Valve with valve cartridge comprising two cylinders

Abstract

The invention relates to a valve (10) for regulating a flow between a first port (16) and a second port (18). The valve housing (12) includes a valve chamber (14) connected to a first port (16) and a second port (18). A spool (26) inserted into the valve chamber (14) includes a first cylinder (28) connected to a second cylinder (32), and a piston (34) movably disposed within the second cylinder (32). The piston (35) acts on the valve seat gasket (30). The first cylinder (28) and the second cylinder (32) are arranged in axial alignment and are connected by a releasable connection (44). The valve seat gasket (30) is arranged in a valve seat gasket chamber (62) formed between the first cylinder (28) and the second cylinder (32) and providing an annular opening (80) for engagement of the valve seat gasket (30) with the piston (34).

Description

[0001] The present invention relates to a valve, in particular for regulating flow between a first port and a second port.

[0002] Many types and configurations of valves are known in different fields of use. In particular, in the field of industrial refrigeration, regulating valves for high operating pressures up to and above 50 bar are used.

[0003] The present application provides a series of pressure and temperature regulating valves for industrial refrigeration, in particular, an ICM type electric operated valve comprising a steel valve body, a top cover and a functional module. Valve bodies of different sizes and connection types are available, and each valve body can be equipped with multiple top covers and different functional models to give different capacities. The PTFE valve seat provides excellent valve tightness. Combined with an actuator, a compact size assembly is formed. The driving force from the actuator is transmitted via a magnetic coupling passing through a stainless steel top shell. The rotational movement of the magnetic coupling is transmitted to the spindle, which in turn provides vertical movement of the piston and the valve seat to open and close the valve. The valve inlet pressure acting on the lower side of the PTFE valve seat reaches the top of the piston through the hollow piston assembly and balances the pressure acting on the piston.

[0004] In particular, at high pressures, sealing at the actual valve seat is particularly important.It may be seen as an object to provide a valve having a simple construction which allows a secure mounting of the valve seat gasket.

[0005] This object is solved by a valve according to claim 1. The dependent claims relate to preferred embodiments.

[0006] The valve according to the present invention is suitable for regulating the flow of a fluid between a first port and a second port. The fluid may be, for example, a liquid, a gas, or a mixture thereof. The regulating function of the valve preferably includes a closed state in which the first port and the second port are sealed from each other, and a variable degree of valve opening to regulate the amount of fluid passing between the ports according to the pressure difference.

[0007] The valve includes at least a valve housing having a valve chamber and a valve core inserted into the valve chamber.

[0008] The valve housing may be of different shapes, for example depending on the angular arrangement of the first and second ports relative to each other and to the valve chamber; while the ports may be arranged at an angle to each other, the ports are preferably arranged in a straight line with the valve chamber interposed therebetween.

[0009] The valve core comprises at least two cylinder bodies (referred to herein as the first cylinder body and the second cylinder body), which are connected to each other and arranged axially aligned (e.g. along a common central longitudinal axis), preferably superposed on each other, particularly preferably the top part of the first cylinder body is connected to the end part of the second cylinder body. The cylinder body preferably has at least a substantially hollow cylindrical shape, particularly preferably with a circular outer cross section and inner cross section. In different sections along its axial length, the inner diameter and / or outer diameter of the cylinder element can vary, for example gradually forming a cone (e.g. having an inclined and / or curved shape in an axial longitudinal section), and / or suddenly forming an annular shape of different diameters (having a step in an axial longitudinal section). The term "at least a substantially hollow cylindrical shape" can be understood to indicate that the cylinder element can have additional elements, such as radial protrusions and / or radial openings, for example forming one or more radial windows.

[0010] The valve core further comprises a movable piston, preferably axially movable. The first cylinder and / or the second cylinder may form or provide a valve seat comprising a valve seat gasket. The piston is arranged to move in the second cylinder, acting on the valve seat gasket to open or close the valve.

[0011] According to the present invention, the first cylinder body and the second cylinder body are connected by a releasable connector, which can be preferably a threaded connector (for example, formed between an external thread and an internal thread). The internal thread can be, for example, arranged on the first cylinder body, and the external thread is arranged on the second cylinder body, or vice versa. Different from the cylinder body that is formed as a shared integral valve body or (for example, by welding or gluing) is permanently connected, the releasable connector of the first cylinder body and the second cylinder body has the advantage of allowing easy positioning and replacing the valve seat gasket when necessary. Alternative releasable connectors can include, for example, one side or both sides with flanges, curled or beaded connectors, particularly between two flanges on the first cylinder body and the second cylinder body, with a connector (for example, via screws and / or bolts).

[0012] The valve seat is provided with a valve seat gasket arranged in a valve seat gasket chamber. The valve seat gasket chamber is formed between the first cylinder body and the second cylinder body and is provided with at least one annular opening, which is arranged and positioned to allow the piston to engage with the valve seat gasket arranged in the valve seat gasket chamber.

[0013] Thus, the valve seat gasket chamber only partially surrounds the valve seat gasket, leaving at least one annular opening open, as viewed in an axial longitudinal section. The inner surface of the valve seat gasket chamber formed between the first and second cylinder bodies by parts of the first and second cylinder bodies preferably surrounds and thus positions and / or secures the valve seat gasket at least from two opposite sides (preferably axially or radially away from each other). The inner surface further preferably surrounds the valve seat gasket at least from three sides and most preferably from four sides, particularly preferably from two pairs of opposite sides (such as radially and axially), thereby accurately securing the valve seat gasket in place.

[0014] Preferably, the first cylinder body and the second cylinder body are made of a hard and durable material, preferably metal, particularly preferably steel, while the valve seat gasket can be composed entirely or partially of a material softer than the material of the first cylinder body and the second cylinder body, in particular a flexible material, such as an elastomer, PTFE or other gasket material. The valve seat gasket chamber, which partially encloses and surrounds the valve seat gasket, thus serves for precise positioning, mechanical support, and also for protection from mechanical influences of the fluid passing through the open valve, while the annular opening allows the engagement of the piston with the valve seat gasket, thereby sealing the valve in the closed position. Therefore, the annular opening is preferably arranged to connect the valve seat gasket chamber with the inner space of the first cylinder body and / or the second cylinder body.

[0015] The releasable connection, in particular a threaded connection, is used to provide a clear, tight and mechanically stable way of securing the first cylinder body and the second cylinder body to each other.

[0016] According to a preferred embodiment, the first cylinder and / or the second cylinder may comprise a step forming the two inner surfaces (or the side walls of the valve seat gasket chamber). A step is understood to mean an abrupt change in the inner diameter or outer diameter of the respective cylinder, so that in an axial longitudinal section, the two surfaces appear at an angle, preferably at right angles to each other.

[0017] In a preferred embodiment, the top portion of the first cylinder body can be received in the end portion of the second cylinder body, that is, the outer diameter of the top portion of the first cylinder body is shorter than the inner diameter of the end portion of the second cylinder body. The "top portion" of the first cylinder body and the "end portion" of the second cylinder body refer to the axial ends of the corresponding cylinder bodies oriented in the direction of the other cylinder body. The first cylinder body may include steps forming an outer annular space, and the second cylinder body may include steps forming an inner annular space. The valve seat gasket chamber can be formed between these steps, that is, in both the inner annular space and the outer annular space. It should be understood that this configuration can be reversed, that is, the outer diameter of the end portion of the second cylinder body can alternatively be smaller than the top portion of the first cylinder body and received therein.

[0018] According to another preferred embodiment, the valve seat gasket chamber can be formed between a pair of radial annular surfaces and a pair of axial annular surfaces. Specifically, the top portion of the first cylinder body may include a first axially facing annular surface and a first radial annular surface facing outward. The end portion of the second cylinder body may include a second axially facing annular surface and an inwardly facing second radial annular surface. The first axially facing annular surface and the second axially facing annular surface are arranged relative to each other at a certain distance, and the first radial annular surface and the second radial annular surface are also arranged relative to each other at a certain distance, thereby forming a valve seat gasket chamber therebetween.

[0019] In order to form the annular opening, one of the first axially facing annular surface and the second axially facing annular surface may be arranged to be shorter than the other, and / or one of the first radial annular surface and the second radial annular surface may be shorter than the other. It should be understood that this refers to the length as apparent in an axial longitudinal section, and the length of the respective surface is measured in its extension direction (i.e. radial or axial). Preferably, the longer axial surface and the radial surface together form one corner of the valve seat gasket chamber (in an axial longitudinal section), so that the annular opening is formed at the opposite corner (between the end of the shorter axial surface and the end of the shorter radial surface).

[0020] The piston movably arranged relative to the valve seat gasket is preferably at least substantially cylindrical in shape. The front surface of the piston (e.g. oriented toward the first cylinder body and / or toward the valve seat gasket) may be plane, but preferably has at least one raised portion protruding in the axial direction. In a preferred embodiment, the cylinder body may include a central axial protrusion forming a tip in the center, which preferably has a smooth, arc-shaped connection with the rest of the front surface in an axial longitudinal section.

[0021] According to another preferred embodiment, the piston may comprise an axially protruding outer ring. The outer ring may be arranged to engage the valve sealing gasket to seal the valve in the closed position. The shape of the protrusion provides a defined sealing position and a tight seal.

[0022] Preferably, one of the ports (which may be referred to herein as the first port, preferably the inlet), has a direct fluid connection with the interior space of the first cylinder and / or the second cylinder, while the other second port (preferably the outlet) is connected to the interior of the first cylinder and / or the second cylinder only via the valve seat, so that when the piston engages the valve seat gasket, the connection can be sealed. Further preferably, the first cylinder can be received in the valve housing in a sealing manner so that the axial opening of the first cylinder is connected to the first port. The second port can be connected to the interior of the first cylinder and / or the second cylinder via one or more radial openings provided on the first cylinder and / or the second cylinder. Preferably, at least one radial opening (which may be referred to as a window) is provided in the second cylinder. There may be several windows distributed around the circumference of the second cylinder.

[0023] According to a preferred embodiment, the second cylinder may include an outer valve seat annular portion axially arranged between the radial opening and the valve seat gasket. In the closed position of the valve, the front of the piston enters the outer valve seat annular portion so that the front of the piston is received therein (i.e., surrounded thereby), and in the open position of the valve, the piston is arranged axially away from the outer valve seat annular portion, thereby providing an opening between the piston and the outer valve seat annular portion. The outer diameter of the piston and the inner diameter of the outer valve seat annular portion are preferably closely matched so that the two parts are in sliding contact or are provided with a minimum radial clearance so that in the closed position of the valve, there is no or only a minimum opening left between the two parts, thereby effectively closing the valve seat, which is then sealed by the engagement of the piston with the valve seat gasket. Preferably, the outer valve seat annular portion provides a portion of the housing of the valve seat gasket chamber. Further preferably, the annular opening of the valve seat gasket chamber is formed directly adjacent to the outer valve seat annular portion.

[0024] In a particularly preferred embodiment, the axially extending opening area of ​​the second cylinder body can be defined by the position and axial extension of the window (i.e., radial opening). The axially extending opening area can be defined as the axial height of the window. The valve chamber surrounding the first cylinder body and / or the second cylinder body preferably includes an enlarged annular space portion, i.e., a portion with an increased inner diameter. According to a preferred embodiment, the enlarged annular space portion is at least partially axially positioned to overlap with the axially extending opening area. This provides more space for the medium to flow through the window, thereby allowing a higher flow capacity. Further preferably, the axially extending opening area of ​​the second cylinder body completely overlaps the enlarged annular space portion surrounding the second cylinder body, and particularly preferably, the axially extending opening area of ​​the second cylinder body is centered in the enlarged annular space portion surrounding the second cylinder body.

[0025] Although the piston may be solid, it is preferred that an equalizing pressure chamber is provided and that a flow guide channel is connected to the equalizing pressure chamber through the piston. The equalizing pressure chamber may be formed behind the piston (and optionally, partially within the piston) so that at least the front portion of the piston (particularly preferably, the entire piston) is axially arranged between the valve seat and the equalizing pressure chamber. The flow guide channel that passes through the piston includes an inlet formed in the front surface of the piston (i.e., in the surface oriented toward the first cylinder body and / or the valve seat gasket). Preferably, the inlet is arranged in the outer radial portion of the piston, preferably at a position that is more than 50% of the radius (further preferably more than 75% of the radius, particularly preferably more than 80%) from the center of the piston (measured at the center of the inlet).

[0026] As mentioned above, the second cylinder preferably comprises one or more radial openings (windows). Preferably, the position of the inlet of the flow-guiding channel formed in the front surface of the piston is aligned with the position of one of the windows. The windows can be arranged within an angular range of the circumference of the second cylinder, and the inlet can preferably be arranged within an angular range. The size of the angular range can be determined in a cross section perpendicular to the longitudinal axis of the first / second cylinder, and the positioning of the inlet can be determined by its center.

[0027] In a preferred embodiment, the piston may include at least a first guide ring surface and a second guide ring surface on its circumference. The piston diameter at the first guide ring surface and the second guide ring surface may be larger than the piston diameter between the first guide ring surface and the second guide ring surface. The first guide ring surface and the second guide ring surface may be arranged to contact the second cylinder body and may be axially spaced apart from each other (e.g., by more than 50% of the axial length of the piston). This arrangement provides good guidance for the axial movement of the piston in the second cylinder body, which is guided by the guide ring surface sliding against the inner surface of the second cylinder body.

[0028] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings, in which:

[0029] Figure 1 A first embodiment of a valve is shown in perspective view;

[0030] Figure 2 Shown in exploded view Figure 1 valve;

[0031] Figure 3 Shows Figure 1 , Figure 2 An axial longitudinal section of the valve;

[0032] Figure 4a , Figure 4b Shows Figures 1 to 3 An axial longitudinal section of an inner portion of the valve in a closed position (4a) and in an open position (4b);

[0033] Figure 5 Shows Figure 3 The enlarged part B;

[0034] Figure 6 Shown along Figure 4a The cross-sectional view taken from C..C in

[0035] Figure 7 equivalent to Figure 3 A second preferred embodiment of the valve is shown in an axial longitudinal cross-sectional view of FIG.

[0036] Figure 1 A first embodiment of a valve 10 is shown, wherein a valve housing 12 includes a valve chamber 14, a first port (inlet) 16, and a second port (outlet) 18. In the embodiment shown, the valve 10 is a regulating valve for industrial refrigeration, which can be used for low-pressure and high-pressure refrigerants with different refrigerant phases, including two-phase refrigerants, such as liquid refrigerant at the inlet and two-phase refrigerant at the outlet.

[0037] The valve 10 has a top portion 20 with a cap 22 and a cup 24 including a magnet to which an actuator can be magnetically coupled to control the valve opening, ie, regulate the flow of fluid between the first port 16 and the second port 18 .

[0038] Figure 2 An exploded view of the valve 10 is shown. As shown, the valve core 26 is inserted into the valve chamber 14. The valve core 26 includes a first cylinder 28, a valve seat gasket 30, a second cylinder 32, a piston 34, and a spindle 36 having a spindle nut 38.

[0039] The top part 20 and the valve core 26 together may be referred to as a function module 21. Different types of function modules 21 may be mounted to the valve housing 12, for example for different flow capacities.

[0040] The first cylinder 28 and the second cylinder 32 of the valve core 26 are hollow cylinders with varying inner and outer diameters, thereby defining an internal space. The inner and outer diameters of the first cylinder decrease toward its top portion 40, thereby forming a cone. Except for the enlarged end portion 42, the inner diameter of the second cylinder 32 is constant.

[0041] Figure 3 The assembled valve 10 is shown in an axial longitudinal section parallel to the longitudinal axis X.

[0042] As shown, the elements of the spool 26 are sealingly arranged in the valve chamber 14 so that the bottom opening of the first cylinder 28 is directly connected to the first port 16 and the first cylinder 28 and the second cylinder 32 and the radially outer side of the surrounding valve chamber 14 are directly connected to the second port 18 .

[0043] The first cylinder 28 and the second cylinder 32 are coaxially arranged one above the other, wherein the top portion 40 of the first cylinder 28 is connected to the end portion 42 of the second cylinder 32 by a releasable connection, which in the preferred example shown is a threaded connection 44 formed by engagement between internal threads of the end portion 42 of the second cylinder 32 and external threads formed around the top portion 40 of the first cylinder 28. The piston 34 is received inside the second cylinder 32 and is movable relative to the second cylinder in the axial direction (by rotation of the spindle 36 relative to the spindle nut 38).

[0044] The piston 34 has a radially protruding first guide ring 50 arranged toward its top and axially spaced therefrom, and a second guide ring portion 52 also protrudes radially. The outer surfaces of the guide ring portions 50, 52 contact the inner surface of the second cylinder 32 and serve to guide the piston 34 therein. The axial movement of the piston 34 is further guided and rotational movement is prevented by a guide screw 47 fixed to the second cylinder 32 and received in an axial guide groove 49 in the piston 34.

[0045] As in Figure 3 As can be seen in the longitudinal cross-sectional view of the piston 34, the piston 34 includes a central axially protruding tip 48 and an outer raised annular portion 78 (at Figure 5 The outer ring 78 is used to seal the valve 10 by engaging the valve seat gasket 30 as will be explained.

[0046] An equalizing pressure chamber 54 is disposed behind the piston 34 and, in the presently illustrated embodiment, comprises a cavity 55 disposed inside the piston. The equalizing pressure chamber 54 is connected to the front surface 46 of the piston 34 via a passage 56 leading to an inlet 58 in the front surface 46 of the piston 34. The passage 56 and the equalizing pressure chamber 54 serve to equalize the piston 34 with the high pressure from the inlet side (first port 16).

[0047] The second cylinder 32 includes a radial window 60 that connects the interior spaces of the first cylinder 28 and the second cylinder 32 to the surrounding valve chamber 14. In different embodiments, there may be a different number of windows 60, such as only one, two, or more. Figure 6 As shown, two windows 60 are arranged opposite one another and each cover an angular range α of approximately 45°.

[0048] exist Figure 3, the axial height of the window 60 is shown to define an axially extending opening area 82. It should be noted that the valve chamber 14 includes sections of different diameters, the top section surrounding the top portion of the second cylinder 32 has a narrower diameter, and the annular space section 84 surrounding the valve seat has a larger diameter. The inner diameter of the valve chamber 14 becomes two conical sections 86a, 86b. As shown in FIG. Figure 3 As shown, the enlarged annular space section 84 completely overlaps the axially extending opening region 82 .

[0049] The first cylinder 28 and the second cylinder 32 form a valve seat gasket chamber 62 between the top portion 40 of the first cylinder 28 and the end portion 42 of the second cylinder 32. Figure 5 As particularly visible in the enlarged view of , the valve seat gasket chamber 62 is formed between a first outer step 64 provided in the top portion 40 of the first cylinder 28 and a second inner step 66 provided in the end portion 42 of the second cylinder 32 .

[0050] The first outer step 64 provides a first axial annular surface 68 and an outwardly facing first radial annular surface 70. The second inner step 62 disposed in the end portion 42 of the second cylinder 32 forms an inwardly facing second radial annular surface 72 and a second axial annular surface 74. Thus, the valve seat gasket chamber 62 and the valve seat gasket 30 contained therein are bounded on four sides by a pair of axially facing annular surfaces 68, 74 and a pair of radially facing annular surfaces 70, 72.

[0051] The first radial annular surface 70 is shorter than the second radial annular surface 72, and the second axial annular surface 74 is shorter than the first axial annular surface 68. The first axial annular surface 68 and the second radial annular surface 72 are in contact and form the corners of the valve seat gasket chamber 62. An annular opening 80 is formed at the opposite corner, which exposes the valve seat gasket 30 to the interior space of the first cylinder 28 and the second cylinder 32. As will become apparent, the annular opening 80 allows the piston 34 to engage the valve seat gasket 30 through the annular opening 80.

[0052] The second inner step 66 disposed in the end portion 62 of the second cylinder 32 forms a portion of the second cylinder 32, which is referred to herein as an outer valve seat ring portion 76. The outer valve seat ring portion 76 borders the valve seat gasket chamber 62. Radially, the outer valve seat ring portion extends inwardly to provide sliding contact (or minimum clearance) with the circumference of the piston 34.

[0053] As in Figure 5 , Figure 6 As can be seen in particular in FIG. 4 , an inlet 58 of a passage 56 extending through the piston 34 to a cavity 55 (part of the equalization pressure chamber 54 ) is arranged radially outwardly within the front face 46 of the piston 34 . Figure 6A distance R1 is shown between the central longitudinal axis X and the center of the inlet 58 , which is close to the radius R of the piston 34 .

[0054] Further, Figure 6 The inlet 58 is shown positioned within the angular range α of one of the windows 60 .

[0055] In operation of the valve 10, an actuator (not shown) may be mounted to the magnet cup 24 to impart rotation to the spindle 36, thereby actuating the valve nut 38 to adjust the axial position of the piston within the second cylinder 32, thereby closing the valve 10 or providing a variable opening of the valve 10. Figure 4a , Figure 4b Describe the regulating function of valve 10:

[0056] Figure 4a The valve 10 is shown in the closed position, while Figure 4b The open position of the valve 10 is shown.

[0057] exist Figure 4b In the open position of the valve shown, the piston 34 is in an upper position retracted into the second cylinder 32, so that the front surface 46 of the piston 34, in particular the raised outer ring 78 thereof (see Figure 5 ) is arranged at a distance from the valve seat gasket 30 and the outer valve seat annular portion 76. Therefore, a valve opening is provided to allow fluid from the inlet side (first port 16) to pass through the valve seat and enter the valve chamber 14 through the window 30 to flow to the outlet side (second port 18).

[0058] It should be noted that only a small portion of the valve seat gasket 30 is exposed to fluid flow through the valve opening, ie, only that portion of the valve seat gasket 30 is exposed to the annular opening 80 .

[0059] It should be further noted that due to the positioning of the inlet 58 of the passage 56 , the pressure in the equalization chamber 54 will equalize with the pressure at the valve seat (ie, between the circumference of the valve seat gasket 30 and the front surface 46 of the piston 34 ).

[0060] To close the valve 10 , the piston 34 is moved axially until the front surface 46 of the piston 34 , more particularly the raised outer ring 78 thereof, enters and is thereby received in the outer seat annular portion 76 and engages the flexible seat gasket 30 , thereby closing and sealing the valve 10 .

[0061] Figure 7 A second preferred embodiment of a valve 110 is shown which corresponds in many respects to the valve 10 according to the first embodiment. Parts common to both embodiments are denoted by the same reference numerals. In the following, only the differences between the embodiments will be discussed in detail.

[0062] As in the valve 10 according to the first embodiment, the valve 110 has a valve core including a first cylinder 128 and a second cylinder 132 which are releasably connected and coaxial, and a valve seat gasket 30 is fixed in a valve seat gasket chamber 62 formed between the first cylinder 128 and the second cylinder 132. In the second cylinder 132, a piston 34 (actuated by a spindle 36) is movably arranged.

[0063] Compared to the valve 10 according to the first embodiment, the valve 110 according to the second embodiment has a differently shaped valve chamber 112, wherein the inlet 16 and the outlet 18 are arranged at right angles to each other. Similar to the valve chamber 12 of the first embodiment, the valve chamber 112 has an enlarged diameter annular space section 84 surrounding the valve seat. An axially extending opening area 82 defined by the axial height of the window 60 is arranged centrally in the annular space section 84, which further facilitates the flow.

[0064] In the valve 110 according to the second embodiment, the axial movement of the piston 34 is guided and the rotational movement is prevented by the guide pin 147 fixed by the top cover 22 and received in the axial guide groove 49 in the piston 34 .

Claims

1. A valve (10) for regulating flow between a first port (16) and a second port (18), the valve (10) comprising at least: a valve housing (12) comprising a valve chamber (14) connected to said first port (16) and said second port (18), - a valve core (26) inserted into the valve chamber (14), the valve core (26) comprising at least a first cylinder (28) connected to a second cylinder (32), and a piston (34) movably arranged in the second cylinder (32), the piston (35) acting on a valve seat gasket (30), - wherein the first cylinder (28) and the second cylinder (32) are arranged in axial alignment and connected by a releasable connection (44), -Wherein, the valve seat gasket (30) is arranged in a valve seat gasket chamber (62), the valve seat gasket chamber (62) is formed between the first cylinder body (28) and the second cylinder body (32), and the valve seat gasket chamber (62) provides an annular opening (80) for the valve seat gasket (30) to engage with the piston (34).

2. The valve (10) according to claim 1, wherein: - the top portion (40) of the first cylinder (28) is received in the end portion (42) of the second cylinder (32), - and wherein the first cylinder (28) comprises a step (64) forming an outer annular space, - and wherein the second cylinder (32) comprises a step (66) forming an inner annular space, - wherein the valve seat gasket chamber (62) is formed between the steps (64, 66).

3. The valve (10) according to any one of the preceding claims, wherein: - the top portion (40) of the first cylinder (28) comprises a first axially facing annular surface (68) and a first radial annular surface (70), the first radial annular surface (70) facing outwards, - and said end portion (42) of said second cylinder (32) comprises a second axially facing annular surface (74) and a second radial annular surface (72), said second radial annular surface (72) facing inwards, -Wherein, the first axially facing annular surface (68) and the second axially facing annular surface (74) are arranged relative to each other at a certain distance, and the first radial annular surface (70) and the second radial annular surface (72) are arranged relative to each other at a certain distance to form the valve seat gasket chamber (62).

4. The valve (10) according to claim 3, wherein: - one of the first axially facing annular surface (68) and the second axially facing annular surface (74) is shorter than the other, and / or one of the first radial annular surface (70) and the second radial annular surface (72) is shorter than the other, - to form the annular opening (80).

5. The valve (10) according to any one of the preceding claims, wherein: -in, The piston (34) includes an axially projecting outer ring (78) arranged to engage the valve sealing gasket (30).

6. The valve (10) according to any one of the preceding claims, wherein: - the first cylinder (28) is sealingly received in the valve housing (14), the first cylinder (28) comprising an inner space connected to the first port (16), - and said second cylinder (32) comprises at least one radial opening (60) connected to said second port (16).

7. The valve (10) according to any one of the preceding claims, wherein: - the second cylinder (32) comprises one or more radial openings (60), - and among them, The second cylinder (32) includes an outer valve seat annular portion (76) axially disposed between at least one of the radial openings (30) and the valve seat gasket (30), - wherein, in the closed position of the valve (10), a portion of the piston (34) is received in the outer valve seat annular portion (76), - and wherein, in the open position of the valve (10), the piston (34) is arranged axially away from the outer valve seat ring portion (76), thereby providing an opening between the piston (34) and the outer valve seat ring portion (76).

8. The valve (10) according to claim 7, wherein: - the outer valve seat annular portion (76) is part of the outer shell of the valve seat gasket chamber (62), - and wherein the annular opening (80) of the valve seat gasket chamber (62) is formed directly adjacent to the outer valve seat annular portion (76).

9. The valve (10) according to any one of claims 6 to 8, wherein: - the radial opening (60) of the second cylinder (32) extends over an axially extending opening region (82), - and among them, The valve chamber (14) includes an enlarged annular space portion (84) surrounding the first cylinder (28) and / or the second cylinder (32), the enlarged annular space portion (84) being positioned to at least partially overlap the axial opening area (82).

10. The valve (10) according to any one of the preceding claims, wherein: - the piston (34) comprises a front surface (46), -in, A flow guide channel (56) is arranged at least partially through the piston (34), the flow guide channel (56) connecting the equalization pressure chamber (54) with an inlet (58) formed in the front surface (46), - wherein the inlet (58) is arranged in an outer radial portion of the front surface (46).

11. The valve (10) according to claim 10 and any one of claims 6 to 9, wherein: - the angular extent (α) of said second cylinder (32) is limited by at least one said radial opening (60), - and the inlet (58) is arranged within the angular range (α).

12. The valve (10) according to any one of the preceding claims, wherein: - the piston (34) comprises on its circumference at least one first guide ring surface (50) contacting the second cylinder (32), and a second guide ring portion (52) contacting the second cylinder (32), - wherein the first guide ring surface (50) and the second guide ring surface (52) are axially spaced apart from each other, - and wherein the diameter of the piston (34) at the first guide ring surface (50) and the second guide ring surface (52) is greater than the diameter between the first guide ring surface (50) and the second guide ring surface (52).

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