fig. 3 in a sectional view without the drive shown and

[0040] Fig. 5 is a detailed view of a groove geometry of a valve according to the invention in a sectional view and

[0041] Fig. 6 is a detailed view of another groove geometry of a valve according to the invention in a sectional view and

[0042] Fig. 7 is a detailed view of another groove geometry of a valve according to the invention in a sectional view and

[0043] Fig. 8 is a detailed view of another groove geometry of a valve according to the invention in a sectional view and Fig. 9 is a detailed view of the groove geometry of the valve from Fig. 7 in a sectional view and with a prevailing back pressure.

[0044] In the following description of various embodiments of the invention, elements which correspond in their function are given the same reference numbers even if they have a different design or shape.

[0045] For clarity, not all reference symbols are shown in the figures, although the elements may very well be present in the figures. However, identical reference symbols denote functionally and / or structurally identical components and functional units.

[0046] Fig. 1 shows a valve 1 in a perspective view.

[0047] The valve 1 has an axially movable piston 2, wherein the piston 2 is arranged in a valve seat 3. The valve 1 further has a valve body 4. A return element 5 acts on the piston 2. The valve 1 is preferably designed as a sanitary valve in the sanitary sector. The return element 5 is preferably designed as a spring.

[0048] Fig. 2 shows a valve 1 from the prior art in a sectional view.

[0049] The valve 1 has an axially movable piston 2, wherein the piston 2 is arranged in a valve seat 3. The valve 1 further has a valve body 4. A return element 5 acts on the piston 2. The piston 2 has a circumferential groove 6 which has a groove base 7. The groove base 7 is delimited by groove walls 8, 9. The groove walls 8, 9 are arranged orthogonal to a piston axis 10. The piston axis 10 is arranged parallel to a flow direction 11. The flow direction 11 is shown by an arrow. The axial direction is the direction along the flow direction 11. The radial direction is the direction orthogonal to the flow direction 11. A sealing ring 12 is arranged in the groove 6. The sealing ring 12 touches the groove base 7 at a contact point 13.In the prior art, the groove 6 typically has a rectangular geometry; that is, the distance between the groove base 7 and the piston axis 10 is constant. This can lead to unwanted loads on the sealing ring 12 and to problems in adjusting the opening and closing pressure of the valve 1. The invention addresses this and aims to circumvent or eliminate the disadvantages of the prior art.

[0050] Fig. 3 shows a valve 1 according to the invention in a sectional view and a corresponding enlarged detailed view.

[0051] The valve 1 here has similar elements to the valve 1 of Fig. 2, where Fig. 2 represents the prior art, and are not described separately here.

[0052] The piston 2 is arranged in the valve seat 3. The sealing ring 12 is contacted from the outside by a mating contact surface 13a at a contact point 20, wherein the mating contact surface 13a belongs to the valve seat 3 and is arranged obliquely to the piston axis 10. The sealing ring 12 has an axial play 22 in the groove 6. Alternatively, the mating contact surface 13a can be curved. Fig. 3 differs from Fig. 2 in that the groove 6 has an alternative groove geometry. The groove base 7 comprises two surfaces which taper towards one another at an angle. The angle is preferably less than 180°, particularly preferably less than 175°. A recess 14 is formed in the contact region of the two surfaces and between the contact region of the two surfaces around the sealing ring 12. The sealing ring 12 contacts the groove base 7 at two contact points 13, which are located above and below the recess 14.The terms above and below are to be understood in relation to the direction of flow. The sealing ring 12 does not contact the groove walls 8, 9. The sealing ring 12 has an axial play 22 in the groove 6. The sealing ring 12 also contacts the mating contact surface 13a of the valve seat 3 at the contact point 20. In the present exemplary embodiment, the sealing ring 12 is designed as a round cord ring, preferably as an O-ring. The design of the recess 14, which tapers at the above-mentioned angle, ensures that there is no contact between the groove base 7 and the sealing ring 12 in a region of the equator of the cord of the sealing ring 12, wherein in the region of the equator of the cord of the sealing ring 12 there are often defects due to the manufacturing process of sealing rings 12. The invention therefore provides a remedy here.

[0053] The groove base 7 has a zone which encloses an angle of no greater than 20 ° , preferably an angle of no greater than 10 ° , particularly preferably an angle of no greater than 5 ° , with the counter contact surface 13a .

[0054] Fig. 4 shows the valve 1 from Fig. 3 in a sectional view without the drive 15 explicitly shown.

[0055] The drive 15 of the piston 2 can, for example, be a screw drive and additionally or alternatively a hydraulic drive. The screw drive can be mechanically and additionally or alternatively electrically actuated and can adjust the position of the piston 2. The hydraulic drive can be characterized by a hydraulic force that can adjust the piston 2. Alternative drives 15 are also conceivable.

[0056] Fig. 5 shows a detailed view of a groove geometry of a valve 1 according to the invention in a sectional illustration. The distance between the groove base 7 and the piston axis 10 is variable here. The groove base 7 comprises three regions: an inclined region 16 in which the groove base 7 is arranged obliquely to the piston axis 10, a constant region 17 in which the groove base 7 is arranged parallel to the piston axis 10, and a stepped region 18 in which a step 19 is formed. The step 19 is preferably rounded. In the flow direction 11, the sequence of the regions is as follows: inclined region 16, constant region 17, stepped region 18. The sealing ring 12 contacts the groove base 7 at two contact points 13, one of the two contact points 13 being located in the inclined region 16 and the other of the two contact points 13 being located in the stepped region 18. The sealing ring 12 contacts the valve seat 3 at the counter contact surface 13a at the contact point 20.The mating contact surface 13a is arranged obliquely to the piston axis 10. Alternatively, the mating contact surface 13a can be curved. The sealing ring 12 has a clearance 22 in the groove 6 on both axial sides.

[0057] In the inclined region 16 , the groove base 7 has a slope which encloses an angle of less than 45 ° with the piston axis 10 and additionally or alternatively an angle greater than 0 ° , preferably an angle greater than 5 ° .

[0058] The groove base 7 has a recess 14 so that the equator of the cord of the sealing ring 12 remains free of contact. In this example, the recess 14 is wedge-shaped, but it can alternatively have other shapes. The recess 14 is located between the inclined area 16 and the step 19.

[0059] The normal vectors of the groove base 7 in the inclined region 16 and the mating contact surface 13a form an obtuse angle. The groove walls 8, 9 are non-contact with the sealing ring 12.

[0060] The arrangement of the contact points 13 ensures that the mechanical load on the sealing ring 12 is relatively low.

[0061] Fig. 6 shows a detailed view of another groove geometry of a valve 1 according to the invention in a sectional view.

[0062] The groove 6 has the groove walls 8, 9 and the groove base 7. The groove base 7 here comprises three regions: the stepped region 18, in which the step 19 is formed, which is preferably rounded, the constant region 17, in which the groove base 7 is arranged parallel to the piston axis 10, and the inclined region 16, in which the groove base 7 is arranged obliquely to the piston axis 10. The groove base 7 has a zone (in this case, the oblique region 16) which forms an angle of no greater than 20°, preferably an angle of no greater than 10°, particularly preferably an angle of no greater than 5°, with the counter-contact surface 13a. The counter-contact surface 13a is arranged obliquely to the piston axis 10. The counter-contact surface 13a can alternatively be curved. In the flow direction 11, the sequence of the regions is as follows: stepped region 18, constant region 17, inclined region 16.The sealing ring 12 contacts the groove base 7 at two contact points 13, one contact point 13 being in the step area 18 and the other contact point 13 being in the inclined area 16.

[0063] The sealing ring 12 contacts the valve seat 3 at the mating contact surface 13a at the contact point 20. The normal vectors of the groove base 7 in the inclined region 16 and the mating contact surface 13a form an acute angle. An acute angle defines an angle between 0° and 90°. An obtuse angle defines an angle between 90° and 180°.

[0064] A connecting line between the contact point 13, which lies in the inclined area 16 and is formed between the groove base 7 and the sealing ring 12, and the contact point 20 forms a straight line which runs through a center of the cord of the sealing ring 12.

[0065] In this case, the center can be characterized, for example, by an area that extends around a cord center point of the sealing ring 12 with a radius of not more than 10%, in particular not more than 5%, of a cord thickness of the sealing ring 12 and / or with a radius of at most five times, in particular at most twice, a manufacturing tolerance of the sealing ring 12.

[0066] The groove walls 8, 9 are non-contact with the sealing ring 12. The sealing ring 12 has an axial clearance 22 in the groove 6. The arrangement of the contact points 13 ensures that the mechanical load on the sealing ring 12 is relatively low.

[0067] The groove base 7 has a recess 14 so that the equator of the cord of the sealing ring 12 remains free of contact. The recess 14 is wedge-shaped in the present embodiment, but it can also take on other shapes. The recess 14 is located between the inclined region 16 and the step 19.

[0068] Fig. 7 shows a detailed view of another groove geometry of a valve 1 according to the invention in a sectional view.

[0069] The distance between the groove base 7 and the piston axis 10 (only shown schematically) is variable. The sealing ring 12 contacts the groove base 7 at the contact point 13. A radius of curvature of the groove base 7 is greater than a radius of curvature of the cord of the sealing ring 12. The sealing ring 12 additionally contacts the mating contact surface 13a of the valve seat 3. The mating contact surface 13a is arranged obliquely to the piston axis 10. The mating contact surface 13a can alternatively be curved. The groove walls 8, 9 are contact-free with respect to the sealing ring 12. The sealing ring 12 has the axial play 22 in the groove 6 on both sides of the groove walls 8, 9. The sealing ring 12 can slide on the curved groove base 7 in a dynamically loaded state. The special design of the groove geometry described here has the advantage that the sealing ring 12 is only slightly stressed, which can increase its service life.An axial region 21 can be defined around the contact point 13, in which the distance between the piston axis 10 and the groove base 7 assumes at least two different values. The axial region 21 can be positioned arbitrarily around the contact point 13; both symmetrical arrangements relative to the contact point 13 and non-symmetrical arrangements relative to the contact point 13 are possible.

[0070] The groove 6 has a curved area 19a .

[0071] Fig. 8 shows a detailed view of another groove geometry of a valve 1 according to the invention in a sectional view. Fig. 8 shows a groove geometry approximately similar to Fig. 7.

[0072] The distance between the groove base 7 and the piston axis 10 (shown schematically here) is variable. The groove base 7 comprises two curved regions 19a, 19b. The radii of curvature of the curved region 19a and the curved region 19b are equal. The radius of curvature of the curved regions 19a, 19b is greater than the radius of curvature of the cord of the sealing ring 12.

[0073] The groove base 7 has a recess 14 at which the equator of the cord of the sealing ring 12 remains contact-free. This is the main difference between Fig. 7 and Fig. 8. In the present exemplary embodiment, the recess 14 is trough-shaped. The recess 14 can alternatively be wedge-shaped or angular. The recess 14 can alternatively be partially circular. The recess 14 is arranged between the curved region 19a and the curved region 19b.

[0074] The sealing ring 12 contacts the groove base 7 at the curved area 19a and the curved area 19b. The sealing ring 12 also contacts the mating contact surface 13a at the contact point 20, which is arranged obliquely to the piston axis 10. Alternatively, the mating contact surface 13a can be curved. The groove walls 8, 9 remain non-contact with the sealing ring 12. The sealing ring 12 has the aforementioned axial clearance 22 in the groove 6.

[0075] The design of the groove geometry in the present exemplary embodiment ensures that the mechanical loads on the sealing ring 12 are minimized in static or dynamic conditions.

[0076] Fig. 9 shows a detailed view of the groove geometry of the valve 1 from Fig. 7 in a sectional view.

[0077] In the present exemplary embodiment, back pressure prevails. The sealing ring 12 contacts the groove base 7 at the contact point 13 and the groove wall 9. The other groove wall 8 remains contact-free with respect to the sealing ring 12. The sealing ring 12 additionally contacts the mating contact surface 13a at the contact point 20. The mating contact surface 13a is formed obliquely to the piston axis 10 (shown schematically). Alternatively, the mating contact surface 13a can be curved. The back pressure is characterized by a pressure which acts counter to the typically prevailing flow pressure. This can be the case, for example, in a backflow preventer.

[0078] The groove 6 has the curved area 19a .

[0079] It is proposed that in a valve 1 , wherein the valve 1 has an axially movable piston 2 , wherein the piston 2 is arranged in a valve seat 3 , wherein the piston has a circumferential groove 6 with a groove base 7 , in which a sealing ring 12 is arranged , at least in an axial sectional plane a ( location - dependent ) distance between a piston axis 10 and the groove base 7 in an axial region 21 around a contact point 13 between the sealing ring 12 and the groove base 7 has at least two different values ​​( at two different

[0080] axial positions).

[0081] / List of reference symbols

[0082] List of reference symbols valve piston valve seat

[0083] valve body

[0084] Reset element

[0085] Nut

[0086] Groove base

[0087] Groove wall

[0088] (other) groove wall

[0089] Piston axis

[0090] Flow direction

[0091] sealing ring

[0092] Contact point, contact points a counter contact surface

[0093] recess

[0094] drive

[0095] Inclined area

[0096] Constant range

[0097] Step area

[0098] Stage a curved area b ( other ) curved area

[0099] Point of contact

[0100] Axial area

[0101] Game

[0102] / Claims

Claims

Claims valve (1), in particular sanitary valve, wherein the valve (1) has an axially movable piston (2), wherein the piston (2) is arranged in a valve seat (3), wherein the piston (2) has a circumferential groove (6) with a groove base (7), in which a sealing ring (12) is arranged, characterized in that at least in one axial sectional plane, a distance between a piston axis (10) and the groove base (7) in an axial region (21) around a contact point (13) formed between the sealing ring (12) and the groove base (7) assumes at least two different values. Valve (1) according to claim 1, characterized in that the two different values ​​lie on different sides of the contact point (13). Valve (1) according to the preamble of claim 1 or according to one of the preceding claims, characterized in that a contour of the groove base (7) in the or an axial region (21), in particular a second contact point (13), a clear rest position of the sealing ring (12) on the groove base (7), preferably along a complete revolution of the sealing ring (12) around the piston (2), is defined. Valve (1) according to the preamble of claim 1 or according to one of the preceding claims, characterized in that at least in an axial sectional plane, a connecting line between one or the contact point (13) and a contact point (20), wherein the contact point (13) is formed between the groove base (7) and the sealing ring (12) and the contact point (20) is formed between the sealing ring (12) and the valve seat (3), forms a straight line which passes through a center of a cord of the sealing ring (12). runs. Valve (1) according to one of the preceding claims, characterized in that the sealing ring (12) has an axial play (22) in the groove (6). Valve (1) according to one of the preceding claims, characterized in that the axial region (21) is not larger than a quarter, in particular not larger than an eighth, of an axial extension of the sealing ring (12) and / or that the axial region (21) can be selected to be as small as desired. Valve (1) according to one of the preceding claims, characterized in that a return element (5), in particular a spring, acts on the piston (2). Valve according to one of the preceding claims, characterized in that the valve seat (3) has a Has a counter-contact surface (13a) against which the sealing ring (12) preferably rests tightly. Valve (1) according to one of the preceding claims, characterized in that the counter-contact surface (13a) is arranged obliquely and / or curved to the piston axis (10). Valve (1) according to one of the preceding claims, characterized in that the groove base (7) has a zone which encloses an angle of no greater than 20°, preferably an angle of no greater than 10°, particularly preferably an angle of no greater than 5°, with the counter-contact surface (13a). Valve (1) according to one of the preceding claims, characterized in that the groove base (7) has a recess (14) such that an equator of the cord of the sealing ring (12) remains contact-free. Valve (1) according to one of the preceding claims, characterized in that the groove base (7) has at least one, in particular rounded, step (19) which contacts the sealing ring (12). Valve (1) according to one of the preceding claims, characterized in that the groove base (7) has a radius of curvature which is greater than a radius of curvature of the cord of the sealing ring (12). Valve (1) according to one of the preceding claims, characterized in that the groove base (7) has a bevel which encloses an angle of less than 45° and / or greater than 0°, in particular greater than 5°, with the piston axis (10). Valve (1) according to one of the preceding claims, characterized in that a drive (15) of the piston (2) is achieved via a drive device, in particular a screw drive and / or a hydraulic drive.Valve (1) according to one of the preceding claims, characterized in that the recess (14) is trough-shaped or tapers at an angle, in particular wherein the angle is less than 180°, in particular less than 175°. Valve (1) according to one of the preceding claims, characterized in that the sealing ring (12) is designed as a round and / or oval cord ring, in particular as an O-ring. Valve (1) according to one of the preceding claims, characterized in that the sealing ring (12) remains contact-free on at least one groove wall (8, 9), in particular wherein the groove wall (8, 9) is arranged orthogonally to the piston axis. Valve (1) according to the preamble of claim 1 or according to one of the preceding claims, characterized in that at least in the closed state of the valve (1) a contact point (13) between the sealing ring (12) and the groove base (7) is spaced from an equator of the sealing ring (12) is arranged. / Summary

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